js-testDiff
About
Deep object diffing function for JavaScript; returns true if input 1 differs in any way from input 2. Original code was taken from Differentia.js and ported to TypeScript.
The testDiff function was originally created as a unit testing utility and it was primarily designed/used to test Differentia's search algorithm strategy system, setting a "gold standard" for that library's quality and algorithmic correctness.
The key difference with this version of testDiff is that I removed its "search index" functionality, as it introduced more complexity than it was worth.
Feel free to scavenge the original code as I have: https://github.com/Floofies/Differentia.js/blob/master/spec/testUtils.js
Building
Run npm run build
to compile and test module dist/index.js
.
I have pre-compiled the most up-to-date files in dist
. Enjoy.
unitTest.js
can be safely ignored, as it's a development-only dependency for test.mjs
.
Syntax
import { testDiff } from "testDiff";
testDiff( input1:any, input2:any, [ deep:boolean = false ] );
Parameters:
input1
, input2
Two values/objects to compare against each other.
deep
(Optional) (Default = true
)
TestDiff performs "deep" object/array traversal by default, comparing all reachable values; set this operand to false
to disable traversal and nested comparisons.
Return Value:
Returns true
if input1
's structure, properties, or values differ in any way from input2
, or false
if otherwsie.
Usage Examples
Example 1: Arbitrary values.
Can handle any arbitrary values, as well as objects/arrays.
const myArray1 = "Hello World!";
const myArray2 = "This is a test";
const result = testDiff(myArray1, myArray2);
Example 2: Flat arrays/objects.
const myArray1 = [1,2,3];
const myArray2 = [4,5,6];
const result = testDiff(myArray1, myArray2);
Example 3: Nested arrays/objects.
const myArray1 = ["Hello",["World!"]];
const myArray2 = ["Hello",["Developer!"]];
const result = testDiff(myArray1, myArray2);
Example 4: Nested arrays. Traversal disabled.
In this example, the function returns false
even though the arrays' contents differ; they are regarded as the same because there are no differences at the top, and disabling traversal prevents the algorithm from seeing deeper differences.
const myArray1 = ["Hello",["World!"]];
const myArray2 = ["Hello",["Developer!"]];
const result = testDiff(myArray1, myArray2, false);