test_coverage

A simple command-line tool to collect test coverage information from Dart VM tests. It is useful if you need to generate coverage reports locally during development.

Usage

Add dev dependency to your pubspec.yaml:

dev_dependencies:
  test_coverage: ^0.4.2

Run pub get to install. Then, in the root of your project run:

pub run test_coverage

Result is saved in coverage/lcov.info. If you have lcov tool installed on your system (for Mac it's brew install lcov) you can generate coverage reports using genhtml command:

genhtml -o coverage coverage/lcov.info
# Open in the default browser (mac):
open coverage/index.html

Integrations

Resulting coverage/lcov.info file is ready to be consumed by Codecov command-line tool, so no extra step is needed.

This library was not tested with coveralls yet.

Generating badge image

Coverage badge SVG image is automatically generated and saved to coverage_badge.svg in your project root directory. You can add it to Git and use in README.md on Github as follows:

![Coverage](https://raw.githubusercontent.com/{you}/{repo}/master/coverage_badge.svg?sanitize=true)

If you don't need it you can pass --no-badge flag when running test coverage.

Known limitations

This library was created to run Dart VM tests. It has not been tested and likely won't work for Dart code targeting web platform (compiled to JavaScript). There is no need to use this tool for Flutter as it allows collecting coverage information with flutter test --coverage.

How it works

The tool performs following steps:

1. Generates `test/.test_coverage.dart` file (a "test all" script).

Scans your test/ directory to find all *_test.dart files and creates test/.test_coverage.dart which imports all found test files and runs corresponding main() of all tests functions within the same file (and process), which simplifies collection of coverage information.

It is recommended to add this file to your .gitignore.

Below is an example of test/.test_coverage.dart:

// Auto-generated by test_coverage. Do not edit by hand.
// Consider adding this file to your .gitignore.

import 'some_test.dart' as some_test;
import 'nested/other_test.dart' as other_test;
import 'some_other_test.dart' as some_other_test;

void main() {
  some_test.main();
  other_test.main();
  some_other_test.main();
}

2. Runs the tests

Following command is used to run the tests:

dart --pause-isolates-on-exit --enable_asserts --enable-vm-service \
  test/.test_coverage.dart

3. Collects and formats coverage information

When test execution is completed the tool uses functionality of the coverage package to collect and format coverage report.

Feel free to file feature requests and bug reports at the issue tracker.

4. Minimal coverage percentage

Set minimal coverage percentage to pass min-coverage percentage value of coverage.

5. See test output

print-test-output to show test output.

Show output of tests