stop resolvers after execution ends

addresses: #3792

Author: yaacovCR

src/execution/__tests__/nonnull-test.ts

@@ -2,6 +2,7 @@ import { expect } from 'chai';
 import { describe, it } from 'mocha';
 
 import { expectJSON } from '../../__testUtils__/expectJSON.js';
+import { resolveOnNextTick } from '../../__testUtils__/resolveOnNextTick.js';
 
 import type { PromiseOrValue } from '../../jsutils/PromiseOrValue.js';
 
@@ -526,6 +527,68 @@ describe('Execute: handles non-nullable types', () => {
     });
   });
 
+  describe('cancellation with null bubbling', () => {
+    function nestedPromise(n: number): string {
+      return n > 0 ? `promiseNest { ${nestedPromise(n - 1)} }` : 'promise';
+    }
+
+    it('returns an single error without cancellation', async () => {
+      const query = `
+        {
+          promiseNonNull,
+          ${nestedPromise(4)}
+        }
+      `;
+
+      const result = await executeQuery(query, throwingData);
+      expectJSON(result).toDeepEqual({
+        data: null,
+        errors: [
+          // does not include syncNullError because result returns prior to it being added
+          {
+            message: 'promiseNonNull',
+            path: ['promiseNonNull'],
+            locations: [{ line: 3, column: 11 }],
+          },
+        ],
+      });
+    });
+
+    it('stops running despite error', async () => {
+      const query = `
+        {
+          promiseNonNull,
+          ${nestedPromise(10)}
+        }
+      `;
+
+      let counter = 0;
+      const rootValue = {
+        ...throwingData,
+        promiseNest() {
+          return new Promise((resolve) => {
+            counter++;
+            resolve(rootValue);
+          });
+        },
+      };
+      const result = await executeQuery(query, rootValue);
+      expectJSON(result).toDeepEqual({
+        data: null,
+        errors: [
+          {
+            message: 'promiseNonNull',
+            path: ['promiseNonNull'],
+            locations: [{ line: 3, column: 11 }],
+          },
+        ],
+      });
+      const counterAtExecutionEnd = counter;
+      await resolveOnNextTick();
+      expect(counter).to.equal(counterAtExecutionEnd);
+    });
+  });
+
   describe('Handles non-null argument', () => {
     const schemaWithNonNullArg = new GraphQLSchema({
       query: new GraphQLObjectType({

src/execution/execute.ts

@@ -165,11 +165,13 @@ export interface ExecutionContext {
   validatedExecutionArgs: ValidatedExecutionArgs;
   errors: Array<GraphQLError> | undefined;
   canceller: Canceller | undefined;
+  completed: boolean;
   cancellableStreams: Set<CancellableStreamRecord> | undefined;
 }
 
 interface IncrementalContext {
   errors: Array<GraphQLError> | undefined;
+  completed: boolean;
   deferUsageSet?: DeferUsageSet | undefined;
 }
 
@@ -317,6 +319,7 @@ export function experimentalExecuteQueryOrMutationOrSubscriptionEvent(
     validatedExecutionArgs,
     errors: undefined,
     canceller: abortSignal ? new Canceller(abortSignal) : undefined,
+    completed: false,
     cancellableStreams: undefined,
   };
   try {
@@ -367,8 +370,12 @@ export function experimentalExecuteQueryOrMutationOrSubscriptionEvent(
 
     if (isPromise(graphqlWrappedResult)) {
       return graphqlWrappedResult.then(
-        (resolved) => buildDataResponse(exeContext, resolved),
+        (resolved) => {
+          exeContext.completed = true;
+          return buildDataResponse(exeContext, resolved);
+        },
         (error: unknown) => {
+          exeContext.completed = true;
           exeContext.canceller?.unsubscribe();
           return {
             data: null,
@@ -377,8 +384,10 @@ export function experimentalExecuteQueryOrMutationOrSubscriptionEvent(
         },
       );
     }
+    exeContext.completed = true;
     return buildDataResponse(exeContext, graphqlWrappedResult);
   } catch (error) {
+    exeContext.completed = true;
     // TODO: add test case for synchronous null bubbling to root with cancellation
     /* c8 ignore next */
     exeContext.canceller?.unsubscribe();
@@ -1757,6 +1766,10 @@ function completeObjectValue(
   incrementalContext: IncrementalContext | undefined,
   deferMap: ReadonlyMap<DeferUsage, DeferredFragmentRecord> | undefined,
 ): PromiseOrValue<GraphQLWrappedResult<ObjMap<unknown>>> {
+  if ((incrementalContext ?? exeContext).completed) {
+    throw new Error('Completed, aborting.');
+  }
+
   // If there is an isTypeOf predicate function, call it with the
   // current result. If isTypeOf returns false, then raise an error rather
   // than continuing execution.
@@ -2274,6 +2287,7 @@ function collectExecutionGroups(
         groupedFieldSet,
         {
           errors: undefined,
+          completed: false,
           deferUsageSet,
         },
         deferMap,
@@ -2333,6 +2347,7 @@ function executeExecutionGroup(
       deferMap,
     );
   } catch (error) {
+    incrementalContext.completed = true;
     return {
       pendingExecutionGroup,
       path: pathToArray(path),
@@ -2342,21 +2357,27 @@ function executeExecutionGroup(
 
