diff --git a/README.md b/README.md
index 86e1152..0176ed0 100644
--- a/README.md
+++ b/README.md
@@ -1,3 +1,48 @@
-# react-component-playground [![Build Status](https://travis-ci.org/skidding/react-component-playground.svg?branch=master)](https://travis-ci.org/skidding/react-component-playground) [![Coverage Status](https://coveralls.io/repos/skidding/react-component-playground/badge.svg?branch=master)](https://coveralls.io/r/skidding/react-component-playground?branch=master)
+# React Component Playground
+[![Build Status](https://travis-ci.org/skidding/react-component-playground.svg?branch=master)](https://travis-ci.org/skidding/react-component-playground) [![Coverage Status](https://coveralls.io/repos/skidding/react-component-playground/badge.svg?branch=master)](https://coveralls.io/r/skidding/react-component-playground?branch=master)
 
-Isolated loader for React components.
+ComponentPlayground provides a minimal frame for loading and testing React
+components in isolation.
+
+Working with ComponentPlayground improves the component design because it
+surfaces any implicit dependencies. It also forces you to define sane inputs
+for every component, making them more predictable and easier to debug down
+the road.
+
+Features include:
+
+- Rendering full-screen components or with the navigation pane on the side.
+- Injecting predefined state into components via [ComponentTree](https://github.com/skidding/react-component-tree)
+- Real-time editing of props and state with instant feedback
+
+Before diving deeper, you need to understand what a component _fixture_ looks
+like. It's the same thing as a snapshot in the ComponentTree utility. Read more
+on the project [README](https://github.com/skidding/react-component-tree#componenttreeserialize).
+
+`components` is by far the most important of the ComponentPlayground [props](https://github.com/skidding/react-component-playground/blob/master/src/components/component-playground.jsx#L19-L26).
+This is an example:
+
+```js
+{
+  ComponentOne: {
+    class: require('./components/ComponentOne.jsx'),
+    fixtures: {
+      normal: {
+        fooProp: 'bar'
+      },
+      paused: {
+        fooProp: 'bar',
+        state: {
+          paused: true
+        }
+      }
+    }
+  },
+  ComponentTwo: {
+    class: require('./components/ComponentTwo.jsx'),
+    fixtures: {
+      //...
+    }
+  }
+};
+```
diff --git a/package.json b/package.json
index 33bbaeb..64a80cf 100644
--- a/package.json
+++ b/package.json
@@ -1,6 +1,6 @@
 {
   "name": "react-component-playground",
-  "version": "0.1.1",
+  "version": "0.2.0",
   "description": "Isolated loader for React components",
   "main": "build/bundle.js",
   "repository": {
diff --git a/src/components/component-playground.jsx b/src/components/component-playground.jsx
index a5d358b..87c37eb 100644
--- a/src/components/component-playground.jsx
+++ b/src/components/component-playground.jsx
@@ -17,7 +17,7 @@ module.exports = React.createClass({
   mixins: [ComponentTree.Mixin],
 
   propTypes: {
-    fixtures: React.PropTypes.object.isRequired,
+    components: React.PropTypes.object.isRequired,
     selectedComponent: React.PropTypes.string,
     selectedFixture: React.PropTypes.string,
     fixtureEditor: React.PropTypes.bool,
@@ -39,35 +39,36 @@ module.exports = React.createClass({
       return props.selectedComponent && props.selectedFixture;
     },
 
-    getSelectedFixtureContents: function(props) {
-      if (!this.isFixtureSelected(props)) {
-        return {};
-      }
-
-      var fixture = props.fixtures[props.selectedComponent]
-                                  [props.selectedFixture];
+    getSelectedComponentClass: function(props) {
+      return props.components[props.selectedComponent].class;
+    },
 
