View Source lcov_ex

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

The docs can be found at https://hexdocs.pm/lcov_ex.

why

Why

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

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

  • VSCode:
    • Using the Coverage Gutters extension.
    • Using the Koverage extension (add "cover" in settings as coverage folder, or output the report to the "coverage" folder, see below).
  • 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 :slightly_smiling_face:

installation

Installation

Add to your dependencies:

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

usage

Usage

mix lcov

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

To run silently use the --quiet option:

mix lcov --quiet

To output the file to a differnt folder, use the --output option:

mix lcov --output coverage
...
Coverage file successfully created at coverage/lcov.info

umbrella-projects

Umbrella projects

For umbrella projects you can choose to keep the individual apps lcov files with the --keep option:

mix lcov --keep
...
Coverage file for my_app created at apps/my_app/cover/lcov.info
Coverage file for my_other_app created at apps/my_other_app/cover/lcov.info

Coverage file for umbrella created at cover/lcov.info

as-test-coverage-tool

As test coverage tool

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/"]]
      ...
    ]

todos

TODOs

  • Add missing FN lines, for the sake of completion.