Support filter diagnostics by severity

Add config LanguageClient_diagnosticsMaxSeverity

Close #846

Author: autozimu

doc/LanguageClient.txt

@@ -367,6 +367,13 @@ supported.
 Default: Empty string ('')
 Valid Options: string
 
+2.28 g:LanguageClient_diagnosticsMaxSeverity  *g:LanguageClient_diagnosticsMaxSeverity*
+
+Maximum severity to show diagnostic messages.
+
+Default: "Hint"
+Valid options: "Error" | "Warning" | "Information" | "Hint"
+
 ==============================================================================
 3. Commands                                           *LanguageClientCommands*
 

src/language_server_protocol.rs

@@ -112,13 +112,15 @@ impl LanguageClient {
 
         let (
             diagnosticsSignsMax,
+            diagnostics_max_severity,
             documentHighlightDisplay,
             selectionUI_autoOpen,
             use_virtual_text,
             echo_project_root,
-        ): (Option<u64>, Value, u8, u8, u8) = self.vim()?.eval(
+        ): (Option<u64>, String, Value, u8, u8, u8) = self.vim()?.eval(
             [
                 "get(g:, 'LanguageClient_diagnosticsSignsMax', v:null)",
+                "get(g:, 'LanguageClient_diagnosticsMaxSeverity', 'Hint')",
                 "get(g:, 'LanguageClient_documentHighlightDisplay', {})",
                 "!!s:GetVar('LanguageClient_selectionUI_autoOpen', 1)",
                 "s:useVirtualText()",
@@ -184,6 +186,18 @@ impl LanguageClient {
 
         let is_nvim = is_nvim == 1;
 
+        let diagnostics_max_severity = match diagnostics_max_severity.to_ascii_uppercase().as_str()
+        {
+            "ERROR" => DiagnosticSeverity::Error,
+            "WARNING" => DiagnosticSeverity::Warning,
+            "INFORMATION" => DiagnosticSeverity::Information,
+            "HINT" => DiagnosticSeverity::Hint,
+            _ => bail!(
+                "Invalid option for LanguageClient_diagnosticsMaxSeverity: {}",
+                diagnostics_max_severity
+            ),
+        };
+
         self.update(|state| {
             state.autoStart = autoStart;
             state.serverCommands.extend(serverCommands);
@@ -196,6 +210,7 @@ impl LanguageClient {
                 serde_json::to_value(&state.diagnosticsDisplay)?.combine(&diagnosticsDisplay),
             )?;
             state.diagnosticsSignsMax = diagnosticsSignsMax;
+            state.diagnostics_max_severity = diagnostics_max_severity;
             state.documentHighlightDisplay = serde_json::from_value(
                 serde_json::to_value(&state.documentHighlightDisplay)?
                     .combine(&documentHighlightDisplay),
@@ -1818,7 +1833,15 @@ impl LanguageClient {
         // Unify name to avoid mismatch due to case insensitivity.
         let filename = filename.canonicalize();
 
-        let mut diagnostics = params.diagnostics;
+        let diagnostics_max_severity = self.get(|state| state.diagnostics_max_severity)?;
+        let mut diagnostics = params
+            .diagnostics
+            .iter()
+            .filter(|&diagnostic| {
+                diagnostic.severity.unwrap_or(DiagnosticSeverity::Hint) <= diagnostics_max_severity
+            })
+            .map(Clone::clone)
+            .collect::<Vec<_>>();
         diagnostics.sort_by_key(
             // First sort by line.
             // Then severity descendingly. Error should come last since when processing item comes

src/types.rs

@@ -148,6 +148,7 @@ pub struct State {
     pub diagnosticsList: DiagnosticsList,
     pub diagnosticsDisplay: HashMap<u64, DiagnosticsDisplay>,
     pub diagnosticsSignsMax: Option<u64>,
+    pub diagnostics_max_severity: DiagnosticSeverity,
     pub documentHighlightDisplay: HashMap<u64, DocumentHighlightDisplay>,
     pub windowLogMessageLevel: MessageType,
     pub settingsPath: String,
@@ -223,6 +224,7 @@ impl State {
             diagnosticsList: DiagnosticsList::Quickfix,
             diagnosticsDisplay: DiagnosticsDisplay::default(),
             diagnosticsSignsMax: None,
+            diagnostics_max_severity: DiagnosticSeverity::Hint,
             documentHighlightDisplay: DocumentHighlightDisplay::default(),
             windowLogMessageLevel: MessageType::Warning,
             settingsPath: format!(".vim{}settings.json", std::path::MAIN_SEPARATOR),

tests/data/sample-cpp/.gitignore

@@ -1 +1,2 @@
 compile_commands.json
+.ccls-cache

tests/data/sample-cpp/simple.c

@@ -0,0 +1,8 @@
+int main() {
+    int rc = 0;
+
+    if (rc == 0) {
+    }
+
+    return rc;
+}