Fix: Include custom type summaries in parent summary

Context

The type: custom feature (added in !364 (merged)) allows summaries to include external data without fetching GitLab resources. However, custom type summaries were not appearing in parent summary outputs due to incorrect filtering logic.

What's in this MR?

Bug Fix:

• Changed filtering logic in summary_policy.rb to use content_available? method
• Custom type summaries now properly included in parent summary output

Code Quality Improvements:

• Added content_available? method to determine if summary should be included in parent
• Added title_present? helper that returns explicit boolean (avoids !! pattern)
• Kept valid? method name (Ruby idiom - describes object state, not action)
• Inlined any_resources? method (only used once)
• Renamed issues to child_summaries for clarity

Testing:

• Added comprehensive integration tests in spec/integration/custom_type_in_parent_summary_spec.rb
• Tests verify custom summaries are included (even with 0 resources)
• Tests verify regular summaries without resources are excluded
• Updated existing unit tests

CI Improvement:

• Updated lefthook to run full test suite on pre-push to catch integration issues

Proof of Work

Create test policy file:

cat > test-custom-type-fix.yml <<'EOF'
resource_rules:
  issues:
    summaries:
      - name: Test Parent Summary
        actions:
          summarize:
            title: "Test: Custom Type in Parent Summary"
            summary: |
              # Test Results
              
              {{items}}

        rules:
          - name: Custom Type Summary
            type: custom
            actions:
              summarize:
                title: "External Data"
                summary: |
                  ## External Data Source
                  
                  This content comes from a custom type summary (no GitLab resources fetched).
                  
                  - Item 1: Test data
                  - Item 2: More test data
                  - Status: Working ✓

          - name: Regular Summary with Resources
            conditions:
              state: opened
              labels:
                - bug
            limits:
              most_recent: 2
            actions:
              summarize:
                item: "- {{title}} ({{web_url}})"
                summary: |
                  ## Recent Bug Issues
                  
                  {{items}}
EOF

Update Gemfile to use local gitlab-triage with this fix:

# In your triage project (e.g., triage-ops)
sed -i.bak 's|gem "gitlab-triage".*|gem "gitlab-triage", path: "../gitlab-triage"|' Gemfile
bundle install

Run the test:

bundle exec gitlab-triage --dry-run \
  --token $GITLAB_API_PRIVATE_TOKEN \
  --source-id gitlab-org/gitlab \
  --policies-file test-custom-type-fix.yml

Expected output (showing both summaries included):

Processing summary: **Test Parent Summary**

Gathering resources for rule: **Custom Type Summary**
* Skipping resource fetch for custom type rule

Gathering resources for rule: **Regular Summary with Resources**
* Found 33 resources...
* Filtering resources...
* Total after filtering: 33 resources
* Limiting resources...
* Total after limiting: 2 resources

The following issue would be created in project `gitlab-org/gitlab`:

>>>
* Title: Test: Custom Type in Parent Summary
* Description: # Test Results

## External Data Source

This content comes from a custom type summary (no GitLab resources fetched).

- Item 1: Test data
- Item 2: More test data
- Status: Working ✓

## Recent Bug Issues

- Duo Agent Platform accessible without Duo Core prerequisite (https://gitlab.com/...)
- Fix type inconsistency between agent_platform_sessions table (https://gitlab.com/...)
>>>

Result: Parent summary correctly includes both the custom type summary (External Data Source) and the regular summary (Recent Bug Issues).

Cleanup:

rm test-custom-type-fix.yml
git checkout Gemfile Gemfile.lock

Related

• Original MR adding type: custom support: !364 (merged)
• Proof of work tests: triage-ops!3812
• Real-world usage: triage-ops!3804