feat: Add DEC mode 2026 support (Synchronized Output) to Jest

CHANGELOG.md

@@ -22,6 +22,7 @@
 - `[@jest/fake-timers]` Exposing new modern timers function `advanceTimersToFrame()` which advances all timers by the needed milliseconds to execute callbacks currently scheduled with `requestAnimationFrame` ([#14598](https://github.com/jestjs/jest/pull/14598))
 - `[jest-matcher-utils]` Add `SERIALIZABLE_PROPERTIES` to allow custom serialization of objects ([#14893](https://github.com/jestjs/jest/pull/14893))
 - `[jest-mock]` Add support for the Explicit Resource Management proposal to use the `using` keyword with `jest.spyOn(object, methodName)` ([#14895](https://github.com/jestjs/jest/pull/14895))
+- `[jest-reporters]` Add support for [DEC mode 2026](https://gist.github.com/christianparpart/d8a62cc1ab659194337d73e399004036)
 - `[jest-runtime]` Exposing new modern timers function `jest.advanceTimersToFrame()` from `@jest/fake-timers` ([#14598](https://github.com/jestjs/jest/pull/14598))
 - `[jest-runtime]` Support `import.meta.filename` and `import.meta.dirname` (available from [Node 20.11](https://nodejs.org/en/blog/release/v20.11.0)) ([#14854](https://github.com/jestjs/jest/pull/14854))
 - `[jest-runtime]` Support `import.meta.resolve` ([#14930](https://github.com/jestjs/jest/pull/14930))

packages/jest-reporters/src/BaseReporter.ts

@@ -5,14 +5,15 @@
  * LICENSE file in the root directory of this source tree.
  */
 
+import type {WriteStream} from 'tty';
 import type {
   AggregatedResult,
   Test,
   TestCaseResult,
   TestContext,
   TestResult,
 } from '@jest/test-result';
-import {preRunMessage} from 'jest-util';
+import {isInteractive, preRunMessage} from 'jest-util';
 import type {Reporter, ReporterOnStartOptions} from './types';
 
 const {remove: preRunMessageRemove} = preRunMessage;
@@ -57,4 +58,16 @@ export default class BaseReporter implements Reporter {
   getLastError(): Error | undefined {
     return this._error;
   }
+
+  protected __beginSynchronizedUpdate(write: WriteStream['write']): void {
+    if (isInteractive) {
+      write('\u001B[?2026h');
+    }
+  }
+
+  protected __endSynchronizedUpdate(write: WriteStream['write']): void {
+    if (isInteractive) {
+      write('\u001B[?2026l');
+    }
+  }
 }

packages/jest-reporters/src/DefaultReporter.ts

@@ -53,8 +53,14 @@ export default class DefaultReporter extends BaseReporter {
     this.__wrapStdio(process.stdout);
     this.__wrapStdio(process.stderr);
     this._status.onChange(() => {
+      this.__beginSynchronizedUpdate(
+        this._globalConfig.useStderr ? this._err : this._out,
+      );
       this.__clearStatus();
       this.__printStatus();
+      this.__endSynchronizedUpdate(
+        this._globalConfig.useStderr ? this._err : this._out,
+      );
     });
   }
 
@@ -69,11 +75,17 @@ export default class DefaultReporter extends BaseReporter {
       buffer = [];
 
       // This is to avoid conflicts between random output and status text
+      this.__beginSynchronizedUpdate(
+        this._globalConfig.useStderr ? this._err : this._out,
+      );
       this.__clearStatus();
       if (string) {
         write(string);
       }
       this.__printStatus();
+      this.__endSynchronizedUpdate(
+        this._globalConfig.useStderr ? this._err : this._out,
+      );
 
       this._bufferedOutput.delete(flushBufferedOutput);
     };
@@ -194,9 +206,7 @@ export default class DefaultReporter extends BaseReporter {
       const testRetryReasons = testResult.retryReasons;
       if (testRetryReasons && testRetryReasons.length > 0) {
         this.log(
-          `${chalk.reset.inverse.bold.yellow(
-            ' LOGGING RETRY ERRORS ',
-          )} ${chalk.bold(testResult.fullName)}`,
+          `${chalk.reset.inverse.bold.yellow(' LOGGING RETRY ERRORS ')} ${chalk.bold(testResult.fullName)}`,
         );
         for (const [index, retryReasons] of testRetryReasons.entries()) {
           let {message, stack} = separateMessageFromStack(retryReasons);
@@ -219,11 +229,7 @@ export default class DefaultReporter extends BaseReporter {
     this.log(getResultHeader(result, this._globalConfig, config));
     if (result.console) {
       this.log(
-        `  ${TITLE_BULLET}Console\n\n${getConsoleOutput(
-          result.console,
-          config,
-          this._globalConfig,
-        )}`,
+        `  ${TITLE_BULLET}Console\n\n${getConsoleOutput(result.console, config, this._globalConfig)}`,
       );
     }
   }