By default, the compiler-cli uses the relative import strategy when
there is no `rootDir` or `rootDirs`. This is expected as everything is
assumed to be somehow reachable through relative imports.
With `rootDirs` that allow for a "virtual file system"-like environment,
the compiler is not necessarily able to always construct proper relative
imports. The compiler includes the `LogicalProjectStrategy` for this
reason. This strategy is able to respect `rootDirs` to construct
relative paths when possible.
This logic currently accidentally triggers when there is a `rootDir`
set. This option is not to be confused with the virtual directory
option called `rootDirs`. The compiler currently confuses this and
accidentally enters this mode when there is just a `rootDir`— breaking
in monorepos that imports can point outside the `rootDir` to e.g. other
compilation unit's `.d.ts` (which is valid; just not `.ts` sources can
live outside the root dir).
This is necessary for our Bazel toolchain migration.
PR Close#60555
22a0e54ac4