Fix broken line buffers

[qRoC]

Line buffer does not work on big strings.

[luketomlinson]

hey @qRoC, thanks for the PR! Do you have some sample output to demonstrate the issue that your changes would fix? I think it could be helpful to have a test to demonstrate the behavior. I was having trouble reproducing this behavior over in #749, so I'd be curious if you have a consistent scenario that breaks.

[qRoC]

The chunk in data event contains either one line of output or a line with the size of the buffer.

So to reproduce this error, just print a string larger than the buffer size.

For example, buffer size is 10 bytes, so for output:

aaa
bbbbbbbbbbccccc
ddd

The data event is fired 4 times:

aaa
bbbbbbbbbb
ccccc
ddd

Real case: cargo build with json output.

I fixed this in qRoC/cargo-actions@fff2c76

[luketomlinson]

hi @qRoC, thank you for your response. I did some more digging, and I think this is a good fix for #749. If we can add a test for this case I will feel confident approving this. If you don't want to take that on, I am happy to take a stab at my own implementation.

[luketomlinson]

Thanks for this PR @qRoC! I'm going to go ahead and merge and add a test later.