/**
 * @fileoverview Main Linter Class
 * @author Gyandeep Singh
 * @author aladdin-add
 */

"use strict";

//------------------------------------------------------------------------------
// Requirements
//------------------------------------------------------------------------------

const
    path = require("node:path"),
    eslintScope = require("eslint-scope"),
    evk = require("eslint-visitor-keys"),
    espree = require("espree"),
    merge = require("lodash.merge"),
    pkg = require("../../package.json"),
    {
        Legacy: {
            ConfigOps,
            ConfigValidator,
            environments: BuiltInEnvironments
        }
    } = require("@eslint/eslintrc/universal"),
    Traverser = require("../shared/traverser"),
    { SourceCode } = require("../languages/js/source-code"),
    applyDisableDirectives = require("./apply-disable-directives"),
    { ConfigCommentParser } = require("@eslint/plugin-kit"),
    NodeEventGenerator = require("./node-event-generator"),
    createReportTranslator = require("./report-translator"),
    Rules = require("./rules"),
    createEmitter = require("./safe-emitter"),
    SourceCodeFixer = require("./source-code-fixer"),
    timing = require("./timing"),
    ruleReplacements = require("../../conf/replacements.json");
const { getRuleFromConfig } = require("../config/flat-config-helpers");
const { FlatConfigArray } = require("../config/flat-config-array");
const { startTime, endTime } = require("../shared/stats");
const { RuleValidator } = require("../config/rule-validator");
const { assertIsRuleSeverity } = require("../config/flat-config-schema");
const { normalizeSeverityToString, normalizeSeverityToNumber } = require("../shared/severity");
const { deepMergeArrays } = require("../shared/deep-merge-arrays");
const jslang = require("../languages/js");
const { activeFlags, inactiveFlags } = require("../shared/flags");
const debug = require("debug")("eslint:linter");
const MAX_AUTOFIX_PASSES = 10;
const DEFAULT_PARSER_NAME = "espree";
const DEFAULT_ECMA_VERSION = 5;
const commentParser = new ConfigCommentParser();
const DEFAULT_ERROR_LOC = { start: { line: 1, column: 0 }, end: { line: 1, column: 1 } };
const parserSymbol = Symbol.for("eslint.RuleTester.parser");
const { LATEST_ECMA_VERSION } = require("../../conf/ecma-version");
const { VFile } = require("./vfile");
const { ParserService } = require("../services/parser-service");
const { FileContext } = require("./file-context");
const { ProcessorService } = require("../services/processor-service");
const { containsDifferentProperty } = require("../shared/option-utils");
const STEP_KIND_VISIT = 1;
const STEP_KIND_CALL = 2;

//------------------------------------------------------------------------------
// Typedefs
//------------------------------------------------------------------------------

/** @typedef {import("../shared/types").ConfigData} ConfigData */
/** @typedef {import("../shared/types").Environment} Environment */
/** @typedef {import("../shared/types").GlobalConf} GlobalConf */
/** @typedef {import("../shared/types").LintMessage} LintMessage */
/** @typedef {import("../shared/types").SuppressedLintMessage} SuppressedLintMessage */
/** @typedef {import("../shared/types").ParserOptions} ParserOptions */
/** @typedef {import("../shared/types").LanguageOptions} LanguageOptions */
/** @typedef {import("../shared/types").Processor} Processor */
/** @typedef {import("../shared/types").Rule} Rule */
/** @typedef {import("../shared/types").Times} Times */
/** @typedef {import("@eslint/core").Language} Language */
/** @typedef {import("@eslint/core").RuleSeverity} RuleSeverity */
/** @typedef {import("@eslint/core").RuleConfig} RuleConfig */
/** @typedef {import("../types").Linter.StringSeverity} StringSeverity */


/* eslint-disable jsdoc/valid-types -- https://github.com/jsdoc-type-pratt-parser/jsdoc-type-pratt-parser/issues/4#issuecomment-778805577 */
/**
 * @template T
 * @typedef {{ [P in keyof T]-?: T[P] }} Required
 */
/* eslint-enable jsdoc/valid-types -- https://github.com/jsdoc-type-pratt-parser/jsdoc-type-pratt-parser/issues/4#issuecomment-778805577 */

/**
 * @typedef {Object} DisableDirective
 * @property {("disable"|"enable"|"disable-line"|"disable-next-line")} type Type of directive
 * @property {number} line The line number
 * @property {number} column The column number
 * @property {(string|null)} ruleId The rule ID
 * @property {string} justification The justification of directive
 */

/**
 * The private data for `Linter` instance.
 * @typedef {Object} LinterInternalSlots
 * @property {ConfigArray|null} lastConfigArray The `ConfigArray` instance that the last `verify()` call used.
 * @property {SourceCode|null} lastSourceCode The `SourceCode` instance that the last `verify()` call used.
 * @property {SuppressedLintMessage[]} lastSuppressedMessages The `SuppressedLintMessage[]` instance that the last `verify()` call produced.
 * @property {Map<string, Parser>} parserMap The loaded parsers.
 * @property {Times} times The times spent on applying a rule to a file (see `stats` option).
 * @property {Rules} ruleMap The loaded rules.
 */

/**
 * @typedef {Object} VerifyOptions
 * @property {boolean} [allowInlineConfig] Allow/disallow inline comments' ability
 *      to change config once it is set. Defaults to true if not supplied.
 *      Useful if you want to validate JS without comments overriding rules.
 * @property {boolean} [disableFixes] if `true` then the linter doesn't make `fix`
 *      properties into the lint result.
 * @property {string} [filename] the filename of the source code.
 * @property {boolean | "off" | "warn" | "error"} [reportUnusedDisableDirectives] Adds reported errors for
 *      unused `eslint-disable` directives.
 * @property {Function} [ruleFilter] A predicate function that determines whether a given rule should run.
 */

/**
 * @typedef {Object} ProcessorOptions
 * @property {(filename:string, text:string) => boolean} [filterCodeBlock] the
 *      predicate function that selects adopt code blocks.
 * @property {Processor.postprocess} [postprocess] postprocessor for report
 *      messages. If provided, this should accept an array of the message lists
 *      for each code block returned from the preprocessor, apply a mapping to
 *      the messages as appropriate, and return a one-dimensional array of
 *      messages.
 * @property {Processor.preprocess} [preprocess] preprocessor for source text.
 *      If provided, this should accept a string of source text, and return an
 *      array of code blocks to lint.
 */

/**
 * @typedef {Object} FixOptions
 * @property {boolean | ((message: LintMessage) => boolean)} [fix] Determines
 *      whether fixes should be applied.
 */

/**
 * @typedef {Object} InternalOptions
 * @property {string | null} warnInlineConfig The config name what `noInlineConfig` setting came from. If `noInlineConfig` setting didn't exist, this is null. If this is a config name, then the linter warns directive comments.
 * @property {StringSeverity} reportUnusedDisableDirectives Severity to report unused disable directives, if not "off" (boolean values were normalized).
 * @property {StringSeverity} reportUnusedInlineConfigs Severity to report unused inline configs, if not "off".
 */

//------------------------------------------------------------------------------
// Helpers
//------------------------------------------------------------------------------

/**
 * Determines if a given object is Espree.
 * @param {Object} parser The parser to check.
 * @returns {boolean} True if the parser is Espree or false if not.
 */
function isEspree(parser) {
    return !!(parser === espree || parser[parserSymbol] === espree);
}

/**
 * Ensures that variables representing built-in properties of the Global Object,
 * and any globals declared by special block comments, are present in the global
 * scope.
 * @param {Scope} globalScope The global scope.
 * @param {Object} configGlobals The globals declared in configuration
 * @param {{exportedVariables: Object, enabledGlobals: Object}} commentDirectives Directives from comment configuration
 * @returns {void}
 */
function addDeclaredGlobals(globalScope, configGlobals, { exportedVariables, enabledGlobals }) {

    // Define configured global variables.
    for (const id of new Set([...Object.keys(configGlobals), ...Object.keys(enabledGlobals)])) {

        /*
         * `ConfigOps.normalizeConfigGlobal` will throw an error if a configured global value is invalid. However, these errors would
         * typically be caught when validating a config anyway (validity for inline global comments is checked separately).
         */
        const configValue = configGlobals[id] === void 0 ? void 0 : ConfigOps.normalizeConfigGlobal(configGlobals[id]);
        const commentValue = enabledGlobals[id] && enabledGlobals[id].value;
        const value = commentValue || configValue;
        const sourceComments = enabledGlobals[id] && enabledGlobals[id].comments;

        if (value === "off") {
            continue;
        }

        let variable = globalScope.set.get(id);

        if (!variable) {
            variable = new eslintScope.Variable(id, globalScope);

            globalScope.variables.push(variable);
            globalScope.set.set(id, variable);
        }

        variable.eslintImplicitGlobalSetting = configValue;
        variable.eslintExplicitGlobal = sourceComments !== void 0;
        variable.eslintExplicitGlobalComments = sourceComments;
        variable.writeable = (value === "writable");
    }

    // mark all exported variables as such
    Object.keys(exportedVariables).forEach(name => {
        const variable = globalScope.set.get(name);

        if (variable) {
            variable.eslintUsed = true;
            variable.eslintExported = true;
        }
    });

    /*
     * "through" contains all references which definitions cannot be found.
     * Since we augment the global scope using configuration, we need to update
     * references and remove the ones that were added by configuration.
     */
    globalScope.through = globalScope.through.filter(reference => {
        const name = reference.identifier.name;
        const variable = globalScope.set.get(name);

        if (variable) {

            /*
             * Links the variable and the reference.
             * And this reference is removed from `Scope#through`.
             */
            reference.resolved = variable;
            variable.references.push(reference);

            return false;
        }

        return true;
    });
}

/**
 * creates a missing-rule message.
 * @param {string} ruleId the ruleId to create
 * @returns {string} created error message
 * @private
 */
function createMissingRuleMessage(ruleId) {
    return Object.hasOwn(ruleReplacements.rules, ruleId)
        ? `Rule '${ruleId}' was removed and replaced by: ${ruleReplacements.rules[ruleId].join(", ")}`
        : `Definition for rule '${ruleId}' was not found.`;
}

