This follows up on https://github.com/martinvonz/jj/pull/3459 and adds a
label to the closing delimeter of each conflict, e.g. "Conflict 1 of 3
ends".
I didn't initially put any label at the ending delimeter since the
starting delimeter is already marked with "Conflict 1 of 3". However,
I'm now realizing that when I resolve conflicts, I usually go from top
to bottom. The first thing I do is delete the starting conflict
delimeter. It is when I get to the *end* of the conflict that I wonder
whether there are any more conflicts left in the file.
For example,
```
<<<<<<< Conflict 1 of 3
+++++++ Contents of side #1
left 3.1
left 3.2
left 3.3
%%%%%%% Changes from base to side #2
-line 3
+right 3.1
>>>>>>>
```
or
```
<<<<<<< Conflict 1 of 1
%%%%%%% Changes from base to side #1
-line 3
+right 3.1
+++++++ Contents of side #2
left 3.1
left 3.2
left 3.3
>>>>>>>
```
Currently, there is no way to disable these, this is TODO for a future
PR. Other TODOs for future PRs: make these labels configurable. After
that, we could support a `diff3/git`-like conflict format as well, in
principle.
Counting conflicts helps with knowing whether you fixed all the
conflicts while you are in the editor.
While labeling "side #1", etc, does not tell you the commit id or
description as requested in #1176, I still think it's an improvement.
Most importantly, I hope this will make `jj`'s conflict format less
scary-looking for new users.
I've used this for a bit, and I like it. Without the labels, I would see
that the two conflicts have a different order of conflict markers, but I
wouldn't be able to remember what that means. For longer diffs, it can
be tricky for me to quickly tell that it's a diff as opposed to one of
the sides. This also creates some hope of being able to navigate a
conflict with more than 2 sides.
Another not-so-secret goal for this is explained in
https://github.com/martinvonz/jj/pull/3109#issuecomment-2014140627. The
idea is a little weird, but I *think* it could be helpful, and I'd like
to experiment with it.
When you use e.g. `git switch` to check out a conflicted commit,
you're going to end up with the `.jjconflicts-*` directories in your
working copy. It's probably not obvious what those mean. This patch
adds a README file to the root tree to try to explain to users what's
going on and how to recover.
The authoritative information about conflicts is stored in the
`jj:trees` commit header. The contents of conflicted commits is only
used for preventing GC. We can therefore add contents to the tree
without much consequence.
if `--use-destination-message/-u` is passed to `jj squash`, the resulting
revision will use the description of the destination revision and the
description(s) of the source revision(s) will be discarded.
The lowercase "warning: " is unified to "Warning: " as it is the jj's
convention afaik.
The _default() suffix could be dropped from these methods, but it's probably
better to break the existing codebase for the moment. Otherwise, the caller
might do writeln!(ui.warning(), "Warning: ..").
Now you can do e.g. `jj squash --from 'foo+::' --into foo` to squash a
whole series into one commit. It doesn't need to be linear; you can
squash a bunch of siblings into another siblings, for example.
This was proposed by @Brixy in
https://github.com/martinvonz/jj/discussions/2882 a while ago. There
seems to be pretty strong consensus that it's a good idea.
I've copied the added test cases from `test_move_command.rs`, just
replacing `move` by `squash`, `--to` by `--into`, and deleting the
test of a no-arg invocation (`jj move` fails, `jj squash` does not -
it defaults to squashing into the parent).
This patch makes `jj squash` us the helper I just extracted from `jj
move`. I had a to add a few small features to it for that.
The `test_squash_command.rs` test changed in a few cases where we do a
partial squash. After this patch, we include the rebased child in the
count of rebased descendants. That seems reasonable and consistent
with partial squash/move further than 1 generation.
this greatly speeds up the time to run all tests, at the cost of slightly larger recompile times for individual tests.
this unfortunately adds the requirement that all tests are listed in `runner.rs` for the crate.
to avoid forgetting, i've added a new test that ensures the directory is in sync with the file.
## benchmarks
before this change, recompiling all tests took 32-50 seconds and running a single test took 3.5 seconds:
```
; hyperfine 'touch lib/src/lib.rs && cargo t --test test_working_copy'
Time (mean ± σ): 3.543 s ± 0.168 s [User: 2.597 s, System: 1.262 s]
Range (min … max): 3.400 s … 3.847 s 10 runs
```
after this change, recompiling all tests take 4 seconds:
```
; hyperfine 'touch lib/src/lib.rs ; cargo t --test runner --no-run'
Time (mean ± σ): 4.055 s ± 0.123 s [User: 3.591 s, System: 1.593 s]
Range (min … max): 3.804 s … 4.159 s 10 runs
```
and running a single test takes about the same:
```
; hyperfine 'touch lib/src/lib.rs && cargo t --test runner -- test_working_copy'
Time (mean ± σ): 4.129 s ± 0.120 s [User: 3.636 s, System: 1.593 s]
Range (min … max): 3.933 s … 4.346 s 10 runs
```
about 1.4 seconds of that is the time for the runner, of which .4 is the time for the linker. so
there may be room for further improving the times.
They are shown next to the change and commit id, since they are other names the
commit can be referred by.
The description is separated from the branches by a ` | ` when there are
branches, so that one can tell the branches from the description without color.
The result looks like this: 
