add domain specific ClientCapabilities struct (#286)

Author: joshuadavidthomas

crates/djls-server/src/server.rs

@@ -73,7 +73,7 @@ impl DjangoLanguageServer {
 
     async fn publish_diagnostics(&self, document: &TextDocument) {
         let supports_pull = self
-            .with_session(super::session::Session::supports_pull_diagnostics)
+            .with_session(|session| session.client_capabilities().supports_pull_diagnostics())
             .await;
 
         if supports_pull {
@@ -117,7 +117,7 @@ impl LanguageServer for DjangoLanguageServer {
         tracing::info!("Initializing server...");
 
         let session = Session::new(&params);
-        let encoding = session.position_encoding();
+        let encoding = session.client_capabilities().position_encoding();
 
         {
             let mut session_lock = self.session.lock().await;
@@ -179,9 +179,9 @@ impl LanguageServer for DjangoLanguageServer {
             let session = session_arc.lock().await;
 
             if let Some(project) = session.project() {
-                let path = project.root(session.database()).clone();
+                let path = project.root(session.db()).clone();
                 tracing::info!("Task: Starting initialization for project at: {}", path);
-                project.initialize(session.database());
+                project.initialize(session.db());
                 tracing::info!("Task: Successfully initialized project: {}", path);
             } else {
                 tracing::info!("Task: No project configured, skipping initialization.");
@@ -261,7 +261,7 @@ impl LanguageServer for DjangoLanguageServer {
 
                 let document = session.get_document(&path)?;
                 let position = params.text_document_position.position;
-                let encoding = session.position_encoding();
+                let encoding = session.client_capabilities().position_encoding();
                 let file_kind = FileKind::from(&path);
                 let template_tags = session.with_db(|db| {
                     if let Some(project) = db.project() {
@@ -279,7 +279,7 @@ impl LanguageServer for DjangoLanguageServer {
                     }
                 });
                 let tag_specs = session.with_db(SemanticDb::tag_specs);
-                let supports_snippets = session.supports_snippets();
+                let supports_snippets = session.client_capabilities().supports_snippets();
 
                 let completions = djls_ide::handle_completion(
                     &document,
@@ -352,7 +352,7 @@ impl LanguageServer for DjangoLanguageServer {
     ) -> LspResult<Option<lsp_types::GotoDefinitionResponse>> {
         let response = self
             .with_session_mut(|session| {
-                let encoding = session.position_encoding();
+                let encoding = session.client_capabilities().position_encoding();
 
                 session.with_db_mut(|db| {
                     let file = params
@@ -380,7 +380,7 @@ impl LanguageServer for DjangoLanguageServer {
     ) -> LspResult<Option<Vec<lsp_types::Location>>> {
         let response = self
             .with_session_mut(|session| {
-                let encoding = session.position_encoding();
+                let encoding = session.client_capabilities().position_encoding();
 
                 session.with_db_mut(|db| {
                     let file = params.text_document_position.text_document.to_file(db)?;
@@ -404,7 +404,7 @@ impl LanguageServer for DjangoLanguageServer {
 
         self.with_session_mut(|session| {
             if session.project().is_some() {
-                let project_root = session.database().project_root_or_cwd();
+                let project_root = session.db().project_root_or_cwd();
 
                 match djls_conf::Settings::new(&project_root) {
                     Ok(new_settings) => {

crates/djls-server/src/session.rs

@@ -35,10 +35,7 @@ pub struct Session {
     /// but not the database (which is owned directly by Session).
     workspace: Workspace,
 
-    client_capabilities: lsp_types::ClientCapabilities,
-
-    /// Position encoding negotiated with client
-    position_encoding: PositionEncoding,
+    client_capabilities: ClientCapabilities,
 
     /// The Salsa database for incremental computation
     db: DjangoDatabase,
@@ -68,12 +65,16 @@ impl Session {
 
         Self {
             workspace,
-            client_capabilities: params.capabilities.clone(),
-            position_encoding: negotiate_position_encoding(&params.capabilities),
+            client_capabilities: ClientCapabilities::negotiate(&params.capabilities),
             db,
         }
     }
 
+    #[must_use]
+    pub fn client_capabilities(&self) -> ClientCapabilities {
+        self.client_capabilities
+    }
+
     #[must_use]
     pub fn db(&self) -> &DjangoDatabase {
         &self.db
@@ -83,11 +84,6 @@ impl Session {
         self.db.set_settings(settings);
     }
 
-    #[must_use]
-    pub fn position_encoding(&self) -> PositionEncoding {
-        self.position_encoding
-    }
-
     /// Execute a read-only operation with access to the database.
     pub fn with_db<F, R>(&self, f: F) -> R
     where
@@ -104,11 +100,6 @@ impl Session {
         f(&mut self.db)
     }
 
-    /// Get a reference to the database for project operations.
-    pub fn database(&self) -> &DjangoDatabase {
-        &self.db
-    }
-
     /// Get the current project for this session
     pub fn project(&self) -> Option<djls_project::Project> {
         self.db.project()
@@ -180,7 +171,7 @@ impl Session {
             &path,
             doc_changes,
             text_document.version,
-            self.position_encoding,
+            self.client_capabilities.position_encoding(),
         )?;
 
         self.handle_file(document.file());
@@ -219,60 +210,77 @@ impl Session {
             }
         }
     }
+}
 
