perf: check cancellation token before analysis and clarify code

src/extension.ts

@@ -1,8 +1,7 @@
-// The module 'vscode' contains the VS Code extensibility API
-// Import the module and reference it with the alias vscode in your code below
 import * as vscode from "vscode";
 import { registerCodeLensProvider } from "./providers/codeLensProvider";
 import { UnifiedFunctionMetrics } from "./metricsAnalyzer/metricsAnalyzerFactory";
+import { ConfigurationManager } from "./configuration";
 
 /** Shared output channel for function complexity details (created once, reused). */
 let detailsChannel: vscode.OutputChannel | undefined;
@@ -13,7 +12,7 @@ let detailsChannel: vscode.OutputChannel | undefined;
  */
 function showFunctionDetails(
   func?: UnifiedFunctionMetrics,
-  _uri?: vscode.Uri
+  uri?: vscode.Uri
 ): void {
   if (!func) {
     return;
@@ -23,9 +22,14 @@ function showFunctionDetails(
     detailsChannel = vscode.window.createOutputChannel("Code Metrics Details");
   }
 
+  const config = ConfigurationManager.getConfiguration(uri);
+  const status = ConfigurationManager.getComplexityStatus(func.complexity, config);
+
   detailsChannel.clear();
   detailsChannel.appendLine(`Function: ${func.name}`);
-  detailsChannel.appendLine(`Cognitive Complexity: ${func.complexity}`);
+  detailsChannel.appendLine(
+    `Cognitive Complexity: ${func.complexity}  ${status.icon} ${status.text}`
+  );
   detailsChannel.appendLine(
     `Location: lines ${func.startLine + 1}–${func.endLine + 1}`
   );

src/providers/codeLensProvider.ts

@@ -141,6 +141,13 @@ export class MetricsCodeLensProvider implements vscode.CodeLensProvider {
       return [];
     }
 
+    // Bail out early if VS Code has already cancelled this request (e.g. the user
+    // typed another character while analysis was pending). This avoids wasting a
+    // potentially expensive tree-sitter parse whose result would be discarded anyway.
+    if (token.isCancellationRequested) {
+      return [];
+    }
+
     try {
       const analysisKey = `${document.uri.toString()}#${document.languageId}#${document.version}`;
       let functions = this.analysisCache.get(analysisKey);
@@ -203,19 +210,10 @@ export class MetricsCodeLensProvider implements vscode.CodeLensProvider {
     document: vscode.TextDocument,
     config: CodeMetricsConfig
   ): vscode.CodeLens[] {
-    const codeLenses: vscode.CodeLens[] = [];
-
-    functions.forEach((func) => {
-      // Only show code lens for functions with complexity > 0
-      if (func.complexity > 0) {
-        const codeLens = this.createCodeLens(func, document, config);
-        if (codeLens) {
-          codeLenses.push(codeLens);
-        }
-      }
-    });
-
-    return codeLenses;
+    return functions
+      .filter((func) => func.complexity > 0)
+      .map((func) => this.createCodeLens(func, document, config))
+      .filter((lens): lens is vscode.CodeLens => lens !== undefined);
   }
 
   private createCodeLens(