add --debug flag and some refactoring related to that

src/cli.ts

@@ -2,7 +2,7 @@ import * as process from 'process';
 import * as yargs from 'yargs';
 import * as cli from 'cli-color';
 
-import { logger } from './logger';
+import { logger, setLogLevel } from './logger';
 import debug from './debug';
 
 type ExitCode = number;
@@ -11,8 +11,12 @@ type Handler = (args:yargs.Arguments) => Promise<ExitCode>
 const wrapMainHandler = (handler: Handler) =>
   // move the configureaws step into here
   function (args: yargs.Arguments) {
+    if (args.debug) {
+      process.env.DEBUG = 'true';
+      setLogLevel('debug');
+    }
     handler(args)
-      .then(exitCode => process.exit(exitCode))
+      .then(process.exit)
       .catch(error => {
         if (error.message) {
           logger.error(error.message);
@@ -279,6 +283,10 @@ export async function main() {
       group: 'AWS Options',
       description: 'AWS profile'})
 
+    .option('debug', {
+      type: 'boolean', default: false,
+      description: 'Log debug information to stderr.'})
+
     .demandCommand(1)
     .usage(usage)
     .alias('v', 'version')

src/debug.ts

@@ -1,4 +1,4 @@
 function debug(): boolean {
-  return typeof process.env.DEBUG === 'string' || process.env.LOG_LEVEL === 'DEBUG';
+  return process.env.LOG_LEVEL === 'DEBUG' || process.env.DEBUG !== undefined;
 }
 export default debug;

src/logger.ts

@@ -1,13 +1,25 @@
 import * as process from 'process';
 import * as _ from 'lodash';
 import * as winston from 'winston';
+import debug from './debug';
 
-export const logger = new winston.Logger({
-  transports: [
-    new winston.transports.Console({
+let LOG_LEVEL: string;
+if (debug()) {
+  LOG_LEVEL = 'debug';
+} else {
+  LOG_LEVEL = _.get(process.env, 'LOG_LEVEL', 'info').toLowerCase();
+}
+
+const consoleLogger = new winston.transports.Console({
       colorize: true,
-      level: _.get(process.env, 'LOG_LEVEL', 'info'),
+      level: LOG_LEVEL,
       prettyPrint: true
-    })
-  ]
+});
+
+export function setLogLevel(level: string) {
+  consoleLogger.level = level;
+}
+
+export const logger = new winston.Logger({
+  transports: [consoleLogger]
 });