test(browser): cover agent contract

src/browser/pw-tools-core.test.ts

@@ -0,0 +1,110 @@
+import { beforeEach, describe, expect, it, vi } from "vitest";
+
+let currentPage: Record<string, unknown> | null = null;
+let currentRefLocator: Record<string, unknown> | null = null;
+
+const sessionMocks = vi.hoisted(() => ({
+  getPageForTargetId: vi.fn(async () => {
+    if (!currentPage) throw new Error("missing page");
+    return currentPage;
+  }),
+  ensurePageState: vi.fn(() => ({
+    console: [],
+    armIdUpload: 0,
+    armIdDialog: 0,
+  })),
+  refLocator: vi.fn(() => {
+    if (!currentRefLocator) throw new Error("missing locator");
+    return currentRefLocator;
+  }),
+}));
+
+vi.mock("./pw-session.js", () => sessionMocks);
+
+async function importModule() {
+  return await import("./pw-tools-core.js");
+}
+
+describe("pw-tools-core", () => {
+  beforeEach(() => {
+    currentPage = null;
+    currentRefLocator = null;
+    for (const fn of Object.values(sessionMocks)) fn.mockClear();
+  });
+
+  it("screenshots an element selector", async () => {
+    const elementScreenshot = vi.fn(async () => Buffer.from("E"));
+    currentPage = {
+      locator: vi.fn(() => ({
+        first: () => ({ screenshot: elementScreenshot }),
+      })),
+      screenshot: vi.fn(async () => Buffer.from("P")),
+    };
+
+    const mod = await importModule();
+    const res = await mod.takeScreenshotViaPlaywright({
+      cdpPort: 18792,
+      targetId: "T1",
+      element: "#main",
+      type: "png",
+    });
+
+    expect(res.buffer.toString()).toBe("E");
+    expect(sessionMocks.getPageForTargetId).toHaveBeenCalled();
+    expect(
+      currentPage.locator as ReturnType<typeof vi.fn>,
+    ).toHaveBeenCalledWith("#main");
+    expect(elementScreenshot).toHaveBeenCalledWith({ type: "png" });
+  });
+
+  it("screenshots a ref locator", async () => {
+    const refScreenshot = vi.fn(async () => Buffer.from("R"));
+    currentRefLocator = { screenshot: refScreenshot };
+    currentPage = {
+      locator: vi.fn(),
+      screenshot: vi.fn(async () => Buffer.from("P")),
+    };
+
+    const mod = await importModule();
+    const res = await mod.takeScreenshotViaPlaywright({
+      cdpPort: 18792,
+      targetId: "T1",
+      ref: "76",
+      type: "jpeg",
+    });
+
+    expect(res.buffer.toString()).toBe("R");
+    expect(sessionMocks.refLocator).toHaveBeenCalledWith(currentPage, "76");
+    expect(refScreenshot).toHaveBeenCalledWith({ type: "jpeg" });
+  });
+
+  it("rejects fullPage for element or ref screenshots", async () => {
+    currentRefLocator = { screenshot: vi.fn(async () => Buffer.from("R")) };
+    currentPage = {
+      locator: vi.fn(() => ({
+        first: () => ({ screenshot: vi.fn(async () => Buffer.from("E")) }),
+      })),
+      screenshot: vi.fn(async () => Buffer.from("P")),
+    };
+
+    const mod = await importModule();
+
+    await expect(
+      mod.takeScreenshotViaPlaywright({
+        cdpPort: 18792,
+        targetId: "T1",
+        element: "#x",
+        fullPage: true,
+      }),
+    ).rejects.toThrow(/fullPage is not supported/i);
+
+    await expect(
+      mod.takeScreenshotViaPlaywright({
+        cdpPort: 18792,
+        targetId: "T1",
+        ref: "1",
+        fullPage: true,
+      }),
+    ).rejects.toThrow(/fullPage is not supported/i);
+  });
+});