Phase 2: convert lib/, index.js and tests to native ES modules

bin/rclnodejs-web.js

@@ -11,20 +11,20 @@
 //
 // For frontend developers who don't want to write a Node.js server.
 // Run `rclnodejs-web --help` or `npx rclnodejs-web web.json` to start
-// the runtime. See demo/web/javascript/README.md for the full demo.
+// demo. See demo/web/javascript/README.md for the full demo.
 
-'use strict';
+import path from 'node:path';
+import fs from 'node:fs';
+import { fileURLToPath } from 'node:url';
 
-const path = require('node:path');
-const fs = require('node:fs');
-
-const {
+import {
   parseArgv,
   loadConfigFile,
   mergeConfig,
-  CliError,
   HELP,
-} = require('../lib/runtime/cli-config.js');
+} from '../lib/runtime/cli-config.js';
+
+const __dirname = path.dirname(fileURLToPath(import.meta.url));
 
 const argv = process.argv.slice(2);
 
@@ -55,14 +55,11 @@ const argv = process.argv.slice(2);
     fail(e);
   }
 
-  // Defer the rclnodejs require until after argv parsing so --help / --version
+  // Defer the rclnodejs import until after argv parsing so --help / --version
   // never pay the (slow, native) load cost.
-  const rclnodejs = require('../index.js');
-  const {
-    createRuntime,
-    WebSocketTransport,
-    HttpTransport,
-  } = require('../lib/runtime');
+  const rclnodejs = (await import('../index.js')).default;
+  const { createRuntime, WebSocketTransport, HttpTransport } =
+    await import('../lib/runtime/index.js');
 
   // Track partial init so the catch block can clean up native handles before
   // process.exit() — without this, a startup failure (e.g. EADDRINUSE on the

eslint.config.mjs

@@ -16,6 +16,10 @@ export default [
             "**/benchmark/",
             "**/docs/",
             "**/demo/electron/",
+            "**/coverage/",
+            "**/dist/",
+            "**/prebuilds/",
+            "**/build/",
         ],
     },
     {
@@ -46,6 +50,22 @@ export default [
             "@typescript-eslint/triple-slash-reference": "off",
         },
     },
+    {
+        plugins: {
+            prettier,
+        },
+        languageOptions: {
+            globals: {
+                ...globals.node,
+            },
+            ecmaVersion: "latest",
+            sourceType: "module",
+        },
+        files: ["lib/**/*.js", "test/**/*.js", "bin/**/*.js", "rosocket/**/*.js", "index.js"],
+        rules: {
+            ...eslintPluginPrettierRecommended.rules,
+        },
+    },
     {
         plugins: {
             prettier,
@@ -57,8 +77,8 @@ export default [
             ecmaVersion: "latest",
             sourceType: "commonjs",
         },
-        files: ["lib/**/*.js", "rosidl_parser/**/*.{js,cjs}", "rosidl_gen/**/*.{js,cjs}",
-            "rostsd_gen/**/*.{js,cjs}", "test/**/*.js", "example/**/*.js", "index.js"],
+        files: ["rosidl_parser/**/*.{js,cjs}", "rosidl_gen/**/*.{js,cjs}",
+            "rostsd_gen/**/*.{js,cjs}", "example/**/*.js"],
         rules: {
             ...eslintPluginPrettierRecommended.rules,
         },

index.js

@@ -12,76 +12,79 @@
 // See the License for the specific language governing permissions and
 // limitations under the License.
 
