From d17256dc40a530a42afe9032658e6a4bef62e405 Mon Sep 17 00:00:00 2001
From: Jonathan Rainville <rainville.jonathan@gmail.com>
Date: Wed, 16 May 2018 11:49:38 -0400
Subject: [PATCH] add JS Doc for processLauncher

---
 lib/process/processLauncher.js | 49 ++++++++++++++++++++++++++++++++++
 1 file changed, 49 insertions(+)

diff --git a/lib/process/processLauncher.js b/lib/process/processLauncher.js
index 0cf8cdf0..7086d696 100644
--- a/lib/process/processLauncher.js
+++ b/lib/process/processLauncher.js
@@ -1,7 +1,18 @@
 const child_process = require('child_process');
 const constants = require('../constants');
 
+
 class ProcessLauncher {
+
+  /**
+   * Constructor of ProcessLauncher. Forks the module and sets up the message handling
+   * @param {Object}    options   Options tp start the process
+   *        * modulePath      {String}    Absolute path to the module to fork
+   *        * logger          {Object}    Logger
+   *        * normalizeInput  {Function}  Function to normalize logs
+   *        * events          {Function}  Events Emitter instance
+   * @return {ProcessLauncher}    The ProcessLauncher instance
+   */
   constructor(options) {
     this.process = child_process.fork(options.modulePath);
     this.logger = options.logger;
@@ -12,6 +23,7 @@ class ProcessLauncher {
     this._subscribeToMessages();
   }
 
+  // Subscribes to messages from the child process and delegates to the right methods
   _subscribeToMessages() {
     const self = this;
     this.process.on('message', (msg) => {
@@ -25,6 +37,7 @@ class ProcessLauncher {
     });
   }
 
+  // Translates logs from the child process to the logger
   _handleLog(msg) {
     if (this.logger[msg.type]) {
       return this.logger[msg.type](this.normalizeInput(msg.message));
@@ -32,6 +45,7 @@ class ProcessLauncher {
     this.logger.debug(this.normalizeInput(msg.message));
   }
 
+  // Handle event calls from the child process
   _handleEvent(msg) {
     const self = this;
     if (!self.events[msg.event]) {
@@ -52,6 +66,7 @@ class ProcessLauncher {
     self.events[msg.event](msg.requestName, ...msg.args);
   }
 
+  // Looks at the subscriptions to see if there is a callback to call
   _checkSubscriptions(msg) {
     const messageKeys = Object.keys(msg);
     const subscriptionsKeys = Object.keys(this.subscriptions);
@@ -87,6 +102,13 @@ class ProcessLauncher {
     }
   }
 
+  /**
+   * Subscribe to a message using a key-value pair
+   * @param {String}    key       Message key to subscribe to
+   * @param {String}    value     Value that the above key must have for the callback to be called
+   * @param {Function}  callback  callback(response)
+   * @return {void}
+   */
   subscribeTo(key, value, callback) {
     if (this.subscriptions[key]) {
       this.subscriptions[key].push(value);
@@ -95,6 +117,13 @@ class ProcessLauncher {
     this.subscriptions[key] = [{value, callback}];
   }
 
+  /**
+   * Unsubscribes from a previously subscribed key-value pair (or key if no value)
+   * @param {String}  key     Message key to unsubscribe
+   * @param {String}  value   [Optional] Value of the key to unsubscribe
+ *                            If there is no value, unsubscribes from all the values of that key
+   * @return {void}
+   */
   unsubscribeTo(key, value) {
     if (!value) {
       this.subscriptions[key] = [];
@@ -108,18 +137,38 @@ class ProcessLauncher {
     }
   }
 
+  /**
+   * Unsubscribes from all subscriptions
+   * @return {void}
+   */
   unsubsribeToAll() {
     this.subscriptions = {};
   }
 
+  /**
+   * Sends a message to the child process. Same as ChildProcess.send()
+   * @params {Object}   message     Message to send
+   * For other parameters, see:
+   *  https://nodejs.org/api/child_process.html#child_process_subprocess_send_message_sendhandle_options_callback
+   * @return {void}
+   */
   send() {
     this.process.send(...arguments);
   }
 
+  /**
+   * Disconnects the child process. It will exit on its own
+   * @return {void}
+   */
   disconnect() {
     this.process.disconnect();
   }
 
+  /**
+   * Kills the child process
+   *  https://nodejs.org/api/child_process.html#child_process_subprocess_kill_signal
+   * @return {void}
+   */
   kill() {
     this.process.kill(...arguments);
   }