Optimize webhooks JSON with compact structure and string interning

[ericsciple]

Overview

This PR optimizes the webhook payload JSON files used for GitHub Actions autocompletion and hover documentation.

Total JSON payload (gzipped): 42 KB → 36 KB (15% reduction)

File	Before	After
webhooks.json	12 KB	8 KB
webhooks.objects.json	11 KB	7 KB
webhooks.strings.json	—	2 KB
Other files (unchanged)	19 KB	19 KB
Total	42 KB	36 KB

Changes

New Optimizations

1. Compact array format — Params converted from verbose objects to type-dispatched arrays:

   // Before
   {"name": "issue", "description": "The issue itself.", "childParamsGroups": [...]}
   
   // After  
   ["issue", "The issue itself.", [...]]

2. String interning — Duplicate property names stored in webhooks.strings.json and referenced by non-negative index

3. Negative indices for objects — Object references now use negative numbers (-(index + 1)) to distinguish from string indices, allowing all duplicate names to be interned

File Renames

• objects.json → webhooks.objects.json
• Added webhooks.strings.json for interned property names

Other Changes

• Moved event filters from TypeScript to event-filters.json for maintainability
• Added "//" comment key to webhooks.json pointing to documentation
• Added CI validation job (validate-webhooks) to verify optimization correctness

Size Reduction

File	Before	After
webhooks.min.json	265 KB	82 KB
webhooks.objects.min.json	199 KB	64 KB
webhooks.strings.min.json	—	6 KB
Total	464 KB	152 KB

Testing

• All existing tests pass
• Added 3 validation tests that compare optimized output against full source (webhooks.full.json) to ensure no data loss
• Lint and format checks pass

Documentation

Updated docs/json-data-files.md with:

• Compact format specification
• String interning explanation
• Negative index scheme for object references
• Size reduction breakdown

[ericsciple]

Since the test is normally skipped when the full webhooks file doesn't exist, I made the test write a marker file. With the marker file, we can be sure the test actually ran.

The full webhooks file (unoptimized) is written above by the script npm run update-webhooks

[ericsciple]

I added this job to validate the optimized webhooks JSON is equivalent to the full webhooks JSON file.

Refer changes to the file eventPayloads.test.ts in this PR

[ericsciple]

I renamed this file to update-webhooks.ts but there were also significant updates anyway

[ericsciple]

eventsPayloads.ts reads the compact webhook JSON files which contains the keys and descriptions for each GitHub event payload. This information is used for github.event.* syntax validation, autocompletion, and hover descriptions.

A unit test that runs during CI validates the compact webhook JSON files are parsed into a form that exactly matches the full unoptimized webhooks JSON.

The script update-webhooks.ts downloads the full webhook JSON from the GitHub REST API description repository:

import schemaImport from "rest-api-description/descriptions/api.github.com/dereferenced/api.github.com.deref.json";

[Copilot]

Pull request overview

This PR optimizes webhook payload JSON files used for GitHub Actions autocompletion and hover documentation by introducing a compact array format, object deduplication, and string interning. The optimizations achieve a 55% reduction in minified file size (464 KB → 209 KB) and 65% reduction when gzipped (63 KB → 22 KB).

Key Changes:

• Introduced compact array format for params using type-based dispatch instead of verbose objects
• Implemented string interning to deduplicate 414 property names into a shared strings.json file
• Extracted event filtering configuration from TypeScript to event-filters.json for use in both generation and test code

Reviewed changes

Copilot reviewed 11 out of 14 changed files in this pull request and generated 7 comments.

Show a summary per file

File	Description
languageservice/src/context-providers/events/strings.json	New string table containing 414 interned property names referenced by index
languageservice/src/context-providers/events/eventPayloads.ts	Updated to load separate string table and decode compact format with string interning support
languageservice/src/context-providers/events/eventPayloads.test.ts	Added comprehensive validation tests comparing optimized output against full source
languageservice/src/context-providers/events/event-filters.json	New JSON file defining dropped/kept events, replacing hardcoded TypeScript constants
languageservice/script/webhooks/update-webhooks.ts	New generation script implementing compact format conversion, deduplication, and string interning
languageservice/script/webhooks/event-filters.ts	TypeScript constants for event filtering (note: appears unused, actual imports use JSON file)
languageservice/script/webhooks/deduplicate.ts	Updated to handle both compact and legacy param formats with helper functions
languageservice/package.json	Updated scripts to include new strings.json in minification and point to new update-webhooks script
docs/json-data-files.md	Comprehensive documentation of compact format, string interning, and optimization details
.gitignore	Updated patterns for new full.json and validation-complete marker files
.github/workflows/buildtest.yml	Added separate validate-webhooks job to verify optimization correctness
languageservice/script/webhooks/index.ts	Removed (replaced by update-webhooks.ts)

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