Allow iterables in traverseAllChildren

src/core/ReactElementValidator.js

@@ -22,6 +22,7 @@ var ReactElement = require('ReactElement');
 var ReactPropTypeLocations = require('ReactPropTypeLocations');
 var ReactCurrentOwner = require('ReactCurrentOwner');
 
+var getIteratorFn = require('getIteratorFn');
 var monitorCodeUse = require('monitorCodeUse');
 
 /**
@@ -68,7 +69,7 @@ function validateExplicitKey(component, parentType) {
 
   warnAndMonitorForKeyUse(
     'react_key_warning',
-    'Each child in an array should have a unique "key" prop.',
+    'Each child in an array or iterator should have a unique "key" prop.',
     component,
     parentType
   );
@@ -123,7 +124,9 @@ function warnAndMonitorForKeyUse(warningID, message, component, parentType) {
   // property, it may be the creator of the child that's responsible for
   // assigning it a key.
   var childOwnerName = null;
-  if (component._owner && component._owner !== ReactCurrentOwner.current) {
+  if (component &&
+      component._owner &&
+      component._owner !== ReactCurrentOwner.current) {
     // Name of the component that originally created this child.
     childOwnerName = component._owner.constructor.displayName;
 
@@ -161,7 +164,6 @@ function monitorUseOfObjectMap() {
  * @internal
  * @param {*} component Statically passed child of any type.
  * @param {*} parentType component's parent's type.
- * @return {boolean}
  */
 function validateChildKeys(component, parentType) {
   if (Array.isArray(component)) {
@@ -174,10 +176,24 @@ function validateChildKeys(component, parentType) {
   } else if (ReactElement.isValidElement(component)) {
     // This component was passed in a valid location.
     component._store.validated = true;
-  } else if (component && typeof component === 'object') {
-    monitorUseOfObjectMap();
-    for (var name in component) {
-      validatePropertyKey(name, component[name], parentType);
+  } else if (component) {
+    var iteratorFn = getIteratorFn(component);
+    // Entry iterators provide implicit keys.
+    if (iteratorFn && iteratorFn !== component.entries) {
+      var iterator = iteratorFn.call(component);
+      var step;
+      while (!(step = iterator.next()).done) {
+        if (ReactElement.isValidElement(step.value)) {
+          validateExplicitKey(step.value, parentType);
+        }
+      }
+    } else if (typeof component === 'object') {
+      monitorUseOfObjectMap();
+      for (var key in component) {
+        if (component.hasOwnProperty(key)) {
+          validatePropertyKey(key, component[key], parentType);
+        }
+      }
     }
   }
 }

src/core/__tests__/ReactElement-test.js

@@ -169,10 +169,101 @@ describe('ReactElement', function() {
 
     expect(console.warn.argsForCall.length).toBe(1);
     expect(console.warn.argsForCall[0][0]).toContain(
-      'Each child in an array should have a unique "key" prop'
+      'Each child in an array or iterator should have a unique "key" prop.'
     );
   });
 
