Fix MultiChild tests so they work with Fiber

Dropped the unnecessary use of findDOMNode.
Dropped unnecessary arrow functions.
Math.random() -> id counter, since this used to be
non-deterministic which is not ideal for unit tests.

getOriginalKeys() used to rely on implementation details
to scan that the internal data structure maintained its
structure, however, since that is unobservable we don't
need to test the internal data structure itself. We're
already testing refs and dom structure which is the only
observable effect of the reorder.

src/renderers/shared/stack/reconciler/__tests__/ReactMultiChildReconcile-test.js

@@ -13,13 +13,10 @@
 
 var React = require('React');
 var ReactDOM = require('ReactDOM');
-var ReactDOMComponentTree = require('ReactDOMComponentTree');
-var ReactInstanceMap = require('ReactInstanceMap');
 
 var stripEmptyValues = function(obj) {
   var ret = {};
-  var name;
-  for (name in obj) {
+  for (var name in obj) {
     if (!obj.hasOwnProperty(name)) {
       continue;
     }
@@ -30,31 +27,23 @@ var stripEmptyValues = function(obj) {
   return ret;
 };
 
-/**
- * Child key names are wrapped like '.$key:0'. We strip the extra chars out
- * here. This relies on an implementation detail of the rendering system.
- */
-var getOriginalKey = function(childName) {
-  var match = childName.match(/^\.\$([^.]+)$/);
-  expect(match).not.toBeNull();
-  return match[1];
-};
+var idCounter = 123;
 
 /**
  * Contains internal static internal state in order to test that updates to
  * existing children won't reinitialize components, when moving children -
  * reusing existing DOM/memory resources.
  */
 class StatusDisplay extends React.Component {
-  state = {internalState: Math.random()};
+  state = {internalState: idCounter++};
 
-  getStatus = () => {
+  getStatus() {
     return this.props.status;
-  };
+  }
 
-  getInternalState = () => {
+  getInternalState() {
     return this.state.internalState;
-  };
+  }
 
   componentDidMount() {
     this.props.onFlush();
@@ -67,7 +56,7 @@ class StatusDisplay extends React.Component {
   render() {
     return (
       <div>
-        {this.state.internalState}
+        {this.props.contentKey}
       </div>
     );
   }
@@ -82,39 +71,29 @@ class FriendsStatusDisplay extends React.Component {
   * Refs are not maintained in the rendered order, and neither is
   * `this._renderedChildren` (surprisingly).
   */
-  getOriginalKeys = () => {
+  getOriginalKeys() {
     var originalKeys = [];
-    // TODO: Update this to a better test that doesn't rely so much on internal
-    // implementation details.
-    var statusDisplays =
-      ReactInstanceMap.get(this)
-      ._renderedComponent
-      ._renderedChildren;
-    var name;
-    for (name in statusDisplays) {
-      var child = statusDisplays[name];
-      var isPresent = !!child;
-      if (isPresent) {
-        originalKeys[child._mountIndex] = getOriginalKey(name);
+    for (var key in this.props.usernameToStatus) {
+      if (this.props.usernameToStatus[key]) {
+        originalKeys.push(key);
       }
     }
     return originalKeys;
-  };
+  }
 
   /**
    * Retrieves the rendered children in a nice format for comparing to the input
    * `this.props.usernameToStatus`.
    */
-  getStatusDisplays = () => {
+  getStatusDisplays() {
     var res = {};
-    var i;
     var originalKeys = this.getOriginalKeys();
-    for (i = 0; i < originalKeys.length; i++) {
+    for (var i = 0; i < originalKeys.length; i++) {
       var key = originalKeys[i];
       res[key] = this.refs[key];
     }
     return res;
-  };
+  }
 
   /**
    * Verifies that by the time a child is flushed, the refs that appeared
@@ -123,29 +102,28 @@ class FriendsStatusDisplay extends React.Component {
    * but our internal layer API depends on this assumption. We need to change
    * it to be more declarative before making ref resolution indeterministic.
    */
-  verifyPreviousRefsResolved = (flushedKey) => {
-    var i;
+  verifyPreviousRefsResolved(flushedKey) {
     var originalKeys = this.getOriginalKeys();
-    for (i = 0; i < originalKeys.length; i++) {
+    for (var i = 0; i < originalKeys.length; i++) {
       var key = originalKeys[i];
       if (key === flushedKey) {
         // We are only interested in children up to the current key.
         return;
       }
       expect(this.refs[key]).toBeTruthy();
     }
-  };
+  }
 
