Build errors fixed. @see: https://github.com/Microsoft/TypeScript-Vue-Starter/issues/36

src/components/Dropdown.tsx

@@ -30,7 +30,7 @@ export class Dropdown extends React.Component<DropdownProps, DropdownState> {
 		position: 'bottom'
 	};
 
-	containerRef: HTMLDivElement | null;
+	containerRef!: HTMLDivElement | null;
 	clickInside = false;
 
 	switch = () => {

src/components/Overlay.tsx

@@ -21,7 +21,7 @@ export class Overlay extends React.Component<OverlayProps, OverlayState> {
 		position: ''
 	};
 
-	overlayRef: Element | null;
+	overlayRef!: Element | null;
 
 	alignToElement = () => {
 		if (this.overlayRef) {

src/components/TextField.tsx

@@ -22,7 +22,7 @@ export interface TextFieldProps {
 }
 
 export class TextField extends React.Component<TextFieldProps, {}> {
-	inputRef: HTMLInputElement | null;
+	inputRef!: HTMLInputElement | null;
 
 	componentDidMount() {
 		if (this.props.autoFocus && this.inputRef !== null) {

src/components/TextFieldContentEditable.tsx

@@ -10,7 +10,7 @@ export interface TextFieldContentEditableProps {
 }
 
 export class TextFieldContentEditable extends React.Component<TextFieldContentEditableProps> {
-	element: HTMLDivElement | null;
+	element!: HTMLDivElement | null;
 
 	handleChange = () => {
 		if (this.element) {