+  it('warns for keys for iterables of elements in rest args', function() {
+    spyOn(console, 'warn');
+    var Component = React.createFactory(ComponentFactory);
+
+    var iterable = {
+      '@@iterator': function() {
+        var i = 0;
+        return {
+          next: function() {
+            var done = ++i > 2;
+            return { value: done ? undefined : Component(), done: done };
+          }
+        };
+      }
+    };
+
+    Component(null, iterable);
+
+    expect(console.warn.argsForCall.length).toBe(1);
+    expect(console.warn.argsForCall[0][0]).toContain(
+      'Each child in an array or iterator should have a unique "key" prop.'
+    );
+  });
+
+  it('does not warns for arrays of elements with keys', function() {
+    spyOn(console, 'warn');
+    var Component = React.createFactory(ComponentFactory);
+
+    Component(null, [ Component({key: '#1'}), Component({key: '#2'}) ]);
+
+    expect(console.warn.argsForCall.length).toBe(0);
+  });
+
+  it('does not warns for iterable elements with keys', function() {
+    spyOn(console, 'warn');
+    var Component = React.createFactory(ComponentFactory);
+
+    var iterable = {
+      '@@iterator': function() {
+        var i = 0;
+        return {
+          next: function() {
+            var done = ++i > 2;
+            return {
+              value: done ? undefined : Component({key: '#' + i}),
+              done: done
+            };
+          }
+        };
+      }
+    };
+
+    Component(null, iterable);
+
+    expect(console.warn.argsForCall.length).toBe(0);
+  });
+
+  it('warns for numeric keys on objects in rest args', function() {
+    spyOn(console, 'warn');
+    var Component = React.createFactory(ComponentFactory);
+
+    Component(null, { 1: Component(), 2: Component() });
+
+    expect(console.warn.argsForCall.length).toBe(1);
+    expect(console.warn.argsForCall[0][0]).toContain(
+      'Child objects should have non-numeric keys so ordering is preserved.'
+    );
+  });
+
+  it('does not warn for numeric keys in entry iterables in rest args', function() {
+    spyOn(console, 'warn');
+    var Component = React.createFactory(ComponentFactory);
+
+    var iterable = {
+      '@@iterator': function() {
+        var i = 0;
+        return {
+          next: function() {
+            var done = ++i > 2;
+            return { value: done ? undefined : [i, Component()], done: done };
+          }
+        };
+      }
+    };
+    iterable.entries = iterable['@@iterator'];
+
+    Component(null, iterable);
+
+    expect(console.warn.argsForCall.length).toBe(0);
+  });
+
   it('does not warn when the element is directly in rest args', function() {
     spyOn(console, 'warn');
     var Component = React.createFactory(ComponentFactory);

src/utils/__tests__/traverseAllChildren-test.js

@@ -125,7 +125,64 @@ describe('traverseAllChildren', function() {
     );
   });
 
-  // Todo: test that nums/strings are converted to ReactComponents.
+  it('should traverse children of different kinds', function() {
+    var div = <div key="divNode" />;
+    var span = <span key="spanNode" />;
+    var a = <a key="aNode" />;
+
+    var traverseContext = [];
+    var traverseFn =
+      jasmine.createSpy().andCallFake(function(context, kid, key, index) {
+        context.push(true);
+      });
+
+    var instance = (
+      <div>
+        {div}
+        {[{span}]}
+        {{a: a}}
+        {'string'}
+        {1234}
+        {true}
+        {false}
+        {null}
+        {undefined}
+      </div>
+    );
+
+    traverseAllChildren(instance.props.children, traverseFn, traverseContext);
+
+    expect(traverseFn.calls.length).toBe(9);
+    expect(traverseContext.length).toEqual(9);
+
+    expect(traverseFn).toHaveBeenCalledWith(
+      traverseContext, div, '.$divNode', 0
+    );
+    expect(traverseFn).toHaveBeenCalledWith(
+      traverseContext, span, '.1:0:$span:$spanNode', 1
+    );
+    expect(traverseFn).toHaveBeenCalledWith(
+      traverseContext, a, '.2:$a:$aNode', 2
+    );
+    expect(traverseFn).toHaveBeenCalledWith(
+      traverseContext, 'string', '.3', 3
+    );
+    expect(traverseFn).toHaveBeenCalledWith(
+      traverseContext, 1234, '.4', 4
+    );
+    expect(traverseFn).toHaveBeenCalledWith(
+      traverseContext, null, '.5', 5
+    );
+    expect(traverseFn).toHaveBeenCalledWith(
+      traverseContext, null, '.6', 6
+    );
+    expect(traverseFn).toHaveBeenCalledWith(
+      traverseContext, null, '.7', 7
+    );
+    expect(traverseFn).toHaveBeenCalledWith(
+      traverseContext, null, '.8', 8
+    );
+  });
 
   it('should be called for each child in nested structure', function() {
     var zero = <div key="keyZero" />;
@@ -231,4 +288,107 @@ describe('traverseAllChildren', function() {
     );
   });
 