   render() {
     var children = [];
-    var key;
-    for (key in this.props.usernameToStatus) {
+    for (var key in this.props.usernameToStatus) {
       var status = this.props.usernameToStatus[key];
       children.push(
         !status ? null :
         <StatusDisplay
           key={key}
           ref={key}
+          contentKey={key}
           onFlush={this.verifyPreviousRefsResolved.bind(this, key)}
           status={status}
         />
@@ -223,35 +201,33 @@ function verifyStatesPreserved(lastInternalStates, statusDisplays) {
  * Verifies that the internal representation of a set of `renderedChildren`
  * accurately reflects what is in the DOM.
  */
-function verifyDomOrderingAccurate(parentInstance, statusDisplays) {
-  var containerNode = ReactDOM.findDOMNode(parentInstance);
+function verifyDomOrderingAccurate(outerContainer, statusDisplays) {
+  var containerNode = outerContainer.firstChild;
   var statusDisplayNodes = containerNode.childNodes;
-  var i;
-  var orderedDomIDs = [];
-  for (i = 0; i < statusDisplayNodes.length; i++) {
-    var inst = ReactDOMComponentTree.getInstanceFromNode(statusDisplayNodes[i]);
-    orderedDomIDs.push(inst._rootNodeID);
+  var orderedDomKeys = [];
+  for (var i = 0; i < statusDisplayNodes.length; i++) {
+    var contentKey = statusDisplayNodes[i].textContent;
+    orderedDomKeys.push(contentKey);
   }
 
-  var orderedLogicalIDs = [];
+  var orderedLogicalKeys = [];
   var username;
   for (username in statusDisplays) {
     if (!statusDisplays.hasOwnProperty(username)) {
       continue;
     }
     var statusDisplay = statusDisplays[username];
-    orderedLogicalIDs.push(
-      ReactInstanceMap.get(statusDisplay)._renderedComponent._rootNodeID
+    orderedLogicalKeys.push(
+      statusDisplay.props.contentKey
     );
   }
-  expect(orderedDomIDs).toEqual(orderedLogicalIDs);
+  expect(orderedDomKeys).toEqual(orderedLogicalKeys);
 }
 
 /**
  * Todo: Check that internal state is preserved across transitions
  */
 function testPropsSequence(sequence) {
-  var i;
   var container = document.createElement('div');
   var parentInstance = ReactDOM.render(
     <FriendsStatusDisplay {...sequence[0]} />,
@@ -261,15 +237,15 @@ function testPropsSequence(sequence) {
   var lastInternalStates = getInternalStateByUserName(statusDisplays);
   verifyStatuses(statusDisplays, sequence[0]);
 
-  for (i = 1; i < sequence.length; i++) {
+  for (var i = 1; i < sequence.length; i++) {
     ReactDOM.render(
       <FriendsStatusDisplay {...sequence[i]} />,
       container
     );
     statusDisplays = parentInstance.getStatusDisplays();
     verifyStatuses(statusDisplays, sequence[i]);
     verifyStatesPreserved(lastInternalStates, statusDisplays);
-    verifyDomOrderingAccurate(parentInstance, statusDisplays);
+    verifyDomOrderingAccurate(container, statusDisplays);
 
     lastInternalStates = getInternalStateByUserName(statusDisplays);
   }

src/renderers/shared/stack/reconciler/__tests__/ReactMultiChildText-test.js

@@ -26,17 +26,17 @@ var testAllPermutations = function(testCases) {
       var expectedResultAfterUpdate = testCases[j + 1];
 
       var container = document.createElement('div');
-      var d = ReactDOM.render(<div>{renderWithChildren}</div>, container);
-      expectChildren(d, expectedResultAfterRender);
+      ReactDOM.render(<div>{renderWithChildren}</div>, container);
+      expectChildren(container, expectedResultAfterRender);
 
-      d = ReactDOM.render(<div>{updateWithChildren}</div>, container);
-      expectChildren(d, expectedResultAfterUpdate);
+      ReactDOM.render(<div>{updateWithChildren}</div>, container);
+      expectChildren(container, expectedResultAfterUpdate);
     }
   }
 };
 
-var expectChildren = function(d, children) {
-  var outerNode = ReactDOM.findDOMNode(d);
+var expectChildren = function(container, children) {
+  var outerNode = container.firstChild;
   var textNode;
   if (typeof children === 'string') {
     textNode = outerNode.firstChild;