Optimize query planner

.changeset/@graphql-tools_delegate-5477-dependencies.md

@@ -0,0 +1,5 @@
+---
+"@graphql-tools/delegate": patch
+---
+dependencies updates:
+  - Removed dependency [`value-or-promise@^1.0.12` ↗︎](https://www.npmjs.com/package/value-or-promise/v/1.0.12) (from `dependencies`)

packages/batch-execute/src/createBatchingExecutor.ts

@@ -5,6 +5,7 @@ import {
   ExecutionResult,
   Executor,
   getOperationASTFromRequest,
+  isAsyncIterable,
 } from '@graphql-tools/utils';
 import { mergeRequests } from './mergeRequests.js';
 import { splitResult } from './splitResult.js';
@@ -18,10 +19,20 @@ export function createBatchingExecutor(
   ) => Record<string, any> = defaultExtensionsReducer,
 ): Executor {
   const loadFn = createLoadFn(executor, extensionsReducer);
-  const loader = new DataLoader(loadFn, dataLoaderOptions);
+  const queryLoader = new DataLoader(loadFn, dataLoaderOptions);
+  const mutationLoader = new DataLoader(loadFn, dataLoaderOptions);
   return function batchingExecutor(request: ExecutionRequest) {
-    const operationAst = getOperationASTFromRequest(request);
-    return operationAst.operation === 'subscription' ? executor(request) : loader.load(request);
+    const operationType = request.operationType ?? getOperationASTFromRequest(request)?.operation;
+    switch (operationType) {
+      case 'query':
+        return queryLoader.load(request);
+      case 'mutation':
+        return mutationLoader.load(request);
+      case 'subscription':
+        return executor(request);
+      default:
+        throw new Error(`Invalid operation type "${operationType}"`);
+    }
   };
 }
 
@@ -40,40 +51,13 @@ function createLoadFn(
         .then((result: ExecutionResult) => [result])
         .catch((err: any) => [err]);
     }
-    const execBatches: Array<Array<ExecutionRequest>> = [];
-    let index = 0;
-    const request = requests[index];
-    let currentBatch: Array<ExecutionRequest> = [request];
-    execBatches.push(currentBatch);
-
-    const operationAst = getOperationASTFromRequest(request);
-    const operationType = operationAst.operation;
-
-    if (operationType == null) {
-      throw new Error('could not identify operation type of document');
-    }
-
-    while (++index < requests.length) {
-      const currentRequest = requests[index];
-      const currentOperationAST = getOperationASTFromRequest(currentRequest);
-      const currentOperationType = currentOperationAST.operation;
-
-      if (operationType === currentOperationType) {
-        currentBatch.push(currentRequest);
-      } else {
-        currentBatch = [currentRequest];
-        execBatches.push(currentBatch);
+    const mergedRequests = mergeRequests(requests, extensionsReducer);
+    return new ValueOrPromise(() => executor(mergedRequests)).then(resultBatches => {
+      if (isAsyncIterable(resultBatches)) {
+        throw new Error('Executor must not return incremental results for batching');
       }
-    }
-
-    return ValueOrPromise.all(
-      execBatches.map(execBatch =>
-        new ValueOrPromise(() => {
-          const mergedRequests = mergeRequests(execBatch, extensionsReducer);
-          return executor(mergedRequests) as ExecutionResult;
-        }).then(resultBatches => splitResult(resultBatches, execBatch.length)),
-      ),
-    ).then(results => results.flat());
+      return splitResult(resultBatches, requests.length);
+    });
   };
 }
 

packages/batch-execute/src/mergeRequests.ts

@@ -52,7 +52,7 @@ import { createPrefix } from './prefix.js';
  *   }
  */
 export function mergeRequests(
-  requests: Array<ExecutionRequest>,
+  requests: ReadonlyArray<ExecutionRequest>,
   extensionsReducer: (
     mergedExtensions: Record<string, any>,
     request: ExecutionRequest,
@@ -113,6 +113,7 @@ export function mergeRequests(
     context: requests[0].context,
     info: requests[0].info,
     operationType,
+    rootValue: requests[0].rootValue,
   };
 }
 

packages/delegate/package.json

@@ -55,8 +55,7 @@
     "@graphql-tools/schema": "^10.0.0",
     "@graphql-tools/utils": "^10.0.0",
     "dataloader": "^2.2.2",
-    "tslib": "^2.5.0",
-    "value-or-promise": "^1.0.12"
+    "tslib": "^2.5.0"
   },
   "publishConfig": {
     "directory": "dist",

packages/delegate/src/delegateToSchema.ts

@@ -6,17 +6,19 @@ import {
   OperationTypeNode,
   validate,
 } from 'graphql';
-import { ValueOrPromise } from 'value-or-promise';
 import { getBatchingExecutor } from '@graphql-tools/batch-execute';
 import { normalizedExecutor } from '@graphql-tools/executor';
 import {
   ExecutionRequest,
+  ExecutionResult,
   Executor,
   getDefinedRootType,
   getOperationASTFromRequest,
   isAsyncIterable,
+  isPromise,
   mapAsyncIterator,
   Maybe,
+  MaybeAsyncIterable,
   memoize1,
 } from '@graphql-tools/utils';
 import { applySchemaTransforms } from './applySchemaTransforms.js';
@@ -100,16 +102,21 @@ export function delegateRequest<
 
   const executor = getExecutor(delegationContext);
 
-  return new ValueOrPromise(() => executor(processedRequest))
-    .then(originalResult => {
-      if (isAsyncIterable(originalResult)) {
-        const iterator = originalResult[Symbol.asyncIterator]();
-        // "subscribe" to the subscription result and map the result through the transforms
-        return mapAsyncIterator(iterator, result => transformer.transformResult(result));
-      }
-      return transformer.transformResult(originalResult);
-    })
-    .resolve();
+  const result$ = executor(processedRequest);
+
+  function handleExecutorResult(executorResult: MaybeAsyncIterable<ExecutionResult<any>>) {
+    if (isAsyncIterable(executorResult)) {
+      const iterator = executorResult[Symbol.asyncIterator]();
+      // "subscribe" to the subscription result and map the result through the transforms
+      return mapAsyncIterator(iterator, result => transformer.transformResult(result));
+    }
+    return transformer.transformResult(executorResult);
+  }
+
+  if (isPromise(result$)) {
+    return result$.then(handleExecutorResult);
+  }
+  return handleExecutorResult(result$);
 }
 
 function getDelegationContext<TContext extends Record<string, any>>({