Add unit tests for pattern_engines.js and individual pattern engines

Author: geoffp

test/pattern_engines_tests.js

@@ -0,0 +1,71 @@
+(function () {
+  'use strict';
+
+  var patternEngines = require('../builder/pattern_engines/pattern_engines');
+  var of = require('../builder/object_factory');
+
+  // the mustache test pattern, stolen from object_factory unit tests
+  var mustacheTestPattern = new of.oPattern('source/_patterns/00-atoms/00-global/00-colors-alt.mustache', '00-atoms/00-global', '00-colors-alt.mustache', {d: 123});
+  var engineNames = Object.keys(patternEngines);
+
+
+  exports['patternEngines support functions'] = {
+    'getEngineNameForPattern returns "mustache" from test pattern': function (test) {
+      var engineName = patternEngines.getEngineNameForPattern(mustacheTestPattern);
+      test.equals(engineName, 'mustache');
+      test.done();
+    },
+    'getEngineForPattern returns a reference to the mustache engine from test pattern': function (test) {
+      var engine = patternEngines.getEngineForPattern(mustacheTestPattern);
+      test.equals(engine, patternEngines.mustache);
+      test.done();
+    }
+  };
+
+  // testProps() utility function: given an object, and a hash of expected
+  // 'property name':'property type' pairs, verify that the object contains each
+  // expected property, and that each property is of the expected type.
+  function testProps(object, propTests, test) {
+
+    // function to test each expected property is present and the correct type
+    function testProp(propName, typeString) {
+      test.ok(object.hasOwnProperty(propName), '"' + propName + '" prop should be present');
+      test.ok(typeof object[propName] === typeString, '"' + propName + '" prop should be of type ' + typeString);
+    }
+
+    // go over each property test and run it
+    Object.keys(propTests).forEach(function (propName) {
+      var propType = propTests[propName];
+      testProp(propName, propType);
+    });
+  }
+
+  exports['patternEngines initialization'] = {
+    'patternEngines object contains at least the default mustache engine': function (test) {
+      test.expect(1);
+      test.ok(patternEngines.hasOwnProperty('mustache'));
+      test.done();
+    }
+  };
+
+  // make one big test group for each pattern engine
+  engineNames.forEach(function (engineName) {
+    exports[engineName + ' patternEngine'] = {
+      'engine contains expected properties and methods': function (test) {
+
+        var propertyTests = {
+          'engine': 'object',
+          'name': 'string',
+          'fileExtension': 'string',
+          'renderPattern': 'function',
+          'findPartials': 'function'
+        };
+
+        test.expect(Object.keys(propertyTests).length * 2);
+        testProps(patternEngines[engineName], propertyTests, test);
+        test.done();
+      }
+    };
+  });
+
+})();