[AAE-622] No implicit returns (#5157)

* enable noImplicitReturns rule

* type fixes

* fix return types

* fix return value

* fix tests

* fix visibility service

* update tests

* add missing types

* fix test

demo-shell/src/app/components/tree-view/tree-view-sample.component.html

@@ -8,12 +8,12 @@
     CLICKED NODE: {{clickedNodeName}}
 </span>
 
-<adf-tree-view-list *ngIf="!errorMessage; else erroOccurred"
+<adf-tree-view-list *ngIf="!errorMessage; else errorOccurred"
         [nodeId]="nodeIdSample"
         (nodeClicked)="onClick($event)"
         (error)="onErrorOccurred($event)">
 </adf-tree-view-list>
-<ng-template #erroOccurred>
+<ng-template #errorOccurred>
     <span>An Error Occurred </span>
     <span>{{errorMessage}}</span>
 </ng-template>

demo-shell/src/app/components/tree-view/tree-view-sample.component.ts

@@ -25,7 +25,7 @@ import { Component } from '@angular/core';
 export class TreeViewSampleComponent {
 
     clickedNodeName: string = '';
-    errorMessage = '';
+    errorMessage: string = '';
 
     nodeIdSample: string = '-my-';
 
@@ -38,7 +38,7 @@ export class TreeViewSampleComponent {
         this.errorMessage = '';
     }
 
-    onErrorOccurred(error) {
+    onErrorOccurred(error: string) {
         this.clickedNodeName = '';
         this.errorMessage = error;
     }