2d9e6278e7
# Objective
Closes #41744
When a multi-key binding switches from Insert mode to Helix normal mode,
subsequent editing actions can place the cursor incorrectly.
While a printable multi-key binding is pending, Zed temporarily inserts
the pending keys into the buffer. Once the binding is matched, Zed
dispatches the associated action and then deletes the pending text.
Because the buffer uses a CRDT, the deleted text remains as tombstoned
fragments. The cursor can still resolve to the correct visible offset
while its selection anchor remains associated with one of those
fragments, affecting the ordering of subsequent edits.
Among the explicit Vim mode-switch actions, `SwitchToHelixNormalMode` is
the only one that preserves the existing selections:
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| src | ||
| test_data | ||
| Cargo.toml | ||
| LICENSE-GPL | ||
| README.md | ||
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.