Xin Zhao
9005ced680
# Objective Closes #41743 When selecting text on the last line, excluding the trailing newline, Vim and Helix modes behave differently from native Vim and Helix when the file has a trailing newline: 1. We cannot use `l` (move right) to include the final `\n` in the selection, while native Vim and Helix allow this. 2. By default, the rendered cursor should appear on the selected character. When that character is the final `\n`, however, Zed renders the cursor on the synthetic empty line after it rather than at the end of the preceding line. This differs from native Vim and Helix, as well as from Zed's behavior for newlines elsewhere in the file. 3. When the final `\n` is selected, it affects subsequent selection motions, as reported in #41743. The cause is several special-case guards for trailing newlines in Visual and Select modes. These guards exist in the cursor rendering logic: https://github.com/zed-industries/zed/blob/73523ec50bafcdab9308fa51808bef074ae898bc/crates/editor/src/element.rs#L201-L213 They also exist in the Visual motion logic for Vim mode and the Select motion logic for Helix mode (the Helix implementation was adopted directly from Vim in #43234): https://github.com/zed-industries/zed/blob/73523ec50bafcdab9308fa51808bef074ae898bc/crates/vim/src/visual.rs#L254-L259 Finally, they exist in the selection extension logic for Vim and Helix (the Helix logic was also adopted from Vim): https://github.com/zed-industries/zed/blob/73523ec50bafcdab9308fa51808bef074ae898bc/crates/vim/src/visual.rs#L273-L284 These guards cause trailing-newline selections to behave inconsistently with selections containing newlines elsewhere in the file. ## Solution Remove all the guards mentioned above, including those in cursor rendering, Visual and Select motions, and selection extension. And due to the cursor rendering logic is also changed, an exsisting test is updated. After removing these guards, I could not reproduce the unexpected behavior described in the existing comments: https://github.com/zed-industries/zed/blob/73523ec50bafcdab9308fa51808bef074ae898bc/crates/vim/src/visual.rs#L247-L253 The only remaining difference is that, when the cursor is on the last line in Visual mode, pressing `j` moves it to the final `\n` rather than to the synthetic empty line after it. In comparison, native Vim and Helix do nothing in this case. ## Testing - Built and tested locally. - Added new GPUI tests. ## Self-Review Checklist: - [x] I've reviewed my own diff for quality, security, and reliability - [x] Unsafe blocks (if any) have justifying comments - [x] The content adheres to Zed's UI standards ([UX/UI](https://github.com/zed-industries/zed/blob/main/CONTRIBUTING.md#uiux-checklist) and [icon](https://github.com/zed-industries/zed/blob/main/crates/icons/README.md) guidelines) - [x] Tests cover the new/changed behavior - [x] Performance impact has been considered and is acceptable Release Notes: - Improved Vim Visual and Helix Select modes when selections include a trailing newline.
This contains the code for Zed's Vim emulation mode.
Vim mode in Zed is supposed to primarily "do what you expect": it mostly tries to copy vim exactly, but will use Zed-specific functionality when available to make things smoother. This means Zed will never be 100% vim compatible, but should be 100% vim familiar!
The backlog is maintained in the #vim channel notes.
Testing against Neovim
If you are making a change to make Zed's behavior more closely match vim/nvim, you can create a test using the NeovimBackedTestContext.
For example, the following test checks that Zed and Neovim have the same behavior when running * in visual mode:
#[gpui::test]
async fn test_visual_star_hash(cx: &mut gpui::TestAppContext) {
let mut cx = NeovimBackedTestContext::new(cx).await;
cx.set_shared_state("ˇa.c. abcd a.c. abcd").await;
cx.simulate_shared_keystrokes(["v", "3", "l", "*"]).await;
cx.assert_shared_state("a.c. abcd ˇa.c. abcd").await;
}
To keep CI runs fast, by default the neovim tests use a cached JSON file that records what neovim did (see crates/vim/test_data), but while developing this test you'll need to run it with the neovim flag enabled:
cargo test -p vim --features neovim test_visual_star_hash
This will run your keystrokes against a headless neovim and cache the results in the test_data directory. Note that neovim must be installed and reachable on your $PATH in order to run the feature.
Testing zed-only behavior
Zed does more than vim/neovim in their default modes. The VimTestContext can be used instead. This lets you test integration with the language server and other parts of zed's UI that don't have a NeoVim equivalent.