Fixed value check on makeCursor

jeroencranendonk-wf · jeffbski · commit 3c66921c175c · 2015-03-09T16:15:51.000-05:00
Certain code paths call makeCursor with four arguments, with 'value'
undefined. Since arguments.length is still four in this case, the
value is not retrieved from rootData, and an incorrect cursor type can
be generated.
diff --git a/contrib/cursor/__tests__/Cursor.ts b/contrib/cursor/__tests__/Cursor.ts
@@ -49,6 +49,13 @@ describe('Cursor', () => {
     expect(deepCursor.deref()).toBe(data.getIn(Immutable.fromJS(['a', 'b'])));
   });
 
+  it('cursor return new cursors of correct type', () => {
+    var data = Immutable.fromJS({ a: [1, 2, 3] });
+    var cursor = Cursor.from(data);
+    var deepCursor = <any>cursor.cursor('a');
+    expect(deepCursor.findIndex).toBeDefined();
+  });
+
   it('can be treated as a value', () => {
     var data = Immutable.fromJS(json);
     var cursor = Cursor.from(data, ['a', 'b']);
diff --git a/contrib/cursor/index.js b/contrib/cursor/index.js
@@ -220,7 +220,7 @@ IndexedCursor.prototype = IndexedCursorPrototype;
 var NOT_SET = {}; // Sentinel value
 
 function makeCursor(rootData, keyPath, onChange, value) {
-  if (arguments.length < 4) {
+  if (value === void 0) {
     value = rootData.getIn(keyPath);
   }
   var size = value && value.size;

Original file line number	Diff line number	Diff line change
`@@ -220,7 +220,7 @@ IndexedCursor.prototype = IndexedCursorPrototype;`
`220`	`220`	`var NOT_SET = {}; // Sentinel value`
`221`	`221`
`222`	`222`	`function makeCursor(rootData, keyPath, onChange, value) {`
`223`		`- if (arguments.length < 4) {`
	`223`	`+ if (value === void 0) {`
`224`	`224`	`value = rootData.getIn(keyPath);`
`225`	`225`	`}`
`226`	`226`	`var size = value && value.size;`