TS2322: Type 'null' is not assignable to type 'void | Diff'

the diff function return type is Diff | void however it returns null in line 152:

Lines 144 to 154 in 41275a6

    
           export function diff( 
        
             a: AnyJson, 
        
             b: AnyJson, 
        
             tolerance = Infinity 
        
           ): Diff | void { 
        
             let result: Diff = []; 
        
             if (gatherDiff(a, b, tolerance, [], result) || result.length > tolerance) 
        
               return [[[], b]]; 
        
             if (result.length === 0) return null; 
        
             return result; 
        
           }

I can prepare a PR if it helps

	export function diff(
	a: AnyJson,
	b: AnyJson,
	tolerance = Infinity
	): Diff \| void {
	let result: Diff = [];
	if (gatherDiff(a, b, tolerance, [], result) \|\| result.length > tolerance)
	return [[[], b]];
	if (result.length === 0) return null;
	return result;
	}