1 files changed, 97 insertions, 0 deletions
diff --git a/test/cdp/session-evaluate-test.ts b/test/cdp/session-evaluate-test.ts
new file mode 100644
index 0000000..c03a4cb
--- /dev/null
+++ b/test/cdp/session-evaluate-test.ts
@@ -0,0 +1,97 @@
+import { test, describe } from "node:test";
+import assert from "node:assert/strict";
+import { evaluateJson } from "../../src/cdp/session";
+import type { CdpSession } from "../../src/cdp/session";
+import { err, ok } from "../../src/util/result";
+
+const isNumberArray = (v: unknown): v is ReadonlyArray<number> =>
+  Array.isArray(v) && v.every((x) => typeof x === "number");
+
+const fakeSession = (payload: unknown): CdpSession =>
+  ({
+    call: async () => ok(payload),
+  }) as unknown as CdpSession;
+
+type Call = { method: string; args: unknown[] };
+
+const recordingSession = (result: unknown): { session: CdpSession; calls: Call[] } => {
+  const calls: Call[] = [];
+  const session = {
+    call: async (...args: unknown[]) => {
+      calls.push({ method: "call", args });
+      return result;
+    },
+    callOnTarget: async (...args: unknown[]) => {
+      calls.push({ method: "callOnTarget", args });
+      return result;
+    },
+  } as unknown as CdpSession;
+  return { session, calls };
+};
+
+describe("evaluateJson", () => {
+  test("unwraps result.value and applies the guard", async () => {
+    const s = fakeSession({ result: { type: "object", value: [1, 2, 3] } });
+    const r = await evaluateJson(s, "[1,2,3]", isNumberArray);
+    assert.equal(r.success, true);
+    if (r.success) assert.deepEqual(r.data, [1, 2, 3]);
+  });
+
+  test("surfaces a page exception as an error", async () => {
+    const s = fakeSession({
+      result: { type: "undefined" },
+      exceptionDetails: { text: "ReferenceError: x is not defined" },
+    });
+    const r = await evaluateJson(s, "x", isNumberArray);
+    assert.equal(r.success, false);
+    if (!r.success) {
+      assert.equal(r.error.kind, "remote_error");
+      assert.match(r.error.message, /ReferenceError/);
+    }
+  });
+
+  test("rejects a value that fails the guard", async () => {
+    const s = fakeSession({ result: { type: "string", value: "nope" } });
+    const r = await evaluateJson(s, "'nope'", isNumberArray);
+    assert.equal(r.success, false);
+    if (!r.success) assert.equal(r.error.kind, "invalid_response");
+  });
+
+  test("dispatches via callOnTarget when opts.sessionId is set", async () => {
+    const { session, calls } = recordingSession(ok({ result: { type: "object", value: [4, 5] } }));
+    const r = await evaluateJson(session, "[4,5]", isNumberArray, { sessionId: "sess-1" });
+    assert.equal(r.success, true);
+    if (r.success) assert.deepEqual(r.data, [4, 5]);
+    assert.equal(calls.length, 1);
+    assert.equal(calls[0]?.method, "callOnTarget");
+    const [, , sessionIdArg] = calls[0]?.args ?? [];
+    assert.equal(sessionIdArg, "sess-1");
+  });
+
+  test("dispatches via call when no opts are given", async () => {
+    const { session, calls } = recordingSession(ok({ result: { type: "object", value: [1] } }));
+    const r = await evaluateJson(session, "[1]", isNumberArray);
+    assert.equal(r.success, true);
+    assert.equal(calls.length, 1);
+    assert.equal(calls[0]?.method, "call");
+    assert.equal(calls.some((c) => c.method === "callOnTarget"), false);
+  });
+
+  test("passes timeoutMs through to the transport options", async () => {
+    const { session, calls } = recordingSession(ok({ result: { type: "object", value: [1] } }));
+    await evaluateJson(session, "[1]", isNumberArray, { timeoutMs: 5000 });
+    const [, , optsArg] = calls[0]?.args ?? [];
+    assert.deepEqual(optsArg, { timeoutMs: 5000 });
+  });
+
+  test("passes through a transport failure unchanged", async () => {
+    const failure = err({ kind: "timeout" as const, message: "timed out" });
+    const { session } = recordingSession(failure);
+    const r = await evaluateJson(session, "[1]", isNumberArray);
+    assert.equal(r.success, false);
+    if (!r.success) {
+      assert.equal(r.error.kind, "timeout");
+      assert.equal(r.error.message, "timed out");
+    }
+  });
+});