mixme/README.md

A library for recursively merging JavaScript objects

# Node.js mixme

![Build Status](https://github.com/adaltas/node-mixme/actions/workflows/test.yml/badge.svg)

Merge multiple object recursively, with TypeScript support. The last object takes precedence over the previous ones. Only objects are merged. Arrays are overwritten.

- Zero dependencies
- Small size
- Pure functions
- ESM and CommonJS support

## API

The API is minimalist. The most popular functions are `merge`, `mutate` and `is_object_literal`.

### Function `camelize(object)`

Clone a object and convert its properties into snake case.

```js
import { snake_case } from "mixme"

snake_case({aA: "1", bB: cC: "2"})
// Return {a_a: "1", b_b: c_c: "2"}
```

### Function `camelize_str(str)`

Convert a camel case string to snake case, used internally by `snake_case`.

```js
import { snake_case_str } from "mixme";

snake_case("myValue");
// Return "my_value"
```

### Function `compare(item_1, item_2)`

Compare two items and return true if their values match.

```js
import { compare } from "mixme";

compare([{ a: 1 }], [{ a: 1 }]);
// Return true

compare({ a: 1 }, { a: 2 });
// Return false
```

### Function `clone(data)`

It is possible to clone a literal object by simply calling `mixme` with this object as the first argument. Use the `clone` function in case you wish to clone any type of argument including arrays:

```js
import { clone } from "mixme";

const target = clone(["a", "b"]);
// target is now a copy of source
```

### Function `is_object_literal(object)`

Use the `is_object_literal` function to ensure an object is literate.

```js
import { is_object_literal } from "mixme";

// {} is literate
is_object_literal({});

// error is not literate
is_object_literal(new Error("Catch me"));

// Array is not literate
is_object_literal([]);
```

### Function `merge(...data)`

The API is minimalist,
Merge all literal object provided as arguments. This function is immutable, the source objects won't be altered.

```js
import { merge } from "mixme";

const target = merge({ a: "1" }, { b: "2" });
// target is {a: "1", b: "2"}
```

### Function `mutate(...data)`

Use the `mutate` function to enrich an object. The first argument will be mutated:

```js
import { mutate } from "mixme";

const source = { a: "1" };
const target = mutate(source, { b: "2" });
target.c = "3";
// source and target are both {a: "1", b: "2", c: "3"}
```

### Function `snake_case(object)`

Clone a object and convert its properties into snake case.

```js
import { snake_case } from "mixme"

snake_case({aA: "1", bB: cC: "2"})
// Return {a_a: "1", b_b: c_c: "2"}
```

### Function `snake_case_str(str)`

Convert a camel case string to snake case, used internally by `snake_case`.

```js
import { snake_case_str } from "mixme";

snake_case("myValue");
// Return "my_value"
```

## Example

Create a new object from two objects:

```js
import { merge } from "mixme";

const obj1 = { a_key: "a value", b_key: "b value" };
const obj2 = { b_key: "new b value" };
const result = merge(obj1, obj2);

assert.eql(result.b_key, "new b value");
```

Merge an existing object with a second one:

```js
import { mutate } from "mixme";

const obj1 = { a_key: "a value", b_key: "b value" };
const obj2 = { b_key: "new b value" };
const result = mutate(obj1, obj2);

assert.eql(result, obj1);
assert.eql(obj1.b_key, "new b value");
```

## Testing

Clone the repo, install the development dependencies and run the tests:

```bash
git clone http://github.com/wdavidw/node-mixme.git .
npm install
npm run test
```

## Developers

To automatically generate a new version:

```bash
npm run release
```

Package publication is handled by the CI/CD with GitHub action.

Note:

- On release, both the publish and test workflows run in parallel. Not very happy about it but I haven't found a better way.

## Contributors

- David Worms: <https://github.com/wdavidw>
- Paul Farault: <https://github.com/PaulFarault>

This package is developed by [Adaltas](https://www.adaltas.com).