Add observatory_pub_packages snapshot to third_party

observatory_pub_packages/matcher/src/string_matchers.dart

+// Copyright (c) 2012, the Dart project authors.  Please see the AUTHORS file
+// for details. All rights reserved. Use of this source code is governed by a
+// BSD-style license that can be found in the LICENSE file.
+
+library matcher.string_matchers;
+
+import 'interfaces.dart';
+
+/// Returns a matcher which matches if the match argument is a string and
+/// is equal to [value] when compared case-insensitively.
+Matcher equalsIgnoringCase(String value) => new _IsEqualIgnoringCase(value);
+
+class _IsEqualIgnoringCase extends _StringMatcher {
+  final String _value;
+  final String _matchValue;
+
+  _IsEqualIgnoringCase(String value)
+      : _value = value,
+        _matchValue = value.toLowerCase();
+
+  bool matches(item, Map matchState) =>
+      item is String && _matchValue == item.toLowerCase();
+
+  Description describe(Description description) =>
+      description.addDescriptionOf(_value).add(' ignoring case');
+}
+
+/// Returns a matcher which matches if the match argument is a string and
+/// is equal to [value], ignoring whitespace.
+///
+/// In this matcher, "ignoring whitespace" means comparing with all runs of
+/// whitespace collapsed to single space characters and leading and trailing
+/// whitespace removed.
+///
+/// For example, the following will all match successfully:
+///
+///     expect("hello   world", equalsIgnoringCase("hello world"));
+///     expect("  hello world", equalsIgnoringCase("hello world"));
+///     expect("hello world  ", equalsIgnoringCase("hello world"));
+///
+/// The following will not match:
+///
+///     expect("helloworld", equalsIgnoringCase("hello world"));
+///     expect("he llo world", equalsIgnoringCase("hello world"));
+Matcher equalsIgnoringWhitespace(String value) =>
+    new _IsEqualIgnoringWhitespace(value);
+
+class _IsEqualIgnoringWhitespace extends _StringMatcher {
+  final String _value;
+  final String _matchValue;
+
+  _IsEqualIgnoringWhitespace(String value)
+      : _value = value,
+        _matchValue = collapseWhitespace(value);
+
+  bool matches(item, Map matchState) =>
+      item is String && _matchValue == collapseWhitespace(item);
+
+  Description describe(Description description) =>
+    description.addDescriptionOf(_matchValue).add(' ignoring whitespace');
+
+  Description describeMismatch(item, Description mismatchDescription,
+                               Map matchState, bool verbose) {
+    if (item is String) {
+      return mismatchDescription.add('is ').
+          addDescriptionOf(collapseWhitespace(item)).
+          add(' with whitespace compressed');
+    } else {
+      return super.describeMismatch(item, mismatchDescription,
+          matchState, verbose);
+    }
+  }
+}
+
+/// Returns a matcher that matches if the match argument is a string and
+/// starts with [prefixString].
+Matcher startsWith(String prefixString) => new _StringStartsWith(prefixString);
+
+class _StringStartsWith extends _StringMatcher {
+  final String _prefix;
+
+  const _StringStartsWith(this._prefix);
+
+  bool matches(item, Map matchState) =>
+      item is String && item.startsWith(_prefix);
+
+  Description describe(Description description) =>
+      description.add('a string starting with ').addDescriptionOf(_prefix);
+}
+
+/// Returns a matcher that matches if the match argument is a string and
+/// ends with [suffixString].
+Matcher endsWith(String suffixString) => new _StringEndsWith(suffixString);
+
+class _StringEndsWith extends _StringMatcher {
+  final String _suffix;
+
+  const _StringEndsWith(this._suffix);
+
+  bool matches(item, Map matchState) =>
+      item is String && item.endsWith(_suffix);
+
+  Description describe(Description description) =>
+      description.add('a string ending with ').addDescriptionOf(_suffix);
+}
+
+/// Returns a matcher that matches if the match argument is a string and
+/// contains a given list of [substrings] in relative order.
+///
+/// For example, `stringContainsInOrder(["a", "e", "i", "o", "u"])` will match
+/// "abcdefghijklmnopqrstuvwxyz".
+
+Matcher stringContainsInOrder(List<String> substrings) =>
+    new _StringContainsInOrder(substrings);
+
+class _StringContainsInOrder extends _StringMatcher {
+  final List<String> _substrings;
+
+  const _StringContainsInOrder(this._substrings);
+
+  bool matches(item, Map matchState) {
+    if (!(item is String)) {
+      return false;
+    }
+    var from_index = 0;
+    for (var s in _substrings) {
+      from_index = item.indexOf(s, from_index);
+      if (from_index < 0) return false;
+    }
+    return true;
+  }
+
+  Description describe(Description description) =>
+      description.addAll('a string containing ', ', ', ' in order',
+                                                  _substrings);
+}
+
+/// Returns a matcher that matches if the match argument is a string and
+/// matches the regular expression given by [re].
+///
+/// [re] can be a [RegExp] instance or a [String]; in the latter case it will be
+/// used to create a RegExp instance.
+Matcher matches(re) => new _MatchesRegExp(re);
+
+class _MatchesRegExp extends _StringMatcher {
+  RegExp _regexp;
+
+  _MatchesRegExp(re) {
+    if (re is String) {
+      _regexp = new RegExp(re);
+    } else if (re is RegExp) {
+      _regexp = re;
+    } else {
+      throw new ArgumentError('matches requires a regexp or string');
+    }
+  }
+
+  bool matches(item, Map matchState) =>
+    item is String ? _regexp.hasMatch(item) : false;
+
+  Description describe(Description description) =>
+      description.add("match '${_regexp.pattern}'");
+}
+
+// String matchers match against a string. We add this intermediate
+// class to give better mismatch error messages than the base Matcher class.
+abstract class _StringMatcher extends Matcher {
+  const _StringMatcher();
+  Description describeMismatch(item, Description mismatchDescription,
+                               Map matchState, bool verbose) {
+    if (!(item is String)) {
+      return mismatchDescription.
+          addDescriptionOf(item).
+          add(' not a string');
+    } else {
+      return super.describeMismatch(item, mismatchDescription,
+          matchState, verbose);
+    }
+  }
+}
+
+/// Utility function to collapse whitespace runs to single spaces
+/// and strip leading/trailing whitespace.
+String collapseWhitespace(String string) {
+  var result = new StringBuffer();
+  var skipSpace = true;
+  for (var i = 0; i < string.length; i++) {
+    var character = string[i];
+    if (_isWhitespace(character)) {
+      if (!skipSpace) {
+        result.write(' ');
+        skipSpace = true;
+      }
+    } else {
+      result.write(character);
+      skipSpace = false;
+    }
+  }
+  return result.toString().trim();
+}
+
+bool _isWhitespace(String ch) =>
+    ch == ' ' || ch == '\n' || ch == '\r' || ch == '\t';