fix(every): index properly increments in predicate

ReactiveX · Oct 2, 2020 · 5686f83 · 5686f83
1 parent d3a083f
commit 5686f83
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Showing 2 changed files with 13 additions and 1 deletion.
diff --git a/spec/operators/every-spec.ts b/spec/operators/every-spec.ts
@@ -32,6 +32,18 @@ describe('every operator', () => {
 
   });
 
+  it('should increment index on each call to the predicate', () => {
+    const indices: number[] = [];
+    of(1, 2, 3, 4).pipe(
+      every((_, i) => {
+        indices.push(i);
+        return true;
+      })
+    ).subscribe();
+
+    expect(indices).to.deep.equal([0, 1, 2, 3]);
+  });
+
   it('should accept thisArg with array observables', () => {
     const thisArg = {};
 

diff --git a/src/internal/operators/every.ts b/src/internal/operators/every.ts
@@ -39,7 +39,7 @@ export function every<T>(
       new OperatorSubscriber(
         subscriber,
         (value) => {
-          if (!predicate.call(thisArg, value, index, source)) {
+          if (!predicate.call(thisArg, value, index++, source)) {
             subscriber.next(false);
             subscriber.complete();
           }