-'use strict';
-
-const DistroUtils = require('./lib/distro.js');
-const RMWUtils = require('./lib/rmw.js');
-const { Clock, ROSClock } = require('./lib/clock.js');
-const ClockEvent = require('./lib/clock_event.js');
-const ClockType = require('./lib/clock_type.js');
-const ClockChange = require('./lib/clock_change.js');
-const { compareVersions } = require('./lib/utils.js');
-const Context = require('./lib/context.js');
-const debug = require('debug')('rclnodejs');
-const Duration = require('./lib/duration.js');
-const fs = require('fs');
-const generator = require('./rosidl_gen/index.cjs');
-const loader = require('./lib/interface_loader.js');
-const logging = require('./lib/logging.js');
-const NodeOptions = require('./lib/node_options.js');
-const {
+import fs from 'fs';
+import path from 'path';
+import { spawn } from 'child_process';
+import createDebug from 'debug';
+import DistroUtils from './lib/distro.js';
+import RMWUtils from './lib/rmw.js';
+import { Clock, ROSClock } from './lib/clock.js';
+import ClockEvent from './lib/clock_event.js';
+import ClockType from './lib/clock_type.js';
+import ClockChange from './lib/clock_change.js';
+import { compareVersions } from './lib/utils.js';
+import Context from './lib/context.js';
+import Duration from './lib/duration.js';
+import generator from './rosidl_gen/index.cjs';
+import loader from './lib/interface_loader.js';
+import logging from './lib/logging.js';
+import NodeOptions from './lib/node_options.js';
+import {
   FloatingPointRange,
   IntegerRange,
   Parameter,
   ParameterDescriptor,
   ParameterType,
   DEFAULT_NUMERIC_RANGE_TOLERANCE,
-} = require('./lib/parameter.js');
-const path = require('path');
-const QoS = require('./lib/qos.js');
-const {
+} from './lib/parameter.js';
+import QoS from './lib/qos.js';
+import {
   QoSPolicyKind,
   QoSOverridingOptions,
-} = require('./lib/qos_overriding_options.js');
-const rclnodejs = require('./lib/native_loader.js');
-const tsdGenerator = require('./rostsd_gen/index.cjs');
-const validator = require('./lib/validator.js');
-const Time = require('./lib/time.js');
-const ActionClient = require('./lib/action/client.js');
-const ActionServer = require('./lib/action/server.js');
-const ActionUuid = require('./lib/action/uuid.js');
-const ClientGoalHandle = require('./lib/action/client_goal_handle.js');
-const { CancelResponse, GoalResponse } = require('./lib/action/response.js');
-const ServerGoalHandle = require('./lib/action/server_goal_handle.js');
-const { toJSONSafe, toJSONString } = require('./lib/message_serialization.js');
-const {
+} from './lib/qos_overriding_options.js';
+import rclnodejs from './lib/native_loader.js';
+import tsdGenerator from './rostsd_gen/index.cjs';
+import validator from './lib/validator.js';
+import Time from './lib/time.js';
+import ActionClient from './lib/action/client.js';
+import ActionServer from './lib/action/server.js';
+import ActionUuid from './lib/action/uuid.js';
+import ClientGoalHandle from './lib/action/client_goal_handle.js';
+import { CancelResponse, GoalResponse } from './lib/action/response.js';
+import ServerGoalHandle from './lib/action/server_goal_handle.js';
+import { toJSONSafe, toJSONString } from './lib/message_serialization.js';
+import {
   getActionClientNamesAndTypesByNode,
   getActionServerNamesAndTypesByNode,
   getActionNamesAndTypes,
-} = require('./lib/action/graph.js');
-const ServiceIntrospectionStates = require('./lib/service_introspection.js');
-const {
-  serializeMessage,
-  deserializeMessage,
-} = require('./lib/serialization.js');
-const ParameterClient = require('./lib/parameter_client.js');
-const errors = require('./lib/errors.js');
-const ParameterWatcher = require('./lib/parameter_watcher.js');
-const ParameterEventHandler = require('./lib/parameter_event_handler.js');
-const waitForMessage = require('./lib/wait_for_message.js');
-const MessageIntrospector = require('./lib/message_introspector.js');
-const MessageInfo = require('./lib/message_info.js');
-const ObservableSubscription = require('./lib/observable_subscription.js');
-const { spawn } = require('child_process');
-const {
+} from './lib/action/graph.js';
+import ServiceIntrospectionStates from './lib/service_introspection.js';
+import { serializeMessage, deserializeMessage } from './lib/serialization.js';
+import ParameterClient from './lib/parameter_client.js';
+import * as errors from './lib/errors.js';
+import ParameterWatcher from './lib/parameter_watcher.js';
+import ParameterEventHandler from './lib/parameter_event_handler.js';
+import waitForMessage from './lib/wait_for_message.js';
+import MessageIntrospector from './lib/message_introspector.js';
+import MessageInfo from './lib/message_info.js';
+import ObservableSubscription from './lib/observable_subscription.js';
+import {
   ValidationProblem,
   getMessageSchema,
   getFieldNames,
   getFieldType,
   validateMessage,
   assertValidMessage,
   createMessageValidator,
-} = require('./lib/message_validation.js');
+} from './lib/message_validation.js';
+// The following three modules participate in a circular dependency with this
+// file (via rate.js). In ESM the circular references are resolved by live
+// bindings, so they are imported here at the top like everything else.
+import Node from './lib/node.js';
+import TimeSource from './lib/time_source.js';
+import Lifecycle from './lib/lifecycle.js';
+
+const debug = createDebug('rclnodejs');
 
 /**
  * Get the version of the generator that was used for the currently present interfaces.
@@ -764,25 +767,16 @@ const _sigHandler = () => {
 };
 process.on('SIGINT', _sigHandler);
 
-module.exports = rcl;
-
-// The following statements are located here to work around a
-// circular dependency issue occurring in rate.js.
-// Do not change the order of the following imports.
-const Node = require('./lib/node.js');
-
 /** {@link Node} class */
 rcl.Node = Node;
 
-const TimeSource = require('./lib/time_source.js');
-
 /** {@link TimeSource} class */
 rcl.TimeSource = TimeSource;
 
-const Lifecycle = require('./lib/lifecycle.js');
-
 /** Lifecycle namespace */
 rcl.lifecycle = Lifecycle;
 
 /** {@link MessageIntrospector} class */
 rcl.MessageIntrospector = MessageIntrospector;
+
+export default rcl;

lib/action/client.js

@@ -12,23 +12,17 @@
 // See the License for the specific language governing permissions and
 // limitations under the License.
 