-      return _.merge({
-        component: props.selectedComponent
-      }, fixture);
+    getSelectedFixtureContents: function(props) {
+      return props.components[props.selectedComponent]
+                  .fixtures[props.selectedFixture];
     },
 
     getSelectedFixtureUserInput: function(props) {
-      if (!this.isFixtureSelected(props)) {
-        return '{}';
-      }
-
       return JSON.stringify(this.getSelectedFixtureContents(props), null, 2);
     },
 
     getFixtureState: function(props, expandedComponents) {
-      return {
-        expandedComponents: this.getExpandedComponents(props,
-                                                       expandedComponents),
-        fixtureContents: this.getSelectedFixtureContents(props),
-        fixtureUserInput: this.getSelectedFixtureUserInput(props),
+      var state = {
+        expandedComponents:
+            this.getExpandedComponents(props, expandedComponents),
+        fixtureContents: {},
+        fixtureUserInput: '{}',
         isFixtureUserInputValid: true
       };
+
+      if (this.isFixtureSelected(props)) {
+        _.assign(state, {
+          fixtureContents: this.getSelectedFixtureContents(props),
+          fixtureUserInput: this.getSelectedFixtureUserInput(props)
+        });
+      }
+
+      return state;
     }
   },
 
@@ -84,44 +85,42 @@ module.exports = React.createClass({
 
   children: {
     preview: function() {
-      var props = {
+      var params = {
+        component: this.constructor.getSelectedComponentClass(this.props),
         // Child should re-render whenever fixture changes
         key: JSON.stringify(this.state.fixtureContents)
       };
 
-      return _.merge(props, this.state.fixtureContents);
+      return _.merge(params, _.omit(this.state.fixtureContents, 'state'));
     }
   },
 
   render: function() {
+    var isFixtureSelected = this.constructor.isFixtureSelected(this.props);
+
     var classes = classNames({
       'component-playground': true,
       'full-screen': this.props.fullScreen
     });
 
-    var homeUrlProps = {
-      fixtureEditor: this.props.fixtureEditor
-    };
-
     return (
       <div className={classes}>
         <div className="header">
-          {this._renderButtons()}
+          {isFixtureSelected ? this._renderButtons() : null}
           <h1>
             <a ref="homeLink"
-               href={stringifyParams(homeUrlProps)}
+               href={stringifyParams({})}
                className="home-link"
                onClick={this.props.router.routeLink}>
               <span className="react">React</span> Component Playground
             </a>
-            {_.isEmpty(this.state.fixtureContents) ? this._renderCosmosPlug()
-                                                   : null}
+            {!isFixtureSelected ? this._renderCosmosPlug() : null}
           </h1>
         </div>
         <div className="fixtures">
           {this._renderFixtures()}
         </div>
-        {this._renderContentFrame()}
+        {isFixtureSelected ? this._renderContentFrame() : null}
       </div>
     );
   },
@@ -135,7 +134,7 @@ module.exports = React.createClass({
 
   _renderFixtures: function() {
     return <ul className="components">
-      {_.map(this.props.fixtures, function(fixtures, componentName) {
+      {_.map(this.props.components, function(component, componentName) {
 
         var classes = classNames({
           'component': true,
@@ -151,7 +150,7 @@ module.exports = React.createClass({
               {componentName}
             </a>
           </p>
-          {this._renderComponentFixtures(componentName, fixtures)}
+          {this._renderComponentFixtures(componentName, component.fixtures)}
         </li>;
 
       }.bind(this))}
@@ -186,8 +185,7 @@ module.exports = React.createClass({
   _renderContentFrame: function() {
     return <div className="content-frame">
       <div ref="previewContainer" className={this._getPreviewClasses()}>
-        {!_.isEmpty(this.state.fixtureContents) ? this.loadChild('preview')
-                                                : null}
+        {this.loadChild('preview')}
       </div>
       {this.props.fixtureEditor ? this._renderFixtureEditor() : null}
     </div>
@@ -209,11 +207,9 @@ module.exports = React.createClass({
   },
 
