fix: check path for indexHtmlFile in onSpecsChange (#31819) (#31821)

* fix: check path for indexHtmlFile in onSpecsChange (#31819)

indexHtmlFile supports absolute paths,
so we need to check if the path is absolute before
fetching it from the project root.

* Update CHANGELOG.md

* Update CHANGELOG.md

updates changelog ref to 14.5.3

---------

Co-authored-by: Bill Glesias <bglesias@gmail.com>

Author: pmaieref

cli/CHANGELOG.md

@@ -1,4 +1,12 @@
 <!-- See the ../guides/writing-the-cypress-changelog.md for details on writing the changelog. -->
+## 14.5.3
+
+_Released 7/30/2025 (PENDING)_
+
+**Bugfixes:**
+
+- Fixed missing support for setting an absolute path for `component.indexHtmlFile` in `@cypress/webpack-dev-server`. Fixes [#31819](https://github.com/cypress-io/cypress/issues/31819).
+
 ## 14.5.2
 
 _Released 7/15/2025_

npm/webpack-dev-server/src/CypressCTWebpackPlugin.ts

@@ -118,8 +118,9 @@ export class CypressCTWebpackPlugin {
     // TODO: don't use a sync fs method here
     // eslint-disable-next-line no-restricted-syntax
     const utimesSync: UtimesSync = inputFileSystem.fileSystem.utimesSync ?? fs.utimesSync
+    const indexHtmlFilePath = path.isAbsolute(this.indexHtmlFile) ? this.indexHtmlFile : path.join(this.projectRoot, this.indexHtmlFile)
 
-    utimesSync(path.join(this.projectRoot, this.indexHtmlFile), new Date(), new Date())
+    utimesSync(indexHtmlFilePath, new Date(), new Date())
   }
 
   /**