Rust Integration with CI Insights

This guide shows how to generate JUnit reports from your Rust tests and upload them to CI Insights using a GitHub Actions workflow.

Rust’s built-in test framework doesn’t natively output JUnit XML reports, but you can use third-party tools to convert the test output to JUnit format.

Install cargo2junit which converts Rust test output to JUnit XML:

cargo install cargo2junit

Then run your tests and pipe the output:

cargo test -- --nocapture 2>&1 | cargo2junit > junit.xml

cargo-nextest is a modern test runner that supports JUnit output natively:

cargo install cargo-nextest

Run tests with JUnit output:

cargo nextest run --message-format junit > junit.xml

You can also create a simple script that runs tests and converts output:

#!/bin/bash
cargo test --message-format json 2>&1 | tee test-results.json
# Convert JSON to JUnit XML using a tool like jq or custom script
# This approach requires additional tooling

For the most reliable results, we recommend using cargo-nextest:

cargo install cargo-nextest
cargo nextest run --message-format junit --output-file junit.xml

After generating the JUnit report, add a step to upload the results to CI Insights using the mergifyio/gha-mergify-ci action.

For example, in your workflow file:

- name: Install cargo-nextest
  uses: taiki-e/install-action@nextest

- name: Run Rust Tests and Generate JUnit Report
  continue-on-error: true
  run: cargo nextest run --message-format junit --output-file junit.xml

- name: Mergify CI Upload
  if: success() || failure()
  uses: mergifyio/gha-mergify-ci@v8
  with:
    token: ${{ secrets.MERGIFY_TOKEN }}
    report_path: junit.xml

Key Points:

• if: success() || failure(): Runs the upload step even if tests fail, ensuring CI Insights has the full report.
• report_path: junit.xml: Points to where your JUnit file is located. Make sure it matches the path you set in your CI job.

Alternative approach using cargo2junit:

- name: Install cargo2junit
  uses: taiki-e/install-action@cargo2junit

- name: Run Rust Tests and Generate JUnit Report
  continue-on-error: true
  run: cargo test -- --nocapture 2>&1 | cargo2junit > junit.xml

- name: Mergify CI Upload
  if: success() || failure()
  uses: mergifyio/gha-mergify-ci@v8
  with:
    token: ${{ secrets.MERGIFY_TOKEN }}
    report_path: junit.xml

Key Points:

• if: success() || failure(): Runs the upload step even if tests fail, ensuring CI Insights has the full report.
• report_path: junit.xml: Points to where your JUnit file is located. Make sure it matches the path you set in your CI job.

If you use a job matrix in your workflow (e.g., to test across multiple versions), ensure you set the job_name input (or MERGIFY_JOB_NAME environment variable) so CI Insights can properly distinguish reports for each matrix job.

For example, with:

jobs:
  example_matrix:
    strategy:
      matrix:
        version: [10, 12, 14]

Your upload step should look like:

- name: Mergify CI Upload
  if: success() || failure()
  uses: mergifyio/gha-mergify-ci@v8
  with:
    job_name: example_matrix (${{ matrix.version }})
    token: ${{ secrets.MERGIFY_TOKEN }}
    report_path: junit.xml

In order to benefit from CI Insights Quarantine, you need to add continue-on-error: true in your GitHb Actions step that execute your tests and generates the JUnit file. The step running the gha-mergify-ci action will determine the success or failure conclusion, considering quarantined tests.

After pushing these changes:

1. Your GitHub Actions workflow will execute your Rust tests.
2. A JUnit report (junit.xml) is generated.
3. The Mergify CI action uploads the report to CI Insights.

You can then review your test results, including any failures or flaky tests, directly in the CI Insights dashboard.

• Tool Installation: Ensure cargo-nextest or cargo2junit is properly installed before running tests.
• Output Format: Verify that the chosen tool generates valid JUnit XML format.
• The CLI provides information about the upload. Check the logs in GitHub Actions.
• File Paths: Double-check that the output file matches the path used in report_path.
• Permissions: Make sure the MERGIFY_TOKEN is valid and setup in your GitHub Actions secrets as explained in the docs.
• Workflow Conditions: If your step is not running, confirm the if condition is actually triggered in your job.