/**
 * Updates a given location based on the language offsets. This allows us to
 * change 0-based locations to 1-based locations. We always want ESLint
 * reporting lines and columns starting from 1.
 * @param {Object} location The location to update.
 * @param {number} location.line The starting line number.
 * @param {number} location.column The starting column number.
 * @param {number} [location.endLine] The ending line number.
 * @param {number} [location.endColumn] The ending column number.
 * @param {Language} language The language to use to adjust the location information.
 * @returns {Object} The updated location.
 */
function updateLocationInformation({ line, column, endLine, endColumn }, language) {

    const columnOffset = language.columnStart === 1 ? 0 : 1;
    const lineOffset = language.lineStart === 1 ? 0 : 1;

    // calculate separately to account for undefined
    const finalEndLine = endLine === void 0 ? endLine : endLine + lineOffset;
    const finalEndColumn = endColumn === void 0 ? endColumn : endColumn + columnOffset;

    return {
        line: line + lineOffset,
        column: column + columnOffset,
        endLine: finalEndLine,
        endColumn: finalEndColumn
    };
}

/**
 * creates a linting problem
 * @param {Object} options to create linting error
 * @param {string} [options.ruleId] the ruleId to report
 * @param {Object} [options.loc] the loc to report
 * @param {string} [options.message] the error message to report
 * @param {RuleSeverity} [options.severity] the error message to report
 * @param {Language} [options.language] the language to use to adjust the location information
 * @returns {LintMessage} created problem, returns a missing-rule problem if only provided ruleId.
 * @private
 */
function createLintingProblem(options) {
    const {
        ruleId = null,
        loc = DEFAULT_ERROR_LOC,
        message = createMissingRuleMessage(options.ruleId),
        severity = 2,

        // fallback for eslintrc mode
        language = {
            columnStart: 0,
            lineStart: 1
        }
    } = options;

    return {
        ruleId,
        message,
        ...updateLocationInformation({
            line: loc.start.line,
            column: loc.start.column,
            endLine: loc.end.line,
            endColumn: loc.end.column
        }, language),
        severity,
        nodeType: null
    };
}

/**
 * Wraps the value in an Array if it isn't already one.
 * @template T
 * @param {T|T[]} value Value to be wrapped.
 * @returns {Array} The value as an array.
 */
function asArray(value) {
    return Array.isArray(value) ? value : [value];
}

/**
 * Pushes a problem to inlineConfigProblems if ruleOptions are redundant.
 * @param {ConfigData} config Provided config.
 * @param {Object} loc A line/column location
 * @param {Array} problems Problems that may be added to.
 * @param {string} ruleId The rule ID.
 * @param {Array} ruleOptions The rule options, merged with the config's.
 * @param {Array} ruleOptionsInline The rule options from the comment.
 * @param {"error"|"warn"} severity The severity to report.
 * @returns {void}
 */
function addProblemIfSameSeverityAndOptions(config, loc, problems, ruleId, ruleOptions, ruleOptionsInline, severity) {
    const existingConfigRaw = config.rules?.[ruleId];
    const existingConfig = existingConfigRaw ? asArray(existingConfigRaw) : ["off"];
    const existingSeverity = normalizeSeverityToString(existingConfig[0]);
    const inlineSeverity = normalizeSeverityToString(ruleOptions[0]);
    const sameSeverity = existingSeverity === inlineSeverity;

    if (!sameSeverity) {
        return;
    }

    const alreadyConfigured = existingConfigRaw
        ? `is already configured to '${existingSeverity}'`
        : "is not enabled so can't be turned off";
    let message;

    if ((existingConfig.length === 1 && ruleOptions.length === 1) || existingSeverity === "off") {
        message = `Unused inline config ('${ruleId}' ${alreadyConfigured}).`;
    } else if (!containsDifferentProperty(ruleOptions.slice(1), existingConfig.slice(1))) {
        message = ruleOptionsInline.length === 1
            ? `Unused inline config ('${ruleId}' ${alreadyConfigured}).`
            : `Unused inline config ('${ruleId}' ${alreadyConfigured} with the same options).`;
    }

    if (message) {
        problems.push(createLintingProblem({
            ruleId: null,
            message,
            loc,
            language: config.language,
            severity: normalizeSeverityToNumber(severity)
        }));
    }
}

/**
 * Creates a collection of disable directives from a comment
 * @param {Object} options to create disable directives
 * @param {("disable"|"enable"|"disable-line"|"disable-next-line")} options.type The type of directive comment
 * @param {string} options.value The value after the directive in the comment
 * comment specified no specific rules, so it applies to all rules (e.g. `eslint-disable`)
 * @param {string} options.justification The justification of the directive
 * @param {ASTNode|token} options.node The Comment node/token.
 * @param {function(string): {create: Function}} ruleMapper A map from rule IDs to defined rules
 * @param {Language} language The language to use to adjust the location information.
 * @param {SourceCode} sourceCode The SourceCode object to get comments from.
 * @returns {Object} Directives and problems from the comment
 */
function createDisableDirectives({ type, value, justification, node }, ruleMapper, language, sourceCode) {
    const ruleIds = Object.keys(commentParser.parseListConfig(value));
    const directiveRules = ruleIds.length ? ruleIds : [null];
    const result = {
        directives: [], // valid disable directives
        directiveProblems: [] // problems in directives
    };
    const parentDirective = { node, value, ruleIds };

    for (const ruleId of directiveRules) {

        const loc = sourceCode.getLoc(node);

        // push to directives, if the rule is defined(including null, e.g. /*eslint enable*/)
        if (ruleId === null || !!ruleMapper(ruleId)) {


            if (type === "disable-next-line") {
                const { line, column } = updateLocationInformation(
                    loc.end,
                    language
                );

                result.directives.push({
                    parentDirective,
                    type,
                    line,
                    column,
                    ruleId,
                    justification
                });
            } else {
                const { line, column } = updateLocationInformation(
                    loc.start,
                    language
                );

                result.directives.push({
                    parentDirective,
                    type,
                    line,
                    column,
                    ruleId,
                    justification
                });
            }
        } else {
            result.directiveProblems.push(createLintingProblem({ ruleId, loc, language }));
        }
    }
    return result;
}

/**
 * Parses comments in file to extract file-specific config of rules, globals
 * and environments and merges them with global config; also code blocks
 * where reporting is disabled or enabled and merges them with reporting config.
 * @param {SourceCode} sourceCode The SourceCode object to get comments from.
 * @param {function(string): {create: Function}} ruleMapper A map from rule IDs to defined rules
 * @param {string|null} warnInlineConfig If a string then it should warn directive comments as disabled. The string value is the config name what the setting came from.
 * @param {ConfigData} config Provided config.
 * @returns {{configuredRules: Object, enabledGlobals: {value:string,comment:Token}[], exportedVariables: Object, problems: LintMessage[], disableDirectives: DisableDirective[]}}
 * A collection of the directive comments that were found, along with any problems that occurred when parsing
 */
function getDirectiveComments(sourceCode, ruleMapper, warnInlineConfig, config) {
    const configuredRules = {};
    const enabledGlobals = Object.create(null);
    const exportedVariables = {};
    const problems = [];
    const disableDirectives = [];
    const validator = new ConfigValidator({
        builtInRules: Rules
    });

    sourceCode.getInlineConfigNodes().filter(token => token.type !== "Shebang").forEach(comment => {

        const directive = commentParser.parseDirective(comment.value);

        if (!directive) {
            return;
        }

        const {
            label,
            value,
            justification: justificationPart
        } = directive;

        const lineCommentSupported = /^eslint-disable-(next-)?line$/u.test(label);

        if (comment.type === "Line" && !lineCommentSupported) {
            return;
        }

        const loc = sourceCode.getLoc(comment);

        if (warnInlineConfig) {
            const kind = comment.type === "Block" ? `/*${label}*/` : `//${label}`;

            problems.push(createLintingProblem({
                ruleId: null,
                message: `'${kind}' has no effect because you have 'noInlineConfig' setting in ${warnInlineConfig}.`,
                loc,
                severity: 1
            }));
            return;
        }

        if (label === "eslint-disable-line" && loc.start.line !== loc.end.line) {
            const message = `${label} comment should not span multiple lines.`;

            problems.push(createLintingProblem({
                ruleId: null,
                message,
                loc
            }));
            return;
        }

        switch (label) {
            case "eslint-disable":
            case "eslint-enable":
            case "eslint-disable-next-line":
            case "eslint-disable-line": {
                const directiveType = label.slice("eslint-".length);
                const { directives, directiveProblems } = createDisableDirectives({
                    type: directiveType,
                    value,
                    justification: justificationPart,
                    node: comment
                }, ruleMapper, jslang, sourceCode);

                disableDirectives.push(...directives);
                problems.push(...directiveProblems);
                break;
            }

            case "exported":
                Object.assign(exportedVariables, commentParser.parseListConfig(value));
                break;

            case "globals":
            case "global":
                for (const [id, idSetting] of Object.entries(commentParser.parseStringConfig(value))) {
                    let normalizedValue;

                    try {
                        normalizedValue = ConfigOps.normalizeConfigGlobal(idSetting);
                    } catch (err) {
                        problems.push(createLintingProblem({
                            ruleId: null,
                            loc,
                            message: err.message
                        }));
                        continue;
                    }

                    if (enabledGlobals[id]) {
                        enabledGlobals[id].comments.push(comment);
                        enabledGlobals[id].value = normalizedValue;
                    } else {
                        enabledGlobals[id] = {
                            comments: [comment],
                            value: normalizedValue
                        };
                    }
                }
                break;

            case "eslint": {
                const parseResult = commentParser.parseJSONLikeConfig(value);

                if (parseResult.ok) {
                    Object.keys(parseResult.config).forEach(name => {
                        const rule = ruleMapper(name);
                        const ruleValue = parseResult.config[name];