   _renderButtons: function() {
-    var isFixtureSelected = this.constructor.isFixtureSelected(this.props);
-
     return <ul className="buttons">
       {this._renderFixtureEditorButton()}
-      {isFixtureSelected ? this._renderFullScreenButton() : null}
+      {this._renderFullScreenButton()}
     </ul>;
   },
 
@@ -224,16 +220,11 @@ module.exports = React.createClass({
     });
 
     var fixtureEditorUrlProps = {
-      fixtureEditor: !this.props.fixtureEditor
+      fixtureEditor: !this.props.fixtureEditor,
+      selectedComponent: this.props.selectedComponent,
+      selectedFixture: this.props.selectedFixture
     };
 
-    if (this.constructor.isFixtureSelected(this.props)) {
-      _.extend(fixtureEditorUrlProps, {
-        selectedComponent: this.props.selectedComponent,
-        selectedFixture: this.props.selectedFixture
-      });
-    }
-
     return <li className={classes}>
       <a href={stringifyParams(fixtureEditorUrlProps)}
          ref="fixtureEditorButton"
@@ -255,6 +246,12 @@ module.exports = React.createClass({
     </li>;
   },
 
+  componentDidMount: function() {
+    if (this.refs.preview) {
+      this._injectPreviewChildState();
+    }
+  },
+
   componentWillReceiveProps: function(nextProps) {
     if (nextProps.selectedComponent !== this.props.selectedComponent ||
         nextProps.selectedFixture !== this.props.selectedFixture) {
@@ -263,6 +260,17 @@ module.exports = React.createClass({
     }
   },
 
+  componentDidUpdate: function(prevProps, prevState) {
+    if (this.refs.preview && (
+        // Avoid deep comparing the fixture contents when component and/or
+        // fixture changed, because it's more expensive
+        this.props.selectedComponent !== prevProps.selectedComponent ||
+        this.props.selectedFixture !== prevProps.selectedFixture ||
+        !_.isEqual(this.state.fixtureContents, prevState.fixtureContents))) {
+      this._injectPreviewChildState();
+    }
+  },
+
   onComponentClick: function(componentName, event) {
     event.preventDefault();
 
@@ -286,7 +294,7 @@ module.exports = React.createClass({
 
     try {
       var fixtureContents =
-        this.constructor.getSelectedFixtureContents(this.props);
+          _.cloneDeep(this.constructor.getSelectedFixtureContents(this.props));
 
       if (userInput) {
         _.merge(fixtureContents, JSON.parse(userInput));
@@ -324,5 +332,13 @@ module.exports = React.createClass({
                           fixtureName === this.props.selectedFixture;
 
     return classNames(classes);
+  },
+
+  _injectPreviewChildState: function() {
+    var state = this.state.fixtureContents.state;
+
+    if (!_.isEmpty(state)) {
+      ComponentTree.injectState(this.refs.preview, _.cloneDeep(state));
+    }
   }
 });
diff --git a/tests/components/component-playground/children.js b/tests/components/component-playground/children.js
index 3cdfca4..3b751f5 100644
--- a/tests/components/component-playground/children.js
+++ b/tests/components/component-playground/children.js
@@ -4,28 +4,37 @@ var ComponentTree = require('react-component-tree'),
 
 describe('ComponentPlayground component', function() {
   var component,
-      props,
+      params,
       childParams;
 
-  function render(extraProps) {
+  function render(extraParams) {
     // Alow tests to extend fixture before rendering
-    _.merge(props, extraProps);
+    _.merge(params, extraParams);
 
     component = ComponentTree.render({
       component: ComponentPlayground,
-      snapshot: props,
+      snapshot: params,
       container: document.createElement('div')
     });
 
-    childParams = component.children.preview.call(component);
+    if (params.selectedComponent) {
+      childParams = component.children.preview.call(component);
+    }
   }
 
   beforeEach(function() {
     // Don't render any children
     sinon.stub(ComponentTree.loadChild, 'loadChild');
 
