@coven/compare@0.3.2

Built and signed on GitHub Actions

Built and signed on GitHub Actions

⚖️ Minimalist diffing.

This library takes 2 values in a curried fashion, a left or "original" value first and then a right or "new" value, finally returning an iterator with all the differences between said values. The yielded differences are represented by 3 kinds:

• Create: Missing left and existing right.
• Update: Different left and right values.
• Delete: Existing left and missing right.

Plain update

If we compare the string 2 different strings, we do it like this:

import { compare } from "@coven/compare";

compare("Coven")("Engineering");

And we only get a single yielded "update", that looks like this:

({
	kind: "UPDATE",
	left: "Coven",
	path: [], // A generator that will yield nothing because is the root value
	right: "Engineering",
});

Object update

If we compare two objects like this:

import { compare } from "@coven/compare";

compare({ example: 13 })({ example: 42 });

The yielded update will have values yielded from its path:

({
	kind: "UPDATE",
	left: 13,
	right: 42,
	path: ["example"],
});

Object delete

Let's say we update that same object to an empty one:

import { compare } from "@coven/compare";

compare({ example: 13 })({});

Yields this:

({
	kind: "DELETE",
	left: 13,
	path: ["example"],
});

Object create

Let's say we update that same object from an empty one:

import { compare } from "@coven/compare";

compare({})({ example: 42 });

Yields this:

({
	kind: "CREATE",
	right: 42,
	path: ["example"],
});

Multiple differences

Now let's see what's yielded if we compare two objects with the 3 type of differences:

import { compare } from "@coven/compare";

compare({
	original: "old",
	updated: "old",
})({
	created: "new",
	updated: "new",
});

That yields all 3 kind of differences:

({ kind: "DELETE", left: "old", path: ["original"] });
({ kind: "UPDATE", left: "old", right: "new", path: ["updated"] });
({ kind: "CREATE", right: "new", path: ["created"] });

Like all Coven Engineering libraries, it has 100% test coverage and it's built in top of modern tech compatible with all JavaScript runtimes.

Other links

• Coverage.