Supick (super pick)

Empowered but easy to use lodash Pick alternative with configurable and extensive schema and

Supick creates an object/array composed of the deeply picked object properties/array of picked object properties.

$3

npm i supick

``javascript
const pick = require("supick");

const person = {
name: "John Doe",
car: {
model: "BMW X5",
year: 2019,
color: "black",

},
hobby: "music"
};

pick(person, "name, car: {model, year}"); // ==> { name: "John Doe", { car: { model: "BMW X5", year: 2019 } } }
`

Schema format rules:

1. Schema could be string, array of strings(lodash pick style), object(mongodb projection style) or customizer function
2. You may use trailing whitespaces, newlines and carret returns - they are ignored.
3. You may enclose schema in brackets: '{a, b, c, d: {d_a, d_b}}'
4. Use commas to separate prop names on each level. Trailing comma is ignored.
5. Use colon ":" and curly brackets ("{", "}") to specify inner properties.
6. You may use supick both for objects and arrays, for example: schema "a: 1, b: 2" works this way:
- pick({ a: 1, b: 2, c: 3 }, 'a, b') => { a: 1, b: 2 }
- pick([{ a: 1, b: 2, c: 3 }, { a: 1, b: 2, c: 3 }, { a: 1, b: 2, c: 3 }], 'a, b') => [{ a: 1, b: 2 }, { a: 1, b: 2 }, { a: 1, b: 2 }]
7. Customizer function is very flexible way to add some extra logic. Customizer function must return truthy or falsy value to determine if property should be picked. Function receives 4 arguments: key(property name), value(property value), path(parent properties concatenated with dot delimiter), depth(depth of current nested property).

Schema examples:

1. String: '{ a, b, c: { d, e }, f: { g: { h, i }, j } }'.
2. Array of strings(lodash-style): ['a', 'b', 'c: { d, e }', 'f: { g: { h, i }, j }'].
3. Object(mongodb projection-style): { a: true, b: true, c: { d: true, e: true }, f: { g: { h: true, i: true }, j: true } } // "true" could be replaced to 1
4. Customizer function:
`javascript
function (key, value, path, depth) {
if (['a', 'b', 'c', 'e'].includes(key)) return true; // pick all properties with names a, b, c, e
if (path.startsWith('f')) return true; // pick f property and all its nested properties
if (depth === 0) return true; // pick all top level properties
return false;
}
`

Big example with nested objects and arrays:

`javascript
const person = {
"name" : "John Doe",
"age": 35,
"family" : {
"wife" : {
"name": "Susan",
"age": 32
},
"children": [
{
"name": "Alex",
"age": 5,
"hobby": "dancing"
},
{
"name": "Alice",
"age": 3,
"hobby": "music"
}
]
},
"cars": [
{
"model": "BMW X5",
"year": 2015
},
{
"model": "Tesla Model S",
"year": 2018
}
]
};

const schema =
{
name,
family: {
wife,
children: {
name,
age
}
},
cars: { model }
};

`

pick(obj, schema); will result in this =>

`javascript
{
"name" : "John Doe",
"family" : {
"wife" : { "name": "Susan", "age": 32 },
"children": [
{ "name": "Alex", "age": 5 },
{ "name": "Alice", "age": 3 }
]
},
"cars": [
{ "model": "BMW X5" },
{ "model": "Tesla Model S" }
]
};
`

More examples in test file index.test.js`