New expectation functions plus convert old tests to use these.

lib/unittest/numeric_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 if the match argument is greater
+ * than the given [value].
+ */
+IMatcher greaterThan(value) =>
+  new _OrderingComparison(value, false, false, true, 'greater than');
+
+/**
+ * Returns a matcher which matches if the match argument is greater
+ * than or equal to the given [value].
+ */
+IMatcher greaterThanOrEqualTo(value) =>
+  new _OrderingComparison(value, true, false, true, 'greater than or equal to');
+
+/**
+ * Returns a matcher which matches if the match argument is less
+ * than the given [value].
+ */
+IMatcher lessThan(value) =>
+  new _OrderingComparison(value, false, true, false, 'less than');
+
+/**
+ * Returns a matcher which matches if the match argument is less
+ * than or equal to the given [value].
+ */
+IMatcher lessThanOrEqualTo(value) =>

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

Is this really better than doing:

expect(foo > bar)

?

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

It gives better error messages. Either can be used. See the header comments in
expect.dart.

+  new _OrderingComparison(value, true, true, false, 'less than or equal to');
+
+/**
+ * Returns a matcher which matches if the match argument is zero.
+ */
+IMatcher isZero() {

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

Make these constants.

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

Done.

+  return new _OrderingComparison(0, true, false, false, 'equal to');
+}
+
+/**
+ * Returns a matcher which matches if the match argument is non-zero.
+ */
+IMatcher isNonZero() {
+  return new _OrderingComparison(0, false, true, true, 'not equal to');
+}
+
+/**
+ * Returns a matcher which matches if the match argument is positive
+ * (0 inclusive).
+ */
+IMatcher isPositive() {
+  return new _OrderingComparison(0, true, false, true, 'positive', false);
+}
+
+/**
+ * Returns a matcher which matches if the match argument is negative
+ * (0 exclusive).
+ */
+IMatcher isNegative() {
+  return new _OrderingComparison(0, false, true, false, 'negative', false);
+}
+
+bool _isNumeric(value) {
+  return value is int || value is double;

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

"is num"

But I would just get rid of this. You can always do:

expect(foo is num)

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

This isn't a matcher - it's a utility function used by the matchers.

[Bob Nystrom, 2012/06/01 18:22:22]

Oh, right. Sorry. In either case, you can still simplify its implementation to
"value is num". "int" and "double" are both subinterfaces of that and it has no
other subinterfaces.

This is only being called in one place now (isCloseTo). Just get rid of this and
do "is num" there?

+}
+
+class _OrderingComparison extends _NumericMatcher {
+
+  var _value; // Expected value.

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

Make these doc comments. Make the fields final.

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

Done.

+  bool _equalValue; // Return this if values are equal.
+  bool _lessThanValue; // Return this if test value < expected.
+  bool _greaterThanValue; // Return this if test value > expected.
+  String _comparisonDescription; // Textual name of inequality.
+  bool _valueInDescription; // include value in description?
+
+  _OrderingComparison(
+    this._value,
+    bool this._equalValue,

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

Remove these type annotations.

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

Done.

+    bool this._lessThanValue,
+    bool this._greaterThanValue,
+    String this._comparisonDescription,
+    [bool this._valueInDescription = true]) {
+    if (!_isNumeric(_value)) {
+      throw new IllegalArgumentException(
+        'Expected value for ${_comparisonDescription} must be numeric');
+    }
+  }
+
+  bool matches(item) {
+    if (!_isNumeric(item)) {

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

Should we allow this on user-defined types that implement comparison operators?

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

Done.

+      return false;
+    }
+    if (item == _value) {
+      return _equalValue;
+    } else if (item < _value) {
+      return _lessThanValue;
+    } else {
+      return _greaterThanValue;
+    }
+  }
+
+  IDescription describe(IDescription description) =>

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

I would use a {} body here.

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

Done.

