RobotWebTools / rclnodejs / 23227191864 / 1

86%

develop: 86%

push

github

Add waitForMessage utility for one-shot message reception (#1444)

Adds `waitForMessage()`, the rclnodejs equivalent of rclpy's `wait_for_message(msg_type, node, topic, time_to_wait)`. This utility creates a temporary subscription, waits for the first message to arrive on a topic, and returns it as a Promise. The temporary subscription is always cleaned up — on success, timeout, or error. Supports an optional timeout and QoS profile. The node must be spinning before calling this function.

**New files:**

- `lib/wait_for_message.js` — Core implementation. Creates a temporary subscription with a one-shot callback that resolves the Promise on first message. Uses a `settled` guard to prevent double-resolution. Cleanup runs unconditionally via the `settle()` helper. Accepts optional `{ timeout, qos }` options.
- `test/test-wait-for-message.js` — 7 tests covering: successful message reception, timeout rejection, first-message-only semantics, different message types (String, Int32), indefinite wait without timeout, subscription cleanup after receiving, and subscription cleanup on timeout.

**Modified files:**

- `index.js` — Added `require('./lib/wait_for_message.js')` and re-exported as `waitForMessage` property on the module.
- `types/index.d.ts` — Added `WaitForMessageOptions` interface and generic `waitForMessage<T>(typeClass, node, topic, options?)` function declaration.

Fix: #1443

1477 of 1866 branches covered (79.15%)

Branch coverage included in aggregate %.

3036 of 3382 relevant lines covered (89.77%)

452.37 hits per line