Use /v3/index.json for NuGet feed check

lib/start-proxy-action.js

@@ -122879,6 +122879,18 @@ async function checkProxyEnvironment(logger, language) {
 // src/start-proxy/reachability.ts
 var https = __toESM(require("https"));
 var import_https_proxy_agent = __toESM(require_dist2());
+var connectionTestConfig = {
+  nuget_feed: { path: "v3/index.json" }
+};
+function makeTestUrl(config, base) {
+  if (config?.path === void 0) {
+    return base;
+  }
+  if (base.pathname.endsWith(config.path)) {
+    return base;
+  }
+  return new URL(config.path, base);
+}
 var ReachabilityError = class extends Error {
   constructor(statusCode) {
     super();
@@ -122932,6 +122944,7 @@ async function checkConnections(logger, proxy, backend) {
       backend = new NetworkReachabilityBackend(proxy);
     }
     for (const registry of proxy.registries) {
+      const config = connectionTestConfig[registry.type];
       const address = getAddressString(registry);
       const url = URL.parse(address);
       if (url === null) {
@@ -122940,9 +122953,10 @@ async function checkConnections(logger, proxy, backend) {
         );
         continue;
       }
+      const testUrl = makeTestUrl(config, url);
       try {
         logger.debug(`Testing connection to ${url}...`);
-        const statusCode = await backend.checkConnection(url);
+        const statusCode = await backend.checkConnection(testUrl);
         logger.info(`Successfully tested connection to ${url} (${statusCode})`);
         result.add(registry);
       } catch (e) {

src/start-proxy/reachability.test.ts

@@ -8,6 +8,7 @@ import {
 } from "./../testing-utils";
 import {
   checkConnections,
+  connectionTestConfig,
   ReachabilityBackend,
   ReachabilityError,
 } from "./reachability";
@@ -118,3 +119,34 @@ test("checkConnections - handles invalid URLs", async (t) => {
     `Finished testing connections`,
   ]);
 });
+
+test("checkConnections - appends extra paths", async (t) => {
+  const backend = new MockReachabilityBackend();
+  const checkConnection = sinon.stub(backend, "checkConnection").resolves(200);
+
+  const messages = await withRecordingLoggerAsync(async (logger) => {
+    const reachable = await checkConnections(
+      logger,
+      {
+        ...proxyInfo,
+        registries: [{ ...nugetFeed, url: "https://api.nuget.org/" }],
+      },
+      backend,
+    );
+  });
+  checkExpectedLogMessages(t, messages, [
+    `Testing connection to https://api.nuget.org/`,
+    `Successfully tested connection to https://api.nuget.org/`,
+    `Finished testing connections`,
+  ]);
+
+  t.true(
+    checkConnection.calledWith(
+      sinon.match(
+        new URL(
+          `https://api.nuget.org/${connectionTestConfig["nuget_feed"]?.path}`,
+        ),
+      ),
+    ),
+  );
+});

src/start-proxy/reachability.ts

@@ -7,6 +7,35 @@ import { getErrorMessage } from "../util";
 
 import { getAddressString, ProxyInfo, Registry } from "./types";
 
+/** Represents registry-specific connection test configurations. */
+export interface ConnectionTestConfig {
+  /** An optional path to append to the end of the base url. */
+  path?: string;
+}
+
+/** A partial mapping of registry types to extra connection test configurations. */
+export const connectionTestConfig: Partial<
+  Record<string, ConnectionTestConfig>
+> = {
+  nuget_feed: { path: "v3/index.json" },
+};
+
+/**
+ * Applies the registry-specific check configuration to the base URL, if any and applicable.
+ */
+export function makeTestUrl(
+  config: ConnectionTestConfig | undefined,
+  base: URL,
+): URL {
+  if (config?.path === undefined) {
+    return base;
+  }
+  if (base.pathname.endsWith(config.path)) {
+    return base;
+  }
+  return new URL(config.path, base);
+}
+
 export class ReachabilityError extends Error {
   constructor(public readonly statusCode?: number | undefined) {
     super();
@@ -92,6 +121,7 @@ export async function checkConnections(
     }
 
     for (const registry of proxy.registries) {
+      const config = connectionTestConfig[registry.type];
       const address = getAddressString(registry);
       const url = URL.parse(address);
 
@@ -102,9 +132,11 @@ export async function checkConnections(
         continue;
       }
 
+      const testUrl = makeTestUrl(config, url);
+
       try {
         logger.debug(`Testing connection to ${url}...`);
-        const statusCode = await backend.checkConnection(url);
+        const statusCode = await backend.checkConnection(testUrl);
 
         logger.info(`Successfully tested connection to ${url} (${statusCode})`);
         result.add(registry);