Patch to improve Dart LSP support for LanguageClient-Neovim

lcnv-dart-lsp-fixes.patch

diff --git a/src/language_server_protocol.rs b/src/language_server_protocol.rs
index 1b3d7cb..d38aaf3 100644
--- a/src/language_server_protocol.rs
+++ b/src/language_server_protocol.rs
@@ -1197,6 +1197,14 @@ impl LanguageClient {
                             related_information: Some(true),
                             ..PublishDiagnosticsCapability::default()
                         }),
+                        code_action: Some(CodeActionCapability {
+                            code_action_literal_support: Some(CodeActionLiteralSupport {
+                                code_action_kind: CodeActionKindLiteralSupport {
+                                    value_set: vec!["quickfix".to_owned(), "assist".to_owned(), "refactor".to_owned()],
+                                },
+                            }),
+                            ..CodeActionCapability::default()
+                        }),
                         code_lens: Some(GenericCapability {
                             dynamic_registration: Some(true),
                         }),
@@ -3172,6 +3180,10 @@ impl LanguageClient {
             virtual_texts.extend(self.virtual_texts_from_code_lenses(filename)?.into_iter());
         }
 
+        if UseVirtualText::All == use_virtual_text {
+            virtual_texts.extend(self.virtual_texts_from_close_labels(filename)?.into_iter());
+        }
+
         if self.get(|state| state.is_nvim)? {
             let namespace_id = self.get_or_create_namespace(&LCNamespace::VirtualText)?;
             self.vim()?.set_virtual_texts(
@@ -3233,7 +3245,7 @@ impl LanguageClient {
                         .push_str(format!(" | {}", text).as_str()),
                     None => virtual_texts.push(VirtualText {
                         line,
-                        text,
+                        text: format!("// {}", text),
                         hl_group: "Comment".into(),
                     }),
                 }
@@ -3243,6 +3255,32 @@ impl LanguageClient {
         Ok(virtual_texts)
     }
 
+    fn virtual_texts_from_close_labels(&self, filename: &str) -> Fallible<Vec<VirtualText>> {
+        let mut virtual_texts = vec![];
+        let close_labels = self.get(|state| state.close_labels.get(filename).cloned().unwrap_or_default())?;
+
+        for cl in close_labels {
+            let line = cl.lnum;
+            let text = cl.label;
+
+            match virtual_texts
+                .iter()
+                .position(|v: &VirtualText| v.line == line)
+            {
+                Some(idx) => virtual_texts[idx]
+                    .text
+                    .push_str(format!(" | {}", text).as_str()),
+                None => virtual_texts.push(VirtualText {
+                    line,
+                    text,
+                    hl_group: "Comment".into(),
+                }),
+            }
+        }
+
+        Ok(virtual_texts)
+    }
+
     pub fn languageClient_handleCompleteDone(&self, params: &Value) -> Fallible<()> {
         let filename = self.vim()?.get_filename(params)?;
         let position = self.vim()?.get_position(params)?;
@@ -3657,6 +3695,37 @@ impl LanguageClient {
         Ok(())
     }
 
