stub out angular with webpack

src/popup2/services/validation.service.ts

@@ -0,0 +1,37 @@
+import { Injectable } from '@angular/core';
+
+import { ToasterService } from 'angular2-toaster';
+
+import { I18nService } from 'jslib/abstractions/i18n.service';
+
+@Injectable()
+export class ValidationService {
+    constructor(private toasterService: ToasterService, private i18nService: I18nService) { }
+
+    showError(data: any): string[] {
+        const defaultErrorMessage = this.i18nService.t('unexpectedError');
+        const errors: string[] = [];
+
+        if (data == null || typeof data !== 'object') {
+            errors.push(defaultErrorMessage);
+        } else if (data.validationErrors == null) {
+            errors.push(data.message ? data.message : defaultErrorMessage);
+        } else {
+            for (const key in data.validationErrors) {
+                if (!data.validationErrors.hasOwnProperty(key)) {
+                    continue;
+                }
+
+                data.validationErrors[key].forEach((item: string) => {
+                    errors.push(item);
+                });
+            }
+        }
+
+        if (errors.length > 0) {
+            this.toasterService.popAsync('error', this.i18nService.t('errorOccurred'), errors[0]);
+        }
+
+        return errors;
+    }
+}