Create a new code-coverage module for scorecard

[christoph-jerolimov]

Scorecard is a backstage plugin and supports multiple metric, grouped as modules in folder workspaces/scorecard/plugins.

There are already modules that support GitHub, OpenSSF, SonarQube. Add a new module for code-coverage.

That is different then the codecov module mentioned in #3473. Because codecov is dedicated for the codecov provider, while this "code-coverage" module is for the Backstage Community Plugin "code-coverage" from https://github.com/backstage/community-plugins/tree/main/workspaces/code-coverage.

With this, this new code-coverage module would support tools like cobertura, jacoco, and lcov.

This module will repopulate this code coverage values from that plugin into the scorecard plugin. For this, this new metrics should load the data from the code-coverage-backend and provide them as MetricProvider(s) in the newly created scorecard-backend-module-code-coverage module.

The https://github.com/backstage/community-plugins/blob/main/workspaces/code-coverage/plugins/code-coverage-backend/README.md explain which data are available throw the history API call:

GET /api/code-coverage/report?entity=component:default/entity-name

{
  "aggregate": {
    "branch": {
      "available": 0,
      "covered": 0,
      "missed": 0,
      "percentage": 0
    },
    "line": {
      "available": 5,
      "covered": 4,
      "missed": 1,
      "percentage": 80
    }
  },
  "entity": {
    "kind": "Component",
    "name": "entity-name",
    "namespace": "default"
  },
  "files": [
    {
      "branchHits": {},
      "filename": "main.go",
      "lineHits": {
        "117": 12,
        "142": 8,
        "34": 8,
        "42": 0,
        "58": 6
      }
    }
  ]
}

Based on that data the following metrics should be possible:

1. Code coverage (Lines) (Percentage value based on aggregate.line.percentage)
2. Code coverage - Tracked lines of code (based on aggregate.line.available)
3. Code coverage - Covered lines of code (based on aggregate.line.covered)
4. Code coverage - Missed lines of code (based on aggregate.line.missed)
5. Code coverage (Files) (Percentage value based on aggregate.branch.percentage)
6. Code coverage - Tracked lines of code (based on aggregate.branch.available)
7. Code coverage - Covered lines of code (based on aggregate.branch.covered)
8. Code coverage - Missed lines of code (based on aggregate.branch.missed)

All metrics providers should filter for entities with annotation backstage.io/code-coverage.

Add a type definition for the code-coverage Backend response

Add tests and integrate the new code-coverage module as well as the Code Coverage frontend and backend from the Backstage Community plugin into the existing Backstage app.

Add an example entity for code-coverage with the right annotation for it.

[fullsend-ai-triage]

🤖 Finished Triage · ✅ Success · Started 12:13 PM UTC · Completed 12:16 PM UTC
Commit: 7ccaff1 · View workflow run →

[fullsend-ai-triage]

Triage Summary

This is a well-specified feature request to create a new scorecard-backend-module-code-coverage module that integrates with the Backstage Community code-coverage plugin.

What needs to be built:

• A new module at workspaces/scorecard/plugins/scorecard-backend-module-code-coverage
• 8 MetricProviders covering line and branch coverage (percentage, available, covered, missed)
• Entity filtering based on the backstage.io/code-coverage annotation
• Type definitions for the code-coverage-backend API response
• Tests and app integration with an example entity

Implementation guidance:

• Use existing modules (e.g., scorecard-backend-module-sonarqube) as templates
• Fetch data from GET /api/code-coverage/report?entity=component:default/<name>
• Map aggregate.line.* and aggregate.branch.* fields to the 8 metrics specified in the issue
• This is distinct from Create a new codecov module for scorecard #3473 (codecov) — that targets the Codecov provider, this targets the community code-coverage plugin supporting cobertura/jacoco/lcov

Proposed test approach:

- Mock the code-coverage-backend API with known response payloads
- Verify each MetricProvider extracts the correct value from the aggregate
  (e.g., line percentage = 80 from example payload)
- Test entity annotation filtering (only backstage.io/code-coverage entities)
- Test error handling for unreachable API or unexpected response shapes

---

Labels: This feature request targets the scorecard workspace with a new code-coverage module.

[christoph-jerolimov]

/fs-code

[fullsend-ai-coder]

🤖 Finished Code · ✅ Success · Started 12:48 PM UTC · Completed 1:27 PM UTC
Commit: 7ccaff1 · View workflow run →