Add eval test

test/integration/middleware/with-eval/lib/utils.js

@@ -0,0 +1,8 @@
+export async function usingEval() {
+  // eslint-disable-next-line no-eval
+  return { value: eval('100') }
+}
+
+export async function notUsingEval() {
+  return { value: 100 }
+}

test/integration/middleware/with-eval/pages/_middleware.js

@@ -0,0 +1,19 @@
+import { notUsingEval, usingEval } from '../lib/utils'
+
+export async function middleware(request) {
+  if (request.nextUrl.pathname === '/using-eval') {
+    return new Response(JSON.stringify(await usingEval()), {
+      headers: {
+        'Content-Type': 'application/json',
+      },
+    })
+  }
+
+  if (request.nextUrl.pathname === '/not-using-eval') {
+    return new Response(JSON.stringify(await notUsingEval()), {
+      headers: {
+        'Content-Type': 'application/json',
+      },
+    })
+  }
+}

test/integration/middleware/with-eval/test/index.test.js

@@ -0,0 +1,67 @@
+/* eslint-env jest */
+
+import { join } from 'path'
+import {
+  fetchViaHTTP,
+  findPort,
+  killApp,
+  launchApp,
+  nextBuild,
+} from 'next-test-utils'
+
+const context = {}
+const DYNAMIC_CODE_ERROR = `Dynamic Code Evaluation (e. g. 'eval', 'new Function') not allowed in Middleware`
+
+jest.setTimeout(1000 * 60 * 2)
+context.appDir = join(__dirname, '../')
+
+describe('Middleware usage of dynamic code evaluation', () => {
+  describe('dev mode', () => {
+    let output = ''
+
+    beforeAll(async () => {
+      context.appPort = await findPort()
+      context.app = await launchApp(context.appDir, context.appPort, {
+        onStdout(msg) {
+          output += msg
+        },
+        onStderr(msg) {
+          output += msg
+        },
+      })
+    })
+
+    beforeEach(() => (output = ''))
+    afterAll(() => killApp(context.app))
+
+    it('shows a warning when running code with eval', async () => {
+      const res = await fetchViaHTTP(context.appPort, `/using-eval`)
+      const json = await res.json()
+      expect(json.value).toEqual(100)
+      expect(output).toContain(DYNAMIC_CODE_ERROR)
+    })
+
+    it('does not show warning when no code uses eval', async () => {
+      const res = await fetchViaHTTP(context.appPort, `/not-using-eval`)
+      const json = await res.json()
+      expect(json.value).toEqual(100)
+      expect(output).not.toContain(DYNAMIC_CODE_ERROR)
+    })
+  })
+
+  describe('production mode', () => {
+    let buildResult
+
+    beforeAll(async () => {
+      buildResult = await nextBuild(context.appDir, undefined, {
+        stderr: true,
+        stdout: true,
+      })
+    })
+
+    it('should have middleware warning during build', () => {
+      expect(buildResult.stderr).toContain(`Failed to compile`)
+      expect(buildResult.stderr).toContain(DYNAMIC_CODE_ERROR)
+    })
+  })
+})