Tap

Because Erlang's tracing is awesome and doing compile time debugging sucks!

Description

Tap enables tracing of Elixir and Erlang functions in a intuitive and safe way.

iex(1)> require Tap
Tap
iex(2)> Tap.call(String.trim(_, _), limit: 4)
1
iex(3)> String.trim("test", "t")
"es"
14:23:22.863903 #PID<0.208.0> String.trim("test", "t")
14:23:22.889608 #PID<0.208.0> String.trim/2 --> "es"
iex(4)> String.trim("test", ?t)
14:23:25.876960 #PID<0.208.0> String.trim("test", 116)
14:23:25.877830 #PID<0.208.0> String.trim/2 ** (FunctionClauseError) no function clause matches
14:23:25.877912 Trace stopped: limit of 4 events reached
** (FunctionClauseError) no function clause matching in String.trim/2

    The following arguments were given to String.trim/2:

        # 1
        "test"

        # 2
        116

    Attempted function clauses (showing 1 out of 1):

        def trim(string, to_trim) when is_binary(string) and is_binary(to_trim)

    (elixir 1.20.4) lib/string.ex:1431: String.trim/2
    iex:4: (file)
iex(4)>

Each trace runs in its own OTP trace session, so concurrent traces do not affect each other. A trace started at the shell prompt survives errors in the shell and stops at its event limit or when the shell exits.

Releasing

Run mise run release on a clean working copy of origin/main. The task first shows the changelog section of the next release. After confirmation, it sets the version in src/tap.app.src, regenerates CHANGELOG.md, commits the release, and pushes it to main. The version is computed from the commits since the last release. To override it, pass an explicit version (e.g. mise run release 1.0.0). To only show the changelog section, run mise run release:preview.

CI publishes the package to Hex, tags the release, and creates a GitHub release once lint and tests pass. CI publishes only when the release commit is the head of main. If the release fails, push a fix and run the task again.