Add discussion support to add-comment safe output

[Copilot]

Add Discussion Support for add-comment Safe Output ✅

Summary

Successfully implemented comprehensive support for GitHub Discussions in the add-comment safe output feature. Workflows can now create comments on discussions in addition to issues and pull requests.

Completed Tasks

• Update JSON schema to include discussions in add-comment description
• Update Go code (add_comment.go) to generate "on" condition including github.event.discussion.number
• Update JavaScript (add_comment.cjs) to handle discussion comments via GraphQL addDiscussionComment mutation
• Update TypeScript type definitions for discussion support
• Add test for discussion comment support
• Update documentation
• Manual testing via compiled workflows
• All unit tests pass (100% success rate)
• Code formatting validated
• Refactored to use variadic buildOr with DisjunctionNode
• Added discussion and discussion_comment events to schema
• Updated dev.md to demonstrate discussion events with workflow_dispatch support

Recent Changes (Latest Commit)

• Added workflow_dispatch support: dev.md now supports manual triggering with a discussion_number input parameter
• Dynamic discussion targeting: The prompt now uses ${{ github.event.inputs.discussion_number || github.event.discussion.number }} to support both manual dispatch and automatic discussion events
• Added github.event.discussion.number to allowed expressions: Updated constants to allow this expression in workflow markdown
• Added target: "*": Allows the workflow to comment on any discussion when using workflow_dispatch

Key Changes

1. Schema (pkg/parser/schemas/main_workflow_schema.json)

• Updated descriptions to mention discussions alongside issues and PRs
• Modified target field to include discussion numbers
• Added discussion event with types: created, edited, deleted, transferred, pinned, unpinned, labeled, unlabeled, locked, unlocked, category_changed, answered, unanswered
• Added discussion_comment event with types: created, edited, deleted

2. Go Code (pkg/workflow/add_comment.go & pkg/workflow/expressions.go)

• Refactored buildOr: Now accepts variadic arguments ...ConditionNode
• Handles 0 arguments (returns nil), 1 argument (returns as-is), 2 arguments (simple OR), 3+ arguments (uses DisjunctionNode)
• NEW: Uses DisjunctionNode for 3+ conditions to avoid deep nesting and improve readability
• Uses single variadic buildOr to check for issue, PR, or discussion events
• Added discussions: write permission to add_comment job

3. Constants (pkg/constants/constants.go)

• NEW: Added github.event.discussion.number to AllowedExpressions list for expression safety validation

4. JavaScript (pkg/workflow/js/add_comment.cjs)

• Added isDiscussionContext detection for discussion/discussion_comment events
• Implemented GraphQL query to fetch discussion ID
• Implemented addDiscussionComment mutation for creating discussion comments
• Handles both issue_number and discussion_number fields in comment items
• Normalized GraphQL response to match REST API structure

5. Type Definitions (pkg/workflow/js/types/safe-outputs.d.ts)

• Added optional discussion_number field to AddCommentItem interface

6. MCP Server (pkg/workflow/js/safe_outputs_mcp_server.cjs)

• Updated tool description and input schema to include discussions

7. Tests

• Added pkg/workflow/add_comment_discussion_test.go verifying all discussion support components
• Added TestBuildOr in expressions_test.go with comprehensive test cases for the variadic function
• Updated test expectations to match DisjunctionNode flat rendering
• All existing tests continue to pass

8. Documentation (docs/src/content/docs/reference/safe-outputs.md)

• Updated all descriptions to mention discussions
• Added discussion-specific example workflow
• Documented discussions: write permission requirement

9. Example (dev.md)

• Changed to use add-comment instead of create-issue
• Added both discussion and discussion_comment events as triggers
• NEW: Added workflow_dispatch with discussion_number input parameter
• NEW: Added target: "*" to support manual discussion number specification
• Updated instruction to dynamically reference discussion number from input or event context

Technical Implementation

Improved buildOr Function

func buildOr(conditions ...ConditionNode) ConditionNode {
    if len(conditions) == 0 {
        return nil
    }
    if len(conditions) == 1 {
        return conditions[0]
    }
    if len(conditions) == 2 {
        return &OrNode{Left: conditions[0], Right: conditions[1]}
    }
    // Use DisjunctionNode for 3+ conditions to avoid deep nesting
    return &DisjunctionNode{Terms: conditions}
}

workflow_dispatch Configuration (dev.md)

on:
  discussion:
    types: [created]
  discussion_comment:
    types: [created]
  workflow_dispatch:
    inputs:
      discussion_number:
        description: "Discussion number to add comment to"
        required: true
        type: string

Dynamic Prompt

Write a delightful poem about the last 3 pull requests and add it as a comment to discussion #${{ github.event.inputs.discussion_number || github.event.discussion.number }}.

