add a diff source for the diff gutter based on the on-disk file contents

helix-term/src/application.rs

@@ -13,7 +13,7 @@ use helix_lsp::{
 use helix_view::{
     align_view,
     document::DocumentSavedEventResult,
-    editor::{ConfigEvent, EditorEvent},
+    editor::{ConfigEvent, DiffSource, EditorEvent},
     graphics::Rect,
     theme,
     tree::Layout,
@@ -351,11 +351,15 @@ impl Application {
             // the Application can apply it.
             ConfigEvent::Update(editor_config) => {
                 let mut app_config = (*self.config.load().clone()).clone();
+                let update_diff_base = app_config.editor.diff_source != editor_config.diff_source;
                 app_config.editor = *editor_config;
                 if let Err(err) = self.terminal.reconfigure(app_config.editor.clone().into()) {
                     self.editor.set_error(err.to_string());
                 };
                 self.config.store(Arc::new(app_config));
+                if update_diff_base {
+                    self.editor.update_diff_base();
+                }
             }
         }
 
@@ -557,6 +561,19 @@ impl Application {
             self.editor.refresh_language_servers(id);
         }
 
+        let diff_source = self.editor.config().diff_source;
+        let doc = doc_mut!(self.editor, &doc_save_event.doc_id);
+        if diff_source == DiffSource::File {
+            if let Some(path) = doc.path().cloned() {
+                doc.update_diff_base(
+                    &path,
+                    &self.editor.diff_provider,
+                    diff_source,
+                    Some(doc.text().clone()),
+                );
+            }
+        }
+
         // TODO: fix being overwritten by lsp
         self.editor.set_status(format!(
             "'{}' written, {}L {}B",

helix-term/src/commands/typed.rs

@@ -1266,10 +1266,12 @@ fn reload(
     }
 
     let scrolloff = cx.editor.config().scrolloff;
+    let diff_source = cx.editor.config().diff_source;
     let (view, doc) = current!(cx.editor);
-    doc.reload(view, &cx.editor.diff_provider).map(|_| {
-        view.ensure_cursor_in_view(doc, scrolloff);
-    })?;
+    doc.reload(view, &cx.editor.diff_provider, diff_source)
+        .map(|_| {
+            view.ensure_cursor_in_view(doc, scrolloff);
+        })?;
     if let Some(path) = doc.path() {
         cx.editor
             .language_servers
@@ -1307,6 +1309,7 @@ fn reload_all(
         .collect();
 
     for (doc_id, view_ids) in docs_view_ids {
+        let diff_source = cx.editor.config().diff_source;
         let doc = doc_mut!(cx.editor, &doc_id);
 
         // Every doc is guaranteed to have at least 1 view at this point.
@@ -1315,7 +1318,7 @@ fn reload_all(
         // Ensure that the view is synced with the document's history.
         view.sync_changes(doc);
 
-        doc.reload(view, &cx.editor.diff_provider)?;
+        doc.reload(view, &cx.editor.diff_provider, diff_source)?;
         if let Some(path) = doc.path() {
             cx.editor
                 .language_servers

helix-view/src/document.rs

@@ -33,7 +33,7 @@ use helix_core::{
     ChangeSet, Diagnostic, LineEnding, Range, Rope, RopeBuilder, Selection, Syntax, Transaction,
 };
 
-use crate::editor::Config;
+use crate::editor::{Config, DiffSource};
 use crate::{DocumentId, Editor, Theme, View, ViewId};
 
 /// 8kB of buffer space for encoding and decoding `Rope`s.
@@ -991,7 +991,12 @@ impl Document {
     }
 
     /// Reload the document from its path.
-    pub fn reload(&mut self, view: &mut View, diff_provider: &Git) -> Result<(), Error> {
+    pub fn reload(
+        &mut self,
+        view: &mut View,
+        diff_provider: &Git,
+        diff_source: DiffSource,
+    ) -> Result<(), Error> {
         let encoding = self.encoding;
         let path = self
             .path()
@@ -1017,23 +1022,7 @@ impl Document {
 
         self.detect_indent_and_line_ending();
 
-        match diff_provider.get_diff_base(&path) {
-            Ok(diff_base) => self.set_diff_base(diff_base),
-            Err(err) => {
-                log::info!("{err:#?}");
-                log::info!("failed to open diff base for for {}", path.display());
-                self.diff_handle = None;
-            }
-        }
-
-        self.version_control_head = match diff_provider.get_current_head_name(&path) {
-            Ok(res) => Some(res),
-            Err(err) => {
-                log::info!("{err:#?}");
-                log::info!("failed to obtain current head name for {}", path.display());
-                None
-            }
-        };
+        self.update_diff_base(&path, diff_provider, diff_source, Some(rope));
 
         Ok(())
     }
@@ -1591,25 +1580,64 @@ impl Document {
     /// Intialize/updates the differ for this document with a new base.
     pub fn set_diff_base(&mut self, diff_base: Vec<u8>) {
         if let Ok((diff_base, ..)) = from_reader(&mut diff_base.as_slice(), Some(self.encoding)) {
-            if let Some(differ) = &self.diff_handle {
-                differ.update_diff_base(diff_base);
-                return;
-            }
-            self.diff_handle = Some(DiffHandle::new(diff_base, self.text.clone()))
+            self.set_diff_base_raw(diff_base);
         } else {
             self.diff_handle = None;
         }
     }
 
