fix: postinstall handling for windows

Author: NathanWalker

packages/nx/src/schematics/application/application.ts

@@ -143,7 +143,6 @@ function addAppFiles(options: Schema, appName: string, extra: string = ''): Rule
           appname,
           directoryAppPath: `${directory}${options.name}`,
           pathOffset: directory ? '../../../' : '../../',
-          pathOffsetWindows: directory ? '..\\..\\..\\' : '..\\..\\',
           libFolderName: PluginHelpers.getLibFoldername('nativescript'),
           angularVersion,
           nsAngularVersion,

packages/nx/src/schematics/application/files_angular/tools/postinstall.js

@@ -15,9 +15,12 @@ try {
 }
 
 // Helpful to trigger ngcc after an install to ensure all has processed properly
-const child = childProcess.spawn(/^win/.test(process.platform) ? '<%= pathOffsetWindows %>node_modules\\.bin\\ngcc' : '<%= pathOffset %>node_modules/.bin/ngcc', ['--tsconfig', 'tsconfig.app.json', '--properties', 'es2015', 'module', 'main', '--first-only'], {
+const relativePath = '<%= pathOffset %>'.split('/').filter(p => !!p);
+const ngccPath = path.join(...relativePath, 'node_modules', '.bin', 'ngcc');
+const child = childProcess.spawn(ngccPath, ['--tsconfig', 'tsconfig.app.json', '--properties', 'es2015', 'module', 'main', '--first-only'], {
   cwd: process.cwd(),
   stdio: 'inherit',
+  shell: process.platform == 'win32'
 });
 child.on('close', (code) => {