Initial version of Rosie

spec/javascripts/rosie.spec.js

@@ -0,0 +1,126 @@
+describe('Factory', function() {
+  afterEach(function() {
+    Factory.factories = {};
+  });
+
+  describe('build', function() {
+    describe('with a constructor', function() {
+      var Thing = function(attrs) {
+        for(var attr in attrs) {
+          this[attr] = attrs[attr];
+        }
+      };
+
+      beforeEach(function() {
+        Factory.define('thing', Thing).attr('name', 'Thing 1');
+      });
+
+      it('should return a new instance of that constructor', function() {
+        expect(Factory.build('thing') instanceof Thing).toBe(true);
+        expect(Factory.build('thing').constructor).toBe(Thing);
+      });
+
+      it('should set attributes', function() {
+        expect(Factory.build('thing')).toEqual({name: 'Thing 1'});
+      });
+    });
+
+    describe('without a constructor', function() {
+      beforeEach(function() {
+        Factory.define('thing').attr('name', 'Thing 1');
+      });
+
+      it('should return object with attributes set', function() {
+        expect(Factory.build('thing')).toEqual({name:'Thing 1'});
+      });
+
+      it('should allow overriding attributes', function() {
+        expect(Factory.build('thing', {name:'changed'})).toEqual({name:'changed'});
+      });
+    });
+  });
+
+  describe('attributes', function() {
+    beforeEach(function() {
+      Factory.define('thing').attr('name', 'Thing 1');
+    });
+
+    it('should return object with attributes set', function() {
+      expect(Factory.attributes('thing')).toEqual({name:'Thing 1'});
+    });
+
+    it('should allow overriding attributes', function() {
+      expect(Factory.attributes('thing', {name:'changed'})).toEqual({name:'changed'});
+    });
+  });
+
+  describe('prototype', function() {
+    var factory;
+
+    beforeEach(function() {
+      factory = new Factory();
+    });
+
+    describe('attr', function() {
+      it('should add given value to attributes', function() {
+        factory.attr('foo', 'bar');
+        expect(factory.attributes().foo).toEqual('bar');
+      });
+
+      it('should invoke function', function() {
+        var calls = 0;
+        factory.attr('dynamic', function() { return ++calls; });
+        expect(factory.attributes().dynamic).toEqual(1);
+        expect(factory.attributes().dynamic).toEqual(2);
+      });
+
+      it('should return the factory', function() {
+        expect(factory.attr('foo', 1)).toBe(factory);
+      });
+    });
+
+    describe('sequence', function() {
+      it('should return the factory', function() {
+        expect(factory.sequence('id')).toBe(factory);
+      });
+
+      it('should return an incremented value for each invocation', function() {
+        factory.sequence('id');
+        expect(factory.attributes().id).toEqual(1);
+        expect(factory.attributes().id).toEqual(2);
+        expect(factory.attributes().id).toEqual(3);
+      });
+
+      it('should increment different sequences independently', function() {
+        factory.sequence('id');
+        factory.sequence('count');
+
+        expect(factory.attributes()).toEqual({id: 1, count: 1});
+        expect(factory.attributes()).toEqual({id: 2, count: 2});
+      });
+
+      it('should use custom function', function() {
+        factory.sequence('name', function(i) { return 'user' + i; });
+        expect(factory.attributes().name).toEqual('user1');
+      });
+    });
+
+    describe('attributes', function() {
+      beforeEach(function() {
+        factory.attr('foo', 1).attr('bar', 2);
+      });
+
+      it('should allow overriding an attribute', function() {
+        expect(factory.attributes({bar:3})).toEqual({foo:1, bar:3});
+      });
+
+      it('should allow overriding an attribute with a falsy value', function() {
+        expect(factory.attributes({bar:false})).toEqual({foo:1, bar:false});
+      });
+
+      it('should allow adding new attributes', function() {
+        expect(factory.attributes({baz:3})).toEqual({foo:1, bar:2, baz:3});
+      });
+    });
+  });
+});

src/rosie.js

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+var Factory = function(constructor) {
+  this.construct = constructor;
+  this.attrs = {};
+  this.sequences = {};
+};
+
+Factory.prototype = {
+  attr: function(attr, value) {
+    callback = typeof value == 'function' ? value : function() { return value; };
+    this.attrs[attr] = callback;
+    return this;
+  },
+
+  sequence: function(attr, callback) {
+    var factory = this;
+    callback = callback || function(i) { return i; };
+    this.attrs[attr] = function() {
+      factory.sequences[attr] = factory.sequences[attr] || 0;
+      return callback(++factory.sequences[attr]);
+    };
+    return this;
+  },
+
+  attributes: function(attrs) {
+    attrs = attrs || {};
+    for(var attr in this.attrs) {
+      if(!attrs.hasOwnProperty(attr)) {
+        attrs[attr] =  this.attrs[attr]();
+      }
+    }
+    return attrs;
+  },
+
+  build: function(attrs) {
+    var result = this.attributes(attrs);
+    return this.construct ? new this.construct(result) : result;
+  }
+};
+
+Factory.factories = {};
+
+Factory.define = function(name, constructor) {
+  var factory = new Factory(constructor);
+  this.factories[name] = factory;
+  return factory;
+};
+
+Factory.build = function(name, attrs) {
+  return this.factories[name].build(attrs);
+};
+
+Factory.attributes = function(name, attrs) {
+  return this.factories[name].attributes(attrs);
+};