revset: add working_copies() function

[ckoehler]

It includes the working copy commit of every workspace of the repo.

Implements #3384

Checklist

If applicable:

• I have updated CHANGELOG.md
• I have updated the documentation (README.md, docs/, demos/)
• I have updated the config schema (cli/src/config-schema.json)
• I have added tests to cover my changes

[ckoehler]

Not sure how to test this, would appreciate some pointers. Is there an easy way to create a repo with two workspaces, create some commits, and then compare those to the output of working_copies()? Sounds involved.

Nevermind, this looks straightforward: https://github.com/martinvonz/jj/blob/main/lib/tests/test_revset.rs#L332

[martinvonz]

Not sure how to test this, would appreciate some pointers. Is there an easy way to create a repo with two workspaces, create some commits, and then compare those to the output of working_copies()? Sounds involved.

Maybe it can be done similar to how we do it for @ here:

jj/lib/tests/test_revset.rs

Lines 331 to 372 in 7b3f8e8

	#[test]
	fn test_resolve_working_copy() {
	let settings = testutils::user_settings();
	let test_repo = TestRepo::init();
	let repo = &test_repo.repo;
	let mut tx = repo.start_transaction(&settings);
	let mut_repo = tx.mut_repo();
	let commit1 = write_random_commit(mut_repo, &settings);
	let commit2 = write_random_commit(mut_repo, &settings);
	let ws1 = WorkspaceId::new("ws1".to_string());
	let ws2 = WorkspaceId::new("ws2".to_string());
	// Cannot resolve a working-copy commit for an unknown workspace
	assert_matches!(
	RevsetExpression::working_copy(ws1.clone())
	.resolve_user_expression(mut_repo, &FailingSymbolResolver),
	Err(RevsetResolutionError::WorkspaceMissingWorkingCopy { name }) if name == "ws1"
	);
	// Add some workspaces
	mut_repo
	.set_wc_commit(ws1.clone(), commit1.id().clone())
	.unwrap();
	mut_repo
	.set_wc_commit(ws2.clone(), commit2.id().clone())
	.unwrap();
	let resolve = |ws_id: WorkspaceId| -> Vec<CommitId> {
	RevsetExpression::working_copy(ws_id)
	.evaluate_programmatic(mut_repo)
	.unwrap()
	.iter()
	.collect()
	};
	// Can resolve "@" shorthand with a default workspace ID
	assert_eq!(resolve(ws1), vec![commit1.id().clone()]);
	// Can resolve an explicit checkout
	assert_eq!(resolve(ws2), vec![commit2.id().clone()]);
	}

[yuja]

thanks.