[解決済み] 型 '{}' は型 '{ title: string; text: string; }' に代入できません。

import { Component } from '@angular/core';
import { FormControl, FormGroup, Validators } from '@angular/forms';

@Component({
    selector: 'article-editor',
    template: `
    <p>Title: <input [formControl]="titleControl"></p>
    <p>Text: <input [formControl]="textControl"></p>
    <p><button (click)="saveArticle()">Save</button></p>
    <hr />
    <p>Preview:</p>
    <div style="border:1px solid #999;margin:50px;">
      <h1>{{article.title}}</h1>
      <p>{{article.text}}</p>
    </div>
  `
})
export class ArticleEditorComponent {
    article: { title: string, text: string } = {};

    titleControl: FormControl = new FormControl(null, Validators.required);
    textControl: FormControl = new FormControl(null, Validators.required);
    articleFormGroup: FormGroup = new FormGroup({
        title: this.titleControl,
        text: this.textControl
    });

    saveArticle() {
        if (this.articleFormGroup.valid) {
            this.article = this.articleFormGroup.value;
        } else {
            console.log('Missing field(s)!');
        }
    }
}