Improve error message if Taskfile provided via stdin is invalid. Also, skip if empty?

[gregtatum]

Description

I just migrated a pre-push git hook to Taskfile.

➤ cat .git/hooks/pre-push
#!/bin/sh
set -e

task test-all

This fails with a mysterious

➤ git push
task: Failed to parse __stdin__:
yaml: line 1: cannot unmarshal !!str into taskfile
error: failed to push some refs to 'github.com:gregtatum/indie-web.git'

Running the following works:

task test-all

I realized that the hook was piping stdin in to the command. I worked around it with:

➤ cat .git/hooks/pre-push
#!/bin/sh
set -e

cat > /dev/null | task test-all

However, it would be nice to not have a cryptic error when stdin is being written to.

Version

Task version: v3.35.1 (h1:zjQ3tLv+LIStDDTzOQx8F97NE/8FSTanjZuwgy/hwro=)

Operating system

macOS

Experiments Enabled

No response

Example Taskfile

[trulede]

Since you are redirecting stdin to Task, Task attempts to read the stdin looking for a valid taskfile.
As the input is not a valid taskfile you get the error, which is accurate and, all things given, clear.

Do you expect something else for the message? A suggestion perhaps.

[gregtatum]

yaml: line 1: cannot unmarshal !!str into taskfile

A better error message would solve this I think.

Could not parse stdin as a valid taskfile

[pd93]

I don't see a bug here. @gregtatum reported this in v3.35.1 where Task's behavior was to implicitly read from stdin when we detected that its size was non-zero. This caused the issues described in #1593 and is the reason for the error in this issue. I don't believe the error is cryptic - it is just unexpected in this scenario.

This behavior was patched out in #1623 by making reading from stdin explicit (users now need to call Task with -t - to get stdin). This patch was released in v3.37 and using anything since then should not require the cat > /dev/null | task workaround described here.