+    pub fn dart_handleCloseLabels(&self, params: &Value) -> Fallible<()> {
+        info!("Begin {}", NOTIFICATION__DartCloseLabels);
+        let params: CloseLabelParams = serde_json::from_value(params.clone())?;
+        let mut filename = params.uri.filepath()?.to_string_lossy().into_owned();
+        // Workaround bug: remove first '/' in case of '/C:/blabla'.
+        if filename.starts_with('/') && filename.chars().nth(2) == Some(':') {
+            filename.remove(0);
+        }
+        // Unify name to avoid mismatch due to case insensitivity.
+        let filename = filename.canonicalize();
+        let close_labels = params
+            .labels
+            .into_iter()
+            .map(|lab| {
+                CloseLabel {
+                    label: lab.label,
+                    lnum: lab.range.end.line,
+                }
+            })
+            .collect::<Vec<_>>();
+        
+        self.update(|state| {
+            state
+                .close_labels
+                .insert(filename.clone(), close_labels.clone());
+            Ok(())
+        })?;
+        info!("End {}", NOTIFICATION__DartCloseLabels);
+        Ok(())
+    }
+
     pub fn window_progress(&self, params: &Value) -> Fallible<()> {
         info!("Begin {}", NOTIFICATION__WindowProgress);
         let params: WindowProgressParams = params.clone().to_lsp()?;
diff --git a/src/logger.rs b/src/logger.rs
index e7c22e4..ad2d25e 100644
--- a/src/logger.rs
+++ b/src/logger.rs
@@ -74,7 +74,7 @@ fn create_config(path: &Option<PathBuf>, level: LevelFilter) -> Fallible<Config>
                 .write(true)
                 .truncate(true)
                 .open(&path)
-                .with_context(|err| format!("Failed to open file ({}): {}", path, err))?;
+                .with_context(|err| format!("Failed to open file ({:?}): {}", path, err))?;
             #[allow(clippy::write_literal)]
             writeln!(
                 f,
diff --git a/src/rpchandler.rs b/src/rpchandler.rs
index 7811be7..5a337d3 100644
--- a/src/rpchandler.rs
+++ b/src/rpchandler.rs
@@ -183,6 +183,7 @@ impl LanguageClient {
             NOTIFICATION__RustBeginBuild => self.rust_handleBeginBuild(&params)?,
             NOTIFICATION__RustDiagnosticsBegin => self.rust_handleDiagnosticsBegin(&params)?,
             NOTIFICATION__RustDiagnosticsEnd => self.rust_handleDiagnosticsEnd(&params)?,
+            NOTIFICATION__DartCloseLabels => self.dart_handleCloseLabels(&params)?,
             NOTIFICATION__WindowProgress => self.window_progress(&params)?,
             NOTIFICATION__ServerExited => self.languageClient_serverExited(&params)?,
 
diff --git a/src/types.rs b/src/types.rs
index f0a4b26..813e6d0 100644
--- a/src/types.rs
+++ b/src/types.rs
@@ -54,6 +54,7 @@ pub const NOTIFICATION__ClearDocumentHighlight: &str = "languageClient/clearDocu
 pub const NOTIFICATION__RustBeginBuild: &str = "rustDocument/beginBuild";
 pub const NOTIFICATION__RustDiagnosticsBegin: &str = "rustDocument/diagnosticsBegin";
 pub const NOTIFICATION__RustDiagnosticsEnd: &str = "rustDocument/diagnosticsEnd";
+pub const NOTIFICATION__DartCloseLabels: &str = "dart/textDocument/publishClosingLabels";
 // This is an RLS extension but the name is general enough to assume it might be implemented by
 // other language servers or planned for inclusion in the base protocol.
 pub const NOTIFICATION__WindowProgress: &str = "window/progress";
@@ -110,6 +111,24 @@ pub enum UseVirtualText {
     No,
 }
 
+#[derive(Debug, Clone, PartialEq, Serialize, Deserialize)]
+pub struct CloseLabel {
+    pub label: String,
+    pub lnum: u64,
+}
+
+#[derive(Debug, Clone, PartialEq, Serialize, Deserialize)]
+pub struct CloseLabelParams {
+    pub uri: Url,
+    pub labels: Vec<CloseLabelParamsLabel>,
+}
+
+#[derive(Debug, Clone, PartialEq, Serialize, Deserialize)]
+pub struct CloseLabelParamsLabel {
+    pub label: String,
+    pub range: Range,
+}
+
 #[derive(Serialize)]
 pub struct State {
     // Program state.
@@ -135,6 +154,8 @@ pub struct State {
     pub diagnostics: HashMap<String, Vec<Diagnostic>>,
     // filename => codeLens.
     pub code_lens: HashMap<String, Vec<CodeLens>>,
+    // filename => closeLabels.
+    pub close_labels: HashMap<String, Vec<CloseLabel>>,
     #[serde(skip_serializing)]
     pub line_diagnostics: HashMap<(String, u64), String>,
     pub sign_next_id: u64,
@@ -221,6 +242,7 @@ impl State {
             semantic_scope_to_hl_group_table: HashMap::new(),
             semantic_highlights: HashMap::new(),
             code_lens: HashMap::new(),
+            close_labels: HashMap::new(),
             diagnostics: HashMap::new(),
             line_diagnostics: HashMap::new(),
             sign_next_id: 75_000,