Merge pull request #2507 from Philipp-M/multiple-language-servers

Add support for multiple language servers per language

1 files changed, 77 insertions, 35 deletions

diff --git a/helix-view/src/document.rs b/helix-view/src/document.rs
index eb376567..bd3c465d 100644
--- a/helix-view/src/document.rs
+++ b/helix-view/src/document.rs
@@ -6,7 +6,7 @@ use futures_util::FutureExt;
 use helix_core::auto_pairs::AutoPairs;
 use helix_core::doc_formatter::TextFormat;
 use helix_core::encoding::Encoding;
-use helix_core::syntax::Highlight;
+use helix_core::syntax::{Highlight, LanguageServerFeature};
 use helix_core::text_annotations::{InlineAnnotation, TextAnnotations};
 use helix_core::Range;
 use helix_vcs::{DiffHandle, DiffProviderRegistry};
@@ -179,8 +179,8 @@ pub struct Document {
     version: i32, // should be usize?
     pub(crate) modified_since_accessed: bool,
 
-    diagnostics: Vec<Diagnostic>,
-    language_server: Option<Arc<helix_lsp::Client>>,
+    pub(crate) diagnostics: Vec<Diagnostic>,
+    pub(crate) language_servers: HashMap<LanguageServerName, Arc<Client>>,
 
     diff_handle: Option<DiffHandle>,
     version_control_head: Option<Arc<ArcSwap<Box<str>>>>,
@@ -580,7 +580,7 @@ where
     *mut_ref = f(mem::take(mut_ref));
 }
 
-use helix_lsp::lsp;
+use helix_lsp::{lsp, Client, LanguageServerName};
 use url::Url;
 
 impl Document {
@@ -616,7 +616,7 @@ impl Document {
             last_saved_time: SystemTime::now(),
             last_saved_revision: 0,
             modified_since_accessed: false,
-            language_server: None,
+            language_servers: HashMap::new(),
             diff_handle: None,
             config,
             version_control_head: None,
@@ -730,10 +730,12 @@ impl Document {
             return Some(formatting_future.boxed());
         };
 
-        let language_server = self.language_server()?;
         let text = self.text.clone();
+        // finds first language server that supports formatting and then formats
+        let language_server = self
+            .language_servers_with_feature(LanguageServerFeature::Format)
+            .next()?;
         let offset_encoding = language_server.offset_encoding();
-
         let request = language_server.text_document_formatting(
             self.identifier(),
             lsp::FormattingOptions {
@@ -797,13 +799,12 @@ impl Document {
                 if self.path.is_none() {
                     bail!("Can't save with no path set!");
                 }
-
                 self.path.as_ref().unwrap().clone()
             }
         };
 
         let identifier = self.path().map(|_| self.identifier());
-        let language_server = self.language_server.clone();
+        let language_servers = self.language_servers.clone();
 
         // mark changes up to now as saved
         let current_rev = self.get_current_revision();
@@ -847,14 +848,13 @@ impl Document {
                 text: text.clone(),
             };
 
-            if let Some(language_server) = language_server {
+            for (_, language_server) in language_servers {
                 if !language_server.is_initialized() {
                     return Ok(event);
                 }
-
-                if let Some(identifier) = identifier {
+                if let Some(identifier) = &identifier {
                     if let Some(notification) =
-                        language_server.text_document_did_save(identifier, &text)
+                        language_server.text_document_did_save(identifier.clone(), &text)
                     {
                         notification.await?;
                     }
@@ -1004,11 +1004,6 @@ impl Document {
         Ok(())
     }
 
-    /// Set the LSP.
-    pub fn set_language_server(&mut self, language_server: Option<Arc<helix_lsp::Client>>) {
-        self.language_server = language_server;
-    }
-
     /// Select text within the [`Document`].
     pub fn set_selection(&mut self, view_id: ViewId, selection: Selection) {
         // TODO: use a transaction?
@@ -1159,7 +1154,7 @@ impl Document {
 
             if emit_lsp_notification {
                 // emit lsp notification
-                if let Some(language_server) = self.language_server() {
+                for language_server in self.language_servers() {
                     let notify = language_server.text_document_did_change(
                         self.versioned_identifier(),
                         &old_doc,
@@ -1415,18 +1410,13 @@ impl Document {
             .map(|language| language.language_id.as_str())
     }
 
