apollo-server-tests
Overview
executeOperation initializes automatically - no startup needed for
unit-style tests against the schema in-process. For HTTP-layer tests
(CORS, middleware, response headers), use supertest against an
ephemeral-port server.
When to use
- Unit tests for resolvers using
executeOperation.
- Integration tests for HTTP-layer behaviour using
supertest.
- Production-config gates: assert introspection / APQ /
hideSchemaDetails settings match your production config.
Authoring
Install
npm install --save-dev @apollo/server supertest @types/supertest
In-process tests with executeOperation
import { ApolloServer } from '@apollo/server';
import { typeDefs, resolvers } from './schema';
const testServer = new ApolloServer({ typeDefs, resolvers });
test('returns greeting', async () => {
const response = await testServer.executeOperation({
query: 'query SayHelloWorld($name: String) { hello(name: $name) }',
variables: { name: 'world' },
});
// Parse/validation/execution errors surface in `errors`, not thrown
if (response.body.kind !== 'single') throw new Error('expected single');
expect(response.body.singleResult.errors).toBeUndefined();
expect(response.body.singleResult.data?.hello).toBe('Hello world!');
});
Context injection (auth, datasources)
const res = await testServer.executeOperation(
{ query: GET_LAUNCH, variables: { id: 1 } },
{
contextValue: {
user: { id: 1, email: 'a@a.a' },
dataSources: { userAPI, launchAPI },
},
},
);
contextValue bypasses the production context function (which parses headers).
HTTP-layer tests with supertest
import { startStandaloneServer } from '@apollo/server/standalone';
import request from 'supertest';
let server: ApolloServer;
let url: string;
beforeAll(async () => {
server = new ApolloServer({ typeDefs, resolvers });
({ url } = await startStandaloneServer(server, {
listen: { port: 0 }, // OS picks port → parallel-test safe
}));
});
afterAll(async () => {
await server?.stop();
});
it('says hello over HTTP', async () => {
const response = await request(url)
.post('/')
.send({ query: '{ hello }' });
expect(response.status).toBe(200);
expect(response.body.data?.hello).toBeDefined();
});
Running
Standard test commands
npm test # jest / vitest pick up *.test.ts
npx jest schema.test.ts -t "introspection"
Production-config tests (most important)
Assert prod-time security defaults under NODE_ENV=production:
import { ApolloServer } from '@apollo/server';
test('introspection disabled when production', async () => {
process.env.NODE_ENV = 'production';
const prodServer = new ApolloServer({
typeDefs, resolvers,
introspection: process.env.NODE_ENV !== 'production',
});
const resp = await prodServer.executeOperation({
query: '{ __schema { types { name } } }',
});
if (resp.body.kind !== 'single') throw new Error('expected single');
expect(resp.body.singleResult.errors).toBeDefined();
expect(resp.body.singleResult.errors?.[0].message).toMatch(/introspection/i);
});
test('hideSchemaDetailsFromClientErrors strips did-you-mean', async () => {
const server = new ApolloServer({
typeDefs, resolvers,
hideSchemaDetailsFromClientErrors: true,
});
const resp = await server.executeOperation({
query: '{ usre { id } }', // typo
});
if (resp.body.kind !== 'single') throw new Error('expected single');
expect(JSON.stringify(resp.body.singleResult.errors)).not.toMatch(/did you mean/i);
});
Persisted-query mode test
Strict allowlist (APQ) mode:
test('strict APQ rejects unregistered hash', async () => {
const server = new ApolloServer({
typeDefs, resolvers,
persistedQueries: false, // turn off auto-register
plugins: [/* strict-allowlist plugin from manifest */],
});
const { url } = await startStandaloneServer(server, { listen: { port: 0 } });
const resp = await request(url).post('/').send({
extensions: { persistedQuery: { version: 1, sha256Hash: 'deadbeef'.repeat(8) } },
});
expect(resp.body.errors[0].extensions.code).toMatch(/PERSISTED_QUERY/);
});
Parsing results
The executeOperation response shape is discriminated:
type ExecuteOperationResult =
| { body: { kind: 'single'; singleResult: { data?: ...; errors?: ... } } }
| { body: { kind: 'incremental'; ... } };
Always check kind === 'single' first. The errors array contains
GraphQLError objects with message, path, extensions.code
(e.g., 'BAD_USER_INPUT', 'UNAUTHENTICATED',
'PERSISTED_QUERY_NOT_FOUND').
For supertest: standard HTTP response; response.body.errors if
GraphQL-level error, response.status if transport error.
CI integration
# .github/workflows/graphql-tests.yml
name: graphql
on: [pull_request]
jobs:
test:
runs-on: ubuntu-latest
steps:
- uses: actions/checkout@v5
- uses: actions/setup-node@v4
with:
node-version: '20'
- run: npm ci
- run: npm test
- name: Production-config assertions
env:
NODE_ENV: production
run: npx jest tests/production-config/ --forceExit
The production-config jobs run separately with NODE_ENV=production
so the actual prod-time defaults are exercised.
Anti-patterns
| Anti-pattern | Why it fails | Fix |
|---|
Tests in NODE_ENV=test only | Production defaults differ; introspection-disabled gate untested | Separate prod-config test job |
executeOperation for HTTP-layer concerns | Skips middleware, CORS, headers | Use supertest for HTTP-layer |
Hardcoded port 4000 in tests | Parallel CI conflicts | port: 0 |
Forgetting server.stop() in afterAll | Connection leak across tests | Always stop |
Asserting errors[0].message string | Brittle to wording / i18n | Assert extensions.code |
Skipping contextValue injection | Tests use real auth headers; flaky | Inject mocked context per test |
| One mega-test for the whole schema | Failures hard to diagnose | One test per resolver / operation |
data access without checking errors | Errors masked; false positives | Check errors === undefined first |
Limitations
executeOperation skips HTTP. Auth via headers, CORS,
rate-limiting middleware are not exercised. Use supertest for those.- Doesn't test subscriptions over WS. Subscriptions need a
WebSocket server; use
graphql-ws test patterns.
- Doesn't catch type-level bugs at runtime. Test the runtime
behaviour, not the type definitions.
- Doesn't replace contract tests. Mocked context can drift from
prod; pair with schema-regression contract tests.
References