feat: use vsts-task-installer User-Agent for NuGet download statistics

.github/copilot-instructions.md

@@ -63,7 +63,7 @@ The install-analyzers task interacts with NuGet via two APIs:
 Key design decisions:
 - `parseRegistrationIndex()` is a pure function (no I/O) for easy testing
 - `queryNuGetRegistration()` is a shared module usable by any task needing NuGet version info
-- `User-Agent: ALCops-AzureDevOps` is set on all HTTP requests for NuGet.org statistics tracking
+- `User-Agent: vsts-task-installer/{version}` is set on NuGet HTTP requests, matching a known client pattern in NuGet.org's CDN log parser for download statistics visibility
 - Unlisted versions are filtered out during version resolution
 - `resolveVersion()` returns a `ResolvedVersion` with both the version string and the `packageContentUrl` from the Registration API (avoids redundant URL construction)
 

shared/user-agent.ts

@@ -0,0 +1,10 @@
+import * as os from 'os';
+
+/**
+ * Build the User-Agent string sent on NuGet HTTP requests.
+ * Uses the `vsts-task-installer` known-client pattern recognised by NuGet.org's
+ * CDN log parser so downloads appear in per-package statistics.
+ */
+export function getUserAgent(version: string): string {
+    return `vsts-task-installer/${version} (Node.js ${process.version}; ${os.type()} ${os.release()})`;
+}

tasks/install-analyzers/src/nuget-api.ts

@@ -5,9 +5,12 @@ import { NUGET_PACKAGE_NAME, NUGET_FLAT_CONTAINER, RegistrationVersion } from '.
 import { Logger, nullLogger } from '../../../shared/logger';
 import { queryNuGetRegistration } from '../../../shared/nuget-registration';
 import { httpsGetBuffer } from '../../../shared/http-client';
+import { getUserAgent } from '../../../shared/user-agent';
+import taskJson from '../task.json';
 
 const packageId = NUGET_PACKAGE_NAME.toLowerCase();
-const USER_AGENT = 'ALCops-AzureDevOps';
+const { Major, Minor, Patch } = taskJson.version;
+const USER_AGENT = getUserAgent(`${Major}.${Minor}.${Patch}`);
 
 export interface ResolvedVersion {
     version: string;

tests/install-analyzers/nuget-api.test.ts

@@ -222,7 +222,7 @@ describe('downloadPackage', () => {
         try {
             await downloadPackage('1.0.0', tmpDir);
             const calledOpts = mockRequest.mock.calls[0][1] as { headers?: Record<string, string> };
-            expect(calledOpts.headers?.['User-Agent']).toBe('ALCops-AzureDevOps');
+            expect(calledOpts.headers?.['User-Agent']).toMatch(/^vsts-task-installer\/\d+\.\d+\.\d+ \(Node\.js v/);
         } finally {
             fs.rmSync(tmpDir, { recursive: true, force: true });
         }

tests/shared/user-agent.test.ts

@@ -0,0 +1,20 @@
+import { describe, it, expect } from 'vitest';
+import { getUserAgent } from '../../shared/user-agent';
+
+describe('getUserAgent', () => {
+    it('returns vsts-task-installer format with version', () => {
+        const ua = getUserAgent('1.2.3');
+        expect(ua).toMatch(/^vsts-task-installer\/1\.2\.3 \(Node\.js v\d+\.\d+\.\d+; \w+ .+\)$/);
+    });
+
+    it('includes process.version and os info', () => {
+        const ua = getUserAgent('0.0.1');
+        expect(ua).toContain(`Node.js ${process.version}`);
+        expect(ua).toContain('vsts-task-installer/0.0.1');
+    });
+
+    it('works with pre-release style versions', () => {
+        const ua = getUserAgent('2.0.0-beta.1');
+        expect(ua).toMatch(/^vsts-task-installer\/2\.0\.0-beta\.1 \(/);
+    });
+});