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].
+ */
+Matcher 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].
+ */
+Matcher 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].
+ */
+Matcher 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].
+ */
+Matcher lessThanOrEqualTo(value) =>
+  new _OrderingComparison(value, true, true, false, 'less than or equal to');
+
+/**
+ * A matcher which matches if the match argument is zero.
+ */
+final Matcher isZero =
+  const _OrderingComparison(0, true, false, false, 'equal to');
+
+
+/**
+ * A matcher which matches if the match argument is non-zero.
+ */
+final Matcher isNonZero =
+  const _OrderingComparison(0, false, true, true, 'not equal to');
+
+/**
+ * A matcher which matches if the match argument is positive
+ * (0 inclusive).
+ */
+final Matcher isPositive =
+  const _OrderingComparison(0, true, false, true, 'positive', false);
+
+/**
+ * A matcher which matches if the match argument is negative
+ * (0 exclusive).
+ */
+final Matcher isNegative =
+  const _OrderingComparison(0, false, true, false, 'negative', false);
+
+bool _isNumeric(value) {
+  return value is int || value is double;
+}
+
+class _OrderingComparison extends BaseMatcher {
+  /** Expected value. */
+  final _value;
+  /** What to return if actual == expected */
+  final bool _equalValue;
+  /** What to return if actual < expected */
+  final bool _lessThanValue;
+  /** What to return if actual > expected */
+  final bool _greaterThanValue;
+  /** Textual name of the inequality */
+  final String _comparisonDescription;
+  /** Whether to include the expected value in the description */
+  final bool _valueInDescription;
+
+  const _OrderingComparison(
+    this._value,
+    this._equalValue,
+    this._lessThanValue,
+    this._greaterThanValue,
+    this._comparisonDescription,
+    [this._valueInDescription = true]);
+
+  bool matches(item) {
+    if (item == _value) {
+      return _equalValue;
+    } else if (item < _value) {
+      return _lessThanValue;
+    } else {
+      return _greaterThanValue;
+    }
+  }
+
+  Description describe(Description description) {
+    return description.add('a value ').
+        add(_comparisonDescription).
+        add(' ').
+        addDescriptionOf(_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].
+ */
+Matcher closeTo(value, delta) => new _IsCloseTo(value, delta);
+
+class _IsCloseTo extends BaseMatcher {
+  final num _value, _delta;
+
+  const _IsCloseTo(this._value, this._delta);
+
+  bool matches(item) {
+    if (!_isNumeric(item)) {
+      return false;
+    }
+    var diff = item - _value;
+    if (diff < 0) diff = -diff;
+    return (diff <= _delta);
+  }
+
+  Description describe(Description description) =>
+    description.add('a numeric value within ').
+        addDescriptionOf(_delta).
+        add(' of ').
+        addDescriptionOf(_value);
+
+  Description describeMismatch(item, Description mismatchDescription) {
+    if (item is !num) {
+      return mismatchDescription.
+          addDescriptionOf(item).
+          add(' not numeric');
+    } else {
+      var diff = item - _value;
+      if (diff < 0) diff = -diff;
+      return mismatchDescription.
+          addDescriptionOf(item).
+          add(' differed by ').
+          addDescriptionOf(diff);
+    }
+  }
+}
+
+/**
+ * Returns a matcher which matches if the match argument is greater
+ * than or equal to [low] and less than or equal to [high].
+ */
+Matcher inInclusiveRange(low, high) => new _InRange(low, high, true, true);
+
+/**
+ * Returns a matcher which matches if the match argument is greater
+ * than [low] and less than [high].
+ */
+Matcher inExclusiveRange(low, high) => new _InRange(low, high, false, false);
+
+/**
+ * Returns a matcher which matches if the match argument is greater
+ * than [low] and less than or equal to [high].
+ */
+Matcher inOpenClosedRange(low, high) => new _InRange(low, high, false, true);
+
+/**
+ * Returns a matcher which matches if the match argument is greater
+ * than or equal to a [low] and less than [high].
+ */
+Matcher inClosedOpenRange(low, high) => new _InRange(low, high, true, false);
+
+class _InRange extends BaseMatcher {
+  final num _low, _high;
+  final bool _lowMatchValue, _highMatchValue;
+
+  const _InRange(this._low, this._high,
+    this._lowMatchValue, this._highMatchValue);
+
+  bool matches(value) {
+    if (value is !num) {
+      return false;
+    }
+    if (value < _low || value > _high) {
+      return false;
+    }
+    if (value == _low) {
+      return _lowMatchValue;
+    }
+    if (value == _high) {
+      return _highMatchValue;
+    }
+    return true;
+  }
+
+  Description describe(Description description) =>
+      description.add("be in range from "
+        "$_low (${_lowMatchValue ? 'inclusive' : 'exclusive'}) to "
+        "$_high (${_highMatchValue ? 'inclusive' : 'exclusive'})");
+
+  Description describeMismatch(item, Description mismatchDescription) {
+    if (item is !num) {
+      return mismatchDescription.
+          addDescriptionOf(item).
+          add(' not numeric');
+    } else {
+      return super.describeMismatch(item, mismatchDescription);
+    }
+  }
+}
+