-    props = {
-      fixtures: {},
+    params = {
+      components: {
+        FirstComponent: {
+          class: 'FirstComponent',
+          fixtures: {
+            'default state': {}
+          }
+        }
+      },
       router: {
         routeLink: sinon.spy()
       }
@@ -37,19 +46,16 @@ describe('ComponentPlayground component', function() {
   })
 
   describe('children', function() {
-    it('should not render child without fixture contents', function() {
+    it('should not render child without selected fixture', function() {
       render();
 
       expect(ComponentTree.loadChild.loadChild).to.not.have.been.called;
     });
 
-    it('should render child with fixture contents', function() {
+    it('should render child with selected fixture', function() {
       render({
-        state: {
-          fixtureContents: {
-            component: 'MyComponent'
-          }
-        }
+        selectedComponent: 'FirstComponent',
+        selectedFixture: 'default state'
       });
 
       expect(ComponentTree.loadChild.loadChild).to.have.been.called;
@@ -57,28 +63,44 @@ describe('ComponentPlayground component', function() {
 
     describe('with fixture contents', function() {
       beforeEach(function() {
-        _.extend(props, {
+        _.assign(params, {
+          selectedComponent: 'FirstComponent',
           // Children draw their props from state.fixtureContents. Generating
           // state from props is tested in the state.js suite
           state: {
             fixtureContents: {
-              component: 'MyComponent',
               width: 200,
-              height: 100
+              height: 100,
+              state: {
+                paused: true
+              }
             }
           }
         });
       });
 
+      it('should send component class to preview child', function() {
+        render();
+
+        expect(childParams.component)
+              .to.equal(params.components['FirstComponent'].class);
+      });
+
       it('should send fixture contents to preview child', function() {
         render();
 
         var fixtureContents = component.state.fixtureContents;
-        expect(childParams.component).to.equal(fixtureContents.component);
         expect(childParams.width).to.equal(fixtureContents.width);
         expect(childParams.height).to.equal(fixtureContents.height);
       });
 
+      it('should not send state as prop to preview child', function() {
+        render();
+
+        var fixtureContents = component.state.fixtureContents;
+        expect(childParams.state).to.be.undefined;
+      });
+
       it('should use fixture contents as key for preview child', function() {
         render();
 
@@ -91,15 +113,13 @@ describe('ComponentPlayground component', function() {
       it('should clone fixture contents sent to child', function() {
         var obj = {};
 
-        render({
-          state: {
-            fixtureContents: {
-              shouldBeCloned: obj
-            }
-          }
-        });
+        params.state.fixtureContents.nested = {
+          shouldBeCloned: obj
+        };
+
+        render();
 
-        expect(childParams.shouldBeCloned).to.not.equal(obj);
+        expect(childParams.nested.shouldBeCloned).to.not.equal(obj);
       });
     });
   });
diff --git a/tests/components/component-playground/events.js b/tests/components/component-playground/events.js
index 7e74bd2..cdcf01b 100644
--- a/tests/components/component-playground/events.js
+++ b/tests/components/component-playground/events.js
@@ -6,15 +6,15 @@ var React = require('react/addons'),
 describe('ComponentPlayground component', function() {
   var utils = React.addons.TestUtils,
       component,
-      props;
+      params;
 
-  function render(extraProps) {
+  function render(extraParams) {
     // Alow tests to extend fixture before rendering
-    _.merge(props, extraProps);
+    _.merge(params, extraParams);
 
     component = ComponentTree.render({
       component: ComponentPlayground,
-      snapshot: props,
+      snapshot: params,
       container: document.createElement('div')
     });
   };
@@ -30,8 +30,8 @@ describe('ComponentPlayground component', function() {
     // Don't render any children
     sinon.stub(ComponentTree.loadChild, 'loadChild');
 
