Get Artifacts as Job Outputs

A GitHub Action that retrieves artifacts from previous jobs in a workflow and makes them available as job outputs. This is particularly useful when you need to consolidate outputs from multiple matrix jobs or access data from previous workflow steps.

Overview

This action helps you consolidate outputs from multiple jobs in a GitHub Actions workflow. It downloads artifacts from previous jobs, extracts their contents, and makes them available as outputs that can be referenced in subsequent steps.

Features

• Automatically detects and downloads artifacts from dependent jobs

• Handles matrix jobs

• Supports custom output file names

• Works with both successful and failed job runs

• Handles job reruns and multiple attempts

Use Cases

• Consolidating test results from matrix jobs
• Gathering build artifacts for deployment
• Combining reports or metrics from parallel jobs
• Processing outputs from multiple workflow steps

Usage

Basic Example

jobs:
  generate_results:
    runs-on: ubuntu-latest
    strategy:
      fail-fast: false
      matrix: 
        name: ["first", "second", "third"]
    steps:
      - uses: actions/checkout@v4
      - run: echo '{"result": "${{ matrix.name }} was successful"}' > outputs.json
      - name: Gather Results
        uses: actions/upload-artifact@v4
        with:
          name: ${{ matrix.name }}
          path: outputs.json

  gather_output:
    needs: [generate_results]
    runs-on: ubuntu-latest
    env:
      GITHUB_TOKEN: ${{ secrets.GITHUB_TOKEN }}
    steps:
      - id: previous_jobs
        uses: snapsheet/get-artifacts-as-outputs@0.1.1
        with:
          output_filename: outputs.json
        # ...when this job's outputs are accessed, it will have the following format:
        # {
        #   "first": { "summary": "first was successful" },
        #   "second": { "summary": "second was successful" },
        #   "third": { "summary": "third was successful" }
        # }

      - name: Generate Outputs
        id: markdown
        run: |
          echo '${{ steps.previous_jobs.outputs.generate_results }}' | jq -r 'keys[] as $k | "\($k) results: \(.[$k] | .summary)"'
        # (will print out the following)
        # first results: first was successful
        # second results: second was successful
        # third results: third was successful

Dependencies

This project relies on having a GITHUB_TOKEN defined in the environment variables, with permission to read artifacts for this repository.

Inputs

Input	Description	Required
output_filename	Name of the file that contains the job outputs	Yes

Outputs

A JSON object, where each key-value pair has a key corresponding to the job name, and value representing the content of the file found in the artifact(s), read as strings.

Example

{
  "Some Job (1)": "{\"summary\": \"it was a success\" }",
  "Some Job (2)": "{\"summary\": \"somewhat of a success\" }",
  "Some Job (3)": "{\"summary\": \"total failure\" }"
}

How It Works

1. The action identifies all jobs that the current job depends on (specified in needs)
2. For each dependent job:
   • Retrieves artifacts generated by that job
   • Downloads and extracts the artifact contents
   • Reads the specified output file
   • Makes the contents available as a job output with the same name as the dependent job

Development

# Install dependencies
npm install

# Build the project
npm run build

# The project uses Jest for testing and maintains 100% line coverage (except for index.ts). Run tests with:
npm test

# To create a distribution branch for testing: 
# This creates a new branch named `dist/<current-branch-name>` with the compiled code that can be tagged for releases.
npm run dist-branch

Project Structure

• src/ - Source code
• __tests__/ - Test files and fixtures
• dist/ - Compiled output (generated)

License

MIT License - see LICENSE file for details.

Contributing

1. Fork the repository
2. Create a feature branch
3. Commit your changes
4. Push to the branch
5. Create a Pull Request
6. @snapsheet will review and merge your changes

References

For more examples, see the test workflow in __tests__/fixtures/workflow.yml.