1 files changed, 18 insertions, 1 deletions
diff --git a/test/cdp/discovery-test.ts b/test/cdp/discovery-test.ts
index 7fc18fb..61b42b7 100644
--- a/test/cdp/discovery-test.ts
+++ b/test/cdp/discovery-test.ts
@@ -1,6 +1,6 @@
 import { test, describe } from "node:test";
 import assert from "node:assert/strict";
-import { endpointFromEnv } from "../../src/cdp/discovery";
+import { endpointFromEnv, parseVersionResponse } from "../../src/cdp/discovery";
 
 describe("BU_CDP_WS endpoint override", () => {
   test("an unset variable leaves discovery to run normally", () => {
@@ -27,3 +27,20 @@ describe("BU_CDP_WS endpoint override", () => {
     assert.equal(endpointFromEnv({ BU_CDP_WS: "   " }), undefined);
   });
 });
+
+describe("/json/version parsing", () => {
+  test("extracts webSocketDebuggerUrl from a well-formed response", () => {
+    const raw = JSON.stringify({ Browser: "Chrome/154.0", webSocketDebuggerUrl: "ws://127.0.0.1:9222/devtools/browser/abc" });
+    assert.equal(parseVersionResponse(raw), "ws://127.0.0.1:9222/devtools/browser/abc");
+  });
+
+  test("a response without the url yields null", () => {
+    assert.equal(parseVersionResponse(JSON.stringify({ Browser: "Chrome/154.0" })), null);
+  });
+
+  test("a non-string url, a non-object body, and invalid JSON all yield null", () => {
+    assert.equal(parseVersionResponse(JSON.stringify({ webSocketDebuggerUrl: 42 })), null);
+    assert.equal(parseVersionResponse(JSON.stringify([1, 2])), null);
+    assert.equal(parseVersionResponse("not json"), null);
+  });
+});