Changed lines rendered blank in v4 with custom renderContent

[denis-sokolov]

In 4.0.5, if DiffViewer has a custom renderContent, the component sometimes silently renders a blank line.

Turns out, word compareMethod is not compatible with renderContent, if renderContent returns anything but a string. Ironically, the type of it allows to return only non-strings:

react-diff-viewer-continued/src/index.tsx

Lines 53 to 54 in 8bc70d3

	// Render prop to format final string before displaying them in the UI.
	renderContent?: (source: string) => ReactElement;

Reproduce:

<DiffViewer
  compareMethod={DiffMethod.WORDS}
  newValue="Foo Bar"
  oldValue="Foo"
  renderContent={str => <div>{str}</div>}
  />

The cause seems to be this silent return statement, introduced in c0c99f5:

react-diff-viewer-continued/src/index.tsx

Line 197 in 8bc70d3

if (typeof content !== "string") return;