Add QoS overriding options for publishers and subscriptions (#1468)

Allow QoS policies to be overridden at deployment time via ROS parameters, without changing source code. When `qosOverridingOptions` is passed to `createPublisher()` or `createSubscription()`, the node declares read-only parameters (e.g. `qos_overrides./chatter.subscription.depth`) whose values can be set at startup. Ported from rclpy's `QoSOverridingOptions` (rclpy/qos_overriding_options.py).

Usage with rclnodejs:
```bash
node my_app.js --ros-args -p "qos_overrides./chatter.subscription.depth:=1"
node my_app.js --ros-args --params-file qos.yaml
```
The `--ros-args` are received via `process.argv`, processed by `rclnodejs.init()`, and applied when `declareParameter()` finds matching overrides in `_parameterOverrides`.

**New: `lib/qos_overriding_options.js`** — `QoSPolicyKind` enum (HISTORY, DEPTH, RELIABILITY, DURABILITY, LIVELINESS, AVOID_ROS_NAMESPACE_CONVENTIONS), `QoSOverridingOptions` class with `withDefaultPolicies()` factory, `declareQosParameters()` engine that declares parameters per whitelisted policy and applies overrides to the QoS profile in-place, and enum↔string conversion helpers. Includes `_resolveQoS()` to convert string profile names to mutable QoS objects.

**Modified: `lib/node.js`** — `_createPublisher()` and `createSubscription()` check for `options.qosOverridingOptions`, resolve QoS profile strings, and call `declareQosParameters()` before creating the entity.

**Modified: `index.js`** — Exports `QoSPolicyKind` and `QoSOverridingOptions`.

**New: `test/test-qos-overriding-options.js`** — 11 tests: enum values, factory method, custom policies with entityId, publisher/subscription parameter declaration and value verification, entity ID suffix in parameter names, validation callback accept/reject, string QoS resolution, no-override baseline, and end-to-end parameter override proving the QoS object is mutated in-place.

Fix: #1467

Author: minggangw

index.js

@@ -39,6 +39,10 @@ const {
 } = require('./lib/parameter.js');
 const path = require('path');
 const QoS = require('./lib/qos.js');
+const {
+  QoSPolicyKind,
+  QoSOverridingOptions,
+} = require('./lib/qos_overriding_options.js');
 const rclnodejs = require('./lib/native_loader.js');
 const tsdGenerator = require('./rostsd_gen/index.js');
 const validator = require('./lib/validator.js');
@@ -258,6 +262,12 @@ let rcl = {
   /** {@link QoS} class */
   QoS: QoS,
 
+  /** {@link QoSPolicyKind} enum */
+  QoSPolicyKind: QoSPolicyKind,
+
+  /** {@link QoSOverridingOptions} class */
+  QoSOverridingOptions: QoSOverridingOptions,
+
   /** {@link RMWUtils} */
   RMWUtils: RMWUtils,
 

lib/node.js

@@ -48,6 +48,10 @@ const Service = require('./service.js');
 const Subscription = require('./subscription.js');
 const ObservableSubscription = require('./observable_subscription.js');
 const MessageInfo = require('./message_info.js');
+const {
+  declareQosParameters,
+  _resolveQoS,
+} = require('./qos_overriding_options.js');
 const TimeSource = require('./time_source.js');
 const Timer = require('./timer.js');
 const TypeDescriptionService = require('./type_description_service.js');
@@ -705,6 +709,10 @@ class Node extends rclnodejs.ShadowNode {
    * @param {object} options - The options argument used to parameterize the publisher.
    * @param {boolean} options.enableTypedArray - The topic will use TypedArray if necessary, default: true.
    * @param {QoS} options.qos - ROS Middleware "quality of service" settings for the publisher, default: QoS.profileDefault.
+   * @param {QoSOverridingOptions} [options.qosOverridingOptions] - If provided, declares read-only ROS parameters
+   *  for the specified QoS policies (e.g. `qos_overrides./topic.publisher.depth`). These can be overridden at
+   *  startup via `--ros-args -p` or `--params-file`. If qos is a profile string, it will be resolved to a
+   *  mutable QoS object before overrides are applied.
    * @param {PublisherEventCallbacks} eventCallbacks - The event callbacks for the publisher.
    * @return {Publisher} - An instance of Publisher.
    */
@@ -752,6 +760,21 @@ class Node extends rclnodejs.ShadowNode {
       );
     }
 
+    // Apply QoS overriding options if provided
+    if (options.qosOverridingOptions) {
+      const resolvedTopic = this.resolveTopicName(topic);
+      if (typeof options.qos === 'string' || !(options.qos instanceof QoS)) {
+        options.qos = _resolveQoS(options.qos);
+      }
+      declareQosParameters(
+        'publisher',
+        this,
+        resolvedTopic,
+        options.qos,
+        options.qosOverridingOptions
+      );
+    }
+
     let publisher = publisherClass.createPublisher(
       this,
       typeClass,
@@ -795,6 +818,10 @@ class Node extends rclnodejs.ShadowNode {
    * @param {string[]} [options.contentFilter.parameters=undefined] - Array of strings that give values to
    *  the ‘parameters’ (i.e., "%n" tokens) in the filter_expression. The number of supplied parameters must
    *  fit with the requested values in the filter_expression (i.e., the number of %n tokens). default: undefined.
+   * @param {QoSOverridingOptions} [options.qosOverridingOptions] - If provided, declares read-only ROS parameters
+   *  for the specified QoS policies (e.g. `qos_overrides./topic.subscription.depth`). These can be overridden at
+   *  startup via `--ros-args -p` or `--params-file`. If qos is a profile string, it will be resolved to a
+   *  mutable QoS object before overrides are applied.
    * @param {SubscriptionCallback} callback - The callback to be call when receiving the topic subscribed. The topic will be an instance of null-terminated Buffer when options.isRaw is true.
    * @param {SubscriptionEventCallbacks} eventCallbacks - The event callbacks for the subscription.
    * @return {Subscription} - An instance of Subscription.
@@ -848,6 +875,21 @@ class Node extends rclnodejs.ShadowNode {
       );
     }
 
+    // Apply QoS overriding options if provided
+    if (options.qosOverridingOptions) {
+      const resolvedTopic = this.resolveTopicName(topic);
+      if (typeof options.qos === 'string' || !(options.qos instanceof QoS)) {
+        options.qos = _resolveQoS(options.qos);
+      }
+      declareQosParameters(
+        'subscription',
+        this,
+        resolvedTopic,
+        options.qos,
+        options.qosOverridingOptions
+      );
+    }
+
     let subscription = Subscription.createSubscription(
       this,
       typeClass,