refactor: address PR feedback on User-Agent implementation

Address feedback from PR review:

1. Remove unused error parameters from catch blocks
   - Changed `} catch (error) {` to `} catch {` throughout userAgent.ts
   - Cleaner syntax when error is not used

2. Remove userAgent utility exports from public API
   - Removed `export * from './util/userAgent'` from index.ts
   - These are internal utilities, not part of public SDK interface
   - Kept EnvoyAPIOptions type export for public use

3. Update documentation to remove "legacy" terminology
   - Constructor JSDoc now treats both signatures as equal alternatives
   - Changed "Legacy usage" to "Simple usage with access token only"
   - Changed "New usage" to "Usage with custom User-Agent"
   - Updated inline comment from "legacy" to neutral language

4. Add test for emoji and unexpected characters
   - New test verifies SDK handles unusual characters gracefully
   - Tests emoji (🚀) and non-ASCII characters (中文)
   - Ensures JSON serialization works correctly with special chars

All 63 tests pass.

Co-Authored-By: Claude Sonnet 4.5 <noreply@anthropic.com>

Author: Raghav Boorgapally

src/base/EnvoyAPI.ts

@@ -80,22 +80,22 @@ export default class EnvoyAPI {
   /**
    * Create an EnvoyAPI client instance
    *
-   * @param options - Either an access token string (for backward compatibility)
-   *                  or an EnvoyAPIOptions object with accessToken and optional userAgent
+   * @param options - Either an access token string or an EnvoyAPIOptions object
+   *                  with accessToken and optional userAgent
    *
    * @example
-   * // Legacy usage (still supported)
+   * // Simple usage with access token only
    * const client = new EnvoyAPI('access-token-here');
    *
    * @example
-   * // New usage with custom User-Agent
+   * // Usage with custom User-Agent for tracking and debugging
    * const client = new EnvoyAPI({
    *   accessToken: 'access-token-here',
    *   userAgent: 'MyApp/1.0.0'
    * });
    */
   constructor(options: EnvoyAPIOptions | string) {
-    // Support both string (legacy) and options object (new)
+    // Support both string and options object formats
     const { accessToken, userAgent } = typeof options === 'string'
       ? { accessToken: options, userAgent: undefined }
       : options;

src/index.ts

@@ -62,7 +62,6 @@ export * from './sdk/middleware';
 export * from './util/EnvoySignatureVerifier';
 export * from './util/axiosConstructor';
 export * from './util/errorHandling';
-export * from './util/userAgent';
 
 export type { EnvoyAPIOptions } from './base/EnvoyAPI';
 

src/util/userAgent.ts

@@ -6,7 +6,7 @@ try {
   // Import version from package.json
   // Note: In compiled code, this resolves correctly
   version = require('../../package.json').version;
-} catch (error) {
+} catch {
   // If package.json can't be loaded, use fallback version
   // This ensures SDK initialization never fails
   // Silently fail - User-Agent is telemetry, not critical functionality
@@ -39,7 +39,7 @@ function getNodeVersion(): string {
     if (process?.version) {
       return process.version.replace('v', '');
     }
-  } catch (error) {
+  } catch {
     // Ignore error, use fallback
   }
   return 'unknown';
@@ -52,7 +52,7 @@ function getNodeVersion(): string {
 function getPlatform(): string {
   try {
     return os.platform();
-  } catch (error) {
+  } catch {
     // If os.platform() fails, return fallback
     return 'unknown';
   }
@@ -74,7 +74,7 @@ export function buildUserAgent(customUserAgent?: string): string {
     const nodeVersion = getNodeVersion();
     const baseUA = `envoy-integrations-sdk/${version} node/${nodeVersion}`;
     return customUserAgent ? `${baseUA} ${customUserAgent}` : baseUA;
-  } catch (error) {
+  } catch {
     // Critical fallback - should never happen, but ensures SDK always works
     // Silently fail - User-Agent is telemetry, not critical functionality
     return 'envoy-integrations-sdk/unknown node/unknown';
@@ -109,7 +109,7 @@ export function buildClientInfo(customUserAgent?: string): ClientInfo {
     }
 
     return clientInfo;
-  } catch (error) {
+  } catch {
     // Critical fallback - return minimal safe info
     // Silently fail - User-Agent is telemetry, not critical functionality
     return {
@@ -135,7 +135,7 @@ export function buildClientInfoHeader(customUserAgent?: string): string {
   try {
     const clientInfo = buildClientInfo(customUserAgent);
     return JSON.stringify(clientInfo);
-  } catch (error) {
+  } catch {
     // Critical fallback - return minimal valid JSON
     // Silently fail - User-Agent is telemetry, not critical functionality
     // Return minimal valid JSON that won't break parsing

test/base/EnvoyAPI.test.ts

@@ -145,6 +145,25 @@ describe('EnvoyAPI', () => {
         const parsedClientInfo = JSON.parse(clientInfoHeader);
         expect(parsedClientInfo.application).toBe(customUserAgent);
       });
+
+      it('handles userAgent with emoji and unexpected characters', () => {
+        const customUserAgent = 'MyApp🚀/1.0.0 (test版本)';
+        const api = new EnvoyAPI({
+          accessToken: testAccessToken,
+          userAgent: customUserAgent,
+        });
+
+        // SDK should not fail even with unusual characters
+        expect(api).toBeDefined();
+        expect(api.axios.defaults.headers.authorization).toBe(`Bearer ${testAccessToken}`);
+        expect(api.axios.defaults.headers['User-Agent']).toContain(customUserAgent);
+
+        // JSON serialization should handle these characters
+        const clientInfoHeader = api.axios.defaults.headers['X-Envoy-Client-Info'] as string;
+        expect(() => JSON.parse(clientInfoHeader)).not.toThrow();
+        const parsedClientInfo = JSON.parse(clientInfoHeader);
+        expect(parsedClientInfo.application).toBe(customUserAgent);
+      });
     });
 
     describe('authorization header', () => {