moved to root directory

Matchmaker/modules/config.js

@@ -0,0 +1,49 @@
+// Copyright Epic Games, Inc. All Rights Reserved.
+
+//-- Provides configuration information from file and combines it with default values and command line arguments --//
+//-- Hierachy of values: Default Values < Config File < Command Line arguments --//
+
+const fs = require('fs');
+const path = require('path');
+const argv = require('yargs').argv;
+
+function initConfig(configFile, defaultConfig){
+	defaultConfig = defaultConfig || {};
+
+	// Using object spread syntax: https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Operators/Spread_syntax#Spread_in_object_literals
+	let config = {...defaultConfig};
+	try{
+		let configData = fs.readFileSync(configFile, 'UTF8');
+		fileConfig = JSON.parse(configData);	
+		config = {...config, ...fileConfig}
+		// Update config file with any additional defaults (does not override existing values if default has changed)
+		fs.writeFileSync(configFile, JSON.stringify(config, null, '\t'), 'UTF8');
+	} catch(err) {
+		if (err.code === 'ENOENT') {
+			console.log("No config file found, writing defaults to log file " + configFile);
+			fs.writeFileSync(configFile, JSON.stringify(config, null, '\t'), 'UTF8');
+		} else if (err instanceof SyntaxError) {
+			console.log(`ERROR: Invalid JSON in ${configFile}, ignoring file config, ${err}`)
+		} else {
+			console.log(`ERROR: ${err}`);
+		}
+	}
+
+	try{
+		//Make a copy of the command line args and remove the unneccessary ones
+		//The _ value is an array of any elements without a key
+		let commandLineConfig = {...argv}
+		delete commandLineConfig._;
+		delete commandLineConfig.help;
+		delete commandLineConfig.version;
+		delete commandLineConfig['$0'];
+		config = {...config, ...commandLineConfig}
+	} catch(err) {
+		console.log(`ERROR: ${err}`);
+	}
+	return config;
+}
+
+module.exports = {
+	init: initConfig
+}