                        if (!rule) {
                            problems.push(createLintingProblem({ ruleId: name, loc }));
                            return;
                        }

                        if (Object.hasOwn(configuredRules, name)) {
                            problems.push(createLintingProblem({
                                message: `Rule "${name}" is already configured by another configuration comment in the preceding code. This configuration is ignored.`,
                                loc
                            }));
                            return;
                        }

                        let ruleOptions = asArray(ruleValue);

                        /*
                         * If the rule was already configured, inline rule configuration that
                         * only has severity should retain options from the config and just override the severity.
                         *
                         * Example:
                         *
                         *   {
                         *       rules: {
                         *           curly: ["error", "multi"]
                         *       }
                         *   }
                         *
                         *   /* eslint curly: ["warn"] * /
                         *
                         *   Results in:
                         *
                         *   curly: ["warn", "multi"]
                         */
                        if (

                            /*
                             * If inline config for the rule has only severity
                             */
                            ruleOptions.length === 1 &&

                            /*
                             * And the rule was already configured
                             */
                            config.rules && Object.hasOwn(config.rules, name)
                        ) {

                            /*
                             * Then use severity from the inline config and options from the provided config
                             */
                            ruleOptions = [
                                ruleOptions[0], // severity from the inline config
                                ...asArray(config.rules[name]).slice(1) // options from the provided config
                            ];
                        }

                        try {
                            validator.validateRuleOptions(rule, name, ruleOptions);
                        } catch (err) {

                            /*
                             * If the rule has invalid `meta.schema`, throw the error because
                             * this is not an invalid inline configuration but an invalid rule.
                             */
                            if (err.code === "ESLINT_INVALID_RULE_OPTIONS_SCHEMA") {
                                throw err;
                            }

                            problems.push(createLintingProblem({
                                ruleId: name,
                                message: err.message,
                                loc
                            }));

                            // do not apply the config, if found invalid options.
                            return;
                        }

                        configuredRules[name] = ruleOptions;
                    });
                } else {
                    const problem = createLintingProblem({
                        ruleId: null,
                        loc,
                        message: parseResult.error.message
                    });

                    problem.fatal = true;
                    problems.push(problem);
                }

                break;
            }

            // no default
        }
    });

    return {
        configuredRules,
        enabledGlobals,
        exportedVariables,
        problems,
        disableDirectives
    };
}

/**
 * Parses comments in file to extract disable directives.
 * @param {SourceCode} sourceCode The SourceCode object to get comments from.
 * @param {function(string): {create: Function}} ruleMapper A map from rule IDs to defined rules
 * @param {Language} language The language to use to adjust the location information
 * @returns {{problems: LintMessage[], disableDirectives: DisableDirective[]}}
 * A collection of the directive comments that were found, along with any problems that occurred when parsing
 */
function getDirectiveCommentsForFlatConfig(sourceCode, ruleMapper, language) {
    const disableDirectives = [];
    const problems = [];

    if (sourceCode.getDisableDirectives) {
        const {
            directives: directivesSources,
            problems: directivesProblems
        } = sourceCode.getDisableDirectives();

        problems.push(...directivesProblems.map(directiveProblem => createLintingProblem({
            ...directiveProblem,
            language
        })));

        directivesSources.forEach(directive => {
            const { directives, directiveProblems } = createDisableDirectives(directive, ruleMapper, language, sourceCode);

            disableDirectives.push(...directives);
            problems.push(...directiveProblems);
        });
    }

    return {
        problems,
        disableDirectives
    };
}

/**
 * Normalize ECMAScript version from the initial config
 * @param {Parser} parser The parser which uses this options.
 * @param {number} ecmaVersion ECMAScript version from the initial config
 * @returns {number} normalized ECMAScript version
 */
function normalizeEcmaVersion(parser, ecmaVersion) {

    if (isEspree(parser)) {
        if (ecmaVersion === "latest") {
            return espree.latestEcmaVersion;
        }
    }

    /*
     * Calculate ECMAScript edition number from official year version starting with
     * ES2015, which corresponds with ES6 (or a difference of 2009).
     */
    return ecmaVersion >= 2015 ? ecmaVersion - 2009 : ecmaVersion;
}

/**
 * Normalize ECMAScript version from the initial config into languageOptions (year)
 * format.
 * @param {any} [ecmaVersion] ECMAScript version from the initial config
 * @returns {number} normalized ECMAScript version
 */
function normalizeEcmaVersionForLanguageOptions(ecmaVersion) {

    switch (ecmaVersion) {
        case 3:
            return 3;

        // void 0 = no ecmaVersion specified so use the default
        case 5:
        case void 0:
            return 5;

        default:
            if (typeof ecmaVersion === "number") {
                return ecmaVersion >= 2015 ? ecmaVersion : ecmaVersion + 2009;
            }
    }

    /*
     * We default to the latest supported ecmaVersion for everything else.
     * Remember, this is for languageOptions.ecmaVersion, which sets the version
     * that is used for a number of processes inside of ESLint. It's normally
     * safe to assume people want the latest unless otherwise specified.
     */
    return LATEST_ECMA_VERSION;
}

const eslintEnvPattern = /\/\*\s*eslint-env\s(.+?)(?:\*\/|$)/gsu;

/**
 * Checks whether or not there is a comment which has "eslint-env *" in a given text.
 * @param {string} text A source code text to check.
 * @returns {Object|null} A result of parseListConfig() with "eslint-env *" comment.
 */
function findEslintEnv(text) {
    let match, retv;

    eslintEnvPattern.lastIndex = 0;

    while ((match = eslintEnvPattern.exec(text)) !== null) {
        if (match[0].endsWith("*/")) {
            retv = Object.assign(
                retv || {},
                commentParser.parseListConfig(commentParser.parseDirective(match[0].slice(2, -2)).value)
            );
        }
    }

    return retv;
}

/**
 * Convert "/path/to/<text>" to "<text>".
 * `CLIEngine#executeOnText()` method gives "/path/to/<text>" if the filename
 * was omitted because `configArray.extractConfig()` requires an absolute path.
 * But the linter should pass `<text>` to `RuleContext#filename` in that
 * case.
 * Also, code blocks can have their virtual filename. If the parent filename was
 * `<text>`, the virtual filename is `<text>/0_foo.js` or something like (i.e.,
 * it's not an absolute path).
 * @param {string} filename The filename to normalize.
 * @returns {string} The normalized filename.
 */
function normalizeFilename(filename) {
    const parts = filename.split(path.sep);
    const index = parts.lastIndexOf("<text>");

    return index === -1 ? filename : parts.slice(index).join(path.sep);
}

/**
 * Normalizes the possible options for `linter.verify` and `linter.verifyAndFix` to a
 * consistent shape.
 * @param {VerifyOptions} providedOptions Options
 * @param {ConfigData} config Config.
 * @returns {Required<VerifyOptions> & InternalOptions} Normalized options
 */
function normalizeVerifyOptions(providedOptions, config) {

    const linterOptions = config.linterOptions || config;

    // .noInlineConfig for eslintrc, .linterOptions.noInlineConfig for flat
    const disableInlineConfig = linterOptions.noInlineConfig === true;
    const ignoreInlineConfig = providedOptions.allowInlineConfig === false;
    const configNameOfNoInlineConfig = config.configNameOfNoInlineConfig
        ? ` (${config.configNameOfNoInlineConfig})`
        : "";

    let reportUnusedDisableDirectives = providedOptions.reportUnusedDisableDirectives;

    if (typeof reportUnusedDisableDirectives === "boolean") {
        reportUnusedDisableDirectives = reportUnusedDisableDirectives ? "error" : "off";
    }
    if (typeof reportUnusedDisableDirectives !== "string") {
        if (typeof linterOptions.reportUnusedDisableDirectives === "boolean") {
            reportUnusedDisableDirectives = linterOptions.reportUnusedDisableDirectives ? "warn" : "off";
        } else {
            reportUnusedDisableDirectives = linterOptions.reportUnusedDisableDirectives === void 0 ? "off" : normalizeSeverityToString(linterOptions.reportUnusedDisableDirectives);
        }
    }

    const reportUnusedInlineConfigs = linterOptions.reportUnusedInlineConfigs === void 0 ? "off" : normalizeSeverityToString(linterOptions.reportUnusedInlineConfigs);

    let ruleFilter = providedOptions.ruleFilter;

    if (typeof ruleFilter !== "function") {
        ruleFilter = () => true;
    }

    return {
        filename: normalizeFilename(providedOptions.filename || "<input>"),
        allowInlineConfig: !ignoreInlineConfig,
        warnInlineConfig: disableInlineConfig && !ignoreInlineConfig
            ? `your config${configNameOfNoInlineConfig}`
            : null,
        reportUnusedDisableDirectives,
        reportUnusedInlineConfigs,
        disableFixes: Boolean(providedOptions.disableFixes),
        stats: providedOptions.stats,
        ruleFilter
    };
}

/**
 * Combines the provided parserOptions with the options from environments
 * @param {Parser} parser The parser which uses this options.
 * @param {ParserOptions} providedOptions The provided 'parserOptions' key in a config
 * @param {Environment[]} enabledEnvironments The environments enabled in configuration and with inline comments
 * @returns {ParserOptions} Resulting parser options after merge
 */
function resolveParserOptions(parser, providedOptions, enabledEnvironments) {

    const parserOptionsFromEnv = enabledEnvironments
        .filter(env => env.parserOptions)
        .reduce((parserOptions, env) => merge(parserOptions, env.parserOptions), {});
    const mergedParserOptions = merge(parserOptionsFromEnv, providedOptions || {});
    const isModule = mergedParserOptions.sourceType === "module";

    if (isModule) {

        /*
         * can't have global return inside of modules
         * TODO: espree validate parserOptions.globalReturn when sourceType is setting to module.(@aladdin-add)
         */
        mergedParserOptions.ecmaFeatures = Object.assign({}, mergedParserOptions.ecmaFeatures, { globalReturn: false });
    }

    mergedParserOptions.ecmaVersion = normalizeEcmaVersion(parser, mergedParserOptions.ecmaVersion);

    return mergedParserOptions;
}

/**
 * Converts parserOptions to languageOptions for backwards compatibility with eslintrc.
 * @param {ConfigData} config Config object.
 * @param {Object} config.globals Global variable definitions.
 * @param {Parser} config.parser The parser to use.
 * @param {ParserOptions} config.parserOptions The parserOptions to use.
 * @returns {LanguageOptions} The languageOptions equivalent.
 */
function createLanguageOptions({ globals: configuredGlobals, parser, parserOptions }) {

    const {
        ecmaVersion,
        sourceType
    } = parserOptions;

    return {
        globals: configuredGlobals,
        ecmaVersion: normalizeEcmaVersionForLanguageOptions(ecmaVersion),
        sourceType,
        parser,
        parserOptions
    };
}