-    props = {
-      fixtures: {},
+    params = {
+      components: {},
       router: {
         routeLink: sinon.spy()
       }
@@ -47,10 +47,12 @@ describe('ComponentPlayground component', function() {
   describe('events', function() {
     describe('clicking on components', function() {
       beforeEach(function() {
-        props.fixtures = {
+        params.components = {
           FirstComponent: {},
           SecondComponent: {
-            'simple state': {}
+            fixtures: {
+              'simple state': {}
+            }
           }
         };
       });
@@ -103,7 +105,7 @@ describe('ComponentPlayground component', function() {
         });
 
         afterEach(function() {
-          expect(props.router.routeLink).to.have.been.called;
+          expect(params.router.routeLink).to.have.been.called;
         });
 
         it('should route link on home button', function() {
@@ -126,15 +128,22 @@ describe('ComponentPlayground component', function() {
     });
 
     describe('editing fixture', function() {
-      var initialFixtureContents = {
-        myProp: 'dolor sit'
-      };
-
       beforeEach(function() {
         render({
+          components: {
+            MyComponent: {
+              fixtures: {
+                'simple state': {}
+              }
+            }
+          },
+          selectedComponent: 'MyComponent',
+          selectedFixture: 'simple state',
           fixtureEditor: true,
           state: {
-            fixtureContents: initialFixtureContents
+            fixtureContents: {
+              lorem: 'dolor sit'
+            }
           }
         });
       });
@@ -154,8 +163,7 @@ describe('ComponentPlayground component', function() {
       it('should not update fixture contents on invalid change', function() {
         triggerChange('lorem ipsum');
 
-        expect(component.state.fixtureContents.myProp)
-               .to.equal(initialFixtureContents.myProp);
+        expect(component.state.fixtureContents.lorem).to.equal('dolor sit');
       });
 
       it('should empty fixture contents on empty input', function() {
@@ -183,21 +191,21 @@ describe('ComponentPlayground component', function() {
       });
     });
 
-    describe('editing fixture with selected fixture', function() {
-      var fixtures = {
-        MyComponent: {
-          'simple state': {
-            defaultProp: true,
-            nested: {
-              nestedProp: true
-            }
-          }
-        }
-      };
-
+    describe('editing and extending fixture', function() {
       beforeEach(function() {
-        _.extend(props, {
-          fixtures: fixtures,
+        _.assign(params, {
+          components: {
+            MyComponent: {
+              fixtures: {
+                'simple state': {
+                  defaultProp: true,
+                  nested: {
+                    nestedProp: true
+                  }
+                }
+              }
+            }
+          },
           selectedComponent: 'MyComponent',
           selectedFixture: 'simple state',
           fixtureEditor: true
@@ -216,8 +224,8 @@ describe('ComponentPlayground component', function() {
       it('should not alter the original fixture contents', function() {
         triggerChange('{"nested": {"nestedProp": false}}');
 
-        expect(fixtures.MyComponent['simple state'].nested.nestedProp)
-              .to.be.true;
+        expect(params.components.MyComponent
+               .fixtures['simple state'].nested.nestedProp).to.be.true;
       });
     });
   });
diff --git a/tests/components/component-playground/render.js b/tests/components/component-playground/render.js
index af49f98..da1f851 100644
--- a/tests/components/component-playground/render.js
+++ b/tests/components/component-playground/render.js
@@ -7,15 +7,15 @@ var $ = require('jquery'),
 describe('ComponentPlayground component', function() {
   var component,
       $component,
-      props;
+      params;
 
   function render(extraProps) {
     // Alow tests to extend fixture before rendering
-    _.merge(props, extraProps);
+    _.merge(params, extraProps);
 
     component = ComponentTree.render({
       component: ComponentPlayground,
-      snapshot: props,
+      snapshot: params,
       container: document.createElement('div')
     });
     $component = $(component.getDOMNode());
@@ -31,15 +31,19 @@ describe('ComponentPlayground component', function() {
     // Don't render any children
     sinon.stub(ComponentTree.loadChild, 'loadChild');
 
