New expectation functions plus convert old tests to use these.

lib/unittest/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.
+
+/** Returns a matcher which matches strings that are empty. */
+IMatcher isEmptyString() => new _Empty();

[Bob Nystrom, 2012/05/30 23:23:51]

Does this add a lot of value over just doing:

expect(foo, equals(''))

?

+
+class _Empty extends _StringMatcher {
+
+  _Empty();
+
+  bool matches(item) => (item is String && item.length == 0);
+
+  IDescription describe(IDescription description) =>
+    description.append('empty string');
+}
+
+/**
+ * Returns a matcher which matches if the interpolated string form of the
+ * match argument matches the given [matcher]. That is:
+ *
+ *   expect(foo, isInterpolated(bar))
+ *
+ * is equivalent to:
+ *
+ *   expect("${foo}", bar)
+ */
+IMatcher isInterpolated(matcher) => new _IsInterpolated(wrapMatcher(matcher));

[Bob Nystrom, 2012/05/30 23:23:51]

I think this is equivalent to toString(). Do we need this?

[gram, 2012/06/01 17:33:15]

Done.

+
+class _IsInterpolated extends Matcher {
+  Matcher _matcher;
+
+  _IsInterpolated(this._matcher) {
+    if (!(_matcher is Matcher)) {
+      throw new IllegalArgumentException('isInterpolated expects Matcher');
+    }
+  }
+
+  bool matches(item) => _matcher.matches("${item}");
+
+  IDescription describe(IDescription description) =>
+    description.appendDescriptionOf(_matcher).append(' interpolated');
+}
+
+/**
+ * Returns a matcher which matches if the match argument is a string and
+ * is equal to [value] when compared case-insensitively.
+ */
+IMatcher equalToIgnoringCase(String value) => new _IsEqualIgnoringCase(value);

[Bob Nystrom, 2012/05/30 23:23:51]

"equalTo" -> "equals"

[gram, 2012/06/01 17:33:15]

Done.

+
+class _IsEqualIgnoringCase extends _StringMatcher {
+
+  String _value;
+  String _matchValue;
+
+  _IsEqualIgnoringCase(String this._value) {
+    if (!(_value is String)) {

[Bob Nystrom, 2012/05/30 23:23:51]

Remove this check.

[gram, 2012/06/01 17:33:15]

Done.

+      throw new IllegalArgumentException('equalToIgnoringCase requires string');
+    }
+    _matchValue = _value.toLowerCase();
+  }
+
+  bool matches(item) =>
+    (item is String && _matchValue == item.toLowerCase());
+
+  IDescription describe(IDescription description) =>
+    description.appendDescriptionOf(_value).append(' ignoring case');
+}
+
+//---------------------------------------------------------------------
+// Utility functions

[Bob Nystrom, 2012/05/30 23:23:51]

Remove this comment?

[gram, 2012/06/01 17:33:15]

I removed the --- at least.

+
+bool isWhiteSpace(String ch) => (' \n\r\t'.indexOf(ch) >= 0);

[Bob Nystrom, 2012/05/30 23:23:51]

There is some debate here, but I think this should be "isWhitespace". At least
in the context of programming, I usually see whitespace as a single word. Also,
make private?

[gram, 2012/06/01 17:33:15]

Done.

+
+String _stripspace(_string) {

[Bob Nystrom, 2012/05/30 23:23:51]

"_normalizeWhitespace"?

[gram, 2012/06/01 17:33:15]

Done.

[gram, 2012/06/01 17:33:15]

Done.

+  StringBuffer result = new StringBuffer();
+  bool skipSpace = true;
+  for (var i = 0; i < _string.length; i++) {
+    var character = _string[i];
+    if (isWhiteSpace(character)) {
+      if (!skipSpace) {
+        result.add(' ');
+        skipSpace = true;
+      }
+    } else {
+      result.add(character);
+      skipSpace = false;
+    }
+  }
+  return result.toString().trim();
+}
+
+/**
+ * Returns a matcher which matches if the match argument is a string and
+ * is equal to [value] when compared with all runs of white space

[Bob Nystrom, 2012/05/30 23:23:51]

"whitespace"

[gram, 2012/06/01 17:33:15]

Done.

+ * collapsed to single spaces and leading and trailing whitespace removed.
+ *
+ * For example, equalToIgnoringCase("hello world") will match

[Bob Nystrom, 2012/05/30 23:23:51]

Put inline code in backticks: `equalToIgnoringWhitespace("hello world")`.

Also, "Case" -> "Whitespace".

[gram, 2012/06/01 17:33:15]

Done.

+ * "hello   world", "  hello world" and "hello world  ".
+ */
+IMatcher equalToIgnoringWhitespace(_string) =>

[Bob Nystrom, 2012/05/30 23:23:51]

"equalTo" -> "equals"

[gram, 2012/06/01 17:33:15]

Done.