-'use strict';
-
-const rclnodejs = require('../native_loader.js');
-const ActionInterfaces = require('./interfaces.js');
-const ActionUuid = require('./uuid.js');
-const ClientGoalHandle = require('./client_goal_handle.js');
-const Deferred = require('./deferred.js');
-const DistroUtils = require('../distro.js');
-const Entity = require('../entity.js');
-const loader = require('../interface_loader.js');
-const QoS = require('../qos.js');
-const {
-  TypeValidationError,
-  ActionError,
-  OperationError,
-} = require('../errors.js');
-const { assertValidMessage } = require('../message_validation.js');
+import rclnodejs from '../native_loader.js';
+import ActionInterfaces from './interfaces.js';
+import ActionUuid from './uuid.js';
+import ClientGoalHandle from './client_goal_handle.js';
+import Deferred from './deferred.js';
+import DistroUtils from '../distro.js';
+import Entity from '../entity.js';
+import loader from '../interface_loader.js';
+import QoS from '../qos.js';
+import { TypeValidationError, ActionError, OperationError } from '../errors.js';
+import { assertValidMessage } from '../message_validation.js';
 
 /**
  * @class - ROS Action client.
@@ -577,4 +571,4 @@ class ActionClient extends Entity {
   }
 }
 
-module.exports = ActionClient;
+export default ActionClient;

lib/action/client_goal_handle.js

@@ -12,9 +12,7 @@
 // See the License for the specific language governing permissions and
 // limitations under the License.
 
-'use strict';
-
-const ActionInterfaces = require('./interfaces.js');
+import ActionInterfaces from './interfaces.js';
 
 /**
  * @class - Goal handle for working with Action Clients.
@@ -140,4 +138,4 @@ class ClientGoalHandle {
   }
 }
 
-module.exports = ClientGoalHandle;
+export default ClientGoalHandle;

lib/action/deferred.js

@@ -12,9 +12,7 @@
 // See the License for the specific language governing permissions and
 // limitations under the License.
 
-'use strict';
-
-const { TypeValidationError } = require('../errors.js');
+import { TypeValidationError } from '../errors.js';
 
 /**
  * @class - Wraps a promise allowing it to be resolved elsewhere.
@@ -83,4 +81,4 @@ class Deferred {
   }
 }
 
-module.exports = Deferred;
+export default Deferred;

lib/action/graph.js

@@ -12,9 +12,7 @@
 // See the License for the specific language governing permissions and
 // limitations under the License.
 
-'use strict';
-
-const rclnodejs = require('../native_loader.js');
+import rclnodejs from '../native_loader.js';
 
 /**
  * Get a list of action names and types for action clients associated with a node.
@@ -55,7 +53,7 @@ function getActionNamesAndTypes(node) {
   return rclnodejs.actionGetNamesAndTypes(node.handle);
 }
 
-module.exports = {
+export {
   getActionClientNamesAndTypesByNode,
   getActionServerNamesAndTypesByNode,
   getActionNamesAndTypes,

lib/action/interfaces.js

@@ -12,9 +12,7 @@
 // See the License for the specific language governing permissions and
 // limitations under the License.
 
-'use strict';
-
-const loader = require('../interface_loader.js');
+import loader from '../interface_loader.js';
 
 const CANCEL_GOAL_SERVICE = 'action_msgs/srv/CancelGoal';
 const GOAL_INFO_MESSAGE = 'action_msgs/msg/GoalInfo';
@@ -75,4 +73,4 @@ class ActionInterfaces {
   }
 }
 
-module.exports = ActionInterfaces;
+export default ActionInterfaces;

lib/action/response.js

@@ -12,8 +12,6 @@
 // See the License for the specific language governing permissions and
 // limitations under the License.
 
-'use strict';
-
 /**
  * Goal events that cause state transitions.
  * @ignore
@@ -57,8 +55,4 @@ const CancelResponse = {
   ACCEPT: 2,
 };
 
-module.exports = {
-  GoalEvent,
-  GoalResponse,
-  CancelResponse,
-};
+export { GoalEvent, GoalResponse, CancelResponse };