material-ui/test/moduleAugmentation

Module augmentation tests

Run the suite from the repository root:

pnpm typescript:module-augmentation

You can also use the workspace command:

pnpm -F ./test/moduleAugmentation typescript:module-augmentation

The package script uses pnpm to build the workspace dependencies before it tests the fixtures. pnpm skips packages without a build script, including this test workspace. The dependencies run their usual build scripts, which clear the output folders, copy authored .d.ts files, and emit declarations from TypeScript source. pnpm runs the build scripts directly, without the Nx cache. This adds build time but prevents stale declarations from hiding errors. Shared dependencies are built once.

This workspace has its own dependencies and a standalone TypeScript configuration. It does not inherit the root source aliases. pnpm links the MUI dependencies to build folders, so imports resolve through the built package exports. Keep the fixtures here to avoid package self-references that can resolve to library source.

Fixture workers start the next test as soon as a worker is free. Each fixture runs in a separate compiler process. The worker count defaults to Node's os.availableParallelism(). Set --concurrency to limit memory use:

pnpm typescript:module-augmentation --concurrency 2

Build concurrency is separate and uses pnpm's workspace concurrency setting.

The compiler uses the installed tsc, including the version selected by CI. The runner checks the compiler's file list and rejects library files outside the build folders or files that are not .d.ts, .d.mts, or .d.cts declarations.

Keep implementation checks separate with pnpm typescript. Do not apply consumer augmentations to library source or suppress declaration diagnostics. The breakpoint fixtures check custom keys, removed keys, invalid keys, and isolation from other fixtures.