extensions/configuration-editing/src/configurationEditingMain.ts/isCompletingInsidePropertyStringValue
function isCompletingInsidePropertyStringValue(document: vscode.TextDocument, location: Location, pos: vscode.Position) {
	if (location.isAtPropertyKey) {
		return false;
	}
	const previousNode = location.previousNode;
	if (previousNode && previousNode.type === 'string') {
		const offset = document.offsetAt(pos);
		return offset > previousNode.offset && offset < previousNode.offset + previousNode.length;
	}
	return false;
}