1 files changed, 47 insertions, 0 deletions
diff --git a/src/cdp/pending-requests.ts b/src/cdp/pending-requests.ts
new file mode 100644
index 0000000..03b19cd
--- /dev/null
+++ b/src/cdp/pending-requests.ts
@@ -0,0 +1,47 @@
+import { type Result, err } from "../util/result";
+import { type CdpError, cdpError } from "./errors";
+
+export type CdpResult = Result<unknown, CdpError>;
+
+export type Pending = {
+  readonly resolve: (v: Result<unknown, CdpError>) => void;
+  readonly timer: ReturnType<typeof setTimeout>;
+  readonly method: string;
+};
+
+export const rejectAllPending = (pending: Map<number, Pending>, reason: string): void => {
+  for (const [, p] of pending) {
+    clearTimeout(p.timer);
+    p.resolve(err(cdpError("transport_closed", reason, p.method)));
+  }
+  pending.clear();
+};
+
+export const sendWithTimeout = (
+  pending: Map<number, Pending>,
+  id: number,
+  method: string,
+  timeoutMs: number,
+  timeoutLabel: string,
+  send: () => void,
+): Promise<CdpResult> =>
+  new Promise((resolve) => {
+    const timer = setTimeout(() => {
+      pending.delete(id);
+      resolve(err(cdpError("timeout", `${timeoutLabel} timeout after ${timeoutMs}ms: ${method}`, method)));
+    }, timeoutMs);
+    pending.set(id, { resolve, timer, method });
+    try {
+      send();
+    } catch (e) {
+      clearTimeout(timer);
+      pending.delete(id);
+      resolve(err(cdpError("transport_closed", e instanceof Error ? e.message : String(e), method)));
+    }
+  });
+
+export const makeOnClose = (closeListeners: Set<() => void>) =>
+  (cb: () => void): (() => void) => {
+    closeListeners.add(cb);
+    return () => closeListeners.delete(cb);
+  };