/**
 * Combines the provided globals object with the globals from environments
 * @param {Record<string, GlobalConf>} providedGlobals The 'globals' key in a config
 * @param {Environment[]} enabledEnvironments The environments enabled in configuration and with inline comments
 * @returns {Record<string, GlobalConf>} The resolved globals object
 */
function resolveGlobals(providedGlobals, enabledEnvironments) {
    return Object.assign(
        Object.create(null),
        ...enabledEnvironments.filter(env => env.globals).map(env => env.globals),
        providedGlobals
    );
}

/**
 * Store time measurements in map
 * @param {number} time Time measurement
 * @param {Object} timeOpts Options relating which time was measured
 * @param {WeakMap<Linter, LinterInternalSlots>} slots Linter internal slots map
 * @returns {void}
 */
function storeTime(time, timeOpts, slots) {
    const { type, key } = timeOpts;

    if (!slots.times) {
        slots.times = { passes: [{}] };
    }

    const passIndex = slots.fixPasses;

    if (passIndex > slots.times.passes.length - 1) {
        slots.times.passes.push({});
    }

    if (key) {
        slots.times.passes[passIndex][type] ??= {};
        slots.times.passes[passIndex][type][key] ??= { total: 0 };
        slots.times.passes[passIndex][type][key].total += time;
    } else {
        slots.times.passes[passIndex][type] ??= { total: 0 };
        slots.times.passes[passIndex][type].total += time;
    }
}

/**
 * Get the options for a rule (not including severity), if any
 * @param {RuleConfig} ruleConfig rule configuration
 * @param {Object|undefined} defaultOptions rule.meta.defaultOptions
 * @returns {Array} of rule options, empty Array if none
 */
function getRuleOptions(ruleConfig, defaultOptions) {
    if (Array.isArray(ruleConfig)) {
        return deepMergeArrays(defaultOptions, ruleConfig.slice(1));
    }
    return defaultOptions ?? [];
}

/**
 * Analyze scope of the given AST.
 * @param {ASTNode} ast The `Program` node to analyze.
 * @param {LanguageOptions} languageOptions The parser options.
 * @param {Record<string, string[]>} visitorKeys The visitor keys.
 * @returns {ScopeManager} The analysis result.
 */
function analyzeScope(ast, languageOptions, visitorKeys) {
    const parserOptions = languageOptions.parserOptions;
    const ecmaFeatures = parserOptions.ecmaFeatures || {};
    const ecmaVersion = languageOptions.ecmaVersion || DEFAULT_ECMA_VERSION;

    return eslintScope.analyze(ast, {
        ignoreEval: true,
        nodejsScope: ecmaFeatures.globalReturn,
        impliedStrict: ecmaFeatures.impliedStrict,
        ecmaVersion: typeof ecmaVersion === "number" ? ecmaVersion : 6,
        sourceType: languageOptions.sourceType || "script",
        childVisitorKeys: visitorKeys || evk.KEYS,
        fallback: Traverser.getKeys
    });
}

/**
 * Runs a rule, and gets its listeners
 * @param {Rule} rule A rule object
 * @param {Context} ruleContext The context that should be passed to the rule
 * @throws {TypeError} If `rule` is not an object with a `create` method
 * @throws {any} Any error during the rule's `create`
 * @returns {Object} A map of selector listeners provided by the rule
 */
function createRuleListeners(rule, ruleContext) {

    if (!rule || typeof rule !== "object" || typeof rule.create !== "function") {
        throw new TypeError(`Error while loading rule '${ruleContext.id}': Rule must be an object with a \`create\` method`);
    }

    try {
        return rule.create(ruleContext);
    } catch (ex) {
        ex.message = `Error while loading rule '${ruleContext.id}': ${ex.message}`;
        throw ex;
    }
}

/**
 * Runs the given rules on the given SourceCode object
 * @param {SourceCode} sourceCode A SourceCode object for the given text
 * @param {Object} configuredRules The rules configuration
 * @param {function(string): Rule} ruleMapper A mapper function from rule names to rules
 * @param {string | undefined} parserName The name of the parser in the config
 * @param {Language} language The language object used for parsing.
 * @param {LanguageOptions} languageOptions The options for parsing the code.
 * @param {Object} settings The settings that were enabled in the config
 * @param {string} filename The reported filename of the code
 * @param {boolean} applyDefaultOptions If true, apply rules' meta.defaultOptions in computing their config options.
 * @param {boolean} disableFixes If true, it doesn't make `fix` properties.
 * @param {string | undefined} cwd cwd of the cli
 * @param {string} physicalFilename The full path of the file on disk without any code block information
 * @param {Function} ruleFilter A predicate function to filter which rules should be executed.
 * @param {boolean} stats If true, stats are collected appended to the result
 * @param {WeakMap<Linter, LinterInternalSlots>} slots InternalSlotsMap of linter
 * @returns {LintMessage[]} An array of reported problems
 * @throws {Error} If traversal into a node fails.
 */
function runRules(
    sourceCode,
    configuredRules,
    ruleMapper,
    parserName,
    language,
    languageOptions,
    settings,
    filename,
    applyDefaultOptions,
    disableFixes,
    cwd,
    physicalFilename,
    ruleFilter,
    stats,
    slots
) {
    const emitter = createEmitter();

    // must happen first to assign all node.parent properties
    const eventQueue = sourceCode.traverse();

    /*
     * Create a frozen object with the ruleContext properties and methods that are shared by all rules.
     * All rule contexts will inherit from this object. This avoids the performance penalty of copying all the
     * properties once for each rule.
     */
    const sharedTraversalContext = new FileContext({
        cwd,
        filename,
        physicalFilename: physicalFilename || filename,
        sourceCode,
        parserOptions: {
            ...languageOptions.parserOptions
        },
        parserPath: parserName,
        languageOptions,
        settings
    });

    const lintingProblems = [];

    Object.keys(configuredRules).forEach(ruleId => {
        const severity = ConfigOps.getRuleSeverity(configuredRules[ruleId]);

        // not load disabled rules
        if (severity === 0) {
            return;
        }

        if (ruleFilter && !ruleFilter({ ruleId, severity })) {
            return;
        }

        const rule = ruleMapper(ruleId);

        if (!rule) {
            lintingProblems.push(createLintingProblem({ ruleId, language }));
            return;
        }

        const messageIds = rule.meta && rule.meta.messages;
        let reportTranslator = null;
        const ruleContext = Object.freeze(
            Object.assign(
                Object.create(sharedTraversalContext),
                {
                    id: ruleId,
                    options: getRuleOptions(configuredRules[ruleId], applyDefaultOptions ? rule.meta?.defaultOptions : void 0),
                    report(...args) {

                        /*
                         * Create a report translator lazily.
                         * In a vast majority of cases, any given rule reports zero errors on a given
                         * piece of code. Creating a translator lazily avoids the performance cost of
                         * creating a new translator function for each rule that usually doesn't get
                         * called.
                         *
                         * Using lazy report translators improves end-to-end performance by about 3%
                         * with Node 8.4.0.
                         */
                        if (reportTranslator === null) {
                            reportTranslator = createReportTranslator({
                                ruleId,
                                severity,
                                sourceCode,
                                messageIds,
                                disableFixes,
                                language
                            });
                        }
                        const problem = reportTranslator(...args);

                        if (problem.fix && !(rule.meta && rule.meta.fixable)) {
                            throw new Error("Fixable rules must set the `meta.fixable` property to \"code\" or \"whitespace\".");
                        }
                        if (problem.suggestions && !(rule.meta && rule.meta.hasSuggestions === true)) {
                            if (rule.meta && rule.meta.docs && typeof rule.meta.docs.suggestion !== "undefined") {

                                // Encourage migration from the former property name.
                                throw new Error("Rules with suggestions must set the `meta.hasSuggestions` property to `true`. `meta.docs.suggestion` is ignored by ESLint.");
                            }
                            throw new Error("Rules with suggestions must set the `meta.hasSuggestions` property to `true`.");
                        }
                        lintingProblems.push(problem);
                    }
                }
            )
        );

        const ruleListenersReturn = (timing.enabled || stats)
            ? timing.time(ruleId, createRuleListeners, stats)(rule, ruleContext) : createRuleListeners(rule, ruleContext);

        const ruleListeners = stats ? ruleListenersReturn.result : ruleListenersReturn;

        if (stats) {
            storeTime(ruleListenersReturn.tdiff, { type: "rules", key: ruleId }, slots);
        }

        /**
         * Include `ruleId` in error logs
         * @param {Function} ruleListener A rule method that listens for a node.
         * @returns {Function} ruleListener wrapped in error handler
         */
        function addRuleErrorHandler(ruleListener) {
            return function ruleErrorHandler(...listenerArgs) {
                try {
                    const ruleListenerReturn = ruleListener(...listenerArgs);

                    const ruleListenerResult = stats ? ruleListenerReturn.result : ruleListenerReturn;

                    if (stats) {
                        storeTime(ruleListenerReturn.tdiff, { type: "rules", key: ruleId }, slots);
                    }

                    return ruleListenerResult;
                } catch (e) {
                    e.ruleId = ruleId;
                    throw e;
                }
            };
        }

        if (typeof ruleListeners === "undefined" || ruleListeners === null) {
            throw new Error(`The create() function for rule '${ruleId}' did not return an object.`);
        }

