fix(last): Allow defaultValue of undefined.

ReactiveX · Mar 3, 2021 · ef3e721 · ef3e721
1 parent 4983760
commit ef3e721
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Showing 2 changed files with 12 additions and 1 deletion.
diff --git a/spec/operators/last-spec.ts b/spec/operators/last-spec.ts
@@ -56,6 +56,17 @@ describe('last', () => {
     });
   });
 
+  it('should allow undefined as a default value', () => {
+    testScheduler.run(({ hot, expectObservable, expectSubscriptions }) => {
+      const e1 = hot('  -----a--a---a-|   ');
+      const e1subs = '  ^-------------!   ';
+      const expected = '--------------(U|)';
+
+      expectObservable(e1.pipe(last((value) => value === 'b', undefined))).toBe(expected, { U: undefined });
+      expectSubscriptions(e1.subscriptions).toBe(e1subs);
+    });
+  });
+
   it('should return last element matches with predicate', () => {
     testScheduler.run(({ hot, expectObservable, expectSubscriptions }) => {
       const e1 = hot('  --a--b--a--b--|   ');

diff --git a/src/internal/operators/last.ts b/src/internal/operators/last.ts
@@ -77,6 +77,6 @@ export function last<T, D>(
     source.pipe(
       predicate ? filter((v, i) => predicate(v, i, source)) : identity,
       takeLast(1),
-      hasDefaultValue ? defaultIfEmpty<T, D>(defaultValue) : throwIfEmpty(() => new EmptyError())
+      hasDefaultValue ? defaultIfEmpty(defaultValue!) : throwIfEmpty(() => new EmptyError())
     );
 }