Log when using non-valid log_level. #2706

lib/util/logger.js

@@ -6,6 +6,7 @@ const fs = require('fs');
 const fx = require('mkdir-recursive');
 const rimraf = require('rimraf');
 const colorizer = winston.format.colorize();
+const assert = require('assert');
 
 // What transports to enable
 const output = settings.get().advanced.log_output;
@@ -21,6 +22,8 @@ if (output.includes('file')) {
 
 // Determine the log level.
 const level = settings.get().advanced.log_level;
+const validLevels = ['info', 'error', 'warn', 'debug'];
+assert(validLevels.includes(level), `'${level}' is not a valid log_level, use one of '${validLevels.join(', ')}'`);
 
 const levelWithCompensatedLength = {
     'info': 'info ',