        // add all the selectors from the rule as listeners
        Object.keys(ruleListeners).forEach(selector => {
            const ruleListener = (timing.enabled || stats)
                ? timing.time(ruleId, ruleListeners[selector], stats) : ruleListeners[selector];

            emitter.on(
                selector,
                addRuleErrorHandler(ruleListener)
            );
        });
    });

    const eventGenerator = new NodeEventGenerator(emitter, {
        visitorKeys: sourceCode.visitorKeys ?? language.visitorKeys,
        fallback: Traverser.getKeys,
        matchClass: language.matchesSelectorClass ?? (() => false),
        nodeTypeKey: language.nodeTypeKey
    });

    for (const step of eventQueue) {
        switch (step.kind) {
            case STEP_KIND_VISIT: {
                try {
                    if (step.phase === 1) {
                        eventGenerator.enterNode(step.target);
                    } else {
                        eventGenerator.leaveNode(step.target);
                    }
                } catch (err) {
                    err.currentNode = step.target;
                    throw err;
                }
                break;
            }

            case STEP_KIND_CALL: {
                emitter.emit(step.target, ...step.args);
                break;
            }

            default:
                throw new Error(`Invalid traversal step found: "${step.type}".`);
        }

    }

    return lintingProblems;
}

/**
 * Ensure the source code to be a string.
 * @param {string|SourceCode} textOrSourceCode The text or source code object.
 * @returns {string} The source code text.
 */
function ensureText(textOrSourceCode) {
    if (typeof textOrSourceCode === "object") {
        const { hasBOM, text } = textOrSourceCode;
        const bom = hasBOM ? "\uFEFF" : "";

        return bom + text;
    }

    return String(textOrSourceCode);
}

/**
 * Get an environment.
 * @param {LinterInternalSlots} slots The internal slots of Linter.
 * @param {string} envId The environment ID to get.
 * @returns {Environment|null} The environment.
 */
function getEnv(slots, envId) {
    return (
        (slots.lastConfigArray && slots.lastConfigArray.pluginEnvironments.get(envId)) ||
        BuiltInEnvironments.get(envId) ||
        null
    );
}

/**
 * Get a rule.
 * @param {LinterInternalSlots} slots The internal slots of Linter.
 * @param {string} ruleId The rule ID to get.
 * @returns {Rule|null} The rule.
 */
function getRule(slots, ruleId) {
    return (
        (slots.lastConfigArray && slots.lastConfigArray.pluginRules.get(ruleId)) ||
        slots.ruleMap.get(ruleId)
    );
}

/**
 * Normalize the value of the cwd
 * @param {string | undefined} cwd raw value of the cwd, path to a directory that should be considered as the current working directory, can be undefined.
 * @returns {string | undefined} normalized cwd
 */
function normalizeCwd(cwd) {
    if (cwd) {
        return cwd;
    }
    if (typeof process === "object") {
        return process.cwd();
    }

    // It's more explicit to assign the undefined
    // eslint-disable-next-line no-undefined -- Consistently returning a value
    return undefined;
}

/**
 * The map to store private data.
 * @type {WeakMap<Linter, LinterInternalSlots>}
 */
const internalSlotsMap = new WeakMap();

/**
 * Throws an error when the given linter is in flat config mode.
 * @param {Linter} linter The linter to check.
 * @returns {void}
 * @throws {Error} If the linter is in flat config mode.
 */
function assertEslintrcConfig(linter) {
    const { configType } = internalSlotsMap.get(linter);

    if (configType === "flat") {
        throw new Error("This method cannot be used with flat config. Add your entries directly into the config array.");
    }
}

//------------------------------------------------------------------------------
// Public Interface
//------------------------------------------------------------------------------

/**
 * Object that is responsible for verifying JavaScript text
 * @name Linter
 */
class Linter {

    /**
     * Initialize the Linter.
     * @param {Object} [config] the config object
     * @param {string} [config.cwd] path to a directory that should be considered as the current working directory, can be undefined.
     * @param {Array<string>} [config.flags] the feature flags to enable.
     * @param {"flat"|"eslintrc"} [config.configType="flat"] the type of config used.
     */
    constructor({ cwd, configType = "flat", flags = [] } = {}) {

        flags.forEach(flag => {
            if (inactiveFlags.has(flag)) {
                throw new Error(`The flag '${flag}' is inactive: ${inactiveFlags.get(flag)}`);
            }

            if (!activeFlags.has(flag)) {
                throw new Error(`Unknown flag '${flag}'.`);
            }
        });

        internalSlotsMap.set(this, {
            cwd: normalizeCwd(cwd),
            flags,
            lastConfigArray: null,
            lastSourceCode: null,
            lastSuppressedMessages: [],
            configType, // TODO: Remove after flat config conversion
            parserMap: new Map([["espree", espree]]),
            ruleMap: new Rules()
        });

        this.version = pkg.version;
    }

    /**
     * Getter for package version.
     * @static
     * @returns {string} The version from package.json.
     */
    static get version() {
        return pkg.version;
    }

    /**
     * Indicates if the given feature flag is enabled for this instance.
     * @param {string} flag The feature flag to check.
     * @returns {boolean} `true` if the feature flag is enabled, `false` if not.
     */
    hasFlag(flag) {
        return internalSlotsMap.get(this).flags.includes(flag);
    }

    /**
     * Lint using eslintrc and without processors.
     * @param {VFile} file The file to lint.
     * @param {ConfigData} providedConfig An ESLintConfig instance to configure everything.
     * @param {VerifyOptions} [providedOptions] The optional filename of the file being checked.
     * @throws {Error} If during rule execution.
     * @returns {(LintMessage|SuppressedLintMessage)[]} The results as an array of messages or an empty array if no messages.
     */
    #eslintrcVerifyWithoutProcessors(file, providedConfig, providedOptions) {

        const slots = internalSlotsMap.get(this);
        const config = providedConfig || {};
        const options = normalizeVerifyOptions(providedOptions, config);

        // Resolve parser.
        let parserName = DEFAULT_PARSER_NAME;
        let parser = espree;

        if (typeof config.parser === "object" && config.parser !== null) {
            parserName = config.parser.filePath;
            parser = config.parser.definition;
        } else if (typeof config.parser === "string") {
            if (!slots.parserMap.has(config.parser)) {
                return [{
                    ruleId: null,
                    fatal: true,
                    severity: 2,
                    message: `Configured parser '${config.parser}' was not found.`,
                    line: 0,
                    column: 0,
                    nodeType: null
                }];
            }
            parserName = config.parser;
            parser = slots.parserMap.get(config.parser);
        }

        // search and apply "eslint-env *".
        const envInFile = options.allowInlineConfig && !options.warnInlineConfig
            ? findEslintEnv(file.body)
            : {};
        const resolvedEnvConfig = Object.assign({ builtin: true }, config.env, envInFile);
        const enabledEnvs = Object.keys(resolvedEnvConfig)
            .filter(envName => resolvedEnvConfig[envName])
            .map(envName => getEnv(slots, envName))
            .filter(env => env);

        const parserOptions = resolveParserOptions(parser, config.parserOptions || {}, enabledEnvs);
        const configuredGlobals = resolveGlobals(config.globals || {}, enabledEnvs);
        const settings = config.settings || {};
        const languageOptions = createLanguageOptions({
            globals: config.globals,
            parser,
            parserOptions
        });

        if (!slots.lastSourceCode) {
            let t;

            if (options.stats) {
                t = startTime();
            }

            const parserService = new ParserService();
            const parseResult = parserService.parseSync(
                file,
                {
                    language: jslang,
                    languageOptions
                }
            );

            if (options.stats) {
                const time = endTime(t);
                const timeOpts = { type: "parse" };

                storeTime(time, timeOpts, slots);
            }

            if (!parseResult.ok) {
                return parseResult.errors;
            }

            slots.lastSourceCode = parseResult.sourceCode;
        } else {

            /*
             * If the given source code object as the first argument does not have scopeManager, analyze the scope.
             * This is for backward compatibility (SourceCode is frozen so it cannot rebind).
             */
            if (!slots.lastSourceCode.scopeManager) {
                slots.lastSourceCode = new SourceCode({
                    text: slots.lastSourceCode.text,
                    ast: slots.lastSourceCode.ast,
                    hasBOM: slots.lastSourceCode.hasBOM,
                    parserServices: slots.lastSourceCode.parserServices,
                    visitorKeys: slots.lastSourceCode.visitorKeys,
                    scopeManager: analyzeScope(slots.lastSourceCode.ast, languageOptions)
                });
            }
        }

        const sourceCode = slots.lastSourceCode;
        const commentDirectives = options.allowInlineConfig
            ? getDirectiveComments(sourceCode, ruleId => getRule(slots, ruleId), options.warnInlineConfig, config)
            : { configuredRules: {}, enabledGlobals: {}, exportedVariables: {}, problems: [], disableDirectives: [] };

        addDeclaredGlobals(
            sourceCode.scopeManager.scopes[0],
            configuredGlobals,
            { exportedVariables: commentDirectives.exportedVariables, enabledGlobals: commentDirectives.enabledGlobals }
        );

        const configuredRules = Object.assign({}, config.rules, commentDirectives.configuredRules);

        let lintingProblems;

        try {
            lintingProblems = runRules(
                sourceCode,
                configuredRules,
                ruleId => getRule(slots, ruleId),
                parserName,
                jslang,
                languageOptions,
                settings,
                options.filename,
                true,
                options.disableFixes,
                slots.cwd,
                providedOptions.physicalFilename,
                null,
                options.stats,
                slots
            );
        } catch (err) {
            err.message += `\nOccurred while linting ${options.filename}`;
            debug("An error occurred while traversing");
            debug("Filename:", options.filename);
            if (err.currentNode) {
                const { line } = sourceCode.getLoc(err.currentNode).start;

                debug("Line:", line);
                err.message += `:${line}`;
            }
            debug("Parser Options:", parserOptions);
            debug("Parser Path:", parserName);
            debug("Settings:", settings);

            if (err.ruleId) {
                err.message += `\nRule: "${err.ruleId}"`;
            }

            throw err;
        }

        return applyDisableDirectives({
            language: jslang,
            sourceCode,
            directives: commentDirectives.disableDirectives,
            disableFixes: options.disableFixes,
            problems: lintingProblems
                .concat(commentDirectives.problems)
                .sort((problemA, problemB) => problemA.line - problemB.line || problemA.column - problemB.column),
            reportUnusedDisableDirectives: options.reportUnusedDisableDirectives
        });