   if (isPromise(result)) {
     return result.then(
-      (resolved) =>
-        buildCompletedExecutionGroup(
+      (resolved) => {
+        incrementalContext.completed = true;
+        return buildCompletedExecutionGroup(
           incrementalContext.errors,
           pendingExecutionGroup,
           path,
           resolved,
-        ),
-      (error: unknown) => ({
-        pendingExecutionGroup,
-        path: pathToArray(path),
-        errors: withError(incrementalContext.errors, error as GraphQLError),
-      }),
+        );
+      },
+      (error: unknown) => {
+        incrementalContext.completed = true;
+        return {
+          pendingExecutionGroup,
+          path: pathToArray(path),
+          errors: withError(incrementalContext.errors, error as GraphQLError),
+        };
+      },
     );
   }
 
+  incrementalContext.completed = true;
   return buildCompletedExecutionGroup(
     incrementalContext.errors,
     pendingExecutionGroup,
@@ -2411,7 +2432,7 @@ function buildSyncStreamItemQueue(
         initialPath,
         initialItem,
         exeContext,
-        { errors: undefined },
+        { errors: undefined, completed: false },
         fieldDetailsList,
         info,
         itemType,
@@ -2442,7 +2463,7 @@ function buildSyncStreamItemQueue(
           itemPath,
           value,
           exeContext,
-          { errors: undefined },
+          { errors: undefined, completed: false },
           fieldDetailsList,
           info,
           itemType,
@@ -2534,7 +2555,7 @@ async function getNextAsyncStreamItemResult(
     itemPath,
     iteration.value,
     exeContext,
-    { errors: undefined },
+    { errors: undefined, completed: false },
     fieldDetailsList,
     info,
     itemType,
@@ -2581,11 +2602,16 @@ function completeStreamItem(
       incrementalContext,
       new Map(),
     ).then(
-      (resolvedItem) =>
-        buildStreamItemResult(incrementalContext.errors, resolvedItem),
-      (error: unknown) => ({
-        errors: withError(incrementalContext.errors, error as GraphQLError),
-      }),
+      (resolvedItem) => {
+        incrementalContext.completed = true;
+        return buildStreamItemResult(incrementalContext.errors, resolvedItem);
+      },
+      (error: unknown) => {
+        incrementalContext.completed = true;
+        return {
+          errors: withError(incrementalContext.errors, error as GraphQLError),
+        };
+      },
     );
   }
 
@@ -2614,6 +2640,7 @@ function completeStreamItem(
       result = { rawResult: null, incrementalDataRecords: undefined };
     }
   } catch (error) {
+    incrementalContext.completed = true;
     return {
       errors: withError(incrementalContext.errors, error),
     };
@@ -2633,14 +2660,20 @@ function completeStreamItem(
         return { rawResult: null, incrementalDataRecords: undefined };
       })
       .then(
-        (resolvedItem) =>
-          buildStreamItemResult(incrementalContext.errors, resolvedItem),
-        (error: unknown) => ({
-          errors: withError(incrementalContext.errors, error as GraphQLError),
-        }),
+        (resolvedItem) => {
+          incrementalContext.completed = true;
+          return buildStreamItemResult(incrementalContext.errors, resolvedItem);
+        },
+        (error: unknown) => {
+          incrementalContext.completed = true;
+          return {
+            errors: withError(incrementalContext.errors, error as GraphQLError),
+          };
+        },
       );
   }
 
+  incrementalContext.completed = true;
   return buildStreamItemResult(incrementalContext.errors, result);
 }