Like other language specific modules this module is module for holding
rust specific helpers. This commit adds a test() function, which
simplifies using rust's internal unittest mechanism.
Rust tests are generally placed in the same code files as they are
testing, in contrast to languages like C/C++ and python which generally
place the tests in separate translation units. For meson this is
somewhat problematic from a repetition point of view, as the only
changes are generally adding --test, and possibly some dependencies.
The rustmod.test() method provides a mechanism to remove the repatition:
it takes a rust target, copies it, and then addes the `--test` option,
then creates a Test() target with the `rust` protocol. You can pass
additional dependencies via the `dependencies` keyword. This all makes
for a nice, DRY, test definition.
Rust has it's own built in unit test format, which is invoked by
compiling a rust executable with the `--test` flag to rustc. The tests
are then run by simply invoking that binary. They output a custom test
format, which this patch adds parsing support for. This means that we
can report each subtest in the junit we generate correctly, which should
be helpful for orchestration systems like gitlab and jenkins which can
parse junit XML.
Dylan Baker
Josh Soref