Brent Westbrook 08c56c83cf Factor out the mdtest crate (#24616) ...

Summary
--

This is a first step toward adding mdtests for Ruff. I actually wrote
the code
in the opposite order, first copy-pasting `ty_test` to a `ruff_test`
crate, and then
factoring out the shared code, but I figured it would be easier to
review in
this order. I also opened a stacked PR with the `ruff_test` changes
(#24617)
to show that the API works well for that too.

The main change here is moving several of the modules from `ty_test` to
a new
`mdtest` crate:
- `assertion`
- `diagnostic`
- `matcher`
- `parser`

Beyond moving these files to the new crate, I made `Matcher` functions
take a
`&dyn Db` to support passing a different concrete type from `ruff_test`,
and I
also made the parser generic over an `MdtestConfig` trait to allow Ruff
to use a
separate config struct. I also introduced new `TestConfig` and `TestDb`
types to allow
testing the `matcher` and `parser` within the `mdtest` crate without
depending
on either the real ty `Db` or `ty_test` config type.

The lib.rs file from `ty_test` was essentially split in half, with the
shared
code moved to the `mdtest` crate and the ty-specific parts kept in
`ty_test`.

Test Plan
--

All existing mdtests and the unit tests from `ty_test` should still
pass, and
the stacked branch with the `ruff_test` crate tests the split API

2026-04-16 10:32:24 -04:00

..

src

…

Cargo.toml

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