Reject local-cli promises with Error objects

Reviewed By: davidaurelio

Differential Revision: D5581520

fbshipit-source-id: 4929906ac79271c17e65fbdf5ba635f06efefd76

local-cli/dependencies/dependencies.js

@@ -19,7 +19,7 @@ const {ASSET_REGISTRY_PATH} = require('../core/Constants');
 function dependencies(argv, config, args, packagerInstance) {
   const rootModuleAbsolutePath = args.entryFile;
   if (!fs.existsSync(rootModuleAbsolutePath)) {
-    return Promise.reject(`File ${rootModuleAbsolutePath} does not exist`);
+    return Promise.reject(new Error(`File ${rootModuleAbsolutePath} does not exist`));
   }
 
   const transformModulePath =

local-cli/library/library.js

@@ -35,7 +35,7 @@ function library(argv, config, args) {
   }
 
   if (fs.existsSync(libraryDest)) {
-    return Promise.reject(`Library already exists in ${libraryDest}`);
+    return Promise.reject(new Error(`Library already exists in ${libraryDest}`));
   }
 
   walk(source).forEach(f => {