Improve auth error message, encourage reauth.

lib/auth.js

@@ -20,6 +20,12 @@ var scopes = require('./scopes');
 
 portfinder.basePort = 9005;
 
+var INVALID_CREDENTIAL_ERROR = new FirebaseError(
+  'Authentication Error: Your credentials are no longer valid. Please run ' + chalk.bold('firebase login --reauth') + '\n\n' +
+  'For CI servers and headless environments, generate a new token with ' + chalk.bold('firebase login:ci'),
+  {exit: 1}
+);
+
 var FIFTEEN_MINUTES_IN_MS = 15 * 60 * 1000;
 var SCOPES = [
   scopes.EMAIL,
@@ -66,18 +72,14 @@ var _getTokensFromAuthorizationCode = function(code, callbackUrl) {
     }
   }).then(function(res) {
     if (!_.has(res, 'body.access_token') && !_.has(res, 'body.refresh_token')) {
-      throw new FirebaseError('Authentication Error.', {
-        exit: 1
-      });
+      throw INVALID_CREDENTIAL_ERROR;
     }
     lastAccessToken = _.assign({
       expires_at: Date.now() + res.body.expires_in * 1000
     }, res.body);
     return lastAccessToken;
   }, function() {
-    throw new FirebaseError('Authentication Error.', {
-      exit: 1
-    });
+    throw INVALID_CREDENTIAL_ERROR;
   });
 };
 
@@ -214,9 +216,7 @@ var _refreshAccessToken = function(refreshToken, authScopes) {
     }
   }).then(function(res) {
     if (!_.isString(res.body.access_token)) {
-      throw new FirebaseError('Authentication Error.', {
-        exit: 1
-      });
+      throw INVALID_CREDENTIAL_ERROR;
     }
     lastAccessToken = _.assign({
       expires_at: Date.now() + res.body.expires_in * 1000,
@@ -239,16 +239,7 @@ var _refreshAccessToken = function(refreshToken, authScopes) {
       );
     }
 
-    if (err.message === 'invalid_grant') {
-      _logoutCurrentSession(refreshToken);
-      throw new FirebaseError('Your refresh token has been revoked, please run ' +
-          chalk.bold('firebase login') + ' to obtain a new one.', {
-            exit: 1
-          });
-    }
-    throw new FirebaseError('Authentication Error.', {
-      exit: 1
-    });
+    throw INVALID_CREDENTIAL_ERROR;
   });
 };