feat: add web search tools extension

.pi/agent/extensions/web-search/src/tools/web-fetch.test.ts

@@ -0,0 +1,62 @@
+import test from "node:test";
+import assert from "node:assert/strict";
+import { createWebFetchTool } from "./web-fetch.ts";
+
+test("web_fetch prepareArguments folds a single url into urls", () => {
+  const tool = createWebFetchTool({
+    resolveProvider: async () => {
+      throw new Error("not used");
+    },
+  });
+
+  assert.deepEqual(tool.prepareArguments?.({ url: "https://exa.ai/docs" }), {
+    url: "https://exa.ai/docs",
+    urls: ["https://exa.ai/docs"],
+  });
+});
+
+test("web_fetch defaults to text and returns formatted fetch results", async () => {
+  let capturedRequest: Record<string, unknown> | undefined;
+
+  const tool = createWebFetchTool({
+    resolveProvider: async () => ({
+      name: "exa-main",
+      type: "exa",
+      async search() {
+        throw new Error("not used");
+      },
+      async fetch(request) {
+        capturedRequest = request as unknown as Record<string, unknown>;
+        return {
+          providerName: "exa-main",
+          results: [
+            {
+              url: "https://exa.ai/docs",
+              title: "Docs",
+              text: "Body",
+            },
+          ],
+        };
+      },
+    }),
+  });
+
+  const result = await tool.execute("tool-1", { urls: ["https://exa.ai/docs"] }, undefined, undefined, undefined);
+
+  assert.equal(capturedRequest?.text, true);
+  assert.match((result.content[0] as { text: string }).text, /Body/);
+  assert.equal((result.details as { results: Array<{ title: string }> }).results[0]?.title, "Docs");
+});
+
+test("web_fetch rejects malformed URLs", async () => {
+  const tool = createWebFetchTool({
+    resolveProvider: async () => {
+      throw new Error("should not resolve provider for invalid URLs");
+    },
+  });
+
+  await assert.rejects(
+    () => tool.execute("tool-1", { urls: ["not-a-url"] }, undefined, undefined, undefined),
+    /Invalid URL/,
+  );
+});