-    /// Check if the client supports pull diagnostics.
-    ///
-    /// Returns true if the client has indicated support for textDocument/diagnostic requests.
-    /// When true, the server should not push diagnostics and instead wait for pull requests.
-    #[must_use]
-    pub fn supports_pull_diagnostics(&self) -> bool {
-        self.client_capabilities
+impl Default for Session {
+    fn default() -> Self {
+        Self::new(&lsp_types::InitializeParams::default())
+    }
+}
+
+#[derive(Debug, Clone, Copy)]
+pub struct ClientCapabilities {
+    pull_diagnostics: bool,
+    snippets: bool,
+    position_encoding: PositionEncoding,
+}
+
+impl ClientCapabilities {
+    fn negotiate(capabilities: &lsp_types::ClientCapabilities) -> Self {
+        let pull_diagnostics = capabilities
             .text_document
             .as_ref()
-            .and_then(|td| td.diagnostic.as_ref())
-            .is_some()
-    }
+            .and_then(|text_doc| text_doc.diagnostic.as_ref())
+            .is_some();
 
-    /// Check if the client supports snippet completions
-    #[must_use]
-    pub fn supports_snippets(&self) -> bool {
-        self.client_capabilities
+        let snippets = capabilities
             .text_document
             .as_ref()
-            .and_then(|td| td.completion.as_ref())
-            .and_then(|c| c.completion_item.as_ref())
-            .and_then(|ci| ci.snippet_support)
-            .unwrap_or(false)
+            .and_then(|text_document| text_document.completion.as_ref())
+            .and_then(|completion| completion.completion_item.as_ref())
+            .and_then(|completion_item| completion_item.snippet_support)
+            .unwrap_or(false);
+
+        let client_encodings = capabilities
+            .general
+            .as_ref()
+            .and_then(|general| general.position_encodings.as_ref())
+            .map_or(&[][..], |kinds| kinds.as_slice());
+
+        let position_encoding = [
+            PositionEncoding::Utf8,
+            PositionEncoding::Utf32,
+            PositionEncoding::Utf16,
+        ]
+        .into_iter()
+        .find(|&preferred| {
+            client_encodings
+                .iter()
+                .any(|kind| kind.to_position_encoding() == Some(preferred))
+        })
+        .unwrap_or(PositionEncoding::Utf16);
+
+        Self {
+            pull_diagnostics,
+            snippets,
+            position_encoding,
+        }
     }
-}
 
-impl Default for Session {
-    fn default() -> Self {
-        Self::new(&lsp_types::InitializeParams::default())
+    #[must_use]
+    pub fn supports_pull_diagnostics(&self) -> bool {
+        self.pull_diagnostics
     }
-}
 
-fn negotiate_position_encoding(capabilities: &lsp_types::ClientCapabilities) -> PositionEncoding {
-    let client_encodings = capabilities
-        .general
-        .as_ref()
-        .and_then(|general| general.position_encodings.as_ref())
-        .map_or(&[][..], |encodings| encodings.as_slice());
-
-    for preferred in [
-        PositionEncoding::Utf8,
-        PositionEncoding::Utf32,
-        PositionEncoding::Utf16,
-    ] {
-        if client_encodings
-            .iter()
-            .any(|kind| kind.to_position_encoding() == Some(preferred))
-        {
-            return preferred;
-        }
+    #[must_use]
+    pub fn supports_snippets(&self) -> bool {
+        self.snippets
     }
 
-    PositionEncoding::Utf16
+    #[must_use]
+    pub fn position_encoding(&self) -> PositionEncoding {
+        self.position_encoding
+    }
 }
 
 #[cfg(test)]
@@ -367,7 +375,7 @@ mod tests {
             ..Default::default()
         };
         assert_eq!(
-            negotiate_position_encoding(&capabilities),
+            ClientCapabilities::negotiate(&capabilities).position_encoding(),
             PositionEncoding::Utf8
         );
     }
@@ -385,7 +393,7 @@ mod tests {
             ..Default::default()
         };
         assert_eq!(
-            negotiate_position_encoding(&capabilities),
+            ClientCapabilities::negotiate(&capabilities).position_encoding(),
             PositionEncoding::Utf32
         );
     }
@@ -403,7 +411,7 @@ mod tests {
             ..Default::default()
         };
         assert_eq!(
-            negotiate_position_encoding(&capabilities),
+            ClientCapabilities::negotiate(&capabilities).position_encoding(),
             PositionEncoding::Utf16
         );
     }
@@ -412,7 +420,7 @@ mod tests {
     fn test_negotiate_fallback_with_no_capabilities() {
         let capabilities = lsp_types::ClientCapabilities::default();
         assert_eq!(
-            negotiate_position_encoding(&capabilities),
+            ClientCapabilities::negotiate(&capabilities).position_encoding(),
             PositionEncoding::Utf16
         );
     }