The core idea of this change is to make `collect_coverage` an `sh_binary` instead of a single `.sh` file as the former can be executed on Windows via the native launcher it creates. However, this requires a bunch of work in the test framework:
* Ensure that the `collect_coverage` script has its runfiles included in `TestActionBuilder`. Along the way and to ensure consistency, clean up unnecessary cases for the runfiles of the LCOV merger tool.
* Add support for launching the coverage wrapper to `tw`, which didn't have any logic for this case.
* Hide the runfiles env variables meant for the test from the coverage wrapper. The wrapper has its own runfiles tree and would otherwise be mislead to reuse the test's runfiles tree, which doesn't work. Instead, wrap the environment before invoking the wrapper and then unwrap them in the wrapper.
* Modify the coverage output generator to emit `\n` line endings on all platforms for consistency (and to get existing tests to pass).

With these changes, `bazel_coverage_starlark_test` now passes on Windows after adding batch test variants of shell tests. Support for Java and C++ will be added in future PRs.

Work towards bazelbuild#6374
Work towards bazelbuild#18839

Closes bazelbuild#26603.

PiperOrigin-RevId: 799018475
Change-Id: Icdb1e6e4698b2a749fbb17f7e1a9aaa34e895d70

The core idea of this change is to make `collect_coverage` an `sh_binary` instead of a single `.sh` file as the former can be executed on Windows via the native launcher it creates. However, this requires a bunch of work in the test framework:
* Ensure that the `collect_coverage` script has its runfiles included in `TestActionBuilder`. Along the way and to ensure consistency, clean up unnecessary cases for the runfiles of the LCOV merger tool.
* Add support for launching the coverage wrapper to `tw`, which didn't have any logic for this case.
* Hide the runfiles env variables meant for the test from the coverage wrapper. The wrapper has its own runfiles tree and would otherwise be mislead to reuse the test's runfiles tree, which doesn't work. Instead, wrap the environment before invoking the wrapper and then unwrap them in the wrapper.
* Modify the coverage output generator to emit `\n` line endings on all platforms for consistency (and to get existing tests to pass).

With these changes, `bazel_coverage_starlark_test` now passes on Windows after adding batch test variants of shell tests. Support for Java and C++ will be added in future PRs.

Work towards bazelbuild#6374
Work towards bazelbuild#18839

Closes bazelbuild#26603.

PiperOrigin-RevId: 799018475
Change-Id: Icdb1e6e4698b2a749fbb17f7e1a9aaa34e895d70

The core idea of this change is to make `collect_coverage` an
`sh_binary` instead of a single `.sh` file as the former can be executed
on Windows via the native launcher it creates. However, this requires a
bunch of work in the test framework:
* Ensure that the `collect_coverage` script has its runfiles included in
`TestActionBuilder`. Along the way and to ensure consistency, clean up
unnecessary cases for the runfiles of the LCOV merger tool.
* Add support for launching the coverage wrapper to `tw`, which didn't
have any logic for this case.
* Hide the runfiles env variables meant for the test from the coverage
wrapper. The wrapper has its own runfiles tree and would otherwise be
mislead to reuse the test's runfiles tree, which doesn't work. Instead,
wrap the environment before invoking the wrapper and then unwrap them in
the wrapper.
* Modify the coverage output generator to emit `\n` line endings on all
platforms for consistency (and to get existing tests to pass).

With these changes, `bazel_coverage_starlark_test` now passes on Windows
after adding batch test variants of shell tests. Support for Java and
C++ will be added in future PRs.

Work towards #6374 Work
towards #18839

Closes #26603.

PiperOrigin-RevId: 799018475
Change-Id: Icdb1e6e4698b2a749fbb17f7e1a9aaa34e895d70

Commit: 74285e2

Co-authored-by: Fabian Meumertzheim <fabian@meumertzhe.im>