+    new _IsEqualIgnoringWhiteSpace(_string);
+
+class _IsEqualIgnoringWhiteSpace extends _StringMatcher {
+
+  String _value;
+  String _matchValue;
+
+  _IsEqualIgnoringWhiteSpace(this._value) {
+    if (!(_value is String)) {

[Bob Nystrom, 2012/05/30 23:23:51]

Remove check.

[gram, 2012/06/01 17:33:15]

Done.

+      throw new
+        IllegalArgumentException('equalToIgnoringWhitespace requires string');
+    }
+    _matchValue = _stripspace(_value);
+  }
+
+  bool matches(item) => (item is String && _matchValue == _stripspace(item));

[Bob Nystrom, 2012/05/30 23:23:51]

Unneeded ().

[gram, 2012/06/01 17:33:15]

Done.

+
+  IDescription describe(IDescription description) =>
+    description.appendDescriptionOf(_matchValue).

[Bob Nystrom, 2012/05/30 23:23:51]

I would use a {} here. If not, +2 indent.

[gram, 2012/06/01 17:33:15]

Done.

+                   append(' ignoring whitespace');
+
+  IDescription describeMismatch(item, IDescription mismatchDescription) {
+    if (item is String) {
+      return mismatchDescription.append('was ').
+          appendDescriptionOf(_stripspace(item));
+    } else {
+      return super.describeMismatch(item, mismatchDescription);
+    }
+  }
+}
+
+/**
+ * Returns a matcher that matches if the match argument is a string and
+ * starts with [value].
+ */
+IMatcher startsWith(substring) => new _StringStartsWith(substring);
+
+class _StringStartsWith extends _StringMatcher {
+
+  String _substring;
+
+  _StringStartsWith(String this._substring) {
+    if (!(_substring is String)) {
+      throw new
+        IllegalArgumentException('startsWith requires a string');
+    }
+  }
+
+  bool matches(item) => (item is String && item.startsWith(_substring));
+
+  IDescription describe(IDescription description) =>
+      description.append('a string starting with ').
+          appendDescriptionOf(_substring);
+}
+
+/**
+ * Returns a matcher that matches if the match argument is a string and
+ * ends with [value].
+ */
+IMatcher endsWith(value) => new _StringEndsWith(value);
+
+class _StringEndsWith extends _StringMatcher {
+
+  String _substring;
+
+  _StringEndsWith(String this._substring) {
+    if (!(_substring is String)) {
+      throw new
+        IllegalArgumentException('endsWith requires a string');

[Bob Nystrom, 2012/05/30 23:23:51]

Indent +2.

[gram, 2012/06/01 17:33:15]

Done.

+    }
+  }
+
+  bool matches(item) => (item is String && item.endsWith(_substring));
+
+  IDescription describe(IDescription description) =>
+      description.append('a string ending with ').
+          appendDescriptionOf(_substring);
+}
+
+/**
+ * Returns a matcher that matches if the match argument is a string and
+ * contains [substring].
+ */
+IMatcher containsString(substring) => new _StringContains(substring);

[Bob Nystrom, 2012/05/30 23:23:51]

Can we do a single unified contains() that works with collections and strings?

[gram, 2012/06/01 17:33:15]

Done.

+
+class _StringContains extends _StringMatcher {
+
+  String _substring;
+
+  _StringContains(String this._substring) {
+    if (!(_substring is String)) {
+      throw new
+        IllegalArgumentException('containsString requires a string');
+    }
+  }
+
+  bool matches(item) => (item is String && item.indexOf(_substring) >= 0);
+
+  IDescription describe(IDescription description) =>
+      description.append('a string containing ').
+          appendDescriptionOf(_substring);
+}
+
+/**
+ * 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".
+ */
+IMatcher stringContainsInOrder(substrings) =>
+    new _StringContainsInOrder(substrings);
+
+class _StringContainsInOrder extends _StringMatcher {
+
+  List<String> _substrings;
+
+  _StringContainsInOrder(List<String> this._substrings) {
+    if (!(_substrings is List)) {
+      throw new IllegalArgumentException(
+        'stringContainsInOrder requires a list of strings');
+    }
+    for (var s in _substrings) {
+      if (!(s is String)) {
+        throw new IllegalArgumentException(
+          'stringContainsInOrder requires a list of strings');
+      }
+    }
+  }
+
+  bool matches(item) {
+    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;
+  }
+
+  IDescription describe(IDescription description) =>
+    description.appendList('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.
+ */
+IMatcher 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 IllegalArgumentException('matches requires a regexp or string');
+    }
+  }
+
+  bool matches(String item) => _regexp.hasMatch(item);
+
+  IDescription  describe(IDescription description) =>

[Bob Nystrom, 2012/05/30 23:23:51]

Extra space.

[gram, 2012/06/01 17:33:15]

Done.

+      description.append("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.
+class _StringMatcher extends Matcher {
+  IDescription describeMismatch(item, IDescription mismatchDescription) {
+    if (!(item is String)) {
+      return mismatchDescription.
+          appendDescriptionOf(item).
+          append(' not a string');
+    } else {
+      return super.describeMismatch(item, mismatchDescription);
+    }
+  }
+}