feat(index): alias '@' to src dir in bundleMain (#487)

* Alias 'src' to '@' path when build main process.

Alias 'src' to '@' path when build main process.

* fix(tests/commands): check for item in emtpy object

* fix(index): remove unnecessary whitespace

Author: jason-chang

__tests__/commands.spec.js

@@ -123,7 +123,7 @@ describe('electron:build', () => {
     expect(Object.keys(mainConfig)).not.toContain('module')
     //   Ts files are not resolved
     expect(
-      mainConfig.resolve ? mainConfig.resolve.extensions : []
+      mainConfig.resolve.extensions ? mainConfig.resolve.extensions : []
     ).not.toContain('ts')
     //   Proper entry file is used
     expect(mainConfig.entry.background[0]).toBe('projectPath/src/background.js')
@@ -406,7 +406,7 @@ describe('electron:serve', () => {
     expect(Object.keys(mainConfig)).not.toContain('module')
     //   Ts files are not resolved
     expect(
-      mainConfig.resolve ? mainConfig.resolve.extensions : []
+      mainConfig.resolve.extensions ? mainConfig.resolve.extensions : []
     ).not.toContain('ts')
     //   Proper entry file is used
     expect(mainConfig.entry.index[0]).toBe('projectPath/src/background.js')

index.js

@@ -575,6 +575,8 @@ function bundleMain ({
         additionalFormatters: [formatter]
       }
     ])
+  config.resolve.alias.set('@', api.resolve('src'))
+
   if (usesTypescript) {
     config.resolve.extensions.merge(['.js', '.ts'])
     config.module