test(integration): emit console error when test fails (#35507)

kwonoj · web-flow · commit abfbf41eec61 · 2022-03-28T21:46:56.000Z
Minor improvements to the integration test runner to emit process's stdout when its execution failed. We have `console.log` for the output, but it doesn't emit actually since jest suppresses console output unlesss _assertion_ fails. If we throws in `before*` hook, since there's no actual assertion fails jest won't release captured console logs. PR adds one straightforward workaround (https://stackoverflow.com/questions/48695717/console-log-statements-output-nothing-at-all-in-jest) to emit if process exits with non-zero errorcode. To avoid any existing behavior, this is not enabled for the cases when process successfully exits. ## Bug - [ ] Related issues linked using `fixes #number` - [ ] Integration tests added - [ ] Errors have helpful link attached, see `contributing.md` ## Feature - [ ] Implements an existing feature request or RFC. Make sure the feature request has been accepted for implementation before opening a PR. - [ ] Related issues linked using `fixes #number` - [x] Integration tests added - [ ] Documentation added - [ ] Telemetry added. In case of a feature if it's used or not. - [ ] Errors have helpful link attached, see `contributing.md` ## Documentation / Examples - [ ] Make sure the linting passes by running `yarn lint`
diff --git a/test/integration/production/test/index.test.js b/test/integration/production/test/index.test.js
@@ -26,6 +26,7 @@ import dynamicImportTests from './dynamic'
 import processEnv from './process-env'
 import security from './security'
 import { promisify } from 'util'
+import { error } from 'console'
 
 const glob = promisify(globOriginal)
 
@@ -53,10 +54,14 @@ describe('Production Usage', () => {
     context.appPort = appPort
     app = await nextStart(appDir, appPort, { cwd: appDir })
     output = (result.stderr || '') + (result.stdout || '')
-    console.log(output)
 
     if (result.code !== 0) {
+      error(output)
       throw new Error(`Failed to build, exited with code ${result.code}`)
+    } else {
+      // Note: jest captures calls to console and only emits when there's assertion fails,
+      // so this won't log anything for normal test execution path.
+      console.log(output)
     }
   })
   afterAll(async () => {
