Module Tezt_core.RegressionSource

Run Tezt regression tests and capture their output.

NOTE: consider using dune cram when it becomes available: https://dune.readthedocs.io/en/stable/tests.html#cram-tests

Sourceval register : __FILE__:string -> title:string -> tags:string list -> ?file:string -> (unit -> unit Lwt.t) -> unit

Register a regression test.

This function is a wrapper around Test.register. It adds the "regression" tag to the tags list provided by the argument.

Output which is captured (with capture) is recorded in a file named <ROOT>/<DIR>/expected/<BASE>/<FILE>.out where:

  • <ROOT> is the root directory of the project, read from environment variable DUNE_SOURCEROOT if available, else PWD if available, else using Sys.getcwd;
  • <DIR> is Filename.dirname __FILE__;
  • <BASE> is Filename.basename __FILE__;
  • <FILE> is ~file, which defaults to a sanitized and possibly truncated version of ~title.
Sourceval capture : ?eol:bool -> string -> unit

Capture some output of a regression test.

Call this to record a string into the expected output file of the current test. A newline character \n will be added after it if eol is true (which is the default).

This function only records its argument when called while a regression test is running, i.e. from the body of Regression.register. If you call it outside of Regression.register, it has no effect. So you can define a function that captures and use it with or without regression testing.

A typical use is to define custom process hooks that substitute non-deterministic parts of the output with deterministic ones. See also hooks.

Hooks that enable regression testing when attached to a process ran from a registered regression test function.

The hooks will capture the spawned command, its arguments and the output of its execution.