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Selectors API

A collection of helper functions to get a subset of keys for a set of objects. Typically used by select.

contains​

Returns all keys that contain the specified substring.

Parameters​

substring​

string

The substring that must exist in the keys.

ignoreCase​

boolean = true

If true, matches without considering whether letters are upper or lower case (default: true).

Usage​

const data = [
  { foo: 1, bar: 20, foobar: 300, FoObAR: 90 },
];

tidy(data, select([contains('oba')]))
// output:
[{ foobar: 300, FoObAR: 90 }]

tidy(data, select([contains('oba', false)]))
// output:
[{ foobar: 300 }]

endsWith​

Returns all keys that end with the specified substring.

Parameters​

suffix​

string

The suffix that must exist in the keys.

ignoreCase​

boolean = true

If true, matches without considering whether letters are upper or lower case (default: true).

Usage​

const data = [
  { foo: 1, bar: 20, foobar: 300, FoObAR: 90 },
];

tidy(data, select([endsWith('bAR')]))
// output:
[{ foobar: 300, FoObAR: 90 }]

tidy(data, select([endsWith('bAR', false)]))
// output:
[{ FoObAR: 90 }]

everything​

Returns all keys for items in the collection. It is naive and looks only at the first element in the collection.

Usage​

const data = [
  { foo: 1, bar: 20, foobar: 300, FoObAR: 90 },
];

tidy(data, select(['foobar', everything(), '-FoObAR']))
// output:
[{ foobar: 300, foo: 1, bar: 20 }]

matches​

Returns all keys that start with the specified substring.

Parameters​

regex​

RegExp

The regular expression used to match keys against. You must provide the i flag to have case ignored.

Usage​

const data = [
  { foo: 1, bar: 20, foobar: 300, FoObAR: 90 },
];

tidy(data, select([matches(/oba/i)]))
// output:
[{ foobar: 300, FoObAR: 90 }]

tidy(data, select([matches(/oba/)]))
// output:
[{ foobar: 300 }]

negate​

Converts the output of any given selector(s) to be prefixed with -, so when combined with select, those keys are dropped.

Parameters​

selectors​

| string /* keys in the object */  
| (items: T[]) => string[] /* selector functions */
| (string | (items: T[]) => string[])[]

Single or array of selector keys or functions.

Usage​

const data = [{
  date: '2021-01-01',
  test_bigint: 123,
  test: 12,
  foo_bigint: 99,
  bar: 13,
}];

tidy(data, 
  select([negate(endsWith('_bigint')), '-date']))
// output:
[{ test: 12, bar: 13 }]

// same as:
tidy(data, 
  select(['-test_bigint', '-foo_bigint', '-date']))

numRange​

Returns all keys that start with the specified substring combined with a numerical suffix within a specified range.

Parameters​

prefix​

string

The prefix for the keys that will have the numbers appended to.

range​

[number, number]

The [min, max] numbers to generate the keys over.

width?​

number | undefined

How many leading zeroes the numbers should have, defaults to none.

Usage​

const data = [
  { foo07: 1, foo08: 20, foo10: 300, foo11: 90, foo12: 12, bar08: 8, foo: 1 },
];

tidy(data, select([numRange('foo', [8, 11], 2)]))
// output:
[{ foo08: 20, foo10: 300, foo11: 90 }]

startsWith​

Returns all keys that start with the specified substring.

Parameters​

prefix​

string

The prefix that must exist in the keys.

ignoreCase​

boolean = true

If true, matches without considering whether letters are upper or lower case (default: true).

Usage​

const data = [
  { foo: 1, bar: 20, foobar: 300, FoObAR: 90 },
];

tidy(data, select([startsWith('bAR')]))
// output:
[{ foobar: 300, FoObAR: 90 }]

tidy(data, select([startsWith('bAR', false)]))
// output:
[{ FoObAR: 90 }]