    }

    /**
     * Same as linter.verify, except without support for processors.
     * @param {string|SourceCode} textOrSourceCode The text to parse or a SourceCode object.
     * @param {ConfigData} providedConfig An ESLintConfig instance to configure everything.
     * @param {VerifyOptions} [providedOptions] The optional filename of the file being checked.
     * @throws {Error} If during rule execution.
     * @returns {(LintMessage|SuppressedLintMessage)[]} The results as an array of messages or an empty array if no messages.
     */
    _verifyWithoutProcessors(textOrSourceCode, providedConfig, providedOptions) {
        const slots = internalSlotsMap.get(this);
        const filename = normalizeFilename(providedOptions.filename || "<input>");
        let text;

        // evaluate arguments
        if (typeof textOrSourceCode === "string") {
            slots.lastSourceCode = null;
            text = textOrSourceCode;
        } else {
            slots.lastSourceCode = textOrSourceCode;
            text = textOrSourceCode.text;
        }

        const file = new VFile(filename, text, {
            physicalPath: providedOptions.physicalFilename
        });

        return this.#eslintrcVerifyWithoutProcessors(file, providedConfig, providedOptions);
    }

    /**
     * Verifies the text against the rules specified by the second argument.
     * @param {string|SourceCode} textOrSourceCode The text to parse or a SourceCode object.
     * @param {ConfigData|ConfigArray} config An ESLintConfig instance to configure everything.
     * @param {(string|(VerifyOptions&ProcessorOptions))} [filenameOrOptions] The optional filename of the file being checked.
     *      If this is not set, the filename will default to '<input>' in the rule context. If
     *      an object, then it has "filename", "allowInlineConfig", and some properties.
     * @returns {LintMessage[]} The results as an array of messages or an empty array if no messages.
     */
    verify(textOrSourceCode, config, filenameOrOptions) {
        debug("Verify");

        const { configType, cwd } = internalSlotsMap.get(this);

        const options = typeof filenameOrOptions === "string"
            ? { filename: filenameOrOptions }
            : filenameOrOptions || {};

        const configToUse = config ?? {};

        if (configType !== "eslintrc") {

            /*
             * Because of how Webpack packages up the files, we can't
             * compare directly to `FlatConfigArray` using `instanceof`
             * because it's not the same `FlatConfigArray` as in the tests.
             * So, we work around it by assuming an array is, in fact, a
             * `FlatConfigArray` if it has a `getConfig()` method.
             */
            let configArray = configToUse;

            if (!Array.isArray(configToUse) || typeof configToUse.getConfig !== "function") {
                configArray = new FlatConfigArray(configToUse, { basePath: cwd });
                configArray.normalizeSync();
            }

            return this._distinguishSuppressedMessages(this._verifyWithFlatConfigArray(textOrSourceCode, configArray, options, true));
        }

        if (typeof configToUse.extractConfig === "function") {
            return this._distinguishSuppressedMessages(this._verifyWithConfigArray(textOrSourceCode, configToUse, options));
        }

        /*
         * If we get to here, it means `config` is just an object rather
         * than a config array so we can go right into linting.
         */

        /*
         * `Linter` doesn't support `overrides` property in configuration.
         * So we cannot apply multiple processors.
         */
        if (options.preprocess || options.postprocess) {
            return this._distinguishSuppressedMessages(this._verifyWithProcessor(textOrSourceCode, configToUse, options));
        }
        return this._distinguishSuppressedMessages(this._verifyWithoutProcessors(textOrSourceCode, configToUse, options));
    }

    /**
     * Verify with a processor.
     * @param {string|SourceCode} textOrSourceCode The source code.
     * @param {FlatConfig} config The config array.
     * @param {VerifyOptions&ProcessorOptions} options The options.
     * @param {FlatConfigArray} [configForRecursive] The `ConfigArray` object to apply multiple processors recursively.
     * @returns {(LintMessage|SuppressedLintMessage)[]} The found problems.
     */
    _verifyWithFlatConfigArrayAndProcessor(textOrSourceCode, config, options, configForRecursive) {
        const slots = internalSlotsMap.get(this);
        const filename = options.filename || "<input>";
        const filenameToExpose = normalizeFilename(filename);
        const physicalFilename = options.physicalFilename || filenameToExpose;
        const text = ensureText(textOrSourceCode);
        const file = new VFile(filenameToExpose, text, {
            physicalPath: physicalFilename
        });

        const preprocess = options.preprocess || (rawText => [rawText]);
        const postprocess = options.postprocess || (messagesList => messagesList.flat());

        const processorService = new ProcessorService();
        const preprocessResult = processorService.preprocessSync(file, {
            processor: {
                preprocess,
                postprocess
            }
        });

        if (!preprocessResult.ok) {
            return preprocessResult.errors;
        }

        const filterCodeBlock =
            options.filterCodeBlock ||
            (blockFilename => blockFilename.endsWith(".js"));
        const originalExtname = path.extname(filename);
        const { files } = preprocessResult;

        const messageLists = files.map(block => {
            debug("A code block was found: %o", block.path || "(unnamed)");

            // Keep the legacy behavior.
            if (typeof block === "string") {
                return this._verifyWithFlatConfigArrayAndWithoutProcessors(block, config, options);
            }

            // Skip this block if filtered.
            if (!filterCodeBlock(block.path, block.body)) {
                debug("This code block was skipped.");
                return [];
            }

            // Resolve configuration again if the file content or extension was changed.
            if (configForRecursive && (text !== block.rawBody || path.extname(block.path) !== originalExtname)) {
                debug("Resolving configuration again because the file content or extension was changed.");
                return this._verifyWithFlatConfigArray(
                    block.rawBody,
                    configForRecursive,
                    { ...options, filename: block.path, physicalFilename: block.physicalPath }
                );
            }

            slots.lastSourceCode = null;

            // Does lint.
            return this.#flatVerifyWithoutProcessors(
                block,
                config,
                { ...options, filename: block.path, physicalFilename: block.physicalPath }
            );
        });

        return processorService.postprocessSync(file, messageLists, {
            processor: {
                preprocess,
                postprocess
            }
        });
    }

    /**
     * Verify using flat config and without any processors.
     * @param {VFile} file The file to lint.
     * @param {FlatConfig} providedConfig An ESLintConfig instance to configure everything.
     * @param {VerifyOptions} [providedOptions] The optional filename of the file being checked.
     * @throws {Error} If during rule execution.
     * @returns {(LintMessage|SuppressedLintMessage)[]} The results as an array of messages or an empty array if no messages.
     */
    #flatVerifyWithoutProcessors(file, providedConfig, providedOptions) {

        const slots = internalSlotsMap.get(this);
        const config = providedConfig || {};
        const { settings = {}, languageOptions } = config;
        const options = normalizeVerifyOptions(providedOptions, config);

        if (!slots.lastSourceCode) {
            let t;

            if (options.stats) {
                t = startTime();
            }

            const parserService = new ParserService();
            const parseResult = parserService.parseSync(
                file,
                config
            );

            if (options.stats) {
                const time = endTime(t);

                storeTime(time, { type: "parse" }, slots);
            }

            if (!parseResult.ok) {
                return parseResult.errors;
            }

            slots.lastSourceCode = parseResult.sourceCode;
        } else {

            /*
             * If the given source code object as the first argument does not have scopeManager, analyze the scope.
             * This is for backward compatibility (SourceCode is frozen so it cannot rebind).
             *
             * We check explicitly for `null` to ensure that this is a JS-flavored language.
             * For non-JS languages we don't want to do this.
             *
             * TODO: Remove this check when we stop exporting the `SourceCode` object.
             */
            if (slots.lastSourceCode.scopeManager === null) {
                slots.lastSourceCode = new SourceCode({
                    text: slots.lastSourceCode.text,
                    ast: slots.lastSourceCode.ast,
                    hasBOM: slots.lastSourceCode.hasBOM,
                    parserServices: slots.lastSourceCode.parserServices,
                    visitorKeys: slots.lastSourceCode.visitorKeys,
                    scopeManager: analyzeScope(slots.lastSourceCode.ast, languageOptions)
                });
            }
        }

        const sourceCode = slots.lastSourceCode;

        /*
         * Make adjustments based on the language options. For JavaScript,
         * this is primarily about adding variables into the global scope
         * to account for ecmaVersion and configured globals.
         */
        sourceCode.applyLanguageOptions?.(languageOptions);

        const mergedInlineConfig = {
            rules: {}
        };
        const inlineConfigProblems = [];

        /*
         * Inline config can be either enabled or disabled. If disabled, it's possible
         * to detect the inline config and emit a warning (though this is not required).
         * So we first check to see if inline config is allowed at all, and if so, we
         * need to check if it's a warning or not.
         */
        if (options.allowInlineConfig) {

            // if inline config should warn then add the warnings
            if (options.warnInlineConfig) {
                if (sourceCode.getInlineConfigNodes) {
                    sourceCode.getInlineConfigNodes().forEach(node => {

                        const loc = sourceCode.getLoc(node);
                        const range = sourceCode.getRange(node);

