Add --requirement option for pipx inject

[dukecat0]

• I have added an entry to docs/changelog.md

Summary of changes

Add --requirement option for pipx inject.
Close #934

Test plan

Tested by running

pipx inject black -r requirements.txt

[uranusjr]

Do we want to allow pipx inject foo -r bar.txt? If not maybe we can use add_mutually_exclusive_group (not sure if it can be used grouping arguments and flags together).

[dukecat0]

Do we want to allow pipx inject foo -r bar.txt?

Did you mean something like pipx inject black foo -r bar.txt?

[uranusjr]

Yes, sorry

[dukecat0]

Probably no then, since I guess most users will choose to edit their requirements files directly.

[dukecat0]

If not maybe we can use add_mutually_exclusive_group (not sure if it can be used grouping arguments and flags together).

Seems like it's impossible to do that currently. I've added a check and it will raise an exception if dependencies and --requirement are passed at the same time.

[uranusjr]

Probably need to mention this exclusiveness in the flag help string. Otherwise looks good to me.

[uranusjr]

Instead of reading the files, should we just forward the path to pip to let it parse instead? Requirements files are technically a pip-specific format and parsing them ourselves seems like a big future source of code bloat down the road. Instead we should just redirect all the responsibilities to pip.

[dukecat0]

But the question is that how should we determine package names?

[uranusjr]

Why do we need the package names? This is inject not install.

[dukecat0]

Since we need to forward those package names to pipx_metadata.

[uranusjr]

Would it be viable to do a pip freeze before and after installation and record the diff?

[uranusjr]

But it looks like the installation report will also report the dependencies of a package, which are not specified in requirements.txt. Though we can exclude them from pipx_metadata by checking whether they are in the requires_dist field, I personally think this is too complicated

There’s a field requested for this, we can simply filter out entries with this set to true (meaning it’s from user input i.e. the requirements file).

[dukecat0]

Oops, didn't notice that, thanks for pointing it out!

[dukecat0]

Is it possible for the report to include options passed to pip (such as --pre, --index-url) in the requirements file?

[uranusjr]

I don’t think either is strictly needed since pipx would install those packages with the exact URL (which the report contains), and the flag is irrelevant in this case.

[gaborbernat]

Merge conflicts need fixed.

[gaborbernat]

Seems stalled, we can reopen if you pick it up again.

[jamesmyatt]

I've made a new PR #1252 for this, based partially on this one.