Reject deferred on dispose

Author: Kartik Raj

src/client/common/process/rawProcessApis.ts

@@ -102,6 +102,7 @@ export function plainExec(
         dispose: () => {
             if (!proc.killed) {
                 proc.kill();
+                deferred.reject(new Error('Process was killed'));
             }
         },
     };

src/client/common/utils/async.ts

@@ -50,11 +50,17 @@ class DeferredImpl<T> implements Deferred<T> {
     }
 
     public resolve(_value: T | PromiseLike<T>) {
+        if (this.completed) {
+            return;
+        }
         this._resolve.apply(this.scope ? this.scope : this, [_value]);
         this._resolved = true;
     }
 
     public reject(_reason?: string | Error | Record<string, unknown>) {
+        if (this.completed) {
+            return;
+        }
         this._reject.apply(this.scope ? this.scope : this, [_reason]);
         this._rejected = true;
     }