+  it('should be called for each child in an iterable', function() {
+    var threeDivIterable = {
+      '@@iterator': function() {
+        var i = 0;
+        return {
+          next: function() {
+            if (i++ < 3) {
+              return { value: <div key={'#'+i} />, done: false };
+            } else {
+              return { value: undefined, done: true };
+            }
+          }
+        };
+      }
+    };
+
+    var traverseContext = [];
+    var traverseFn =
+      jasmine.createSpy().andCallFake(function(context, kid, key, index) {
+        context.push(kid);
+      });
+
+    var instance = (
+      <div>
+        {threeDivIterable}
+      </div>
+    );
+
+    traverseAllChildren(instance.props.children, traverseFn, traverseContext);
+    expect(traverseFn.calls.length).toBe(3);
+
+    expect(traverseFn).toHaveBeenCalledWith(
+      traverseContext,
+      traverseContext[0],
+      '.$#1',
+      0
+    );
+    expect(traverseFn).toHaveBeenCalledWith(
+      traverseContext,
+      traverseContext[1],
+      '.$#2',
+      1
+    );
+    expect(traverseFn).toHaveBeenCalledWith(
+      traverseContext,
+      traverseContext[2],
+      '.$#3',
+      2
+    );
+  });
+
+  it('should use keys from entry iterables', function() {
+    var threeDivEntryIterable = {
+      '@@iterator': function() {
+        var i = 0;
+        return {
+          next: function() {
+            if (i++ < 3) {
+              return { value: ['#'+i, <div />], done: false };
+            } else {
+              return { value: undefined, done: true };
+            }
+          }
+        };
+      }
+    };
+    threeDivEntryIterable.entries = threeDivEntryIterable['@@iterator'];
+
+    var traverseContext = [];
+    var traverseFn =
+      jasmine.createSpy().andCallFake(function(context, kid, key, index) {
+        context.push(kid);
+      });
+
+    var instance = (
+      <div>
+        {threeDivEntryIterable}
+      </div>
+    );
+
+    traverseAllChildren(instance.props.children, traverseFn, traverseContext);
+    expect(traverseFn.calls.length).toBe(3);
+
+    expect(traverseFn).toHaveBeenCalledWith(
+      traverseContext,
+      traverseContext[0],
+      '.$#1:0',
+      0
+    );
+    expect(traverseFn).toHaveBeenCalledWith(
+      traverseContext,
+      traverseContext[1],
+      '.$#2:0',
+      1
+    );
+    expect(traverseFn).toHaveBeenCalledWith(
+      traverseContext,
+      traverseContext[2],
+      '.$#3:0',
+      2
+    );
+  });
+
 });

src/utils/getIteratorFn.js

@@ -0,0 +1,43 @@
+/**
+ * Copyright 2013-2014, Facebook, Inc.
+ * All rights reserved.
+ *
+ * This source code is licensed under the BSD-style license found in the
+ * LICENSE file in the root directory of this source tree. An additional grant
+ * of patent rights can be found in the PATENTS file in the same directory.
+ *
+ * @providesModule getIteratorFn
+ * @typechecks static-only
+ */
+
+"use strict";
+
+/* global Symbol */
+var ITERATOR_SYMBOL = typeof Symbol === 'function' && Symbol.iterator;
+var FAUX_ITERATOR_SYMBOL = '@@iterator'; // Before Symbol spec.
+
+/**
+ * Returns the iterator method function contained on the iterable object.
+ *
+ * Be sure to invoke the function with the iterable as context:
+ *
+ *     var iteratorFn = getIteratorFn(myIterable);
+ *     if (iteratorFn) {
+ *       var iterator = iteratorFn.call(myIterable);
+ *       ...
+ *     }
+ *
+ * @param {?object} maybeIterable
+ * @return {?function}
+ */
+function getIteratorFn(maybeIterable) {
+  var iteratorFn = maybeIterable && (
+    (ITERATOR_SYMBOL && maybeIterable[ITERATOR_SYMBOL]) ||
+    maybeIterable[FAUX_ITERATOR_SYMBOL]
+  );
+  if (typeof iteratorFn === 'function') {
+    return iteratorFn;
+  }
+}
+
+module.exports = getIteratorFn;