-    props = {
-      fixtures: {
+    params = {
+      components: {
         FirstComponent: {
-          'blank state': {},
-          'error state': {},
-          'simple state': {}
+          fixtures: {
+            'blank state': {},
+            'error state': {},
+            'simple state': {}
+          }
         },
         SecondComponent: {
-          'simple state': {}
+          fixtures: {
+            'simple state': {}
+          }
         }
       },
       router: {
@@ -59,18 +63,6 @@ describe('ComponentPlayground component', function() {
       expect(component.refs.cosmosPlug).to.exist;
     });
 
-    it('should not render cosmos plug with preview loaded', function() {
-      render({
-        state: {
-          fixtureContents: {
-            myProp: true
-          }
-        }
-      });
-
-      expect(component.refs.cosmosPlug).to.not.exist;
-    });
-
     it('should render each component', function() {
       render();
 
@@ -143,24 +135,11 @@ describe('ComponentPlayground component', function() {
       expect(component.refs.fullScreenButton).to.not.exist;
     });
 
-    it('should render fixture editor button',
+    it('should not render fixture editor button',
        function() {
       render();
 
-      var element = component.refs.fixtureEditorButton.getDOMNode(),
-          urlProps = getUrlProps(element);
-
-      expect(urlProps.fixtureEditor).to.equal(true);
-    });
-
-    it('should add container class on preview element', function() {
-      render({
-        containerClassName: 'my-app-namespace'
-      });
-
-      var $previewDOMNode = $(component.refs.previewContainer.getDOMNode());
-
-      expect($previewDOMNode.hasClass('my-app-namespace')).to.equal(true);
+      expect(component.refs.fixtureEditorButton).to.not.exist;
     });
 
     it('should not render fixture editor by default', function() {
@@ -171,12 +150,28 @@ describe('ComponentPlayground component', function() {
 
     describe('with fixture selected', function() {
       beforeEach(function() {
-        _.extend(props, {
+        _.assign(params, {
           selectedComponent: 'FirstComponent',
           selectedFixture: 'simple state'
         })
       });
 
+      it('should not render cosmos plug', function() {
+        render();
+
+        expect(component.refs.cosmosPlug).to.not.exist;
+      });
+
+      it('should add container class on preview element', function() {
+        render({
+          containerClassName: 'my-app-namespace'
+        });
+
+        var $previewDOMNode = $(component.refs.previewContainer.getDOMNode());
+
+        expect($previewDOMNode.hasClass('my-app-namespace')).to.equal(true);
+      });
+
       it('should add expanded class to selected component', function() {
         render();
 
@@ -207,7 +202,7 @@ describe('ComponentPlayground component', function() {
         expect(urlProps.fullScreen).to.equal(true);
       });
 
-      it('should include component and fixture in fixture editor url',
+      it('should generate fixture editor url',
          function() {
         render();
 
@@ -218,89 +213,101 @@ describe('ComponentPlayground component', function() {
         expect(urlProps.selectedFixture).to.equal('simple state');
         expect(urlProps.fixtureEditor).to.equal(true);
       });
-    });
-
-    describe('with fixture editor open', function() {
-      beforeEach(function() {
-        props.fixtureEditor = true;
-      });
 
-      it('should render fixture editor', function() {
+      it('should include component and fixture in fixture editor url',
+         function() {
         render();
 
-        expect(component.refs.fixtureEditor).to.exist;
+        var element = component.refs.fixtureEditorButton.getDOMNode(),
+            urlProps = getUrlProps(element);
+
+        expect(urlProps.selectedComponent).to.equal('FirstComponent');
+        expect(urlProps.selectedFixture).to.equal('simple state');
+        expect(urlProps.fixtureEditor).to.equal(true);
       });
 
-      it('should add class on preview container', function() {
-        render();
+      describe('with fixture editor open', function() {
+        beforeEach(function() {
+          params.fixtureEditor = true;
+        });
 
