Developer workflows

Get developer tools

Ensure stack is installed (or if you’re a cabal expert, feel free to use that.)

Ensure git is installed. On Windows, it comes with stack.

Here are some useful optional tools:

  • just for automating project tasks
  • GNU Make for automating tasks in a few subdirectories
  • watchexec for re-running commands when files change
  • ghcid gives real-time GHC feedback as you make code changes.
  • shelltestrunner runs hledger's functional tests.
  • quickbench measures and reports time taken by commands.
  • hasktags generates tag files for quick code navigation in editors like Emacs and vim.
  • For browsing and editing Haskell code, popular tools include: Emacs, Vim, IDEA, VS Code, Atom..


stack install ghcid shelltestrunner hasktags
git clone; cd quickbench; stack install  # must run in source dir

Get the code

git clone
cd hledger

Review code

Build in place

See also .

stack build    # hledger hledger-ui ...

This fetches the required GHC version and haskell dependencies from the default stackage snapshot (configured in stack.yaml), then builds all hledger packages. This can take a while! To save time, you can build individual packages, eg just the CLI and TUI.

Note stack does not fetch C libraries such as curses or terminfo, which you might need to install yourself, using your system's package manager. In case of trouble, see download.

If you want to use an older snapshot/GHC for some reason, specify one of the older stack-*.yaml files:

stack --stack-yaml stack8.2.yaml build

Run in place

stack exec -- hledger     # ARGS...
stack exec -- hledger-ui  # ARGS...
stack exec -- which hledger

Build and install

This builds and also copies the hledger executables to ~/.local/bin or the Windows equivalent (which you should add to your $PATH).

stack install    # hledger hledger-ui ...

Run package tests

Runs any HUnit/doctest/easytest tests defined by each hledger package.

stack test    # hledger ...

Run package benchmarks

Runs any performance reports defined by each hledger package.

stack bench    # hledger ...

Run quickbench benchmarks

Times the end-user commands in using quickbench.

just bench

Run functional tests

Runs the shelltestrunner tests defined in hledger/test/, which test the hledger CLI.

just functest

Run haddock tests

Checks for anything that would break haddock doc generation.

just haddocktest

Checks for the unit-tests embedded in documentation.

just doctest

Simulate Travis tests

Locally runs tests similar to what we run on Travis CI.

just travistest

Test with all supported GHC versions/stackage snapshots

just allsnapshotstest


GHCI is GHC's REPL, useful for exploring and calling code interactively.

If you try to run GHCI (or things based on it, like ghcid) right after cloning the hledger repo, you might see an error about CPP macros, eg like on #961. To fix this, build the hledger packages once, eg stack build. (Or stack build hledger might be enough, depending what you are doing.)

Get a GHCI prompt for hledger-lib:

cd hledger-lib; stack ghci hledger-lib

Changing into the package directory isn't actually needed, but it enables a custom .ghci script which sets a more useful short prompt.

Get a GHCI prompt for hledger:

cd hledger; stack ghci hledger

Get a GHCI prompt for hledger-ui:

cd hledger-ui; stack ghci hledger-ui

Get a GHCI prompt for hledger-web:

cd hledger-web; stack ghci hledger-web

hledger-web also needs to find some things in its current directory (like the static/ directory). This normally just works, if not please send details.

Add a test

  • identify what to test
  • choose the test type: unit ? functional ? benchmark ?
  • currently expected to pass or fail ?
  • figure out where it goes
  • write test, verify expected result
  • get it committed

Fix a bug or add a feature

  • research, discuss, validate the issue/feature on irc/list/bug tracker
  • look for related tests, run the tests and check they are passing
  • add a test ?
  • develop a patch
  • include any related issue numbers in the patch name, eg: "fix for blah blah (#NNN)"
  • get it committed

Get your changes accepted

Follow the usual github workflow:

  • fork the main hledger repo on github,
  • git clone it to your local machine,
  • git commit, after (?) pulling and merging the latest upstream changes
  • git push back to github,
  • open a pull request on github,
  • follow up on any discussion there.

If you're new to this process, may be useful.

Add yourself to the contributor list

Work on docs

Most docs tasks are handled by Shake.

List Shake rules:


Generate man/info/txt manuals (in hledger*/) and embed in hledger executables:

./Shake manuals
stack build

Generate html manuals and the hledger website (in site/_site/):

./Shake website

To remove all files generated by Shake:

./Shake Clean

Use ghcid for watching GHC/GHCI

ghcid is the most reliable and fastest way to see GHC's feedback, and optionally run tests or a GHCI command, as you edit. We run it via just, for convenience and to watch multiple packages rather than just one. Run just h ghcid to list related rules.

Watch for compile errors in hledger-lib and hledger:

just ghcid

Watch compile errors and the output of some hledger command:

ghcid -c 'just ghci' -T ':main -f a.j bal --budget -N'

Use --file-watch for watching stack

stack's --file-watch flag will re-run build/test/bench when source files or package.yaml/cabal files change. Eg:

stack test hledger --file-watch

If you find that adding --fast makes this any faster, please update this.

Use entr for watching arbitrary commands

entr is the most robust cross-platform tool for watching files and running a command when they change. Note its first argument must be an executable program, to run a shell command or multiple commands use bash -c "...".

Rerun a single functional test as you change it:

ls hledger/test/budget/budget.test | entr bash -c 'clear; COLUMNS=80 stack exec -- shelltest --execdir hledger/test/budget/budget.test -i12'