[rush] Include seconds in generated change file names so repeated "rush change" runs do not collide (#5818)

* [rush] Include seconds in generated change file names

Running rush change twice in the same minute silently overwrote the
change file from the first run, since generatePath only used minute
granularity. Pass useSeconds so the filename includes seconds, and fix
the useSeconds branch which only replaced the first colon.

Fixes #2195

* [rush] Fix ChangeFile test so it passes on Windows with Node.js v24

The Date constructor spy was bypassed by the V8 fast-path on Windows/Node
v24, so new Date().toJSON() returned the real wall-clock time instead of
the pinned value. Switch to jest.useFakeTimers().setSystemTime() which
intercepts at the engine level and is reliable across platforms.

Also fix the not.toContain(':') assertion to check only path.basename()
instead of the full path. On Windows the generated path starts with a
drive letter (e.g. "D:\...") which legitimately contains a colon and
was causing the assertion to fail even though the timestamp itself had
no colons.

* Keep the Date spy and only scope the colon check to the filename

The earlier switch to jest fake timers froze time for the rest of the
suite and broke the test on every platform. The Date constructor spy
already pins the timestamp correctly, as the original Windows failure
showed the right pinned value. The only real problem was that the colon
check looked at the full path, which on Windows starts with a drive
letter like D: that legitimately contains a colon. Restore the spy and
keep the assertion scoped to the basename.

* Rush change.

Co-authored-by: Ian Clanton-Thuon <iclanton@users.noreply.github.com>

* Rush change.

Co-authored-by: Ian Clanton-Thuon <iclanton@users.noreply.github.com>

* Clean up jest mocking in the new test.

---------

Co-authored-by: Ian Clanton-Thuon <iclanton@users.noreply.github.com>

Author: LeSingh1

common/changes/@microsoft/rush/fix-change-file-timestamp-seconds_2026-06-03-00-00.json

@@ -0,0 +1,11 @@
+{
+  "changes": [
+    {
+      "comment": "Include seconds in the generated change file name so that running `rush change` more than once in the same minute no longer silently overwrites the previously generated change file.",
+      "type": "minor",
+      "packageName": "@microsoft/rush"
+    }
+  ],
+  "packageName": "@microsoft/rush",
+  "email": "LeSingh1@users.noreply.github.com"
+}

libraries/rush-lib/src/api/ChangeFile.ts

@@ -84,10 +84,15 @@ export class ChangeFile {
       console.log('Could not automatically detect git branch name, using timestamp instead.');
     }
 
-    // example filename: yourbranchname_2017-05-01-20-20.json
+    // The timestamp includes seconds so that running "rush change" more than once
+    // in the same minute produces distinct filenames. Without this, the "--overwrite"
+    // flag rarely had any effect, and a second invocation would silently clobber the
+    // change file written by the first one. See GitHub issue #2195.
+    // example filename: yourbranchname_2017-05-01-20-20-30.json
+    const timestamp: string | undefined = this._getTimestamp(true);
     const filename: string = branch
-      ? this._escapeFilename(`${branch}_${this._getTimestamp()}.json`)
-      : `${this._getTimestamp()}.json`;
+      ? this._escapeFilename(`${branch}_${timestamp}.json`)
+      : `${timestamp}.json`;
     const filePath: string = path.join(
       this._rushConfiguration.changesFolder,
       ...this._changeFileData.packageName.split('/'),
@@ -98,7 +103,7 @@ export class ChangeFile {
 
   /**
    * Gets the current time, formatted as YYYY-MM-DD-HH-MM
-   * Optionally will include seconds
+   * When useSeconds is true, the seconds are appended as well: YYYY-MM-DD-HH-MM-SS
    */
   private _getTimestamp(useSeconds: boolean = false): string | undefined {
     // Create a date string with the current time
@@ -120,7 +125,7 @@ export class ChangeFile {
       let formattedTime: string;
       if (useSeconds) {
         // formattedTime === "22-47-49"
-        formattedTime = matches[2].replace(':', '-');
+        formattedTime = matches[2].replace(/:/g, '-');
       } else {
         // formattedTime === "22-47"
         const timeParts: string[] = matches[2].split(':');

libraries/rush-lib/src/api/test/ChangeFile.test.ts

@@ -1,11 +1,42 @@
 // Copyright (c) Microsoft Corporation. All rights reserved. Licensed under the MIT license.
 // See LICENSE in the project root for license information.
 
+import type { GitRepoInfo } from 'git-repo-info';
+
 import { ChangeFile } from '../ChangeFile';
 import { RushConfiguration } from '../RushConfiguration';
 import { ChangeType } from '../ChangeManagement';
+import { Git } from '../../logic/Git';
 
 describe(ChangeFile.name, () => {
+  it('generates a path that includes seconds so repeated invocations do not collide', () => {
+    const rushFilename: string = `${__dirname}/repo/rush-npm.json`;
+    const rushConfiguration: RushConfiguration = RushConfiguration.loadFromConfigurationFile(rushFilename);
+
+    // Pin the branch name so the generated filename is deterministic.
+    jest.spyOn(Git.prototype, 'getGitInfo').mockReturnValue({ branch: 'my-branch' } as Readonly<GitRepoInfo>);
+
+    // Pin the clock to 2017-05-01 20:20:30 UTC so the timestamp is deterministic.
+    jest.useFakeTimers({
+      now: new Date('2017-05-01T20:20:30.000Z').getTime()
+    });
+
+    const changeFile: ChangeFile = new ChangeFile(
+      {
+        packageName: 'a',
+        changes: [],
+        email: 'fake@example.com'
+      },
+      rushConfiguration
+    );
+
+    const generatedPath: string = changeFile.generatePath();
+    // The seconds must be present and the filename must be fully dash-separated
+    // (no leftover colons from the time portion).
+    // Check toContain on the forward-slash-normalised path so it works on Windows too.
+    expect(generatedPath.replace(/\\/g, '/').endsWith('my-branch_2017-05-01-20-20-30.json')).toBe(true);
+  });
+
   it('can add a change', () => {
     const rushFilename: string = `${__dirname}/repo/rush-npm.json`;
     const rushConfiguration: RushConfiguration = RushConfiguration.loadFromConfigurationFile(rushFilename);