TypeError: Cannot read properties of null (reading 'split') in watch mode when a file is deleted

[wjgerritsen-0001]

Current behaviour

In webpack watch mode, deleting any watched source file causes an unhandled crash and terminates the watcher. Webpack's MultiCompiler calls Watching.invalidate(null) when a file is removed from the watch set. The invalidate handler in AssetCompiler passes that null directly to Option.isScript(), which crashes trying to call .split() on it.

Full stack trace:

TypeError: Cannot read properties of null (reading 'split')
    at Option.isScript (node_modules/html-bundler-webpack-plugin/src/Plugin/Option.js:606:29)
    at HtmlBundlerPlugin.invalidate (node_modules/html-bundler-webpack-plugin/src/Plugin/AssetCompiler.js:529:40)
    at Watching.invalidate (node_modules/webpack/lib/Watching.js:407:32)
    at MultiCompiler.js:601:38

Expected behaviour

Deleting a watched file should not crash the watcher. The invalidation should be handled gracefully (either skipped or treated as a non-script resource), allowing watch mode to continue running.

Reproduction

• repository URL
• example code

Configure webpack with html-bundler-webpack-plugin in a multi-compiler setup (array of configs), start webpack --watch, then delete any source file (.ts/.js) that is part of the watched compilation.

The crash occurs because MultiCompiler propagates the invalidate event with null as the filename to all child compilers, including the one running HtmlBundlerPlugin.

Suggested one-line fix in Option.js:606:

// before
const [file] = resource.split('?', 1);

// after
const [file] = (resource ?? '').split('?', 1);

Environment

• OS: Windows
• version of Node.js: 25.2.1
• version of Webpack: 5.94.0
• version of the Plugin: 4.23.0

Additional context

The crash only occurs in multi-compiler mode. A single-config webpack setup may not trigger this code path because MultiCompiler has different invalidation propagation logic.

[webdiscus]

Hello @wjgerritsen-0001,

thanks for the issue reporting. I'll fix it over WE. Any PR is welcome!

[webdiscus]

Hello @wjgerritsen-0001,

the issue is fixed in the version 4.23.1. Can you please try it out and give a feedback.

@SAY-5, thank you for the fix!

[wjgerritsen-0001]

Tested with 4.23.2; The crash is fixed. But the behavior is not what I expected.

I just removed a file (debugger.js) in the project and restored it, but get an unrelated error: index.ts not found:

ERROR in [entry] [initial]
   HTML Bundler Plugin  Failed to execute the function.
  Source file: 'C:\git\casefabric\cafienne-ide2\src\ide_client\index.html'
  C:\git\casefabric\cafienne-ide2\node_modules\html-bundler-webpack-plugin\src\Plugin\Messages\Exception.js:133
    throw new PluginException(message);
    ^

  PluginException: 
   HTML Bundler Plugin  Can't resolve C:\git\casefabric\cafienne-ide2\src\ide_client\index.ts in the file src\ide_client\index.html

      at resolveException (C:\git\casefabric\cafienne-ide2\node_modules\html-bundler-webpack-plugin\src\Plugin\Messages\Exception.js:133:9)
      at Resolver.require (C:\git\casefabric\cafienne-ide2\node_modules\html-bundler-webpack-plugin\src\Plugin\Resolver.js:282:7)
      at C:\git\casefabric\cafienne-ide2\src\ide_client\index.html:1:318
      at Script.runInContext (node:vm:149:12)
      at VMScript.exec (C:\git\casefabric\cafienne-ide2\node_modules\html-bundler-webpack-plugin\src\Common\VMScript.js:39:27)
      at HtmlBundlerPlugin.renderModule (C:\git\casefabric\cafienne-ide2\node_modules\html-bundler-webpack-plugin\src\Plugin\AssetCompiler.js:1658:27)
      at HtmlBundlerPlugin.renderManifest (C:\git\casefabric\cafienne-ide2\node_modules\html-bundler-webpack-plugin\src\Plugin\AssetCompiler.js:1190:26)
      at Hook.eval [as call] (eval at create (C:\git\casefabric\cafienne-ide2\node_modules\tapable\lib\HookCodeFactory.js:19:10), <anonymous>:7:16)
      at Hook.CALL_DELEGATE [as _call] (C:\git\casefabric\cafienne-ide2\node_modules\tapable\lib\Hook.js:14:14)
      at Compilation.getRenderManifest (C:\git\casefabric\cafienne-ide2\node_modules\webpack\lib\Compilation.js:4755:36)
  PluginException: 
   HTML Bundler Plugin  Failed to execute the function.
  Source file: 'C:\git\casefabric\cafienne-ide2\src\ide_client\index.html'
  C:\git\casefabric\cafienne-ide2\node_modules\html-bundler-webpack-plugin\src\Plugin\Messages\Exception.js:133
    throw new PluginException(message);
    ^

