Improvements to web-fetch tool (#1030)

1 files changed, 57 insertions, 0 deletions

diff --git a/packages/core/src/utils/fetch.ts b/packages/core/src/utils/fetch.ts
new file mode 100644
index 00000000..e78a3247
--- /dev/null
+++ b/packages/core/src/utils/fetch.ts
@@ -0,0 +1,57 @@
+/**
+ * @license
+ * Copyright 2025 Google LLC
+ * SPDX-License-Identifier: Apache-2.0
+ */
+
+import { getErrorMessage, isNodeError } from './errors.js';
+import { URL } from 'url';
+
+const PRIVATE_IP_RANGES = [
+  /^10\./,
+  /^127\./,
+  /^172\.(1[6-9]|2[0-9]|3[0-1])\./,
+  /^192\.168\./,
+  /^::1$/,
+  /^fc00:/,
+  /^fe80:/,
+];
+
+export class FetchError extends Error {
+  constructor(
+    message: string,
+    public code?: string,
+  ) {
+    super(message);
+    this.name = 'FetchError';
+  }
+}
+
+export function isPrivateIp(url: string): boolean {
+  try {
+    const hostname = new URL(url).hostname;
+    return PRIVATE_IP_RANGES.some((range) => range.test(hostname));
+  } catch (_e) {
+    return false;
+  }
+}
+
+export async function fetchWithTimeout(
+  url: string,
+  timeout: number,
+): Promise<Response> {
+  const controller = new AbortController();
+  const timeoutId = setTimeout(() => controller.abort(), timeout);
+
+  try {
+    const response = await fetch(url, { signal: controller.signal });
+    return response;
+  } catch (error) {
+    if (isNodeError(error) && error.code === 'ABORT_ERR') {
+      throw new FetchError(`Request timed out after ${timeout}ms`, 'ETIMEDOUT');
+    }
+    throw new FetchError(getErrorMessage(error));
+  } finally {
+    clearTimeout(timeoutId);
+  }
+}