(lint/types/fix): only resize width/height if not set

- previously falsey values like 0, '', null, etc would have been
  resized, even though something like 0 _did_ set a fixed width/height
  - this could be considered breaking, so might leave out or revert
    this commit
    - and setting it to falsey may have intended it to be resized, bc
      setting it to 0 etc doesn't really make sense... but idk people
      can set whatever

src/index.tsx

@@ -90,14 +90,11 @@ export class SignatureCanvas extends Component<SignatureCanvasProps> {
  this._resizeCanvas()
  }
 
- // a few eslint disables of strict-boolean-expressions here because changing
- // these lines would be breaking -- 0s, '', null etc are falsey
  _resizeCanvas = (): void => {
  const canvasProps = this.props.canvasProps ?? {}
  const { width, height } = canvasProps
  // don't resize if the canvas has fixed width and height
- // eslint-disable-next-line @typescript-eslint/strict-boolean-expressions
- if (width && height) {
+ if (typeof width !== 'undefined' && typeof height !== 'undefined') {
  return
  }
 
@@ -107,12 +104,10 @@ export class SignatureCanvas extends Component<SignatureCanvasProps> {
  and only part of the canvas is cleared then. */
  const ratio = Math.max(window.devicePixelRatio ?? 1, 1)
 
- // eslint-disable-next-line @typescript-eslint/strict-boolean-expressions
- if (!width) {
+ if (typeof width === 'undefined') {
  canvas.width = canvas.offsetWidth * ratio
  }
- // eslint-disable-next-line @typescript-eslint/strict-boolean-expressions
- if (!height) {
+ if (typeof height === 'undefined') {
  canvas.height = canvas.offsetHeight * ratio
  }
  // eslint-disable-next-line @typescript-eslint/no-non-null-assertion