Show git diff signs in gutter

Author: sudormrfbin

Cargo.lock

@@ -7,6 +7,7 @@ members = [
   "helix-syntax",
   "helix-lsp",
   "helix-dap",
+  "helix-vcs",
   "xtask",
 ]
 

Cargo.toml

@@ -2146,6 +2146,8 @@ pub mod cmd {
         if doc.path().is_none() {
             bail!("cannot write a buffer without a filename");
         }
+        let id = doc.id();
+
         let fmt = doc.auto_format().map(|fmt| {
             let shared = fmt.shared();
             let callback = make_format_callback(
@@ -2157,11 +2159,17 @@ pub mod cmd {
             jobs.callback(callback);
             shared
         });
-        let future = doc.format_and_save(fmt);
-        cx.jobs.add(Job::new(future).wait_before_exiting());
+        let future = doc.format_and_save(fmt).map(move |_| {
+            let call: job::Callback =
+                Box::new(move |editor: &mut Editor, _compositor: &mut Compositor| {
+                    let _ = editor.refresh_version_control(id);
+                });
+            Ok(call)
+        });
+        cx.jobs
+            .add(Job::with_callback(future).wait_before_exiting());
 
         if path.is_some() {
-            let id = doc.id();
             let _ = cx.editor.refresh_language_server(id);
         }
         Ok(())

helix-term/src/commands.rs

@@ -0,0 +1,14 @@
+[package]
+name = "helix-vcs"
+version = "0.6.0"
+authors = ["Blaž Hrastnik <[email protected]>"]
+edition = "2021"
+license = "MPL-2.0"
+categories = ["editor"]
+repository = "https://github.com/helix-editor/helix"
+homepage = "https://helix-editor.com"
+
+# See more keys and their definitions at https://doc.rust-lang.org/cargo/reference/manifest.html
+
+[dependencies]
+git2 = { version = "0.13", default-features = false }

helix-vcs/Cargo.toml

@@ -0,0 +1,78 @@
+use std::collections::HashMap;
+use std::path::{Path, PathBuf};
+
+use git2::{DiffDelta, DiffHunk, DiffOptions, Repository};
+
+use crate::{LineDiff, LineDiffs};
+
+pub struct Git {
+    repo: Repository,
+    root: PathBuf,
+}
+
+impl std::fmt::Debug for Git {
+    fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
+        f.debug_struct("Git").field("root", &self.root).finish()
+    }
+}
+
+impl Git {
+    pub fn discover_from_path(file: &Path) -> Option<Self> {
+        let repo = Repository::discover(file).ok()?;
+        let root = repo.workdir()?.to_path_buf();
+        Some(Self { repo, root })
+    }
+
+    // Modified from https://github.com/sharkdp/bat/blob/master/src/diff.rs
+    pub fn line_diffs(&mut self, file: &Path) -> Option<LineDiffs> {
+        let mut diff_options = DiffOptions::new();
+        let relative = file.strip_prefix(&self.root).ok()?;
+        diff_options.pathspec(relative);
+        diff_options.context_lines(0);
+
+        let diff = self
+            .repo
+            .diff_index_to_workdir(None, Some(&mut diff_options))
+            .ok()?;
+
+        let mut line_diffs: LineDiffs = HashMap::new();
+
+        let mut mark_section = |start: u32, end: u32, change: LineDiff| {
+            for line in start..=end {
+                line_diffs.insert(line as usize, change);
+            }
+        };
+
+        let hunk_cb = &mut |delta: DiffDelta, hunk: DiffHunk| {
+            let relative_path = delta.new_file().path().unwrap_or_else(|| Path::new(""));
+            if !file.ends_with(relative_path) {
+                return false;
+            }
+
+            let old_lines = hunk.old_lines();
+            let new_start = hunk.new_start();
+            let new_lines = hunk.new_lines();
+            let new_end = new_start + new_lines.saturating_sub(1);
+
+            if old_lines == 0 && new_lines > 0 {
+                mark_section(new_start, new_end, LineDiff::Added);
+            } else if new_lines == 0 && old_lines > 0 {
+                if new_start == 0 {
+                    mark_section(1, 1, LineDiff::DeletedAbove);
+                } else {
+                    mark_section(new_start, new_start, LineDiff::Deleted);
+                }
+            } else {
+                // TODO: modified and added lines nearby render as big modified chunk
+                mark_section(new_start, new_end, LineDiff::Modified);
+            }
+
+            true
+        };
+
+        diff.foreach(&mut |_, _| true, None, Some(hunk_cb), None)
+            .ok()?;
+
+        Some(line_diffs)
+    }
+}

