Support Symfony's Stimulus Bridge

[marcmorente]

This PR resolves #67

Problem

Stimulus controllers in Symfony projects were not being detected by stimulus-parser, causing several issues in stimulus-lsp:

• Missing controllers in LSP diagnostics — False warnings about undefined controller identifiers
• No autocomplete — Controller names not suggested when typing data-controller="..."
• Empty "Stimulus Controllers" view — No controllers displayed in VS Code sidebar
• Incorrect code actions — Unable to create new controllers or navigate to existing ones

Root Cause

Symfony supports two different ways to integrate Stimulus, and the parser needed to support both:

Pattern 1: @symfony/stimulus-bridge (Webpack Encore)

// assets/bootstrap.js
import { startStimulusApp } from '@symfony/stimulus-bridge';

export const app = startStimulusApp(require.context(
    '@symfony/stimulus-bridge/lazy-controller-loader!./controllers',
    true,
    /\.[jt]sx?$/
));

Pattern 2: @symfony/stimulus-bundle (AssetMapper)

// assets/bootstrap.js
import { startStimulusApp } from '@symfony/stimulus-bundle';

startStimulusApp();

The parser originally only supported Pattern 1. Pattern 2 uses a simpler startStimulusApp() call without the require.context() wrapper, which went unrecognized.

Solution

Added comprehensive support for both Symfony Stimulus integration patterns:

For @symfony/stimulus-bridge:

1. Recognize @symfony/stimulus-bridge as a helper package
2. Detect startStimulusApp() calls with require.context() using the @symfony/stimulus-bridge/lazy-controller-loader! prefix
3. Register controllers with the correct stimulus-loading-lazy load mode

For @symfony/stimulus-bundle (AssetMapper):

1. Recognize @symfony/stimulus-bundle as a helper package
2. Detect AssetMapper projects by checking for importmap.php or config/packages/stimulus.yaml
3. Handle startStimulusApp() calls without context arguments
4. Automatically resolve controllers from the controllers/ subdirectory

Result

After this fix, stimulus-lsp correctly:

• Detects all Stimulus controllers in both Webpack Encore and AssetMapper projects
• Shows controllers in the "Stimulus Controllers" view
• Provides accurate diagnostics (no false positives)
• Offers proper autocomplete for controller identifiers
• Enables code actions for creating/navigating to controllers

---

Key Differences at a Glance

Feature	@symfony/stimulus-bridge	@symfony/stimulus-bundle
Symfony integration	Webpack Encore	AssetMapper
Build tool	Webpack	PHP-native (no build step)
Bootstrap pattern	startStimulusApp(require.context(...))	startStimulusApp()
Detection method	Package + lazy loader prefix	Package + file indicators
Controllers directory	./controllers	./controllers

[marcoroth]

Thank you so much @marcmorente! I haven't forgotten about this and I'm going to take a look! 🙏🏼