                        inlineConfigProblems.push(createLintingProblem({
                            ruleId: null,
                            message: `'${sourceCode.text.slice(range[0], range[1])}' has no effect because you have 'noInlineConfig' setting in ${options.warnInlineConfig}.`,
                            loc,
                            severity: 1,
                            language: config.language
                        }));

                    });
                }
            } else {
                const inlineConfigResult = sourceCode.applyInlineConfig?.();

                if (inlineConfigResult) {
                    inlineConfigProblems.push(
                        ...inlineConfigResult.problems
                            .map(problem => createLintingProblem({ ...problem, language: config.language }))
                            .map(problem => {
                                problem.fatal = true;
                                return problem;
                            })
                    );

                    // next we need to verify information about the specified rules
                    const ruleValidator = new RuleValidator();

                    for (const { config: inlineConfig, loc } of inlineConfigResult.configs) {

                        Object.keys(inlineConfig.rules).forEach(ruleId => {
                            const rule = getRuleFromConfig(ruleId, config);
                            const ruleValue = inlineConfig.rules[ruleId];

                            if (!rule) {
                                inlineConfigProblems.push(createLintingProblem({
                                    ruleId,
                                    loc,
                                    language: config.language
                                }));
                                return;
                            }

                            if (Object.hasOwn(mergedInlineConfig.rules, ruleId)) {
                                inlineConfigProblems.push(createLintingProblem({
                                    message: `Rule "${ruleId}" is already configured by another configuration comment in the preceding code. This configuration is ignored.`,
                                    loc,
                                    language: config.language
                                }));
                                return;
                            }

                            try {

                                const ruleOptionsInline = asArray(ruleValue);
                                let ruleOptions = ruleOptionsInline;

                                assertIsRuleSeverity(ruleId, ruleOptions[0]);

                                /*
                                 * If the rule was already configured, inline rule configuration that
                                 * only has severity should retain options from the config and just override the severity.
                                 *
                                 * Example:
                                 *
                                 *   {
                                 *       rules: {
                                 *           curly: ["error", "multi"]
                                 *       }
                                 *   }
                                 *
                                 *   /* eslint curly: ["warn"] * /
                                 *
                                 *   Results in:
                                 *
                                 *   curly: ["warn", "multi"]
                                 */

                                let shouldValidateOptions = true;

                                if (

                                    /*
                                     * If inline config for the rule has only severity
                                     */
                                    ruleOptions.length === 1 &&

                                    /*
                                     * And the rule was already configured
                                     */
                                    config.rules && Object.hasOwn(config.rules, ruleId)
                                ) {

                                    /*
                                     * Then use severity from the inline config and options from the provided config
                                     */
                                    ruleOptions = [
                                        ruleOptions[0], // severity from the inline config
                                        ...config.rules[ruleId].slice(1) // options from the provided config
                                    ];

                                    // if the rule was enabled, the options have already been validated
                                    if (config.rules[ruleId][0] > 0) {
                                        shouldValidateOptions = false;
                                    }
                                } else {

                                    /**
                                     * Since we know the user provided options, apply defaults on top of them
                                     */
                                    const slicedOptions = ruleOptions.slice(1);
                                    const mergedOptions = deepMergeArrays(rule.meta?.defaultOptions, slicedOptions);

                                    if (mergedOptions.length) {
                                        ruleOptions = [ruleOptions[0], ...mergedOptions];
                                    }
                                }

                                if (options.reportUnusedInlineConfigs !== "off") {
                                    addProblemIfSameSeverityAndOptions(
                                        config, loc, inlineConfigProblems, ruleId, ruleOptions, ruleOptionsInline, options.reportUnusedInlineConfigs
                                    );
                                }

                                if (shouldValidateOptions) {
                                    ruleValidator.validate({
                                        plugins: config.plugins,
                                        rules: {
                                            [ruleId]: ruleOptions
                                        }
                                    });
                                }

                                mergedInlineConfig.rules[ruleId] = ruleOptions;
                            } catch (err) {

                                /*
                                 * If the rule has invalid `meta.schema`, throw the error because
                                 * this is not an invalid inline configuration but an invalid rule.
                                 */
                                if (err.code === "ESLINT_INVALID_RULE_OPTIONS_SCHEMA") {
                                    throw err;
                                }

                                let baseMessage = err.message.slice(
                                    err.message.startsWith("Key \"rules\":")
                                        ? err.message.indexOf(":", 12) + 1
                                        : err.message.indexOf(":") + 1
                                ).trim();

                                if (err.messageTemplate) {
                                    baseMessage += ` You passed "${ruleValue}".`;
                                }

                                inlineConfigProblems.push(createLintingProblem({
                                    ruleId,
                                    message: `Inline configuration for rule "${ruleId}" is invalid:\n\t${baseMessage}\n`,
                                    loc,
                                    language: config.language
                                }));
                            }
                        });
                    }
                }
            }
        }

        const commentDirectives = options.allowInlineConfig && !options.warnInlineConfig
            ? getDirectiveCommentsForFlatConfig(
                sourceCode,
                ruleId => getRuleFromConfig(ruleId, config),
                config.language
            )
            : { problems: [], disableDirectives: [] };

        const configuredRules = Object.assign({}, config.rules, mergedInlineConfig.rules);

        let lintingProblems;

        sourceCode.finalize?.();

        try {
            lintingProblems = runRules(
                sourceCode,
                configuredRules,
                ruleId => getRuleFromConfig(ruleId, config),
                void 0,
                config.language,
                languageOptions,
                settings,
                options.filename,
                false,
                options.disableFixes,
                slots.cwd,
                providedOptions.physicalFilename,
                options.ruleFilter,
                options.stats,
                slots
            );
        } catch (err) {
            err.message += `\nOccurred while linting ${options.filename}`;
            debug("An error occurred while traversing");
            debug("Filename:", options.filename);
            if (err.currentNode) {
                const { line } = sourceCode.getLoc(err.currentNode).start;

                debug("Line:", line);
                err.message += `:${line}`;
            }
            debug("Parser Options:", languageOptions.parserOptions);

            // debug("Parser Path:", parserName);
            debug("Settings:", settings);

            if (err.ruleId) {
                err.message += `\nRule: "${err.ruleId}"`;
            }

            throw err;
        }

        return applyDisableDirectives({
            language: config.language,
            sourceCode,
            directives: commentDirectives.disableDirectives,
            disableFixes: options.disableFixes,
            problems: lintingProblems
                .concat(commentDirectives.problems)
                .concat(inlineConfigProblems)
                .sort((problemA, problemB) => problemA.line - problemB.line || problemA.column - problemB.column),
            reportUnusedDisableDirectives: options.reportUnusedDisableDirectives,
            ruleFilter: options.ruleFilter,
            configuredRules
        });


    }

    /**
     * Same as linter.verify, except without support for processors.
     * @param {string|SourceCode} textOrSourceCode The text to parse or a SourceCode object.
     * @param {FlatConfig} providedConfig An ESLintConfig instance to configure everything.
     * @param {VerifyOptions} [providedOptions] The optional filename of the file being checked.
     * @throws {Error} If during rule execution.
     * @returns {(LintMessage|SuppressedLintMessage)[]} The results as an array of messages or an empty array if no messages.
     */
    _verifyWithFlatConfigArrayAndWithoutProcessors(textOrSourceCode, providedConfig, providedOptions) {
        const slots = internalSlotsMap.get(this);
        const filename = normalizeFilename(providedOptions.filename || "<input>");
        let text;

        // evaluate arguments
        if (typeof textOrSourceCode === "string") {
            slots.lastSourceCode = null;
            text = textOrSourceCode;
        } else {
            slots.lastSourceCode = textOrSourceCode;
            text = textOrSourceCode.text;
        }

        const file = new VFile(filename, text, {
            physicalPath: providedOptions.physicalFilename
        });

        return this.#flatVerifyWithoutProcessors(file, providedConfig, providedOptions);
    }

    /**
     * Verify a given code with `ConfigArray`.
     * @param {string|SourceCode} textOrSourceCode The source code.
     * @param {ConfigArray} configArray The config array.
     * @param {VerifyOptions&ProcessorOptions} options The options.
     * @returns {(LintMessage|SuppressedLintMessage)[]} The found problems.
     */
    _verifyWithConfigArray(textOrSourceCode, configArray, options) {
        debug("With ConfigArray: %s", options.filename);

        // Store the config array in order to get plugin envs and rules later.
        internalSlotsMap.get(this).lastConfigArray = configArray;

        // Extract the final config for this file.
        const config = configArray.extractConfig(options.filename);
        const processor =
            config.processor &&
            configArray.pluginProcessors.get(config.processor);

        // Verify.
        if (processor) {
            debug("Apply the processor: %o", config.processor);
            const { preprocess, postprocess, supportsAutofix } = processor;
            const disableFixes = options.disableFixes || !supportsAutofix;

            return this._verifyWithProcessor(
                textOrSourceCode,
                config,
                { ...options, disableFixes, postprocess, preprocess },
                configArray
            );
        }
        return this._verifyWithoutProcessors(textOrSourceCode, config, options);
    }

    /**
     * Verify a given code with a flat config.
     * @param {string|SourceCode} textOrSourceCode The source code.
     * @param {FlatConfigArray} configArray The config array.
     * @param {VerifyOptions&ProcessorOptions} options The options.
     * @param {boolean} [firstCall=false] Indicates if this is being called directly
     *      from verify(). (TODO: Remove once eslintrc is removed.)
     * @returns {(LintMessage|SuppressedLintMessage)[]} The found problems.
     */
    _verifyWithFlatConfigArray(textOrSourceCode, configArray, options, firstCall = false) {
        debug("With flat config: %s", options.filename);

        // we need a filename to match configs against
        const filename = options.filename || "__placeholder__.js";

        // Store the config array in order to get plugin envs and rules later.
        internalSlotsMap.get(this).lastConfigArray = configArray;
        const config = configArray.getConfig(filename);

        if (!config) {
            return [
                {
                    ruleId: null,
                    severity: 1,
                    message: `No matching configuration found for ${filename}.`,
                    line: 0,
                    column: 0,
                    nodeType: null
                }
            ];
        }

