__author__ = "Jon Reid"
__copyright__ = "Copyright 2011 hamcrest.org"
__license__ = "BSD, see License.txt"

from hamcrest.core.base_matcher import BaseMatcher


class SubstringMatcher(BaseMatcher):
    def __init__(self, substring):
        if not isinstance(substring, str):
            raise TypeError(self.__class__.__name__ + " requires string")
        self.substring = substring

    def describe_to(self, description):
        description.append_text("a string ").append_text(self.relationship()).append_text(
            " "
        ).append_description_of(self.substring)
