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

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