Switchr

Switchr provides a simple, clean, and flexible alternative to switch statements.

Installation

npm install switchr

Usage

Methods

• Get
• Set
• Has
• List

Basic Usage

const basicSwitchr = switchr({
  foo: 'foo foo',
  buzz: (str) => {
    return 'buzz buzz ' + str;
  },
  default: 'foobarbuzz'
});

basicSwitchr.get('foo'); // 'foo foo'
basicSwitchr.get('buzz', 'baby'); // 'buzz buzz baby'
basicSwitchr.get('non-existent'); // 'foobarbuzz'

Initialization

• Import

import switchr from 'switchr'; /* ES6 */

/* OR */

const switchr = require('switchr').default; /* require */

• Switchr can be initialized with either an object or array for ultimate flexibility:

// Object
const switchrObject = switchr({
  foo: 'foo',
  bar: 'bar'
});

// Array
const switchrArray = switchr([
  {
    key: 'foo',
    value: 'foo'
  },
  {
    key: 'bar',
    value: 'bar'
  }
]);

• Initializing with an array will allow common functionality between multiple cases using the keys property:

const switchrArray = switchr([
  {
    keys: ['one', 'two', 'three'],
    value: 1
  },
  {
    key: 'four',
    value: 4
  }
]);

switchrArray.get('one'); // 1
switchrArray.get('two'); // 1
switchrArray.get('three'); // 1
switchrArray.get('four'); // 4

• It also accepts functions as values

const switchrWithFunction = switchr({
  foo: (a, b) => {
    return a + b;
  },
});

const switchrWithArrowFunction = switchr({
  bar: (a, b) => {
    return a - b;
  }
});

Get

• The get method retrieves simple values:

const getSwitchr = switchr({
  getMe: 'You got me!'
});

getSwitchr.get('getMe'); // 'You got me!'

• Or executes functions

const getFunctionsSwitchr = switchr({
  getMeFn: () => { // Without arguments
    return 'You got me again!';
  },
  sum: (a, b) => { // With arguments
    return a + b;
  }
});

getSwitchr.get('getMeFn'); // 'You got me again!'
getSwitchr.get('sum', 10, 15); // 25

• get will ignore arguments passed in when the function doesn't expect them:

getSwitchr.get('getMeFn', 10, 15) // 'You got me again!'

• Use a default key to handle cases that don't exist

const switchrWithDefault = switchr({
  foo: 'foo',
  default: 'foobar'
});

switchrWithDefault.get('doesntExist') // 'foobar'

• If no default key exists, get will return null:

const switchrWithoutDefault = switchr({
  foo: 'foo'
});

switchrWithDefault.get('doesntExist') // null

Set

• The set method adds a new case by passing in a key and value:

const setSwitchr = switchr({
  foo: 'foo'
});
setSwitchr.set('bar', 'bar');
setSwitchr.get('bar'); // 'bar'

• set also accepts a callback function:

function multiply(a, b) {
  return a * b;
}

const setSwitchr = switchr({
  foo: 'foo'
});

setSwitchr.set('multiply', multiply);
setSwitchr.get('multiply', 10, 20); // 200

• If a key already exists, set will update that value:

const updateSwitchr = switchr({
  updateMe: 'old value'
});

updateSwitchr.set('updateMe', 'new value!');
updateSwitchr.get('updateMe'); // 'new value!'

Has

• The has method checks to see if a case exists:

const hasSwitchr = switchr({
  foo: 'foo',
});

hasSwitchr.has('foo'); // true
hasSwitchr.has('bar'); // false

List

• The list method returns an array available keys:

const listSwitchr = switchr({
  foo: 'foo',
  bar: 'bar',
  buzz: () => {
    return 'buzz buzz';
  },
  default: 'default value'
});

listSwitchr.list(); // ['foo', 'bar', 'buzz', 'default'];

TypeScript Support

Switcher has full TypeScript support

License

MIT