Ensure verbose mode prints output synchronously

Fixes jestjs#8208
conartist6 · Feb 4, 2021 · 044bdeb · 044bdeb
1 parent c174ada
commit 044bdeb
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Showing 2 changed files with 9 additions and 3 deletions.
diff --git a/packages/jest-reporters/src/DefaultReporter.ts b/packages/jest-reporters/src/DefaultReporter.ts
@@ -43,15 +43,17 @@ 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
+  ): void {
     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 +29,10 @@ 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(): void {}
+
   static filterTestResults(
     testResults: Array<AssertionResult>,
   ): Array<AssertionResult> {