-    pub fn version_control_head(&self) -> Option<Arc<Box<str>>> {
-        self.version_control_head.as_ref().map(|a| a.load_full())
+    pub fn set_diff_base_raw(&mut self, diff_base: Rope) {
+        if let Some(differ) = &self.diff_handle {
+            differ.update_diff_base(diff_base);
+            return;
+        }
+        self.diff_handle = Some(DiffHandle::new(diff_base, self.text.clone()))
     }
 
-    pub fn set_version_control_head(
+    pub fn update_diff_base(
         &mut self,
-        version_control_head: Option<Arc<ArcSwap<Box<str>>>>,
+        path: &Path,
+        diff_provider: &Git,
+        diff_source: DiffSource,
+        text: Option<Rope>,
     ) {
-        self.version_control_head = version_control_head;
+        match diff_source {
+            DiffSource::Git => match diff_provider.get_diff_base(path) {
+                Ok(diff_base) => self.set_diff_base(diff_base),
+                Err(err) => {
+                    log::info!("{err:#?}");
+                    log::info!("failed to open diff base for for {}", path.display());
+                    self.diff_handle = None;
+                }
+            },
+            DiffSource::File => {
+                if let Some(text) = text {
+                    self.set_diff_base_raw(text);
+                } else {
+                    match std::fs::read(path) {
+                        Ok(bytes) => self.set_diff_base(bytes),
+                        Err(err) => {
+                            log::info!("{err:#?}");
+                            log::info!("failed to open diff base for for {}", path.display());
+                            self.diff_handle = None;
+                        }
+                    }
+                }
+            }
+        }
+
+        self.version_control_head = match diff_provider.get_current_head_name(path) {
+            Ok(res) => Some(res),
+            Err(err) => {
+                log::info!("{err:#?}");
+                log::info!("failed to obtain current head name for {}", path.display());
+                None
+            }
+        };
+    }
+
+    pub fn version_control_head(&self) -> Option<Arc<Box<str>>> {
+        self.version_control_head.as_ref().map(|a| a.load_full())
     }
 
     #[inline]

helix-view/src/editor.rs

@@ -73,6 +73,14 @@ where
     )
 }
 
+#[derive(Debug, Default, Clone, Copy, PartialEq, Eq, Serialize, Deserialize)]
+#[serde(rename_all = "kebab-case")]
+pub enum DiffSource {
+    #[default]
+    Git,
+    File,
+}
+
 #[derive(Debug, Clone, PartialEq, Eq, Serialize, Deserialize)]
 #[serde(rename_all = "kebab-case", default, deny_unknown_fields)]
 pub struct GutterConfig {
@@ -289,6 +297,9 @@ pub struct Config {
     pub default_line_ending: LineEndingConfig,
     /// Enables smart tab
     pub smart_tab: Option<SmartTabConfig>,
+    #[serde(default)]
+    /// What the diff gutter should diff against
+    pub diff_source: DiffSource,
 }
 
 #[derive(Debug, Clone, PartialEq, Deserialize, Serialize, Eq, PartialOrd, Ord)]
@@ -843,6 +854,7 @@ impl Default for Config {
             workspace_lsp_roots: Vec::new(),
             default_line_ending: LineEndingConfig::default(),
             smart_tab: Some(SmartTabConfig::default()),
+            diff_source: DiffSource::default(),
         }
     }
 }
@@ -1445,22 +1457,12 @@ impl Editor {
                 self.config.clone(),
             )?;
 
-            match self.diff_provider.get_diff_base(&path) {
-                Ok(diff_base) => doc.set_diff_base(diff_base),
-                Err(err) => {
-                    log::info!("{err:#?}");
-                    log::info!("failed to open diff base for for {}", path.display());
-                }
-            }
-
-            doc.set_version_control_head(match self.diff_provider.get_current_head_name(&path) {
-                Ok(res) => Some(res),
-                Err(err) => {
-                    log::info!("{err:#?}");
-                    log::info!("failed to obtain current head name for {}", path.display());
-                    None
-                }
-            });
+            doc.update_diff_base(
+                &path,
+                &self.diff_provider,
+                self.config().diff_source,
+                Some(doc.text().clone()),
+            );
 
             let id = self.new_document(doc);
             let _ = self.launch_language_servers(id);
@@ -1832,6 +1834,15 @@ impl Editor {
             .as_ref()
             .and_then(|debugger| debugger.current_stack_frame())
     }
+
+    pub fn update_diff_base(&mut self) {
+        let diff_source = self.config().diff_source;
+        for doc in self.documents.values_mut() {
+            if let Some(path) = doc.path().cloned() {
+                doc.update_diff_base(&path, &self.diff_provider, diff_source, None);
+            }
+        }
+    }
 }
 
 fn try_restore_indent(doc: &mut Document, view: &mut View) {