fix(api): type ResolverWrapper against graphql's native GraphQLResolveInfo

knip.json

@@ -5,7 +5,8 @@
     "tests/**/*.ts"
   ],
   "ignore": [
-    "**/generated/**"
+    "**/generated/**",
+    "tests/types/**"
   ],
   "ignoreDependencies": [
     "conventional-changelog-conventionalcommits",

package.json

@@ -24,7 +24,8 @@
     "lint": "eslint src/**/*.ts",
     "lint:fix": "eslint src --fix",
     "deps": "docker compose up",
-    "test": "npm run lint && npm run test:all && npm run build",
+    "test": "npm run lint && npm run test:types && npm run test:all && npm run build",
+    "test:types": "tsc -p tsconfig.type-tests.json",
     "test:all": "jest tests --no-cache --no-watchman --setupFiles dotenv/config",
     "test:unit": "jest tests/unit --no-cache --no-watchman --setupFiles dotenv/config",
     "test:api": "jest tests/api --no-cache --no-watchman --setupFiles dotenv/config",

src/api/execute.ts

@@ -1,5 +1,5 @@
 import { makeExecutableSchema } from '@graphql-tools/schema';
-import { IFieldResolver, IResolvers } from '@graphql-tools/utils';
+import { IResolvers } from '@graphql-tools/utils';
 import {
   DocumentNode,
   GraphQLResolveInfo,
@@ -17,9 +17,14 @@ import { Context, generate, get, getResolvers } from '..';
 import { Models } from '../models/models';
 import { noIntrospection } from '../utils/rules';
 
-export type ResolverWrapper = (
-  resolver: IFieldResolver<unknown, unknown, unknown, unknown>,
-) => IFieldResolver<unknown, unknown, unknown, unknown>;
+// Deliberately expressed with graphql's own `GraphQLResolveInfo` rather than `@graphql-tools/utils`'
+// `IFieldResolver`: the latter augments the resolve info with members (`getAbortSignal`,
+// `getAsyncHelpers`) that graphql 17 has natively but graphql 16 does not, which would make this
+// type unimplementable on graphql 16 by consumers whose resolvers come from graphql-codegen.
+// See tests/types/resolver-wrapper.ts.
+export type FieldResolver = (source: unknown, args: unknown, context: unknown, info: GraphQLResolveInfo) => unknown;
+
+export type ResolverWrapper = (resolver: FieldResolver) => FieldResolver;
 
 export type ExecutorInput = {
   models: Models;

tests/types/resolver-wrapper.ts

@@ -0,0 +1,29 @@
+import type { GraphQLResolveInfo } from 'graphql';
+import type { ExecutorInput, ResolverWrapper } from '../../src';
+
+// This file is never executed — `npm run test:types` type-checks it, and that is the assertion.
+//
+// graphql-codegen emits resolvers against graphql's own `GraphQLResolveInfo`, so a consumer's
+// resolver wrapper is typed that way too. `ResolverWrapper` has to stay assignable from that shape
+// on every graphql major our peer range allows.
+//
+// This regressed once: typing `ResolverWrapper` through `@graphql-tools/utils`' `IFieldResolver`
+// pulled in that package's *augmented* `GraphQLResolveInfo`, which as of utils v12 requires
+// `getAbortSignal` and `getAsyncHelpers`. graphql 17 declares both natively, graphql 16 declares
+// neither — so on graphql 16 the assignments below stopped compiling for every consumer, while the
+// jest suite stayed green (ts-jest runs transpile-only, and the one wrapper it passes is an
+// inferred `(resolver) => resolver` that never pins down the parameter type).
+type ResolverFn<TResult, TParent, TContext, TArgs> = (
+  parent: TParent,
+  args: TArgs,
+  context: TContext,
+  info: GraphQLResolveInfo,
+) => Promise<TResult> | TResult;
+
+declare const consumerWrapper: (
+  resolver: ResolverFn<unknown, unknown, unknown, unknown>,
+) => ResolverFn<unknown, unknown, unknown, unknown>;
+
+export const wrapper: ResolverWrapper = consumerWrapper;
+
+export const executorInput: Pick<ExecutorInput, 'resolverWrapper'> = { resolverWrapper: consumerWrapper };

tsconfig.type-tests.json

@@ -0,0 +1,11 @@
+{
+  "extends": "./tsconfig.json",
+  "include": ["tests/types/**/*.ts"],
+  "exclude": ["node_modules", "dist"],
+  "compilerOptions": {
+    "rootDir": "./",
+    "noEmit": true,
+    "declaration": false,
+    "sourceMap": false
+  }
+}