  PluginException: 
   HTML Bundler Plugin  Can't resolve C:\git\casefabric\cafienne-ide2\src\ide_client\index.ts in the file src\ide_client\index.html

      at resolveException (C:\git\casefabric\cafienne-ide2\node_modules\html-bundler-webpack-plugin\src\Plugin\Messages\Exception.js:133:9)
      at Resolver.require (C:\git\casefabric\cafienne-ide2\node_modules\html-bundler-webpack-plugin\src\Plugin\Resolver.js:282:7)
      at C:\git\casefabric\cafienne-ide2\src\ide_client\index.html:1:318
      at Script.runInContext (node:vm:149:12)
      at VMScript.exec (C:\git\casefabric\cafienne-ide2\node_modules\html-bundler-webpack-plugin\src\Common\VMScript.js:39:27)
      at HtmlBundlerPlugin.renderModule (C:\git\casefabric\cafienne-ide2\node_modules\html-bundler-webpack-plugin\src\Plugin\AssetCompiler.js:1658:27)
      at HtmlBundlerPlugin.renderManifest (C:\git\casefabric\cafienne-ide2\node_modules\html-bundler-webpack-plugin\src\Plugin\AssetCompiler.js:1190:26)
      at Hook.eval [as call] (eval at create (C:\git\casefabric\cafienne-ide2\node_modules\tapable\lib\HookCodeFactory.js:19:10), <anonymous>:7:16)
      at Hook.CALL_DELEGATE [as _call] (C:\git\casefabric\cafienne-ide2\node_modules\tapable\lib\Hook.js:14:14)
      at Compilation.getRenderManifest (C:\git\casefabric\cafienne-ide2\node_modules\webpack\lib\Compilation.js:4755:36)
      at executeFunctionException (C:\git\casefabric\cafienne-ide2\node_modules\html-bundler-webpack-plugin\src\Plugin\Messages\Exception.js:154:9)
      at VMScript.exec (C:\git\casefabric\cafienne-ide2\node_modules\html-bundler-webpack-plugin\src\Common\VMScript.js:48:7)
      at HtmlBundlerPlugin.renderModule (C:\git\casefabric\cafienne-ide2\node_modules\html-bundler-webpack-plugin\src\Plugin\AssetCompiler.js:1658:27)
      at HtmlBundlerPlugin.renderManifest (C:\git\casefabric\cafienne-ide2\node_modules\html-bundler-webpack-plugin\src\Plugin\AssetCompiler.js:1190:26)
      at Hook.eval [as call] (eval at create (C:\git\casefabric\cafienne-ide2\node_modules\tapable\lib\HookCodeFactory.js:19:10), <anonymous>:7:16)
      at Hook.CALL_DELEGATE [as _call] (C:\git\casefabric\cafienne-ide2\node_modules\tapable\lib\Hook.js:14:14)
      at Compilation.getRenderManifest (C:\git\casefabric\cafienne-ide2\node_modules\webpack\lib\Compilation.js:4755:36)
      at C:\git\casefabric\cafienne-ide2\node_modules\webpack\lib\Compilation.js:4775:22
      at symbolIterator (C:\git\casefabric\cafienne-ide2\node_modules\neo-async\async.js:3482:9)
      at timesSync (C:\git\casefabric\cafienne-ide2\node_modules\neo-async\async.js:2297:7)

   HTML Bundler Plugin   config [app] ▶▶▶ (webpack 5.97.1) compiled with 1 error in 106 ms

[webdiscus]

@wjgerritsen-0001 thanks for the feedback.
This is other issue. I will fix it.

[webdiscus]

@wjgerritsen-0001

I can't reproduce your issue. I can remove and restore a file successfully.

Please create a minimal repo with the reproducible issue.
As base code use the manual test sample multi-config.