js-fast-utils

Javascript utility functions

Javascript type verification functions

isDefined

Check if is not undefined.

isObject

Check if is an Object.

isString

Check if is a String.

isFunction

Check if is a Function.

isArray

Check if is a Array.

isNumber

Check if is a Number.

isRegex

Check if is a RegExp.

isNull

Check if is null.

isAsyncFunction

Check if is an async function.

isEmptyObject

Check if is an Object and has no properties.

isEmptyString

Check if is equal to an empty string.

isEmptyArray

Check if is an Array and has zero items.

isEmpty

Check if is null, not defined or a type with no elements/properties/items even if it is defined.

Date functions

isDate

Test a string if can be parsed to Date

Other utility functions

objectMap

Loop into object properties assigning to a new one using predicate function and get a new mapped object.

It's useful for rearranging objects:

const daysOfWeek = {
  sun: { id: 0, name: 'Sunday', abbreviated: 'SUN' },
  mon: { id: 1, name: 'Monday', abbreviated: 'MON' },
  tue: { id: 2, name: 'Tuesday', abbreviated: 'TUE' },
  wed: { id: 3, name: 'Wednesday', abbreviated: 'WED' },
  thu: { id: 4, name: 'Thursday', abbreviated: 'THU' },
  fri: { id: 5, name: 'Friday', abbreviated: 'FRI' },
  sat: { id: 6, name: 'Saturday', abbreviated: 'SAT' }
}

const indexedDaysOfWeek = objectMap(daysOfWeek, ({ id, ...day }) => ({ [id]: day }))
/* indexedDaysOfWeek:
{
  0: {name: "Sunday", abbreviated: "SUN"}
  1: {name: "Monday", abbreviated: "MON"}
  2: {name: "Tuesday", abbreviated: "TUE"}
  3: {name: "Wednesday", abbreviated: "WED"}
  4: {name: "Thursday", abbreviated: "THU"}
  5: {name: "Friday", abbreviated: "FRI"}
  6: {name: "Saturday", abbreviated: "SAT"}
}
*/

objectForeach

Loop into object properties sending key-value pairs to the predicate function.

const groupedByDayOfWeek = {
  monday: {
    detectedPeople: 754,
    inDeniedList: 0
  },
  tuesday: {
    detectedPeople: 548,
    inDeniedList: 2
  }
}

objectForeach(groupedByDayOfWeek, (detectionInfo, dayOfWeek) => {
  if (detectionInfo.inDeniedList > 0) {
    // Do something
  }
})

objectToArrayMap

Convert object properties into array items using the predicate function.

const groupedByDayOfWeek = {
  monday: {
    detectedPeople: 754,
    inDeniedList: 0
  },
  tuesday: {
    detectedPeople: 548,
    inDeniedList: 2
  }
}

const dataArray = objectToArrayMap(groupedByDayOfWeek, (detectionInfo, dayOfWeek) => ({detectionInfo, dayOfWeek}))
/* dataArray:
[
  {
    "detectionInfo":{
      "detectedPeople":754,
      "inDeniedList":0
    },
    "dayOfWeek":"monday"
  },
  {
    "detectionInfo":{
      "detectedPeople":548,
      "inDeniedList":2
    },
    "dayOfWeek":"tuesday"
  }
]
*/

canBeNumber

Verify if can be converted to a Number.

console.log(canBeNumber('1')) // true
console.log(canBeNumber(''), Number('')) // true, 0
console.log(canBeNumber('Not a number')) // false

deleteKeys

Iterate object properties and delete them if they match the predicate.

// For example, an object from a user page edit form that you want to delete the empty properties to not send them to backend api
const userForm = {
  username: '[email protected]',
  password: undefined, // the user did not change the password and the backend do not accept an empty value for this field

  // Other examples
  emptyStringPassword: '',
  emptyObject: {},
  nullValueProp: null
}

deleteKeys(userForm, value => value === undefined)
console.log(userForm) // { username: '[email protected]', emptyStringPassword: '', emptyObject: {}, nullValueProp: null }

// You can use isEmpty to reach undefined, null, empty strings '' and empty objects {}:
deleteKeys(userForm, value => isEmpty(value))
console.log(userForm) // { username: '[email protected]' }

// And them send the put request
const response = await axios.put(userFormApiUrl, { data: userForm })

deleteKeysRecursive

Iterate object properties and delete them recursively if they match the predicate.

// Using the same example in deleteKeys(). Take a look at it first.

const userForm = {
  username: '[email protected]',
  password: undefined, // the user did not change the password and the backend do not accept an empty value for this field

  // Will also delete this entire prop (unlike deleteEmptyKeys())
  objectWithEmptyProps: {
    emptyProp: ''
  }
}

deleteKeysRecursive(userForm, value => isEmpty(value))

console.log(userForm) // { username: '[email protected]' }

mapAsync

Generate a new array by iterate through items and using a async predicate function modify them. The return will be a Promise.

Changes

Version 1.0.0

• Initial release functions

Version 1.1.0

• Add deleteKeys function

• Add deleteKeysRecursive function

Breaking changes!

1. Fix deleteEmptyKeys logic to delete undefined, null, empty strings '' and empty objects {} (before the function was just undefined and empty objects {}).

2. Fix deleteEmptyKeysRecursive logic to delete undefined, null, empty strings '' and empty objects {} (before the function was just undefined and empty objects {}).

Version 1.2.0

Breaking changes!

1. Removed deprecated deleteEmptyKeys function (deleteKeys can be used instead)

2. Removed deprecated deleteEmptyKeysRecursive function (deleteKeysRecursive can be used instead)

TODOS:

• Fix some typescript typings

• Add unity tests