detect-netsdk-diagnostics.yml

# Workflow to detect new NETSDK diagnostic codes in pull requests
#
# This workflow automatically:
# 1. Uses git diff to get changes from .xlf files only
# 2. Scans for newly added NETSDK diagnostic codes (e.g., NETSDK1234:)
# 3. Applies the 'sdk-diagnostic-docs-needed' label when new diagnostics are found
# 4. Posts/updates a comment reminding contributors to update SDK diagnostic documentation
#    in the dotnet/docs repository at docs/core/tools/sdk-errors/
#
# Prerequisites: The 'sdk-diagnostic-docs-needed' label must exist in the repository
#
# Security: Uses pull_request_target to run in the base branch context (safe for forks)
# The workflow checks out the base branch and fetches the PR head, but does not execute any code from the PR.
#
name: Detect New NETSDK Diagnostics

on:
  # Use pull_request_target for safe execution from forks
  # This runs in the context of the base branch, not the PR head
  pull_request_target:
    types: [opened, synchronize]
    branches:
      - main
      - release/*

permissions: read-all

jobs:
  detect-diagnostics:
    name: Detect New NETSDK Diagnostic Codes
    runs-on: ubuntu-latest
    permissions:
      contents: read
    env:
      MAX_DIFF_SIZE_BYTES: 10485760  # 10MB
    outputs:
      found_diagnostics: ${{ steps.detect.outputs.found_diagnostics }}
      has_diagnostics: ${{ steps.detect.outputs.has_diagnostics }}
    
    steps:
      - name: Checkout base branch
        uses: actions/checkout@8e8c483db84b4bee98b60c0593521ed34d9990e8 # v6
        with:
          ref: ${{ github.event.pull_request.base.ref }}
          fetch-depth: 0
          persist-credentials: false

      - name: Fetch PR head
        env:
          GITHUB_TOKEN: ""
          GH_TOKEN: ""
        run: |
          git fetch origin pull/${{ github.event.pull_request.number }}/head:pr-${{ github.event.pull_request.number }}

      - name: Get diff from .xlf files only
        id: get-diff
        env:
          GITHUB_TOKEN: ""
          GH_TOKEN: ""
        run: |
          # Get diff of .xlf files changed by this PR.
          # Use three-dot diff (merge-base) so that only the PR's changes are included,
          # not unrelated changes on the target branch that the PR hasn't been rebased onto.
          # Write to a file to avoid GitHub Actions step output size limits.
          git diff ${{ github.event.pull_request.base.sha }}...${{ github.event.pull_request.head.sha }} -- '*.xlf' > "$RUNNER_TEMP/xlf_diff.txt"

          # Guard against extremely large diffs that could stall the pipeline
          DIFF_SIZE=$(wc -c < "$RUNNER_TEMP/xlf_diff.txt")
          if [ "$DIFF_SIZE" -gt "$MAX_DIFF_SIZE_BYTES" ]; then
            echo "::error::The .xlf diff is $(( DIFF_SIZE / 1048576 ))MB which exceeds the $(( MAX_DIFF_SIZE_BYTES / 1048576 ))MB limit. This likely means the PR contains an unusually large number of translation file changes. Try splitting the .xlf changes into smaller PRs."
            exit 1
          fi

      - name: Detect new NETSDK diagnostics
        id: detect
        uses: actions/github-script@f28e40c7f34bde8b3046d885e986cb6290c5673b # v7
        env:
          XLF_DIFF_PATH: ${{ runner.temp }}/xlf_diff.txt
        with:
          script: |
            const fs = require('fs');
            const diff = fs.readFileSync(process.env.XLF_DIFF_PATH, 'utf8');
            
            // Pattern to match NETSDK diagnostic codes
            const diagnosticPattern = /NETSDK(\d{4}):/g;
            
            // Extract only added lines from the diff (lines starting with +)
            const addedLines = diff.split('\n').filter(line => line.startsWith('+') && !line.startsWith('+++'));
            
