From 044bdeb72e4283b0fc993251e4acba49b8c52880 Mon Sep 17 00:00:00 2001
From: Conrad Buck <conartist6@gmail.com>
Date: Thu, 4 Feb 2021 15:29:58 -0500
Subject: [PATCH] Ensure verbose mode prints output synchronously

Fixes #8208
---
 packages/jest-reporters/src/DefaultReporter.ts | 8 +++++---
 packages/jest-reporters/src/VerboseReporter.ts | 4 ++++
 2 files changed, 9 insertions(+), 3 deletions(-)

diff --git a/packages/jest-reporters/src/DefaultReporter.ts b/packages/jest-reporters/src/DefaultReporter.ts
index 77b1fbe94b46..b49c23022aec 100644
--- 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
index 5d7de322f330..514d2e6ab23e 100644
--- 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> {