Adds two new typeable commands: show-selection-diff-popup and `yank…

…-selection-diff`

These are similar to the `reset-diff-change` command, except that rather
wthan apply the diff base, the unsaved buffer changes (in `diff` syntax)
are shown in a popup (with `show-selection-diff-popup`) or yanked to a
register (using `yank-selection-diff`).

This uses the new `hunks_intersecting_line_ranges` method from #10178,
so probably that PR should be merged first before considering merging
this one.

book/src/generated/typable-cmd.md

@@ -83,6 +83,8 @@
 | `:pipe-to` | Pipe each selection to the shell command, ignoring output. |
 | `:run-shell-command`, `:sh` | Run a shell command |
 | `:reset-diff-change`, `:diffget`, `:diffg` | Reset the diff change at the cursor position. |
+| `:show-selection-diff-popup`, `:diffshow` | Show a popup with the unsaved diff hunks intersecting the primary selection. |
+| `:yank-selection-diff`, `:diffyank` | Yank the unsaved diff hunks intersecting the primary selection. |
 | `:clear-register` | Clear given register. If no argument is provided, clear all registers. |
 | `:redraw` | Clear and re-render the whole UI |
 | `:move` | Move the current buffer and its corresponding file to a different path |

helix-core/src/diff.rs

@@ -178,6 +178,20 @@ pub fn compare_ropes(before: &Rope, after: &Rope) -> Transaction {
  res
 }
 
+/// Compares `old` and `new` to generate a text diff
+pub fn diff_ropes(before: RopeSlice, after: RopeSlice) -> String {
+ let file = InternedInput::new(RopeLines(before), RopeLines(after));
+ imara_diff::diff(
+ Algorithm::Histogram,
+ &file,
+ imara_diff::UnifiedDiffBuilder::new(&file),
+ )
+ // Unsure why we get empty lines...
+ .split_inclusive('\n')
+ .filter(|line| !line.trim().is_empty())
+ .collect()
+}
+
 #[cfg(test)]
 mod tests {
  use super::*;

helix-term/src/commands/typed.rs

@@ -6,6 +6,7 @@ use crate::job::Job;
 
 use super::*;
 
+use helix_core::diff::diff_ropes;
 use helix_core::fuzzy::fuzzy_match;
 use helix_core::indent::MAX_INDENT;
 use helix_core::{line_ending, shellwords::Shellwords};
@@ -2338,6 +2339,104 @@ fn reset_diff_change(
  Ok(())
 }
 
+fn get_diff_change_at_selection(editor: &mut Editor) -> anyhow::Result<String> {
+ let (view, doc) = current!(editor);
+ let Some(handle) = doc.diff_handle() else {
+ bail!("Diff is not available in the current buffer")
+ };
+
+ let diff = handle.load();
+ let doc_text = doc.text().slice(..);
+ let primary_selection = doc.selection(view.id).primary();
+
+ let Some((base_start, base_end, doc_start, doc_end)) = diff
+ .hunks_intersecting_line_ranges([primary_selection.line_range(doc_text)].into_iter())
+ .fold(None, |line_ranges, hunk| match line_ranges {
+ Some((base_start, base_end, doc_start, doc_end)) => Some((
+ hunk.before.start.min(base_start),
+ hunk.before.end.max(base_end),
+ hunk.after.start.min(doc_start),
+ hunk.after.end.max(doc_end),
+ )),
+ None => Some((
+ hunk.before.start,
+ hunk.before.end,
+ hunk.after.start,
+ hunk.after.end,
+ )),
+ })
+ else {
+ bail!("There are no changes in the primary selection");
+ };
+
+ let base = diff.diff_base();
+ let doc = diff.doc();
+ Ok(diff_ropes(
+ base.slice(
+ base.line_to_char(base_start as usize)..base.line_to_char((base_end as usize) + 1) - 1,
+ ),
+ doc.slice(
+ doc.line_to_char(doc_start as usize)..doc.line_to_char((doc_end as usize) + 1) - 1,
+ ),
+ ))
+}
+
+fn show_selection_diff_popup(
+ cx: &mut compositor::Context,
+ args: &[Cow<str>],
+ event: PromptEvent,
+) -> anyhow::Result<()> {
+ if event != PromptEvent::Validate {
+ return Ok(());
+ }
+ ensure!(
+ args.is_empty(),
+ "show-selection-diff-popup takes no arguments"
+ );
+
+ let text = get_diff_change_at_selection(cx.editor)?;
+
+ let callback = async move {
+ let call: job::Callback = Callback::EditorCompositor(Box::new(
+ move |editor: &mut Editor, compositor: &mut Compositor| {
+ let contents =
+ ui::Markdown::new(format!("```diff\n{}```", text), editor.syn_loader.clone());
+ let popup = Popup::new("show-selection-diff-popup", contents).auto_close(true);
+ compositor.replace_or_push("show-selection-diff-popup", popup);
+ },
+ ));
+ Ok(call)
+ };
+ cx.jobs.callback(callback);
+ Ok(())
+}
+
+fn yank_selection_diff(
+ cx: &mut compositor::Context,
+ args: &[Cow<str>],
+ event: PromptEvent,
+) -> anyhow::Result<()> {
+ if event != PromptEvent::Validate {
+ return Ok(());
+ }
+
+ let reg = match args.first() {
+ Some(s) => {
+ ensure!(s.chars().count() == 1, format!("Invalid register {s}"));
+ s.chars().next().unwrap()
+ }
+ None => '+',
+ };
+
+ let text = get_diff_change_at_selection(cx.editor)?;
+
+ cx.editor.registers.write(reg, vec![text])?;
+ cx.editor.set_status(format!(
+ "Yanked diff changes in the primary selection to register {reg}",
+ ));
+ Ok(())
+}
+
 fn clear_register(
  cx: &mut compositor::Context,
  args: &[Cow<str>],
@@ -3073,6 +3172,20 @@ pub const TYPABLE_COMMAND_LIST: &[TypableCommand] = &[
  fun: reset_diff_change,
  signature: CommandSignature::none(),
  },
+ TypableCommand {
+ name: "show-selection-diff-popup",
+ aliases: &["diffshow"],
+ doc: "Show a popup with the unsaved diff hunks intersecting the primary selection.",
+ fun: show_selection_diff_popup,
+ signature: CommandSignature::none(),
+ },
+ TypableCommand {
+ name: "yank-selection-diff",
+ aliases: &["diffyank"],
+ doc: "Yank the unsaved diff hunks intersecting the primary selection.",
+ fun: yank_selection_diff,
+ signature: CommandSignature::all(completers::register),
+ },
  TypableCommand {
  name: "clear-register",
  aliases: &[],