-        expect($(component.refs.previewContainer.getDOMNode())
-               .hasClass('aside-fixture-editor')).to.be.true;
-      });
+        it('should render fixture editor', function() {
+          render();
 
-      it('should populate fixture editor textarea from state', function() {
-        render({
-          state: {
-            fixtureUserInput: 'lorem ipsum'
-          }
+          expect(component.refs.fixtureEditor).to.exist;
         });
 
-        expect(component.refs.fixtureEditor.getDOMNode().value)
-               .to.equal(component.state.fixtureUserInput);
-      });
+        it('should add class on preview container', function() {
+          render();
 
-      it('should generate selected fixture editor button', function() {
-        render();
+          expect($(component.refs.previewContainer.getDOMNode())
+                 .hasClass('aside-fixture-editor')).to.be.true;
+        });
 
-        expect($(component.getDOMNode())
-               .find('.fixture-editor-button')
-               .hasClass('selected-button')).to.be.true;
-      });
+        it('should populate fixture editor textarea from state', function() {
+          render({
+            state: {
+              fixtureUserInput: 'lorem ipsum'
+            }
+          });
 
-      it('should generate url for closing fixture editor', function() {
-        render();
+          expect(component.refs.fixtureEditor.getDOMNode().value)
+                 .to.equal(component.state.fixtureUserInput);
+        });
 
-        var element = component.refs.fixtureEditorButton.getDOMNode(),
-            urlProps = getUrlProps(element);
+        it('should generate selected fixture editor button', function() {
+          render();
 
-        expect(urlProps.fixtureEditor).to.equal(false);
-      });
+          expect($(component.getDOMNode())
+                 .find('.fixture-editor-button')
+                 .hasClass('selected-button')).to.be.true;
+        });
 
-      it('should include fixtor editor in fixture url', function() {
-        var firstFixtureLink = $component.find('.component-fixture a'),
-            urlProps = getUrlProps(firstFixtureLink);
+        it('should generate url for closing fixture editor', function() {
+          render();
 
-        expect(urlProps.selectedComponent).to.equal('FirstComponent');
-        expect(urlProps.selectedFixture).to.equal('blank state');
-        expect(urlProps.fixtureEditor).to.equal(true);
-      });
+          var element = component.refs.fixtureEditorButton.getDOMNode(),
+              urlProps = getUrlProps(element);
 
-      it('should add invalid class on fixture editor on state flag',
-         function() {
-        render({
-          state: {
-            isFixtureUserInputValid: false
-          }
+          expect(urlProps.fixtureEditor).to.equal(false);
         });
 
-        expect($(component.refs.fixtureEditor.getDOMNode())
-               .hasClass('invalid-syntax')).to.be.true;
-      });
-    });
+        it('should include fixtor editor in fixture url', function() {
+          var firstFixtureLink = $component.find('.component-fixture a'),
+              urlProps = getUrlProps(firstFixtureLink);
 
-    it('should generate url for closing editor with fixture', function() {
-      render({
-        selectedComponent: 'FirstComponent',
-        selectedFixture: 'simple state',
-        fixtureEditor: true
+          expect(urlProps.selectedComponent).to.equal('FirstComponent');
+          expect(urlProps.selectedFixture).to.equal('blank state');
+          expect(urlProps.fixtureEditor).to.equal(true);
+        });
+
+        it('should add invalid class on fixture editor on state flag',
+           function() {
+          render({
+            state: {
+              isFixtureUserInputValid: false
+            }
+          });
+
+          expect($(component.refs.fixtureEditor.getDOMNode())
+                 .hasClass('invalid-syntax')).to.be.true;
+        });
       });
 
-      var element = component.refs.fixtureEditorButton.getDOMNode(),
-          urlProps = getUrlProps(element);
+      it('should generate url for closing editor with fixture', function() {
+        render({
+          selectedComponent: 'FirstComponent',
+          selectedFixture: 'simple state',
+          fixtureEditor: true
+        });
 
