This PR adds word/character diff for expanded diff hunks that have both
a deleted and added section, as well as a setting `word_diff_enabled` to
enable/disable word diffs per language.
- `word_diff_enabled`: Defaults to true. Whether or not expanded diff
hunks will show word diff highlights when they're able to.
### Preview
<img width="1502" height="430" alt="image"
src="https://github.com/user-attachments/assets/1a8d5b71-449e-44cd-bc87-d6b65bfca545"
/>
### Architecture
I had three architecture goals I wanted to have when adding word diff
support:
- Caching: We should only calculate word diffs once and save the result.
This is because calculating word diffs can be expensive, and Zed should
always be responsive.
- Don't block the main thread: Word diffs should be computed in the
background to prevent hanging Zed.
- Lazy calculation: We should calculate word diffs for buffers that are
not visible to a user.
To accomplish the three goals, word diffs are computed as a part of
`BufferDiff` diff hunk processing because it happens on a background
thread, is cached until the file is edited, and is only refreshed for
open buffers.
My original implementation calculated word diffs every frame in the
Editor element. This had the benefit of lazy evaluation because it only
calculated visible frames, but it didn't have caching for the
calculations, and the code wasn't organized. Because the hunk
calculations would happen in two separate places instead of just
`BufferDiff`. Finally, it always happened on the main thread because it
was during the `EditorElement` layout phase.
I used Zed's
[`diff_internal`](02b2aa6c50/crates/language/src/text_diff.rs (L230-L267))
as a starting place for word diff calculations because it uses
`Imara_diff` behind the scenes and already has language-specific
support.
#### Future Improvements
In the future, we could add `AST` based word diff highlights, e.g.
https://github.com/zed-industries/zed/pull/43691.
Release Notes:
- git: Show word diff highlight in expanded diff hunks with less than 5
lines.
- git: Add `word_diff_enabled` as a language setting that defaults to
true.
---------
Co-authored-by: David Kleingeld <davidsk@zed.dev>
Co-authored-by: Cole Miller <cole@zed.dev>
Co-authored-by: cameron <cameron.studdstreet@gmail.com>
Co-authored-by: Lukas Wirth <lukas@zed.dev>
We've been considering removing workspace-hack for a couple reasons:
- Lukas ran into a situation where its build script seemed to be causing
spurious rebuilds. This seems more likely to be a cargo bug than an
issue with workspace-hack itself (given that it has an empty build
script), but we don't necessarily want to take the time to hunt that
down right now.
- Marshall mentioned hakari interacts poorly with automated crate
updates (in our case provided by rennovate) because you'd need to have
`cargo hakari generate && cargo hakari manage-deps` after their changes
and we prefer to not have actions that make commits.
Currently removing workspace-hack causes our workspace to grow from
~1700 to ~2000 crates being built (depending on platform), which is
mainly a problem when you're building the whole workspace or running
tests across the the normal and remote binaries (which is where
feature-unification nets us the most sharing). It doesn't impact
incremental times noticeably when you're just iterating on `-p zed`, and
we'll hopefully get these savings back in the future when
rust-lang/cargo#14774 (which re-implements the functionality of hakari)
is finished.
Release Notes:
- N/A
This adds a "workspace-hack" crate, see
[mozilla's](https://hg.mozilla.org/mozilla-central/file/3a265fdc9f33e5946f0ca0a04af73acd7e6d1a39/build/workspace-hack/Cargo.toml#l7)
for a concise explanation of why this is useful. For us in practice this
means that if I were to run all the tests (`cargo nextest r
--workspace`) and then `cargo r`, all the deps from the previous cargo
command will be reused. Before this PR it would rebuild many deps due to
resolving different sets of features for them. For me this frequently
caused long rebuilds when things "should" already be cached.
To avoid manually maintaining our workspace-hack crate, we will use
[cargo hakari](https://docs.rs/cargo-hakari) to update the build files
when there's a necessary change. I've added a step to CI that checks
whether the workspace-hack crate is up to date, and instructs you to
re-run `script/update-workspace-hack` when it fails.
Finally, to make sure that people can still depend on crates in our
workspace without pulling in all the workspace deps, we use a `[patch]`
section following [hakari's
instructions](https://docs.rs/cargo-hakari/0.9.36/cargo_hakari/patch_directive/index.html)
One possible followup task would be making guppy use our
`rust-toolchain.toml` instead of having to duplicate that list in its
config, I opened an issue for that upstream: guppy-rs/guppy#481.
TODO:
- [x] Fix the extension test failure
- [x] Ensure the dev dependencies aren't being unified by Hakari into
the main dependencies
- [x] Ensure that the remote-server binary continues to not depend on
LibSSL
Release Notes:
- N/A
---------
Co-authored-by: Mikayla <mikayla@zed.dev>
Co-authored-by: Mikayla Maki <mikayla.c.maki@gmail.com>
- [x] Fix `[un]stage` hunk operations cancelling pending ones
- [x] Add test
- [ ] bugs I stumbled upon (try to repro again before merging)
- [x] holding `git::StageAndNext` skips hunks randomly
- [x] Add test
- [x] restoring a file keeps it in the git panel
- [x] Double clicking on `toggle staged` fast makes Zed disagree with
`git` CLI
- [x] checkbox shows ✔️ (fully staged) after a single
stage
Release Notes:
- N/A
---------
Co-authored-by: Cole <cole@zed.dev>
Co-authored-by: Max <max@zed.dev>
This PR adds an optimistic update when staging or unstaging diff hunks.
In the process, I've also refactored the logic for staging and unstaging
hunks, to consolidate more of it in the `buffer_diff` crate.
I've also changed the way that we treat untracked files. Previously, we
maintained an empty diff for them, so as not to show unwanted
entire-file diff hunks in a regular editor. But then in the project diff
view, we had to account for this, and replace these empty diffs with
entire-file diffs. This form of state management made it more difficult
to store the pending hunks, so now we always use the same
`BufferDiff`/`BufferDiffSnapshot` for untracked files (with a single
hunk spanning the entire buffer), but we just have a special case in
regular buffers, that avoids showing that entire-file hunk.
* [x] Avoid creating a long queue of `set_index` operations when
staging/unstaging rapidly
* [x] Keep pending hunks when diff is recalculated without base text
changes
* [x] Be optimistic even when staging the single hunk in added/deleted
files
* Testing
Release Notes:
- N/A
---------
Co-authored-by: Cole Miller <m@cole-miller.net>
- [x] Staging hunks
- [x] Unstaging hunks
- [x] Write a randomized test
- [x] Get test passing
- [x] Fix existing bug in diff_base_byte_range computation
- [x] Remote project support
- [ ] ~~Improve performance of
buffer_range_to_unchanged_diff_base_range~~
- [ ] ~~Bug: project diff editor scrolls to top when staging/unstaging
hunk~~ existing issue
- [ ] ~~UI~~ deferred
- [x] Tricky cases
- [x] Correctly handle acting on multiple hunks for a single file
- [x] Remove path from index when unstaging the last staged hunk, if
it's absent from HEAD, or staging the only hunk, if it's deleted in the
working copy
Release Notes:
- Add `ToggleStagedSelectedDiffHunks` action for staging and unstaging
individual diff hunks
Release Notes:
- Render unstaged hunks in the project diff editor with a slashed
background
---------
Co-authored-by: maxbrunsfeld <max@zed.dev>
Co-authored-by: Max Brunsfeld <maxbrunsfeld@gmail.com>
