unit test with data

jest.config.js

@@ -11,4 +11,5 @@ module.exports = {
     },
   },
   setupFiles: ['./test/testSetup.ts'],
+  setupFilesAfterEnv: ['./test/testSetupAfterEnv.ts'],
 }

package.json

@@ -30,7 +30,7 @@
   },
   "prisma": {
     "seed": "ts-node prisma/seed.ts"
-  },  
+  },
   "dependencies": {
     "@apollo/server": "^4.9.5",
     "@prisma/client": "^5.6.0",

src/graphql/resolvers/HelloResolver.spec.ts

@@ -1,5 +1,6 @@
 import { ApolloServer } from '@apollo/server'
 
+import { prisma } from '#src/prisma'
 import { createServer } from '#src/server/server'
 
 let testServer: ApolloServer
@@ -9,19 +10,44 @@ beforeAll(async () => {
 })
 
 describe('HelloResolver', () => {
-  it('return "Hello World!"', async () => {
-    const response = await testServer.executeOperation({
-      query: '{ hello { hello } }',
-    })
-    expect(response.body).toMatchObject({
-      kind: 'single',
-      singleResult: {
-        data: {
-          hello: {
-            hello: 'Hello world!',
+  describe('with no data', () => {
+    it('returns "no data found"', async () => {
+      const response = await testServer.executeOperation({
+        query: '{ hello { hello } }',
+      })
+      expect(response.body).toMatchObject({
+        kind: 'single',
+        singleResult: {
+          data: {
+            hello: {
+              hello: 'no data found',
+            },
           },
         },
-      },
+      })
+    })
+  })
+
+  describe('with data', () => {
+    it('returns "Hello World!"', async () => {
+      await prisma.hello.create({
+        data: {
+          text: 'Hello World!',
+        },
+      })
+      const response = await testServer.executeOperation({
+        query: '{ hello { hello } }',
+      })
+      expect(response.body).toMatchObject({
+        kind: 'single',
+        singleResult: {
+          data: {
+            hello: {
+              hello: 'Hello World!',
+            },
+          },
+        },
+      })
     })
   })
 })

src/graphql/resolvers/HelloResolver.ts

@@ -8,6 +8,6 @@ export class HelloResolver {
   @Query(() => Hello)
   async hello(): Promise<Hello> {
     const data = await prisma.hello.findFirst()
-    return new Hello(data?.text ?? 'Hello World!')
+    return new Hello(data?.text ?? 'no data found')
   }
 }

test/helpers.ts

@@ -0,0 +1,9 @@
+import { prisma } from '#src/prisma'
+
+export const deleteAll = async () => {
+  await prisma.hello.deleteMany()
+}
+
+export const disconnect = async () => {
+  prisma.$disconnect()
+}

test/testSetupAfterEnv.ts

@@ -0,0 +1,10 @@
+import { deleteAll, disconnect } from './helpers'
+
+beforeAll(async () => {
+  await deleteAll()
+})
+
+afterAll(async () => {
+  await deleteAll()
+  await disconnect()
+})