Asserts that a string is part of another string.
string $haystack: The value to search in.
string $needle: The value to search for.
string $message: (optional) A message to display with the assertion. Do not translate messages: use format_string() to embed variables in the message text, not t(). If left blank, a default message will be displayed.
string $group: (optional) The group this message is in, which is displayed in a column in test output. Use 'Debug' to indicate this is debugging output. Do not translate this string. Defaults to 'Other'; most tests do not override this default.
bool TRUE if the assertion succeeded, FALSE otherwise.
protected function assertSubString($haystack, $needle, $message = '', $group = 'Other') {
return $this
->assertTrue(strpos($haystack, $needle) !== FALSE, $message, $group);
}