+    description.append('a value ').
+        append(_comparisonDescription).
+        append(' ').
+        appendDescriptionOf(_value);
+}
+
+/**
+ * Returns a matcher which matches if the match argument is within [delta]
+ * of some [value]; i.e. if the match argument is greater than
+ * than or equal [value]-[delta] and less than or equal to [value]+[delta].
+ */
+IMatcher closeTo(value, delta) => new _IsCloseTo(value, delta);
+
+class _IsCloseTo extends _NumericMatcher {
+
+  var _value, _delta;
+
+  _IsCloseTo(this._value, this._delta) {
+    if (!_isNumeric(_value)) {
+      throw new IllegalArgumentException('IsCloseTo value must be numeric');
+    }
+    if (!_isNumeric(_delta)) {
+      throw new IllegalArgumentException('IsCloseTo delta must be numeric');
+    }
+  }
+
+  bool matches(item) {
+    if (!_isNumeric(item)) {
+      return false;
+    }
+    var diff = item - _value;
+    if (diff < 0) diff = -diff;

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

var diff = Math.abs(item - _value);

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

There is no Math.abs

[Bob Nystrom, 2012/06/01 18:22:22]

Heh, whoops! Every now and then, the corelib designers throw some Smalltalk in
instead of the usual Java. It's actually:

diff = (item - _value).abs();

+    return (diff <= _delta);
+  }
+
+  IDescription describeMismatch(item, IDescription mismatchDescription) {
+    if (_isNumeric(item)) {
+      var diff = item - _value;
+      if (diff < 0) diff = -diff;
+      return mismatchDescription.
+          appendDescriptionOf(item).
+          append(' differed by ').
+          appendDescriptionOf(diff);
+    } else {
+      return super.describeMismatch(item, mismatchDescription);
+    }
+ }
+
+  IDescription describe(IDescription description) =>
+    description.append('a numeric value within ').
+        appendDescriptionOf(_delta).
+        append(' of ').
+        appendDescriptionOf(_value);
+}
+
+/**
+ * Returns a matcher which matches if the match argument is greater
+ * than or equal to a [low] and less than or equal to [high].

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

"to a" -> "to"

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

Done.

+ */
+IMatcher inInclusiveRange(low, high) => new _InRange(low, high, false, false);
+
+/**
+ * Returns a matcher which matches if the match argument is greater
+ * than [low] and less than [high].
+ */
+IMatcher inExclusiveRange(low, high) => new _InRange(low, high, true, true);

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

Add a blank line after each member.

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

Done.

+/**
+ * Returns a matcher which matches if the match argument is greater
+ * than [low] and less than or equal to [high].
+ */
+IMatcher inOpenClosedRange(low, high) => new _InRange(low, high, true, false);
+/**
+ * Returns a matcher which matches if the match argument is greater
+ * than or equal to a [low] and less than [high].
+ */
+IMatcher inClosedOpenRange(low, high) => new _InRange(low, high, false, true);
+
+
+class _InRange extends _NumericMatcher {
+  num _low, _high;
+  bool _lowExclusive, _highExclusive;
+
+  _InRange(num this._low, num this._high,
+    bool this._lowExclusive, bool this._highExclusive) {
+    if (!_isNumeric(_low) || !_isNumeric(_high)) {

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

Delete these checks. That's what checked mode is for.

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

Done.

+      throw new
+        IllegalArgumentException('IsRange range arguments must be numeric');
+    }
+    if (!(_lowExclusive is bool) || !(_highExclusive is bool)) {
+      throw new IllegalArgumentException('IsRange flag arguments must be bool');
+    }
+  }
+
+  bool matches(value) {
+    if (!_isNumeric(value)) {
+      return false;
+    }
+    if (value < _low || value > _high) {
+      return false;
+    }
+    if (_lowExclusive && value == _low) {
+      return false;
+    }
+    if (_highExclusive && value == _high) {
+      return false;
+    }
+    return true;
+  }
+
+  IDescription describe(IDescription description) =>
+      description.append("be in range from "
+        "$_low (${_lowExclusive?'exclusive':'inclusive'}) to "

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

Spaces around ? and :

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

Done.

+        "$_high (${_highExclusive?'exclusive':'inclusive'})");
+
+  IDescription describeMismatch(item, IDescription mismatchDescription) {
+    if (!_isNumeric(item)) {
+      return mismatchDescription.
+          appendDescriptionOf(item).
+          append(' not numeric');
+    } else {
+      return super.describeMismatch(item, mismatchDescription);
+    }
+  }
+}
+
+
+// Numeric matchers match against a number. We add this intermediate
+// class to give better mismatch error messages than the base Matcher class.
+class _NumericMatcher extends Matcher {
+  IDescription describeMismatch(item, IDescription mismatchDescription) {
+    if (!_isNumeric(item)) {
+      return mismatchDescription.
+          appendDescriptionOf(item).
+          append(' not numeric');
+    } else {
+      return super.describeMismatch(item, mismatchDescription);
+    }
+  }
+}