first commit

test/integration/config-syntax-error/pages/index.js

@@ -0,0 +1,3 @@
+export default function Page(props) {
+  return <p>index page</p>
+}

test/integration/config-syntax-error/test/index.test.ts

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+/* eslint-env jest */
+import fs from 'fs-extra'
+import { join } from 'path'
+import { nextBuild } from 'next-test-utils'
+
+const appDir = join(__dirname, '..')
+const nextConfigJS = join(appDir, 'next.config.js')
+const nextConfigMJS = join(appDir, 'next.config.mjs')
+
+describe('Invalid config syntax', () => {
+  ;(process.env.TURBOPACK_DEV ? describe.skip : describe)(
+    'production mode',
+    () => {
+      it('should error when next.config.js contains syntax error', async () => {
+        await fs.writeFile(
+          nextConfigJS,
+          `
+      module.exports = {
+        reactStrictMode: true,,
+      }
+    `
+        )
+        const { stderr } = await nextBuild(appDir, undefined, {
+          stderr: true,
+        })
+        await fs.remove(nextConfigJS)
+
+        expect(stderr).toContain(
+          'Failed to load next.config.js, see more info here https://nextjs.org/docs/messages/next-config-error'
+        )
+        expect(stderr).toContain('SyntaxError')
+      })
+
+      it('should error when next.config.mjs contains syntax error', async () => {
+        await fs.writeFile(
+          nextConfigMJS,
+          `
+      const config = {
+        reactStrictMode: true,,
+      }
+      export default config
+    `
+        )
+        const { stderr } = await nextBuild(appDir, undefined, {
+          stderr: true,
+        })
+        await fs.remove(nextConfigMJS)
+
+        expect(stderr).toContain(
+          'Failed to load next.config.mjs, see more info here https://nextjs.org/docs/messages/next-config-error'
+        )
+        expect(stderr).toContain('SyntaxError')
+      })
+    }
+  )
+})