        // Verify.
        if (config.processor) {
            debug("Apply the processor: %o", config.processor);
            const { preprocess, postprocess, supportsAutofix } = config.processor;
            const disableFixes = options.disableFixes || !supportsAutofix;

            return this._verifyWithFlatConfigArrayAndProcessor(
                textOrSourceCode,
                config,
                { ...options, filename, disableFixes, postprocess, preprocess },
                configArray
            );
        }

        // check for options-based processing
        if (firstCall && (options.preprocess || options.postprocess)) {
            return this._verifyWithFlatConfigArrayAndProcessor(textOrSourceCode, config, options);
        }

        return this._verifyWithFlatConfigArrayAndWithoutProcessors(textOrSourceCode, config, options);
    }

    /**
     * Verify with a processor.
     * @param {string|SourceCode} textOrSourceCode The source code.
     * @param {ConfigData|ExtractedConfig} config The config array.
     * @param {VerifyOptions&ProcessorOptions} options The options.
     * @param {ConfigArray} [configForRecursive] The `ConfigArray` object to apply multiple processors recursively.
     * @returns {(LintMessage|SuppressedLintMessage)[]} The found problems.
     */
    _verifyWithProcessor(textOrSourceCode, config, options, configForRecursive) {
        const slots = internalSlotsMap.get(this);
        const filename = options.filename || "<input>";
        const filenameToExpose = normalizeFilename(filename);
        const physicalFilename = options.physicalFilename || filenameToExpose;
        const text = ensureText(textOrSourceCode);
        const file = new VFile(filenameToExpose, text, {
            physicalPath: physicalFilename
        });

        const preprocess = options.preprocess || (rawText => [rawText]);
        const postprocess = options.postprocess || (messagesList => messagesList.flat());

        const processorService = new ProcessorService();
        const preprocessResult = processorService.preprocessSync(file, {
            processor: {
                preprocess,
                postprocess
            }
        });

        if (!preprocessResult.ok) {
            return preprocessResult.errors;
        }

        const filterCodeBlock =
            options.filterCodeBlock ||
            (blockFilePath => blockFilePath.endsWith(".js"));
        const originalExtname = path.extname(filename);

        const { files } = preprocessResult;

        const messageLists = files.map(block => {
            debug("A code block was found: %o", block.path ?? "(unnamed)");

            // Keep the legacy behavior.
            if (typeof block === "string") {
                return this._verifyWithoutProcessors(block, config, options);
            }

            // Skip this block if filtered.
            if (!filterCodeBlock(block.path, block.body)) {
                debug("This code block was skipped.");
                return [];
            }

            // Resolve configuration again if the file content or extension was changed.
            if (configForRecursive && (text !== block.rawBody || path.extname(block.path) !== originalExtname)) {
                debug("Resolving configuration again because the file content or extension was changed.");
                return this._verifyWithConfigArray(
                    block.rawBody,
                    configForRecursive,
                    { ...options, filename: block.path, physicalFilename: block.physicalPath }
                );
            }

            slots.lastSourceCode = null;

            // Does lint.
            return this.#eslintrcVerifyWithoutProcessors(
                block,
                config,
                { ...options, filename: block.path, physicalFilename: block.physicalPath }
            );
        });

        return processorService.postprocessSync(file, messageLists, {
            processor: {
                preprocess,
                postprocess
            }
        });

    }

    /**
     * Given a list of reported problems, distinguish problems between normal messages and suppressed messages.
     * The normal messages will be returned and the suppressed messages will be stored as lastSuppressedMessages.
     * @param {Array<LintMessage|SuppressedLintMessage>} problems A list of reported problems.
     * @returns {LintMessage[]} A list of LintMessage.
     */
    _distinguishSuppressedMessages(problems) {
        const messages = [];
        const suppressedMessages = [];
        const slots = internalSlotsMap.get(this);

        for (const problem of problems) {
            if (problem.suppressions) {
                suppressedMessages.push(problem);
            } else {
                messages.push(problem);
            }
        }

        slots.lastSuppressedMessages = suppressedMessages;

        return messages;
    }

    /**
     * Gets the SourceCode object representing the parsed source.
     * @returns {SourceCode} The SourceCode object.
     */
    getSourceCode() {
        return internalSlotsMap.get(this).lastSourceCode;
    }

    /**
     * Gets the times spent on (parsing, fixing, linting) a file.
     * @returns {LintTimes} The times.
     */
    getTimes() {
        return internalSlotsMap.get(this).times ?? { passes: [] };
    }

    /**
     * Gets the number of autofix passes that were made in the last run.
     * @returns {number} The number of autofix passes.
     */
    getFixPassCount() {
        return internalSlotsMap.get(this).fixPasses ?? 0;
    }

    /**
     * Gets the list of SuppressedLintMessage produced in the last running.
     * @returns {SuppressedLintMessage[]} The list of SuppressedLintMessage
     */
    getSuppressedMessages() {
        return internalSlotsMap.get(this).lastSuppressedMessages;
    }

    /**
     * Defines a new linting rule.
     * @param {string} ruleId A unique rule identifier
     * @param {Rule} rule A rule object
     * @returns {void}
     */
    defineRule(ruleId, rule) {
        assertEslintrcConfig(this);
        internalSlotsMap.get(this).ruleMap.define(ruleId, rule);
    }

    /**
     * Defines many new linting rules.
     * @param {Record<string, Rule>} rulesToDefine map from unique rule identifier to rule
     * @returns {void}
     */
    defineRules(rulesToDefine) {
        assertEslintrcConfig(this);
        Object.getOwnPropertyNames(rulesToDefine).forEach(ruleId => {
            this.defineRule(ruleId, rulesToDefine[ruleId]);
        });
    }

    /**
     * Gets an object with all loaded rules.
     * @returns {Map<string, Rule>} All loaded rules
     */
    getRules() {
        assertEslintrcConfig(this);
        const { lastConfigArray, ruleMap } = internalSlotsMap.get(this);

        return new Map(function *() {
            yield* ruleMap;

            if (lastConfigArray) {
                yield* lastConfigArray.pluginRules;
            }
        }());
    }

    /**
     * Define a new parser module
     * @param {string} parserId Name of the parser
     * @param {Parser} parserModule The parser object
     * @returns {void}
     */
    defineParser(parserId, parserModule) {
        assertEslintrcConfig(this);
        internalSlotsMap.get(this).parserMap.set(parserId, parserModule);
    }

    /**
     * Performs multiple autofix passes over the text until as many fixes as possible
     * have been applied.
     * @param {string} text The source text to apply fixes to.
     * @param {ConfigData|ConfigArray|FlatConfigArray} config The ESLint config object to use.
     * @param {VerifyOptions&ProcessorOptions&FixOptions} options The ESLint options object to use.
     * @returns {{fixed:boolean,messages:LintMessage[],output:string}} The result of the fix operation as returned from the
     *      SourceCodeFixer.
     */
    verifyAndFix(text, config, options) {
        let messages,
            fixedResult,
            fixed = false,
            passNumber = 0,
            currentText = text;
        const debugTextDescription = options && options.filename || `${text.slice(0, 10)}...`;
        const shouldFix = options && typeof options.fix !== "undefined" ? options.fix : true;
        const stats = options?.stats;

        /**
         * This loop continues until one of the following is true:
         *
         * 1. No more fixes have been applied.
         * 2. Ten passes have been made.
         *
         * That means anytime a fix is successfully applied, there will be another pass.
         * Essentially, guaranteeing a minimum of two passes.
         */
        const slots = internalSlotsMap.get(this);

        // Remove lint times from the last run.
        if (stats) {
            delete slots.times;
            slots.fixPasses = 0;
        }

        do {
            passNumber++;
            let tTotal;

            if (stats) {
                tTotal = startTime();
            }

            debug(`Linting code for ${debugTextDescription} (pass ${passNumber})`);
            messages = this.verify(currentText, config, options);

            debug(`Generating fixed text for ${debugTextDescription} (pass ${passNumber})`);
            let t;

            if (stats) {
                t = startTime();
            }

            fixedResult = SourceCodeFixer.applyFixes(currentText, messages, shouldFix);

            if (stats) {

                if (fixedResult.fixed) {
                    const time = endTime(t);

                    storeTime(time, { type: "fix" }, slots);
                    slots.fixPasses++;
                } else {
                    storeTime(0, { type: "fix" }, slots);
                }
            }

            /*
             * stop if there are any syntax errors.
             * 'fixedResult.output' is a empty string.
             */
            if (messages.length === 1 && messages[0].fatal) {
                break;
            }

            // keep track if any fixes were ever applied - important for return value
            fixed = fixed || fixedResult.fixed;

            // update to use the fixed output instead of the original text
            currentText = fixedResult.output;

            if (stats) {
                tTotal = endTime(tTotal);
                const passIndex = slots.times.passes.length - 1;

                slots.times.passes[passIndex].total = tTotal;
            }

        } while (
            fixedResult.fixed &&
            passNumber < MAX_AUTOFIX_PASSES
        );

        /*
         * If the last result had fixes, we need to lint again to be sure we have
         * the most up-to-date information.
         */
        if (fixedResult.fixed) {
            let tTotal;

            if (stats) {
                tTotal = startTime();
            }

            fixedResult.messages = this.verify(currentText, config, options);

            if (stats) {
                storeTime(0, { type: "fix" }, slots);
                slots.times.passes.at(-1).total = endTime(tTotal);
            }
        }

        // ensure the last result properly reflects if fixes were done
        fixedResult.fixed = fixed;
        fixedResult.output = currentText;

        return fixedResult;
    }
}

module.exports = {
    Linter,

    /**
     * Get the internal slots of a given Linter instance for tests.
     * @param {Linter} instance The Linter instance to get.
     * @returns {LinterInternalSlots} The internal slots.
     */
    getLinterInternalSlots(instance) {
        return internalSlotsMap.get(instance);
    }
};
