Update warn -> Error and check exit code

Author: ijjk

packages/next/export/worker.js

@@ -50,7 +50,7 @@ export default async function({
     const queryWithAutoExportWarn = () => {
       if (hasOrigQueryValues) {
         throw new Error(
-          `\nWarn: you provided query values for ${path} which is an auto-exported page. These can not be applied since the page can no longer be re-rendered on the server. To disable auto-export for this page add \`getInitialProps\`\n`
+          `\nError: you provided query values for ${path} which is an auto-exported page. These can not be applied since the page can no longer be re-rendered on the server. To disable auto-export for this page add \`getInitialProps\`\n`
         )
       }
     }

test/integration/auto-export-query-error/test/index.test.js

@@ -9,11 +9,13 @@ const appDir = path.join(__dirname, '..')
 const outdir = path.join(__dirname, 'out')
 const nextConfig = path.join(appDir, 'next.config.js')
 let stderr
+let exitCode
 
 const runTests = () => {
   it('should show warning for query provided for auto exported page correctly', async () => {
+    expect(exitCode).toBe(1)
     expect(stderr).toContain(
-      'Warn: you provided query values for / which is an auto-exported page. These can not be applied since the page can no longer be re-rendered on the server. To disable auto-export for this page add `getInitialProps`'
+      'Error: you provided query values for / which is an auto-exported page. These can not be applied since the page can no longer be re-rendered on the server. To disable auto-export for this page add `getInitialProps`'
     )
 
     expect(stderr).not.toContain('/amp')
@@ -29,12 +31,13 @@ describe('Auto Export', () => {
   describe('server mode', () => {
     beforeAll(async () => {
       await nextBuild(appDir)
-      const { stderr: curStderr } = await nextExport(
+      const { stderr: curStderr, code: curCode } = await nextExport(
         appDir,
         { outdir },
         { stderr: true }
       )
       stderr = curStderr
+      exitCode = curCode
     })
 
     runTests()
@@ -44,12 +47,13 @@ describe('Auto Export', () => {
     beforeAll(async () => {
       origNextConfig = await fs.readFile(nextConfig, 'utf8')
       await nextBuild(appDir)
-      const { stderr: curStderr } = await nextExport(
+      const { stderr: curStderr, code: curCode } = await nextExport(
         appDir,
         { outdir },
         { stderr: true }
       )
       stderr = curStderr
+      exitCode = curCode
     })
     afterAll(async () => {
       await fs.writeFile(nextConfig, origNextConfig)

test/lib/next-test-utils.js

@@ -111,8 +111,9 @@ export function runNextCommand(argv, options = {}) {
       })
     }
 
-    instance.on('close', () => {
+    instance.on('close', code => {
       resolve({
+        code,
         stdout: stdoutOutput,
         stderr: stderrOutput,
       })