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.

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.

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.