Add .lazy to prevent unhandled exceptions for lazy promises

krakenjs · Sep 24, 2021 · 16f77dd · 16f77dd
1 parent 9a69f2a
commit 16f77dd
Show file tree

Hide file tree

Showing 2 changed files with 27 additions and 0 deletions.
diff --git a/src/promise.js b/src/promise.js
@@ -307,6 +307,11 @@ export class ZalgoPromise<R : mixed> {
         return Promise.resolve(this); // eslint-disable-line compat/compat
     }
 
+    lazy() : ZalgoPromise<R> {
+        this.errorHandled = true;
+        return this;
+    }
+
     static resolve<X, Y>(value : ZalgoPromise<X> | Y) : ZalgoPromise<X | Y> {
 
         if (value instanceof ZalgoPromise) {

diff --git a/test/tests/reject.js b/test/tests/reject.js
@@ -512,4 +512,26 @@ describe('reject cases', () => {
             }, 100);
         }, 100);
     });
+
+    it('should not call unhandled promise method when lazy promise is rejected without having a handler', () => {
+
+        window.addEventListener('error', () => {
+            // pass
+        });
+
+        let error;
+
+        const listener = ZalgoPromise.onPossiblyUnhandledException(err => {
+            error = err;
+        });
+
+        ZalgoPromise.reject(new Error('foobar')).lazy();
+
+        return ZalgoPromise.delay(50).then(() => {
+            listener.cancel();
+            if (error) {
+                throw new Error(`Expected error to not be thrown`);
+            }
+        });
+    });
 });