Clean up remotes's exps

[karajan1001]

fix #6006

1. add a new argument --git-remote to dvc exp remove
2. add some tests for it

• ❗ I have followed the Contributing to DVC checklist.

• 📖 If this PR requires documentation updates, I have created a separate PR (or issue, at least) in dvc.org and linked it here.
  Remove exps in remote git repo. dvc.org#2744

Thank you for the contribution - we'll try to review it as soon as possible. 🙏

[karajan1001]

@dberenbaum @pmrowla
Should I support a more granular remove like in dvc exp push. The current version will clean up all of the exps in the remove repo.

[dberenbaum]

@dberenbaum @pmrowla
Should I support a more granular remove like in dvc exp push. The current version will clean up all of the exps in the remove repo.

Yes, I think granular removal is needed here. My preferred usage would be to make --git-remote act like the existing syntax but operating on the remote git repo instead of the local one:

• dvc exp remove --git-remote origin abc123 removes experiment abc123 from origin.
• dvc exp remove --git-remote origin --all removes all experiments from origin.
• dvc exp remove --git-remote origin --queue does nothing or throws an error.

[jorgeorpinel]

I think argument/flag consistency is a guideline in https://clig.dev/

Thinking about it, I'm a bit confused about the command semantics. dvc push/pull use the default DVC remote or accept a --remote otherwise. dvc exp push/pull/remove however expect a DVC remote as argument. Seems inconsistent.

Maybe the argument these last accept should be the git remote (perhaps made optional if the branch has a default upstream), resembling git push/pull. And then use the default DVC remote or take one via -r. Cc @dberenbaum

[pmrowla]

Thinking about it, I'm a bit confused about the command semantics. dvc push/pull use the default DVC remote or accept a --remote otherwise. dvc exp push/pull/remove however expect a remote as argument. Seems inconsistent.

The mandatory argument for exp push/pull is the git remote. DVC data for the experiments is pushed to the default DVC remote if -r/--remote is not provided, same as dvc push/pull.

Maybe the argument these last accept should be the git remote (perhaps made optional if the branch has a default upstream), resembling git push/pull. And then use the default DVC remote or take one via -r. Cc @dberenbaum

Git branch upstream/tracking remotes are specifically only for git branch refs, they don't apply to any other git ref (including experiments). The reason we require explicit git remote arguments is because the "correct" git behavior for "default remotes" will end up being confusing for users.

[karajan1001]

If

1. there is no __init__.py in the the pytest package ( directory ).
2. Two test file share a same file name.
   There would be a failure like this.

import file mismatch:
imported module 'test_utils' has this __file__ attribute:
  /home/runner/work/dvc/dvc/tests/unit/repo/experiments/test_utils.py
which is not the same as the test file we want to collect:
  /home/runner/work/dvc/dvc/tests/unit/stage/test_utils.py
HINT: remove __pycache__ / .pyc files and/or use a unique basename for your test file modules

[pmrowla]

Looks good, thanks for being patient with all the review requests 👍

[dberenbaum]

One minor issue with the arg parsing. Otherwise looks great!