Add help command

commands/functions-shell.js

@@ -52,6 +52,8 @@ module.exports = new Command('experimental:functions:shell')
         }
       });
       replServer.context.config = emulator.config;
+      replServer.context.help = 'Instructions for the Functions Shell can be found at: ' +
+        'https://firebase.google.com/docs/functions/local-emulator';
     }).then(function() {
       return new RSVP.Promise(function(resolve) {
         process.on('SIGINT', function() {

lib/functionsEmulator.js

@@ -122,9 +122,8 @@ FunctionsEmulator.prototype.start = function(shellMode) {
   }).catch(function(e) {
     utils.logWarning(chalk.yellow('functions:') + ' Failed to load functions source code. ' +
       'Ensure that you have the latest SDK by running ' + chalk.bold('npm i --save firebase-functions') +
-      ' inside the functions directory.' +
-      'Run ' + chalk.bold('firebase serve --only hosting') + ' to only serve hosting files.\n\n' + e);
-    return RSVP.resolve();
+      ' inside the functions directory.');
+    return RSVP.reject(e);
   }).then(function(triggers) {
     instance.triggers = triggers;
     var promises = _.map(triggers, function(trigger) {
@@ -179,7 +178,11 @@ FunctionsEmulator.prototype.start = function(shellMode) {
     }));
   }).then(function() {
     var providerList = _.keys(emulatedProviders).sort().join(',');
-    track('Functions Emulation', providerList, emulatedFunctions.length);
+    if (emulatedFunctions.length > 0) {
+      track('Functions Emulation', providerList, emulatedFunctions.length);
+    } else {
+      return instance.stop();
+    }
   }).catch(function(e) {
     if (e) {
       utils.logWarning(chalk.yellow('functions:') + ' Error from emulator. ' + e.stack);