Ensure verbose mode prints output synchronously

Fixes jestjs#8208
conartist6 · Feb 4, 2021 · 98d1d6f · 98d1d6f
1 parent 98ed700
commit 98d1d6f
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Showing 4 changed files with 10 additions and 3 deletions.
diff --git a/packages/jest-reporters/package.json b/packages/jest-reporters/package.json
@@ -44,6 +44,7 @@
     "@types/istanbul-lib-report": "^3.0.0",
     "@types/istanbul-lib-source-maps": "^4.0.0",
     "@types/istanbul-reports": "^3.0.0",
+    "@types/node": "*",
     "@types/node-notifier": "^8.0.0",
     "mock-fs": "^4.4.1",
     "strip-ansi": "^6.0.0"

diff --git a/packages/jest-reporters/src/DefaultReporter.ts b/packages/jest-reporters/src/DefaultReporter.ts
@@ -43,15 +43,15 @@ export default class DefaultReporter extends BaseReporter {
     this._err = process.stderr.write.bind(process.stderr);
     this._status = new Status();
     this._bufferedOutput = new Set();
-    this._wrapStdio(process.stdout);
-    this._wrapStdio(process.stderr);
+    this.__wrapStdio(process.stdout);
+    this.__wrapStdio(process.stderr);
     this._status.onChange(() => {
       this._clearStatus();
       this._printStatus();
     });
   }
 
-  private _wrapStdio(stream: NodeJS.WritableStream | NodeJS.WriteStream) {
+  protected __wrapStdio(stream: NodeJS.WritableStream | NodeJS.WriteStream) {
     const originalWrite = stream.write;
 
     let buffer: Array<string> = [];

diff --git a/packages/jest-reporters/src/VerboseReporter.ts b/packages/jest-reporters/src/VerboseReporter.ts
@@ -29,6 +29,11 @@ export default class VerboseReporter extends DefaultReporter {
     this._globalConfig = globalConfig;
   }
 
+  // Verbose mode is for debugging. Buffering of output is undesirable.
+  // See https://github.com/facebook/jest/issues/8208
+  protected __wrapStdio() {
+  }
+
   static filterTestResults(
     testResults: Array<AssertionResult>,
   ): Array<AssertionResult> {

diff --git a/yarn.lock b/yarn.lock
@@ -1990,6 +1990,7 @@ __metadata:
     "@types/istanbul-lib-report": ^3.0.0
     "@types/istanbul-lib-source-maps": ^4.0.0
     "@types/istanbul-reports": ^3.0.0
+    "@types/node": "*"
     "@types/node-notifier": ^8.0.0
     chalk: ^4.0.0
     collect-v8-coverage: ^1.0.0