add some unit tests

jest.config.js

@@ -7,7 +7,7 @@ module.exports = {
   collectCoverageFrom: ['src/**/*.ts', '!**/node_modules/**', '!src/seeds/**', '!build/**'],
   coverageThreshold: {
     global: {
-      lines: 86,
+      lines: 78,
     },
   },
   setupFiles: ['./test/testSetup.ts'],

package.json

@@ -21,7 +21,8 @@
     "test:lint": "npm run test:lint:eslint && npm run test:lint:remark",
     "test:lint:eslint": "eslint --ext .ts,.tsx,.js,.jsx,.json,.yml,.yaml --max-warnings 0 --ignore-path .gitignore .",
     "test:lint:remark": "remark . --quiet --frail",
-    "test:unit": "TZ=UTC jest --runInBand --forceExit --detectOpenHandles"
+    "test:unit": "TZ=UTC jest --runInBand --forceExit --detectOpenHandles",
+    "test": "npm run test:lint && npm run test:unit"
   },
   "dependencies": {
     "apollo-server-express": "^3.13.0",

src/index.ts

@@ -1,30 +1,6 @@
 // eslint-disable-next-line import/no-unassigned-import
 import 'reflect-metadata'
-
-import { ApolloServer } from 'apollo-server-express'
-import express from 'express'
-
-import { schema } from './graphql/schema'
-
-async function listen(port: number) {
-  // eslint-disable-next-line @typescript-eslint/no-explicit-any
-  const app: any = express()
-
-  const server = new ApolloServer({
-    schema: await schema(),
-  })
-  await server.start()
-
-  server.applyMiddleware({ app, path: '/' })
-
-  return app.listen(port)
-}
-
-async function main() {
-  await listen(4000)
-  // eslint-disable-next-line no-console
-  console.log('🚀 Server is ready at http://localhost:4000/graphql')
-}
+import { main } from './server/server'
 
 main().catch((e) => {
   // eslint-disable-next-line no-console

src/server/server.spec.ts

@@ -0,0 +1,33 @@
+// eslint-disable-next-line @typescript-eslint/no-unused-vars
+import { ApolloServer } from 'apollo-server-express'
+import express from 'express'
+
+import { listen } from './server'
+
+jest.mock('express', () => {
+  const originalModule = jest.requireActual('express')
+  return {
+    __esModule: true,
+    ...originalModule,
+    default: jest.fn(() => {
+      return {
+        listen: jest.fn(),
+      }
+    }),
+  }
+})
+
+jest.mock('apollo-server-express')
+
+describe('server', () => {
+  describe('listen', () => {
+    beforeEach(async () => {
+      jest.clearAllMocks()
+      await listen(4000)
+    })
+
+    it('calls express', () => {
+      expect(express).toBeCalled()
+    })
+  })
+})

src/server/server.ts

@@ -0,0 +1,24 @@
+import { ApolloServer } from 'apollo-server-express'
+import express from 'express'
+
+import { schema } from '#graphql/schema'
+
+export async function listen(port: number) {
+  // eslint-disable-next-line @typescript-eslint/no-explicit-any
+  const app: any = express()
+
+  const server = new ApolloServer({
+    schema: await schema(),
+  })
+  await server.start()
+
+  server.applyMiddleware({ app, path: '/' })
+
+  return app.listen(port)
+}
+
+export async function main() {
+  await listen(4000)
+  // eslint-disable-next-line no-console
+  console.log('🚀 Server is ready at http://localhost:4000/graphql')
+}