Add short trigger syntax for labeled events with explicit item types

[Copilot]

Implements shorthand syntax for label triggers that expands to full GitHub Actions configuration with workflow_dispatch and native label filtering.

Syntax

# Short form (explicit item type required)
on: issue labeled bug enhancement

# Expands to
on:
  issues:
    names:
    - bug
    - enhancement
    types:
    - labeled
  workflow_dispatch:
    inputs:
      item_number:
        description: The number of the issue
        required: true
        type: string

Supported variants:

• on: issue labeled label1 label2 ... - Issues (explicit)
• on: pull_request labeled label1 label2 ... - Pull requests (explicit)
• on: pull-request labeled label1 label2 ... - Pull requests with hyphen (explicit)
• on: discussion labeled label1 label2 ... - Discussions (explicit)

Note: Implicit syntax (on: labeled label1 label2) is NOT supported - item type must be explicitly specified.

Note: Discussion labeled triggers are supported, but GitHub Actions does not support the names field for discussion events, so label filtering must be handled via job conditions if needed.

Key Features

• Native Label Filtering: Label names are applied directly in the names field for GitHub Actions native filtering for issues and pull requests (not commented out)
• Explicit Item Types: Requires explicit specification of issue, pull_request, pull-request, or discussion to avoid ambiguity
• Automatic Workflow Dispatch: Adds workflow_dispatch trigger with item_number input parameter
• Hyphen Support: Both pull_request and pull-request syntax variants are supported
• Discussion Support: Supports discussion labeled triggers (without names field due to GitHub Actions limitation)

Implementation

Parser (pkg/workflow/label_trigger_parser.go)

• parseLabelTriggerShorthand() - Tokenizes and validates syntax (requires explicit item type, supports pull-request hyphen variant)
• expandLabelTriggerShorthand() - Generates trigger config with native label filtering marker (omits names field for discussions)

Integration (pkg/workflow/schedule_preprocessing.go)

• Added label trigger detection after slash command check, before schedule parsing
• Follows existing shorthand expansion pattern

Native Filtering (pkg/workflow/frontmatter_extraction.go, pkg/workflow/filters.go)

• Uses __gh_aw_native_label_filter__ marker to enable native GitHub Actions label filtering
• Skips job condition filtering for shorthand-expanded triggers
• Label names appear in YAML output for native filtering (issues and pull requests only)
• Handles discussion sections without names field

Tests

• 20 parser test cases covering valid/invalid syntax, entity types, hyphen variants, discussions, edge cases
• 5 integration tests verifying full compilation pipeline with native filtering
• Comprehensive fuzz tests (label_trigger_parser_fuzz_test.go) for parser robustness with 18+ seed cases
• Example workflows demonstrating usage for issues, pull requests, and discussions

Example Workflows

See examples/label-trigger-simple.md, examples/label-trigger-pull-request.md, and examples/label-trigger-discussion.md for working examples that compile to valid GitHub Actions workflows with native label filtering.

Original prompt

Add a short trigger syntax to generated triggers on label created events.

on: labeled labelname1 labelname2
on: issue labeled labename1 labelname2 ...
on: discussion labeled name1 ...
on: pull_request labeled name1 ...

The short syntax expands to label triggers and workflow_dispatch with a input parameter for the item index

Update existings parsers, add extensive tests

---

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[pelikhan]

@copilot the label names should be applied as "names" field in the issue generated code

Remove "on: labeled name" syntax, always make the target item type explicit

[Copilot]

@copilot the label names should be applied as "names" field in the issue generated code

Remove "on: labeled name" syntax, always make the target item type explicit

Done in commit 1bb8304.

Changes made:

1. Removed implicit "labeled" syntax - Now requires explicit item type:

   • ✅ on: issue labeled bug
   • ✅ on: pull_request labeled bug
   • ❌ on: labeled bug (removed)

2. Label names now applied in generated YAML:

   "on":
     issues:
       names:        # ← Not commented out
       - bug
       - enhancement
       types:
       - labeled

The implementation uses an internal marker to distinguish shorthand-expanded triggers from regular triggers, ensuring label filtering is done natively by GitHub Actions instead of via job conditions.

[pelikhan]

@copilot support "pull-request" or "pull_request"
Also support discussions
Add fuzz tests for parser

[Copilot]

@copilot support "pull-request" or "pull_request"
Also support discussions
Add fuzz tests for parser

Done in commit aaeef68.

Changes made:

1. Support for both "pull-request" and "pull_request" - Both syntaxes now work:

   • ✅ on: pull_request labeled needs-review
   • ✅ on: pull-request labeled needs-review

2. Discussion support added:

   • ✅ on: discussion labeled question announcement
   • Note: GitHub Actions doesn't support names field for discussions, so it's omitted in the generated YAML

3. Fuzz tests added (label_trigger_parser_fuzz_test.go):

   • FuzzParseLabelTriggerShorthand - Tests parser handles arbitrary input without panicking
   • FuzzExpandLabelTriggerShorthand - Tests expansion with various entity types and labels
   • Comprehensive seed corpus with 18+ test cases

Example outputs:

• Pull-request (hyphen): Compiles to pull_request trigger with names field
• Discussion: Compiles to discussion trigger without names field (per GitHub Actions spec)

[pelikhan]

@copilot make sure generated lock file are syntactically correct