helix-vcs/src/git.rs

@@ -0,0 +1,16 @@
+use std::collections::HashMap;
+
+mod git;
+
+#[derive(Copy, Clone, Debug)]
+pub enum LineDiff {
+    Added,
+    Deleted,
+    DeletedAbove,
+    Modified,
+}
+
+/// Maps line numbers to changes
+pub type LineDiffs = HashMap<usize, LineDiff>;
+
+pub use git::Git;

helix-vcs/src/lib.rs

@@ -19,6 +19,7 @@ anyhow = "1"
 helix-core = { version = "0.6", path = "../helix-core" }
 helix-lsp = { version = "0.6", path = "../helix-lsp"}
 helix-dap = { version = "0.6", path = "../helix-dap"}
+helix-vcs = { version = "0.6", path = "../helix-vcs"}
 crossterm = { version = "0.23", optional = true }
 
 # Conversion traits

helix-view/Cargo.toml

@@ -118,6 +118,7 @@ pub struct Document {
     pub(crate) modified_since_accessed: bool,
 
     diagnostics: Vec<Diagnostic>,
+    line_diffs: helix_vcs::LineDiffs,
     language_server: Option<Arc<helix_lsp::Client>>,
 }
 
@@ -142,6 +143,7 @@ impl fmt::Debug for Document {
             .field("modified_since_accessed", &self.modified_since_accessed)
             .field("diagnostics", &self.diagnostics)
             // .field("language_server", &self.language_server)
+            .field("line_diffs", &self.line_diffs)
             .finish()
     }
 }
@@ -359,6 +361,7 @@ impl Document {
             last_saved_revision: 0,
             modified_since_accessed: false,
             language_server: None,
+            line_diffs: helix_vcs::LineDiffs::new(),
         }
     }
 
@@ -946,6 +949,14 @@ impl Document {
         self.diagnostics
             .sort_unstable_by_key(|diagnostic| diagnostic.range);
     }
+
+    pub fn line_diffs(&self) -> &helix_vcs::LineDiffs {
+        &self.line_diffs
+    }
+
+    pub fn set_line_diffs(&mut self, line_diffs: helix_vcs::LineDiffs) {
+        self.line_diffs = line_diffs;
+    }
 }
 
 impl Default for Document {

helix-view/src/document.rs

@@ -280,6 +280,7 @@ pub struct Editor {
     pub debugger_events: SelectAll<UnboundedReceiverStream<dap::Payload>>,
     pub breakpoints: HashMap<PathBuf, Vec<Breakpoint>>,
 
+    pub version_control: Option<helix_vcs::Git>,
     pub clipboard_provider: Box<dyn ClipboardProvider>,
 
     pub syn_loader: Arc<syntax::Loader>,
@@ -312,6 +313,8 @@ impl Editor {
         config: Config,
     ) -> Self {
         let language_servers = helix_lsp::Registry::new();
+        let version_control =
+            helix_core::find_root(None, &[]).and_then(|p| helix_vcs::Git::discover_from_path(&p));
 
         // HAXX: offset the render area height by 1 to account for prompt/commandline
         area.height -= 1;
@@ -328,6 +331,7 @@ impl Editor {
             debugger: None,
             debugger_events: SelectAll::new(),
             breakpoints: HashMap::new(),
+            version_control,
             syn_loader,
             theme_loader,
             registers: Registers::default(),
@@ -382,6 +386,13 @@ impl Editor {
         self._refresh();
     }
 
+    pub fn refresh_version_control(&mut self, doc_id: DocumentId) -> Option<()> {
+        let doc = self.documents.get_mut(&doc_id)?;
+        let diffs = self.version_control.as_mut()?.line_diffs(doc.path()?)?;
+        doc.set_line_diffs(diffs);
+        Some(())
+    }
+
     /// Refreshes the language server for a given document
     pub fn refresh_language_server(&mut self, doc_id: DocumentId) -> Option<()> {
         let doc = self.documents.get_mut(&doc_id)?;
@@ -567,8 +578,10 @@ impl Editor {
             let mut doc = Document::open(&path, None, Some(self.syn_loader.clone()))?;
 
             let _ = Self::launch_language_server(&mut self.language_servers, &mut doc);
+            let id = self.new_document(doc);
+            let _ = self.refresh_version_control(id);
 
-            self.new_document(doc)
+            id
         };
 
         self.switch(id, action);