Adds GraphQL errors integration test

test/graphql-api/errors.mocks.ts

@@ -0,0 +1,21 @@
+import { composeMocks, graphql } from 'msw'
+
+const { start } = composeMocks(
+  graphql.query({ operation: 'Login' }, (req, res, ctx) => {
+    return res(
+      ctx.errors([
+        {
+          message: 'This is a mocked error',
+          locations: [
+            {
+              line: 1,
+              column: 2,
+            },
+          ],
+        },
+      ]),
+    )
+  }),
+)
+
+start()

test/graphql-api/errors.test.ts

@@ -0,0 +1,56 @@
+import * as path from 'path'
+import { Response } from 'puppeteer'
+import { TestAPI, runBrowserWith } from '../support/runBrowserWith'
+import { executeOperation } from './utils/executeOperation'
+
+describe('GraphQL: Errors', () => {
+  let api: TestAPI
+
+  beforeAll(async () => {
+    api = await runBrowserWith(path.resolve(__dirname, 'errors.mocks.ts'))
+  })
+
+  afterAll(() => {
+    return api.cleanup()
+  })
+
+  describe('given mocked query errors', () => {
+    let res: Response
+    let body: Record<string, any>
+
+    beforeAll(async () => {
+      res = await executeOperation(api.page, {
+        query: `
+          query Login {
+            user {
+              id
+            }
+          }
+        `,
+      })
+      body = await res.json()
+    })
+
+    it('should return 200 status code', () => {
+      expect(res.status()).toBe(200)
+    })
+
+    it('should not return any data', () => {
+      expect(body).not.toHaveProperty('data')
+    })
+
+    it('should mock the error', () => {
+      expect(body).toHaveProperty('errors', [
+        {
+          message: 'This is a mocked error',
+          locations: [
+            {
+              line: 1,
+              column: 2,
+            },
+          ],
+        },
+      ])
+    })
+  })
+})