refactor: address code review feedback

- Use async vscode.workspace.fs.readFile instead of sync fs.readFileSync
- Add type guard for parse result before casting to ObjectNode
- Extract getNormalizedVersion() as shared utility to reduce duplication
- Add regex pattern documentation and named constant
- Check for workbench.action.chat.open command availability before invoking

Co-authored-by: garrytrinder <11563347+garrytrinder@users.noreply.github.com>

Author: Copilot

src/commands/upgrade-config.ts

@@ -1,6 +1,7 @@
 import * as vscode from 'vscode';
 import { Commands } from '../constants';
 import { DevProxyInstall } from '../types';
+import { getNormalizedVersion } from '../utils';
 
 /**
  * Config upgrade commands.
@@ -25,9 +26,7 @@ async function upgradeConfigsWithCopilot(
     return;
   }
 
-  const devProxyVersion = devProxyInstall.isBeta
-    ? devProxyInstall.version.split('-')[0]
-    : devProxyInstall.version;
+  const devProxyVersion = getNormalizedVersion(devProxyInstall);
 
   const fileList = fileUris?.length
     ? fileUris.map(uri => `- ${vscode.workspace.asRelativePath(uri)}`).join('\n')
@@ -43,6 +42,15 @@ async function upgradeConfigsWithCopilot(
   ].join('\n');
 
   try {
+    // workbench.action.chat.open requires GitHub Copilot Chat extension
+    const allCommands = await vscode.commands.getCommands();
+    if (!allCommands.includes('workbench.action.chat.open')) {
+      vscode.window.showWarningMessage(
+        'GitHub Copilot Chat is not available. Please install the GitHub Copilot extension to use this feature.'
+      );
+      return;
+    }
+
     await vscode.commands.executeCommand('workbench.action.chat.open', {
       query: prompt,
       isPartialQuery: false,

src/detect.ts

@@ -103,3 +103,13 @@ export const getDevProxyExe = (versionPreference: VersionPreference) => {
         ? VersionExeName.Stable
         : VersionExeName.Beta;
 };
+
+/**
+ * Get the normalized Dev Proxy version from an install object.
+ * Strips the beta pre-release suffix for version comparison.
+ */
+export const getNormalizedVersion = (devProxyInstall: DevProxyInstall): string => {
+    return devProxyInstall.isBeta
+        ? devProxyInstall.version.split('-')[0]
+        : devProxyInstall.version;
+};

src/notifications.ts

@@ -1,7 +1,7 @@
 import * as vscode from 'vscode';
 import { DevProxyInstall } from './types';
 import { Commands } from './constants';
-import { findOutdatedConfigFiles } from './utils';
+import { findOutdatedConfigFiles, getNormalizedVersion } from './utils';
 
 export const handleStartNotification = (context: vscode.ExtensionContext) => {
     const devProxyInstall = context.globalState.get<DevProxyInstall>('devProxyInstall');
@@ -68,9 +68,7 @@ export async function handleOutdatedConfigFilesNotification(
         return;
     }
 
-    const devProxyVersion = devProxyInstall.isBeta
-        ? devProxyInstall.version.split('-')[0]
-        : devProxyInstall.version;
+    const devProxyVersion = getNormalizedVersion(devProxyInstall);
 
     const outdatedFiles = await findOutdatedConfigFiles(devProxyVersion);
 

src/utils/config-detection.ts

@@ -1,5 +1,4 @@
 import * as vscode from 'vscode';
-import * as fs from 'fs';
 import parse from 'json-to-ast';
 
 /**
@@ -98,7 +97,9 @@ export function isProxyFile(document: vscode.TextDocument): boolean {
  * @returns The version string (e.g., "0.24.0") or empty string if not found.
  */
 export function extractVersionFromSchemaUrl(schemaUrl: string): string {
-  const match = schemaUrl.match(/\/v(\d+\.\d+\.\d+(?:-[a-zA-Z0-9.-]+)?)\//);
+  // Matches /vX.Y.Z/ or /vX.Y.Z-prerelease/ in schema URLs
+  const versionPattern = /\/v(\d+\.\d+\.\d+(?:-[a-zA-Z0-9.-]+)?)\//;
+  const match = schemaUrl.match(versionPattern);
   return match ? match[1] : '';
 }
 
@@ -118,14 +119,21 @@ export async function findOutdatedConfigFiles(devProxyVersion: string): Promise<
 
   for (const uri of jsonFiles) {
     try {
-      const content = fs.readFileSync(uri.fsPath, 'utf-8');
+      const contentBytes = await vscode.workspace.fs.readFile(uri);
+      const content = Buffer.from(contentBytes).toString('utf-8');
 
       // Quick check before parsing
       if (!content.includes('dev-proxy') || !content.includes('schema')) {
         continue;
       }
 
-      const documentNode = parse(content) as parse.ObjectNode;
+      const rootNode = parse(content);
+
+      if (rootNode.type !== 'Object') {
+        continue;
+      }
+
+      const documentNode = rootNode as parse.ObjectNode;
       const schemaNode = getASTNode(documentNode.children, 'Identifier', '$schema');
 
       if (!schemaNode) {

src/utils/index.ts

@@ -29,4 +29,4 @@ export {
 } from './shell';
 
 // Re-export from detect for convenience
-export { getDevProxyExe } from '../detect';
+export { getDevProxyExe, getNormalizedVersion } from '../detect';