Coverage test: keep stdin open #37
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| subprocess.run(kcov_cmd, shell=True, check=True) | ||
| # Pytest closes stdin by default, but some tests might need itto be open. | ||
| # In the future, should the need arise, we can feed custom data to stdin. | ||
| subprocess.run(kcov_cmd, shell=True, check=True, input=b'') |
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I looked through the documentation, but cannot really understand what is the impact of having input=empty byte. It seems like this means that stdin will be a PIPE? Really not sure what is going on there. Could you expand on what happens (not in the code, but just in a comment here :)))
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stdin won't be a PIPE, it will be a stream composed of the bytes passed here through input=. Without specifying stdin=<something> in the subprocess.run call, stdin gets closed by default. Some tests (looking at you, vmm-reference with stdin serial) expect stdin to be open, even if there's nothing coming through. Since the behavior before was to close it, passing an empty byte stream doesn't break existing behavior while circumventing the problem.
Pytest closes stdin by default, so any processes spawned from it won't have it. As some tests in various rust-vmm crates might need stdin to be open, we mock it with a (currently empty) byte stream, which we can extend in the future. Signed-off-by: Alexandra Iordache <aghecen@amazon.com>
Pytest closes stdin by default, so any processes spawned from it won't have it. As some tests in various rust-vmm crates might need stdin to be open, we mock it with a (currently empty) byte stream, which we can extend in the future.