The hpc-codecov package contains an executable and library codes for generating Codecov JSON coverage report, LCOV tracefile report, or Cobertura XML report from .tix and .mix files made with hpc. The generated report is ready to be uploaded to Codecov with other tools such as Codecov uploader.

The hpc-codecov executable can search .tix and mix files under the directories made by the cabal-install and stack build tools. The executable also has options to explicitly specify the file paths and directories for .tix and mix files, to support generating reports with test data made by other build tools than cabal-install and stack.

hpc-codecov is available from Hackage and Stackage. To install with cabal-install, run:

$ cabal install hpc-codecov

To install with stack, run:

$ stack install hpc-codecov

For Windows, MacOS, and Linux (with glibc and libgmp), pre-compiled binary executables are available here.

To illustrate an example, initializing a sample project named my-project with cabal-install:

$ cabal --version
cabal-install version 3.4.0.0
compiled using version 3.4.0.0 of the Cabal library
$ cabal init --simple --tests --test-dir=test -p my-project

The directory contents look like below:

.
├── app
│   └── Main.hs
├── CHANGELOG.md
├── my-project.cabal
├── src
│   └── MyLib.hs
└── test
    └── MyLibTest.hs

Run tests with coverage option:

$ cabal test --enable-coverage

Write Codecov coverage report to codecov.json:

$ hpc-codecov cabal:my-project-test -X my-project -o codecov.json

Show coverage report contents:

$ cat codecov.json
{"coverage":{"test/MyLibTest.hs":{"4":1}}}

See hpc-codecov-action to generate Codecov coverage report from GitHub workflow.

Show usage information:

$ hpc-codecov --help

Search under the directory made by cabal-install, generating a report for a test suite named my-project-test. Skip searching under the directories with base name my-project, and exclude modules named Main and Paths_my_project from the report. Note the use of comma to separate multiple values for the -x option:

$ hpc-codecov -X my-project -x Main,Paths_my_project cabal:my-project-test

Search under the directry made by cabal-install, generating a report for a test suite named my-project-test. Ignore the entries in .mix file other than ExpBox (i.e.; ignore TopLevelBox, LocalBox, and BinBox constructors of BoxLabel data in .mix file).

$ hpc-codecov --expr-only cabal:my-project-test

Search under the directory made by cabal-install, generating a report for a test suite named my-projejct-test. Ignore the consecutive .mix entries with identical start and end source code positions, which is a sign of compiler-generated source codes. The --ignore-dittos option may affects codes containing record field declarations, derived instances, and TemplateHaskell.

$ hpc-codecov --ignore-dittos cabal:my-project-test

Search under the directory made by stack for a test suite named my-project-test, show verbose information, and write output to codecov.json:

$ hpc-codecov --verbose -o codecov.json stack:my-project-test

Search under the directory made by stack for a combined report of multiple cabal packages, and write output to codecov.json:

$ hpc-codecov stack:all -o codecov.json

Search under the directory made by stack for a combined report of multiple cabal packages, and write the output report in LCOV tracefile format to lcov.info:

$ hpc-codecov stack:all -f lcov -o lcov.info

Search under the directory made by stack for a combined report of multiple cabal packages, and write output report in Cobertura XML format to coverage.xml:

$ hpc-codecov stack:all -f cobertura -o coverage.xml

Search under the directory made by stack for a combined report of multiple cabal packages, running via Docker:

$ docker run --rm -v $PWD:$PWD ghcr.io/8c6794b6/hpc-codecov hpc-codecov -r $PWD stack:all

The following shows two examples for generating a test coverage report of the hpc-codecov package itself without specifying the build tool. One with using the build artifacts made by cabal-install Nix-style local build commands, and another with stack.

First, run the tests with the coverage option to generate .tix and mix files:

$ cabal --version
cabal-install version 3.4.0.0
compiled using version 3.4.0.0 of the Cabal library
$ cabal v2-configure --enable-test --enable-coverage
$ cabal v2-test

Then generate a Codecov JSON coverage data from the .tix and .mix files:

$ proj=hpc-codecov-0.4.0.0
$ tix=$(find ./dist-newstyle -name $proj.tix)
$ mix=$(find ./dist-newstyle -name vanilla -print -quit)/mix/$proj
$ hpc-codecov --mix=$mix --exclude=Paths_hpc_codecov --out=codecov.json $tix

The --out option specifies the output file to write the JSON report. Observing the contents of codecov.json with jq:

$ jq . codecov.json | head -10
{
  "coverage": {
    "src/Trace/Hpc/Codecov/Options.hs": {
      "48": 1,
      "50": 1,
      "52": 1,
      "54": 1,
      "56": 1,
      "59": 1,
      "63": 1,

Send the resulting JSON report file to Codecov with the Codecov uploader. The file name codecov.json is listed in the uploader script as one of the file name patterns to upload, no need to specify the report filename explicitly:

$ codecov -t ${CODECOV_TOKEN}

According to the Codecov FAQ, the uploader should work from Travis, CircleCI, Azure, and GitHub Actions for public projects without the Codecov token (i.e., without the -t ${CODECOV_TOKEN} option).

Build the package and run the tests with the coverage option:

$ stack --numeric-version
2.5.1
$ stack build --test --coverage

As done in cabal-install example, specify the path of .tix and .mix files. Using the path sub-command to get the local hpc root directory and dist directory:

$ hpcroot=$(stack path --local-hpc-root)
$ tix=$(find $hpcroot -name 'test-main.tix')
$ mix=$(stack path --dist-dir)/hpc
$ hpc-codecov --mix=$mix --exclude=Paths_hpc_codecov -o codecov.json $tix

• HPC publication
• Codecov API reference
• LCOV
• Cobertura