            // Find all NETSDK codes in added lines
            const diagnosticCodes = new Set();
            for (const line of addedLines) {
              // Reset regex state for each line to avoid issues with global flag
              diagnosticPattern.lastIndex = 0;
              let match;
              while ((match = diagnosticPattern.exec(line)) !== null) {
                diagnosticCodes.add(`NETSDK${match[1]}`);
              }
            }
            
            const foundDiagnostics = Array.from(diagnosticCodes).sort();
            
            core.setOutput('found_diagnostics', foundDiagnostics.join(','));
            core.setOutput('has_diagnostics', foundDiagnostics.length > 0 ? 'true' : 'false');
            
            if (foundDiagnostics.length > 0) {
              core.info(`Found ${foundDiagnostics.length} new NETSDK diagnostic(s) in .xlf files: ${foundDiagnostics.join(', ')}`);
            } else {
              core.info('No new NETSDK diagnostics found in .xlf files in this PR.');
            }
            
            return foundDiagnostics;

  apply-label-and-comment:
    name: Apply Label and Comment
    runs-on: ubuntu-latest
    needs: detect-diagnostics
    if: needs.detect-diagnostics.outputs.has_diagnostics == 'true'
    permissions:
      pull-requests: write
      issues: write
    
    steps:
      - name: Add label to PR
        uses: actions/github-script@f28e40c7f34bde8b3046d885e986cb6290c5673b # v7
        with:
          script: |
            const { owner, repo } = context.repo;
            const issue_number = context.payload.pull_request.number;
            const labelName = 'sdk-diagnostic-docs-needed';
            
            await github.rest.issues.addLabels({
              owner,
              repo,
              issue_number,
              labels: [labelName]
            });
            
            core.info(`Label '${labelName}' added to PR #${issue_number}`);

      - name: Post or update comment
        uses: actions/github-script@f28e40c7f34bde8b3046d885e986cb6290c5673b # v7
        env:
          DIAGNOSTICS: ${{ needs.detect-diagnostics.outputs.found_diagnostics }}
        with:
          script: |
            const { owner, repo } = context.repo;
            const issue_number = context.payload.pull_request.number;
            const diagnostics = process.env.DIAGNOSTICS.split(',');
            
            // Create the comment body
            const commentIdentifier = '<!-- netsdk-diagnostics-reminder -->';
            const commentBody = `${commentIdentifier}
            ## 📋 SDK Diagnostic Documentation Reminder
            
            This PR introduces **${diagnostics.length}** new SDK diagnostic code${diagnostics.length > 1 ? 's' : ''}:
            ${diagnostics.map(code => `- \`${code}\``).join('\n')}
            
            ### Action Required
            Please ensure that documentation for ${diagnostics.length > 1 ? 'these diagnostics' : 'this diagnostic'} is added or updated in the [dotnet/docs](https://github.com/dotnet/docs) repository at:
            - Path: \`docs/core/tools/sdk-errors/\`
            - Documentation: https://learn.microsoft.com/dotnet/core/tools/sdk-errors/
            
            Each diagnostic should have:
            - A clear description of the error/warning
            - Possible causes
            - Recommended solutions
            - Code examples where applicable
            
            Thank you for helping keep our documentation up to date! 🙏`;
            
            // Check if we already have a comment from this workflow
            const { data: comments } = await github.rest.issues.listComments({
              owner,
              repo,
              issue_number
            });
            
            const existingComment = comments.find(comment => 
              comment.user.type === 'Bot' && 
              comment.body.includes(commentIdentifier)
            );
            
            if (existingComment) {
              // Update existing comment
              await github.rest.issues.updateComment({
                owner,
                repo,
                comment_id: existingComment.id,
                body: commentBody
              });
              core.info(`Updated existing comment #${existingComment.id}`);
            } else {
              // Create new comment
              await github.rest.issues.createComment({
                owner,
                repo,
                issue_number,
                body: commentBody
              });
              core.info('Created new comment');
            }