Thank you for reporting this and for opening a PR. It would be great if we could test this behavior on Windows somehow. Maybe we can find a Windows replacement for cat? Doesn't need to be a cat-equivalent. Just something that we can pass input to. And check if it received the input correctly.

Great idea!
Found that type is the replacement of cat in Windows.
Now the tests work fine 😄

• Stackoverflow - Cat Replacement in Windows
• Microsoft Docs - Type

type cannot handle stdin like cat, just prints the content of the file.

Whoops! I missed that detail 😅
Nice catch!

Although, found 2 alternatives that can handle pipe stdin on Windows,
let me know if you think it looks acceptable or you want me to look into other alternatives 😄

1. findstr x*: StackOverflow

someprog | findstr x* or any other single character followed by
asterisk copies all lines from the pipe stdin to stdout.

~\Desktop\oss\hyperfine\tests> hyperfine --runs=1 --input=example_input_file.txt --show-output "findstr x*"
Benchmark 1: findstr x*
This text is part of a file
  Time (abs ≡):         21.8 ms               [User: 0.0 ms, System: 4.7 ms]

2. more command: Displays one screen of output at a time.
   Microsoft - More and Unixtutorial.org

~\Desktop\oss\hyperfine\tests> hyperfine --runs=1 --input=example_input_file.txt --show-output "more"
Benchmark 1: more
This text is part of a file
  Time (abs ≡):         16.2 ms               [User: 0.0 ms, System: 5.9 ms]

findstr x*: StackOverflow

Thanks for looking into this. I think this is an acceptable hack. We should add a link to that stackoverflow answer to explain what's going on though.

Thank you for reviewing this.
Fixed the issue and added the link as well.

Thank you. I think we can use something like let command = if cfg!(windows) { … } else { … }; to merge the tests for windows and linux again, to remove some duplication.

That makes sense!
How about defining a const for platform-specific standard I/O utility (not sure about naming) with this approach? 🤔

Thank you!