-      expect(urlProps.selectedComponent).to.equal('FirstComponent');
-      expect(urlProps.selectedFixture).to.equal('simple state');
-      expect(urlProps.fixtureEditor).to.equal(false);
+        var element = component.refs.fixtureEditorButton.getDOMNode(),
+            urlProps = getUrlProps(element);
+
+        expect(urlProps.selectedComponent).to.equal('FirstComponent');
+        expect(urlProps.selectedFixture).to.equal('simple state');
+        expect(urlProps.fixtureEditor).to.equal(false);
+      });
     });
   });
 });
diff --git a/tests/components/component-playground/state.js b/tests/components/component-playground/state.js
index ac2ebb0..4be979a 100644
--- a/tests/components/component-playground/state.js
+++ b/tests/components/component-playground/state.js
@@ -4,33 +4,44 @@ var ComponentTree = require('react-component-tree'),
 
 describe('ComponentPlayground component', function() {
   var component,
-      props;
+      params;
 
   function render(extraProps) {
     // Alow tests to extend fixture before rendering
-    _.merge(props, extraProps);
+    _.merge(params, extraProps);
 
     component = ComponentTree.render({
       component: ComponentPlayground,
-      snapshot: props,
+      snapshot: params,
       container: document.createElement('div')
     });
   };
 
   beforeEach(function() {
-    // Don't render any children
-    sinon.stub(ComponentTree.loadChild, 'loadChild');
+    sinon.stub(ComponentTree, 'injectState');
 
-    props = {
-      fixtures: {
+    params = {
+      components: {
         FirstComponent: {
-          'blank state': {
-            myProp: false
+          class: 'FirstComponent',
+          fixtures: {
+            'blank state': {
+              myProp: false,
+              state: {
+                somethingHappened: true
+              }
+            }
           }
         },
         SecondComponent: {
-          'simple state': {
-            myProp: true
+          class: 'SecondComponent',
+          fixtures: {
+            'simple state': {
+              myProp: true,
+              state: {
+                somethingHappened: false
+              }
+            }
           }
         }
       },
@@ -41,7 +52,7 @@ describe('ComponentPlayground component', function() {
   });
 
   afterEach(function() {
-    ComponentTree.loadChild.loadChild.restore();
+    ComponentTree.injectState.restore();
   })
 
   describe('state', function() {
@@ -53,7 +64,7 @@ describe('ComponentPlayground component', function() {
 
     describe('with fixture selected', function() {
       beforeEach(function() {
-        _.extend(props, {
+        _.extend(params, {
           selectedComponent: 'FirstComponent',
           selectedFixture: 'blank state'
         });
@@ -84,6 +95,14 @@ describe('ComponentPlayground component', function() {
               .to.equal(JSON.stringify(fixtureContents, null, 2));
       });
 
+      it('should inject state to preview child', function() {
+        render();
+
+        var args = ComponentTree.injectState.lastCall.args;
+        expect(args[0]).to.equal(component.refs.preview);
+        expect(args[1].somethingHappened).to.equal(true);
+      });
+
       describe('on fixture transition', function() {
         beforeEach(function() {
           render({
@@ -111,7 +130,8 @@ describe('ComponentPlayground component', function() {
         });
 
         it('should reset fixture user input', function() {
-          var fixtureContents = props.fixtures.FirstComponent['blank state'];
+          var fixtureContents =
+              params.components.FirstComponent.fixtures['blank state'];
 
           expect(JSON.parse(component.state.fixtureUserInput).myProp)
                 .to.equal(true);
@@ -120,6 +140,12 @@ describe('ComponentPlayground component', function() {
         it('should reset valid user input flag', function() {
           expect(component.state.isFixtureUserInputValid).to.be.true;
         });
+
+        it('should inject new state to preview child', function() {
+          var args = ComponentTree.injectState.lastCall.args;
+          expect(args[0]).to.equal(component.refs.preview);
+          expect(args[1].somethingHappened).to.equal(false);
+        });
       });
     });
   });