feat: Improve syntax highlighting support for template languages, such as Tera

Cargo.toml

@@ -37,7 +37,7 @@ package.helix-tui.opt-level = 2
 package.helix-term.opt-level = 2
 
 [workspace.dependencies]
-tree-house = { version = "0.1.0", default-features = false }
+tree-house = { git = "https://github.com/nik-rev/tree-house.git", rev = "c5b3f53dbffce5cf8dc42fb5597deddeaa5c9d0a", default-features = false }
 nucleo = "0.5.0"
 slotmap = "1.0.7"
 thiserror = "2.0"

helix-core/src/syntax.rs

@@ -433,8 +433,13 @@ pub struct Syntax {
 const PARSE_TIMEOUT: Duration = Duration::from_millis(500); // half a second is pretty generous
 
 impl Syntax {
-    pub fn new(source: RopeSlice, language: Language, loader: &Loader) -> Result<Self, Error> {
-        let inner = tree_house::Syntax::new(source, language, PARSE_TIMEOUT, loader)?;
+    pub fn new(
+        source: RopeSlice,
+        language: Language,
+        loader: &Loader,
+        path: Option<std::path::PathBuf>,
+    ) -> Result<Self, Error> {
+        let inner = tree_house::Syntax::new(source, language, PARSE_TIMEOUT, loader, path)?;
         Ok(Self { inner })
     }
 
@@ -981,7 +986,7 @@ mod test {
         let grammar = LOADER.get_config(language).unwrap().grammar;
         let query = Query::new(grammar, query_str, |_, _| Ok(())).unwrap();
         let textobject = TextObjectQuery::new(query);
-        let syntax = Syntax::new(source.slice(..), language, &LOADER).unwrap();
+        let syntax = Syntax::new(source.slice(..), language, &LOADER, None).unwrap();
 
         let root = syntax.tree().root_node();
         let test = |capture, range| {
@@ -1070,7 +1075,7 @@ mod test {
     ) {
         let source = Rope::from_str(source);
         let language = LOADER.language_for_name(language_name).unwrap();
-        let syntax = Syntax::new(source.slice(..), language, &LOADER).unwrap();
+        let syntax = Syntax::new(source.slice(..), language, &LOADER, None).unwrap();
 
         let root = syntax
             .tree()

helix-core/tests/indent.rs

@@ -199,7 +199,7 @@ fn test_treesitter_indent(
     let language_config = loader.language(language).config();
     let indent_style = IndentStyle::from_str(&language_config.indent.as_ref().unwrap().unit);
     let text = doc.slice(..);
-    let syntax = Syntax::new(text, language, &loader).unwrap();
+    let syntax = Syntax::new(text, language, &loader, None).unwrap();
     let indent_query = loader.indent_query(language).unwrap();
 
     for i in 0..doc.len_lines() {

helix-term/src/ui/markdown.rs

@@ -54,7 +54,7 @@ pub fn highlighted_code_block<'a>(
     let ropeslice = RopeSlice::from(text);
     let Some(syntax) = loader
         .language_for_match(RopeSlice::from(language))
-        .and_then(|lang| Syntax::new(ropeslice, lang, loader).ok())
+        .and_then(|lang| Syntax::new(ropeslice, lang, loader, None).ok())
     else {
         return styled_multiline_text(text, code_style);
     };

helix-term/src/ui/picker/handlers.rs

@@ -79,7 +79,8 @@ impl<T: 'static + Send + Sync, D: 'static + Send + Sync> AsyncHook
             let text = doc.text().clone();
 
             tokio::task::spawn_blocking(move || {
-                let syntax = match helix_core::Syntax::new(text.slice(..), language, &loader) {
+                let syntax = match helix_core::Syntax::new(text.slice(..), language, &loader, None)
+                {
                     Ok(syntax) => syntax,
                     Err(err) => {
                         log::info!("highlighting picker preview failed: {err}");

helix-view/src/document.rs

@@ -1291,16 +1291,21 @@ impl Document {
     ) {
         self.language = language_config;
         self.syntax = self.language.as_ref().and_then(|config| {
-            Syntax::new(self.text.slice(..), config.language(), loader)
-                .map_err(|err| {
-                    // `NoRootConfig` means that there was an issue loading the language/syntax
-                    // config for the root language of the document. An error must have already
-                    // been logged by `LanguageData::syntax_config`.
-                    if err != syntax::HighlighterError::NoRootConfig {
-                        log::warn!("Error building syntax for '{}': {err}", self.display_name());
-                    }
-                })
-                .ok()
+            Syntax::new(
+                self.text.slice(..),
+                config.language(),
+                loader,
+                self.path().cloned(),
+            )
+            .map_err(|err| {
+                // `NoRootConfig` means that there was an issue loading the language/syntax
+                // config for the root language of the document. An error must have already
+                // been logged by `LanguageData::syntax_config`.
+                if err != syntax::HighlighterError::NoRootConfig {
+                    log::warn!("Error building syntax for '{}': {err}", self.display_name());
+                }
+            })
+            .ok()
         });
     }
 

runtime/queries/tera/injections.scm

@@ -2,3 +2,7 @@
   (#set! injection.language "yaml")
   (#set! injection.combined)
 )
+
+((content) @injection.content
+  (#set! injection.language "<use-2nd-filename-extension>")
+  (#set! injection.combined))