lcov_ex

Test coverage module to generate a lcov.info file for an Elixir project.

Why

Many test coverage tools use lcov files as an input to generate reports.

You can use it as I do to watch inline coverage progress with the following editors:

VSCode, using the Coverage Gutters extension.
Atom, using the lcov-info extension (it requires you to change the output folder to "coverage", see below).

Please let me know if you made it work in your previously unlisted favorite editor. Or, if you're really nice, just add it to this list yourself 🙂

Add to your dependencies:

  def deps do
    [
      {:lcov_ex, "~> 0.2", only: [:dev, :test], runtime: false}
    ]
  end

mix lcov

File should be created at ./cover/lcov.info by default.

To run silently use the --quiet option:

mix lcov --quiet

Alternatively, you can set up LcovEx as your test coverage tool in your project configuration:

  def project do
    [
      ...
      test_coverage: [tool: LcovEx, output: "cover"],
      ...
    ]

And then, run with:

mix test --cover

The output option indicates the output folder for the generated file.

Optionally, the ignore_paths option can be a list of prefixes to ignore when generating the coverage report.

  def project do
    [
      ...
      test_coverage: [tool: LcovEx, output: "cover", ignore_paths: ["test/"]]
      ...
    ]