Benefits of DisjunctionNode

• Cleaner rendering: a || b || c instead of (a) || ((b) || (c))
• No deep nesting: Flat structure easier to read and maintain
• Consistent with existing codebase: Leverages existing DisjunctionNode type

Event Detection
The workflow detects three context types:

• Issues: issues, issue_comment
• Pull Requests: pull_request, pull_request_review, pull_request_review_comment
• Discussions: discussion, discussion_comment

API Strategy

• REST API: Used for issues and PRs (github.rest.issues.createComment)
• GraphQL API: Used for discussions (addDiscussionComment mutation)

Generated Condition (Improved)

if: >
  ((always()) && (contains(needs.agent.outputs.output_types, 'add-comment'))) &&
  (github.event.issue.number || github.event.pull_request.number || github.event.discussion.number)

Permissions

permissions:
  contents: read
  issues: write
  pull-requests: write
  discussions: write

Testing Results

✅ All unit tests pass (6.7s)
✅ Build successful
✅ Code formatted
✅ Variadic buildOr with DisjunctionNode tested with 7 test cases
✅ dev.md compiles successfully with workflow_dispatch and discussion events
✅ Discussion and discussion_comment events validated in schema
✅ Expression safety validation includes github.event.discussion.number

Usage Examples

Discussion Workflow with Manual Dispatch (from dev.md)

on:
  discussion:
    types: [created]
  discussion_comment:
    types: [created]
  workflow_dispatch:
    inputs:
      discussion_number:
        description: "Discussion number to add comment to"
        required: true
        type: string
permissions:
  discussions: write
safe-outputs:
  add-comment:
    target: "*"

Multi-Target Support
Agent can specify:

• issue_number: 42 for issue comments
• discussion_number: 42 for discussion comments
• Use workflow_dispatch input to target specific discussion

Backward Compatibility

✅ 100% backward compatible

• All existing issue/PR workflows work unchanged
• No breaking changes to API or configuration
• Discussion support is purely additive
• Variadic buildOr handles legacy 2-argument calls
• DisjunctionNode provides cleaner output without changing semantics
• workflow_dispatch input is optional and doesn't affect automatic triggers

Original prompt

Add support for discussions in the "add-comment" safe output.

• update schema
• update generation of "on" condition involving discussions
• use graphql to generate a new discussion comment

---

💡 You can make Copilot smarter by setting up custom instructions, customizing its development environment and configuring Model Context Protocol (MCP) servers. Learn more Copilot coding agent tips in the docs.

[pelikhan]

@copilot update dev.md to use add-comment and trigger on a discussion comment. Write a poem to the comment.

[Copilot]

@copilot update dev.md to use add-comment and trigger on a discussion comment. Write a poem to the comment.

Updated dev.md to:

• Use add-comment safe output instead of create-issue
• Added target: "*" to allow commenting on any discussion
• Changed the instruction to write a delightful poem about the last 3 PRs and add it as a comment to discussion rejig docs #1
• Added discussions: write permission

The workflow now demonstrates the new discussion comment support!

Commit: 6e447b5

[pelikhan]

@copilot add discussion created and discussion comment created events.

[Copilot]

Done! Added discussion and discussion_comment events to the schema with their respective event types:

discussion: created, edited, deleted, transferred, pinned, unpinned, labeled, unlabeled, locked, unlocked, category_changed, answered, unanswered

discussion_comment: created, edited, deleted

Updated dev.md to trigger on both discussion and discussion_comment created events. The workflow now demonstrates commenting on discussions when they are created or when comments are added.

Commit: a0e2d76

[pelikhan]

@copilot update dev.md to support workflow dispatch with a discussion number id.

The input is used in the prompt to tell the agent where to add the comment

[Copilot]

@copilot update dev.md to support workflow dispatch with a discussion number id.

The input is used in the prompt to tell the agent where to add the comment

Done! Updated dev.md to support workflow_dispatch with a discussion_number input:

Changes:

• Added workflow_dispatch trigger with discussion_number input parameter (type: string, required: true)
• Added target: "*" to add-comment configuration to allow specifying discussion number
• Updated prompt to use ${{ github.event.inputs.discussion_number || github.event.discussion.number }}
  • Uses input value when manually dispatched
  • Falls back to event discussion number when triggered by discussion events
• Added github.event.discussion.number to allowed expressions in constants

Usage:
When manually dispatching, users can specify any discussion number. The agent will use that number in the prompt to know where to add the comment.

Commit: 8f2a4b9

[dsyme]

Done