Fix some compile bugs.

3 files changed, 13 insertions, 22 deletions

diff --git a/Timeline/ClientApp/src/app/todo/todo-item/todo-item.component.ts b/Timeline/ClientApp/src/app/todo/todo-item/todo-item.component.ts
index 50829769..b5c51229 100644
--- a/Timeline/ClientApp/src/app/todo/todo-item/todo-item.component.ts
+++ b/Timeline/ClientApp/src/app/todo/todo-item/todo-item.component.ts
@@ -1,18 +1,12 @@
-import { Component, Input, OnInit } from '@angular/core';
+import { Component, Input } from '@angular/core';
 
 import { TodoItem } from '../todo-item';
-import { throwIfFalsy } from 'src/app/utilities/language-untilities';
 
 @Component({
   selector: 'app-todo-item',
   templateUrl: './todo-item.component.html',
   styleUrls: ['./todo-item.component.css', '../todo-list-color-block.css']
 })
-export class TodoItemComponent implements OnInit {
-
-  @Input() item: TodoItem | undefined;
-
-  ngOnInit() {
-    throwIfFalsy(this.item, 'item');
-  }
+export class TodoItemComponent {
+  @Input() item!: TodoItem;
 }
diff --git a/Timeline/ClientApp/src/app/user/user-login-success/user-login-success.component.ts b/Timeline/ClientApp/src/app/user/user-login-success/user-login-success.component.ts
index 1369d17d..22f6a41f 100644
--- a/Timeline/ClientApp/src/app/user/user-login-success/user-login-success.component.ts
+++ b/Timeline/ClientApp/src/app/user/user-login-success/user-login-success.component.ts
@@ -1,9 +1,9 @@
-import { Component, OnInit, Input } from '@angular/core';
+import { Component, OnInit } from '@angular/core';
 import { ActivatedRoute } from '@angular/router';
 
 import { UserInfo } from '../entities';
 import { InternalUserService } from '../internal-user-service/internal-user.service';
-import { throwIfFalsy } from 'src/app/utilities/language-untilities';
+import { throwIfNullOrUndefined } from 'src/app/utilities/language-untilities';
 
 @Component({
   selector: 'app-user-login-success',
@@ -14,18 +14,12 @@ export class UserLoginSuccessComponent implements OnInit {
 
   displayLoginSuccessMessage = false;
 
-  userInfo: UserInfo | undefined;
+  userInfo!: UserInfo;
 
   constructor(private route: ActivatedRoute, private userService: InternalUserService) { }
 
   ngOnInit() {
-    const { currentUserInfo } = this.userService;
-
-    if (!currentUserInfo) {
-      throw new Error('Route error. No login now!');
-    }
-
-    this.userInfo = this.userService.currentUserInfo!;
+    this.userInfo = throwIfNullOrUndefined(this.userService.currentUserInfo, () => 'Route error. No login now!');
     this.displayLoginSuccessMessage = this.route.snapshot.paramMap.get('reason') === 'login';
   }
 }
diff --git a/Timeline/ClientApp/src/app/utilities/language-untilities.ts b/Timeline/ClientApp/src/app/utilities/language-untilities.ts
index f898039a..be9df2dc 100644
--- a/Timeline/ClientApp/src/app/utilities/language-untilities.ts
+++ b/Timeline/ClientApp/src/app/utilities/language-untilities.ts
@@ -2,8 +2,11 @@ export function nullIfUndefined<T>(value: T | undefined): T | null {
   return value === undefined ? null : value;
 }
 
-export function throwIfFalsy(value: any, name: string = '<unknown name>') {
-  if (!value) {
-    throw new Error(name + ' is falsy.');
+export function throwIfNullOrUndefined<T>(value: T | null | undefined,
+  lazyMessage: () => string = () => 'Value mustn\'t be falsy'): T | never {
+  if (value === null || value === undefined) {
+    throw new Error(lazyMessage());
+  } else {
+    return value;
   }
 }