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// Copyright 2012 The Closure Library Authors. All Rights Reserved.
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//
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// Licensed under the Apache License, Version 2.0 (the "License");
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// you may not use this file except in compliance with the License.
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// You may obtain a copy of the License at
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//
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//      http://www.apache.org/licenses/LICENSE-2.0
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//
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// Unless required by applicable law or agreed to in writing, software
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// distributed under the License is distributed on an "AS-IS" BASIS,
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// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
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// See the License for the specific language governing permissions and
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// limitations under the License.
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/**
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 * @fileoverview Provides the base Matcher interface. User code should use the
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 * matchers through assertThat statements and not directly.
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 */
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goog.provide('goog.labs.testing.Matcher');
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/**
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 * A matcher object to be used in assertThat statements.
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 * @interface
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 */
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goog.labs.testing.Matcher = function() {};
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/**
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 * Determines whether a value matches the constraints of the match.
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 *
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 * @param {*} value The object to match.
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 * @return {boolean} Whether the input value matches this matcher.
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 */
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goog.labs.testing.Matcher.prototype.matches = function(value) {};
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/**
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 * Describes why the matcher failed.
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 *
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 * @param {*} value The value that didn't match.
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 * @param {string=} opt_description A partial description to which the reason
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 *     will be appended.
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 *
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 * @return {string} Description of why the matcher failed.
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 */
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goog.labs.testing.Matcher.prototype.describe = function(
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    value, opt_description) {};
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/**
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 * Generates a Matcher from the ‘matches’ and ‘describe’ functions passed in.
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 *
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 * @param {!Function} matchesFunction The ‘matches’ function.
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 * @param {Function=} opt_describeFunction The ‘describe’ function.
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 * @return {!Function} The custom matcher.
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 */
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goog.labs.testing.Matcher.makeMatcher = function(
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    matchesFunction, opt_describeFunction) {
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  /**
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   * @constructor
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   * @implements {goog.labs.testing.Matcher}
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   * @final
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   */
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  var matcherConstructor = function() {};
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  /** @override */
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  matcherConstructor.prototype.matches = matchesFunction;
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  if (opt_describeFunction) {
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    /** @override */
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    matcherConstructor.prototype.describe = opt_describeFunction;
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  }
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  return matcherConstructor;
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};
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