-    /// Language ID for the document. Either the `language-id` from the
-    /// `language-server` configuration, or the document language if no
-    /// `language-id` has been specified.
+    /// Language ID for the document. Either the `language-id`,
+    /// or the document language name if no `language-id` has been specified.
     pub fn language_id(&self) -> Option<&str> {
-        let language_config = self.language.as_deref()?;
-
-        language_config
-            .language_server
-            .as_ref()?
-            .language_id
+        self.language_config()?
+            .language_server_language_id
             .as_deref()
-            .or(Some(language_config.language_id.as_str()))
+            .or_else(|| self.language_name())
     }
 
     /// Corresponding [`LanguageConfiguration`].
@@ -1439,10 +1429,45 @@ impl Document {
         self.version
     }
 
-    /// Language server if it has been initialized.
-    pub fn language_server(&self) -> Option<&helix_lsp::Client> {
-        let server = self.language_server.as_deref()?;
-        server.is_initialized().then_some(server)
+    /// maintains the order as configured in the language_servers TOML array
+    pub fn language_servers(&self) -> impl Iterator<Item = &helix_lsp::Client> {
+        self.language_config().into_iter().flat_map(move |config| {
+            config.language_servers.iter().filter_map(move |features| {
+                let ls = &**self.language_servers.get(&features.name)?;
+                if ls.is_initialized() {
+                    Some(ls)
+                } else {
+                    None
+                }
+            })
+        })
+    }
+
+    pub fn remove_language_server_by_name(&mut self, name: &str) -> Option<Arc<Client>> {
+        self.language_servers.remove(name)
+    }
+
+    pub fn language_servers_with_feature(
+        &self,
+        feature: LanguageServerFeature,
+    ) -> impl Iterator<Item = &helix_lsp::Client> {
+        self.language_config().into_iter().flat_map(move |config| {
+            config.language_servers.iter().filter_map(move |features| {
+                let ls = &**self.language_servers.get(&features.name)?;
+                if ls.is_initialized()
+                    && ls.supports_feature(feature)
+                    && features.has_feature(feature)
+                {
+                    Some(ls)
+                } else {
+                    None
+                }
+            })
+        })
+    }
+
+    pub fn supports_language_server(&self, id: usize) -> bool {
+        self.language_servers().any(|l| l.id() == id)
     }
 
     pub fn diff_handle(&self) -> Option<&DiffHandle> {
@@ -1565,12 +1590,29 @@ impl Document {
         &self.diagnostics
     }
 
-    pub fn set_diagnostics(&mut self, diagnostics: Vec<Diagnostic>) {
-        self.diagnostics = diagnostics;
+    pub fn shown_diagnostics(&self) -> impl Iterator<Item = &Diagnostic> + DoubleEndedIterator {
+        self.diagnostics.iter().filter(|d| {
+            self.language_servers_with_feature(LanguageServerFeature::Diagnostics)
+                .any(|ls| ls.id() == d.language_server_id)
+        })
+    }
+
+    pub fn replace_diagnostics(
+        &mut self,
+        mut diagnostics: Vec<Diagnostic>,
+        language_server_id: usize,
+    ) {
+        self.clear_diagnostics(language_server_id);
+        self.diagnostics.append(&mut diagnostics);
         self.diagnostics
             .sort_unstable_by_key(|diagnostic| diagnostic.range);
     }
 
+    pub fn clear_diagnostics(&mut self, language_server_id: usize) {
+        self.diagnostics
+            .retain(|d| d.language_server_id != language_server_id);
+    }
+
     /// Get the document's auto pairs. If the document has a recognized
     /// language config with auto pairs configured, returns that;
     /// otherwise, falls back to the global auto pairs config. If the global