[ADF-4250] Improve Error Content component (#4555)

* [ADF-4250] Improve Error Content component

* [ADF-4250] Fix unit test

lib/core/i18n/en.json

@@ -334,6 +334,36 @@
       "RETURN_BUTTON": {
         "TEXT": "Back to home"
       }
+    },
+    "500": {
+      "TITLE": "An error occurred.",
+      "DESCRIPTION": "Internal server error, try again or contact IT support [500].",
+      "SECONDARY_BUTTON": {
+        "TEXT": ""
+      },
+      "RETURN_BUTTON": {
+        "TEXT": "Back to home"
+      }
+    },
+    "502": {
+      "TITLE": "An error occurred.",
+      "DESCRIPTION": "Bad Gateway, try again or contact IT support [502].",
+      "SECONDARY_BUTTON": {
+        "TEXT": ""
+      },
+      "RETURN_BUTTON": {
+        "TEXT": "Back to home"
+      }
+    },
+    "504": {
+      "TITLE": "An error occurred.",
+      "DESCRIPTION": "The server timed out, try again or contact IT support [504].",
+      "SECONDARY_BUTTON": {
+        "TEXT": ""
+      },
+      "RETURN_BUTTON": {
+        "TEXT": "Back to home"
+      }
     }
   },
   "ABOUT": {

lib/core/templates/error-content/error-content.component.spec.ts

@@ -141,7 +141,7 @@ describe('ErrorContentComponent', () => {
         });
 
         it('should navigate to an error given by the route params', async(() => {
-            spyOn(translateService, 'get').and.returnValue(of('404'));
+            spyOn(translateService, 'instant').and.returnValue(of('404'));
             fixture.detectChanges();
             fixture.whenStable().then(() => {
                 expect(errorContentComponent.errorCode).toBe('404');

lib/core/templates/error-content/error-content.component.ts

@@ -36,6 +36,8 @@ import { TranslationService } from '../../services/translation.service';
 })
 export class ErrorContentComponent implements OnInit, AfterContentChecked {
 
+    static UNKNOWN_ERROR = 'UNKNOWN';
+
     /** Target URL for the secondary button. */
     @Input()
     secondaryButtonUrl: string = 'report-issue';
@@ -46,7 +48,7 @@ export class ErrorContentComponent implements OnInit, AfterContentChecked {
 
     /** Error code associated with this error. */
     @Input()
-    errorCode: string = 'UNKNOWN';
+    errorCode: string = ErrorContentComponent.UNKNOWN_ERROR;
 
     hasSecondButton: boolean;
 
@@ -59,12 +61,17 @@ export class ErrorContentComponent implements OnInit, AfterContentChecked {
         if (this.route) {
             this.route.params.forEach((params: Params) => {
                 if (params['id']) {
-                    this.errorCode = params['id'];
+                    this.errorCode = this.checkErrorExists(params['id']) ? params['id'] : ErrorContentComponent.UNKNOWN_ERROR;
                 }
             });
         }
     }
 
+    checkErrorExists(errorCode: string ) {
+        const errorMessage = this.translateService.instant('ERROR_CONTENT.' + errorCode);
+        return errorMessage !== ('ERROR_CONTENT.' + errorCode);
+    }
+
     getTranslations() {
         this.hasSecondButton = this.translateService.instant(
             'ERROR_CONTENT.' + this.errorCode + '.SECONDARY_BUTTON.TEXT') ? true : false;