j_

it's a toolkit of random and useful functions

Install

yarn add @jmellicker/j_

Array Operations

j_ array ops generally operate on arrays of objects.

Given this array:

const xmen = [
  { name: 'Nightcrawler', power: 'Teleportation', id: 1 },
  { name: 'Cyclops', power: 'Optic blast', id: 2 },
  { name: 'Rogue', power: 'Absorbing powers', id: 3 },
  { name: 'Wolverine', power: 'Regeneration', id: 4 }
]

indexFromArray

Searches an array of objects for a key/value pair and returns the index of the first match.

j_.indexFromArray(xmen, 'power', 'Optic blast') // => 1

indexFromArrayID

Shorthand for indexFromArray specifically for the 'id' key.

j_.indexFromArrayID(xmen, 2) // => 1

queryArrayFirstMatch

Returns the first object in the array that matches the key/value pair.

j_.queryArrayFirstMatch(xmen, 'power', 'Optic blast')
// => { name: "Cyclops", power: "Optic blast", id: 2 }

queryArrayAllMatches

Returns all objects in the array that match the key/value pair.

j_.queryArrayAllMatches(xmen, 'power', 'Teleportation')
// => [{ name: "Nightcrawler", power: "Teleportation", id: 1 }]

queryArrayAllPartialMatches

Returns all objects where the value for the key partially matches (string includes).

j_.queryArrayAllPartialMatches(xmen, 'power', 'optic')
// => [{ name: "Cyclops", power: "Optic blast", id: 2 }]

queryArrayAllUniqueValues

Returns an array of unique values for a specific key.

j_.queryArrayAllUniqueValues(xmen, 'power')
// => ['Teleportation', 'Optic blast', 'Absorbing powers', 'Regeneration']

queryArrayOneOfEach

Returns an object where keys are the unique values of the specified key, and values are the corresponding objects (last match wins).

j_.queryArrayOneOfEach(xmen, 'power')
// => { "Teleportation": {...}, "Optic blast": {...}, ... }

queryArrayMaxValue

Returns the object containing the maximum value for a given key.

j_.queryArrayMaxValue(xmen, 'id')
// => { name: "Wolverine", power: "Regeneration", id: 4 }

removeFirstMatchFromArray

Removes the first object matching the key/value pair from the array (modifies array in place).

j_.removeFirstMatchFromArray(xmen, 'name', 'Cyclops')

sortArrayBy

Sorts an array of objects by a key. Prefix with - for descending order.

j_.sortArrayBy(xmen, 'name') // Ascending
j_.sortArrayBy(xmen, '-id')  // Descending

shuffleArray

Randomly shuffles an array (modifies array in place).

j_.shuffleArray(xmen)

removeKeyFromAllArrayObjs

Removes a specific key from all objects in the array.

j_.removeKeyFromAllArrayObjs(xmen, 'power')

removeMatchedObjectsFromArray

Removes all objects matching the key and one of the values provided (array or comma-separated string).

j_.removeMatchedObjectsFromArray(xmen, 'id', [1, 3])

Object Operations

get

Safely gets a nested property.

const obj = { a: { b: { c: 1 } } }
j_.get(obj, 'a.b.c') // => 1
j_.get(obj, 'a.b.x') // => undefined

isPlainObject

Checks if a value is a plain object.

j_.isPlainObject({}) // => true
j_.isPlainObject([]) // => false
j_.isPlainObject(null) // => false

arrayOfKeyValuesFromObject

Extracts values for a specific key from an object of objects.

const data = { a: { id: 1 }, b: { id: 2 } }
j_.arrayOfKeyValuesFromObject(data, 'id') // => [1, 2]

stringOfKeyValuesFromObject

Same as above but returns a comma-separated string.

j_.stringOfKeyValuesFromObject(data, 'id') // => "1, 2"

queryObjectFirstMatch

Searches an object of objects for the first matching key/value.

j_.queryObjectFirstMatch(data, 'id', 2) // => { id: 2 }

convertObj2array

Converts an object of objects into an array of objects.

j_.convertObj2array(data) // => [{ id: 1 }, { id: 2 }]

mergeObjects

Merges source object into destination object.

j_.mergeObjects({ a: 1 }, { b: 2 }) // => { b: 2, a: 1 }

cloneObject

Creates a deep clone of a JSON-safe object.

const clone = j_.cloneObject(obj)

sortObjectBy

Sorts an object's keys based on the values of a specific sub-key.

j_.sortObjectBy(data, 'id', 'id')

addKeyToTopOfObject

Merges properties of the first object into the second, effectively putting them at the "top" if order matters.

j_.addKeyToTopOfObject({ z: 1 }, { a: 2 }) // => { a: 2, z: 1 } (Note: JS object key order isn't guaranteed)

subVars

Substitutes {{variable}} placeholders in a string with values from an object.

j_.subVars('Hello {{name}}', { name: 'World' }) // => "Hello World"

createTableFromUnstructuredData

Analyzes an array of objects and creates a normalized table structure with all unique columns.

j_.createTableFromUnstructuredData([{ a: 1 }, { b: 2 }])
// => { columnNames: ['a', 'b'], gridData: [...] }

objSub

Performs variable substitution on all string values within an object.

j_.objSub({ msg: 'Hello {{name}}' }, { name: 'Dave' }) // => { msg: "Hello Dave" }

String Operations

Given: const str = 'cat.dog.dolphin'

firstItemOf

Returns the first item based on a delimiter (defaults to auto-detecting , . / |).

j_.firstItemOf(str) // => 'cat'

lastItemOf

Returns the last item.

j_.lastItemOf(str) // => 'dolphin'

nthItemOf

Returns the nth item (1-based index).

j_.nthItemOf(str, 2) // => 'dog'

allButFirstItemOf

Returns everything after the first delimiter.

j_.allButFirstItemOf(str) // => 'dog.dolphin'

allButLastItemOf

Returns everything before the last delimiter.

j_.allButLastItemOf(str) // => 'cat.dog'

randomItemOf

Returns a random item from the delimited string.

j_.randomItemOf(str) // => 'dog' (random)

guessDelimiter

Returns the first matching delimiter from the set [',', '.', '/', '|'].

j_.guessDelimiter('a,b,c') // => ','

removeSpaces

Removes all spaces from a string.

j_.removeSpaces(' h i ') // => 'hi'

dashify

Converts to kebab-case (lowercase with dashes).

j_.dashify('Hello World') // => 'hello-world'

toTitleCase

Converts to Title Case.

j_.toTitleCase('hello world') // => 'Hello World'

decamelize

Converts camelCase to a delimited string (default _).

j_.decamelize('helloWorld') // => 'hello_world'

snakeToCamel

Converts snake_case to camelCase.

j_.snakeToCamel('hello_world') // => 'helloWorld'

camelToSnake

Converts camelCase to snake_case.

j_.camelToSnake('helloWorld') // => 'hello_world'

slugify

Converts text to a URL-friendly slug, handling special characters.

j_.slugify('Hello World & Universe') // => 'hello-world-and-universe'

Quote Operations

replaceHtmlAttributeQuotes

Replaces escaped double quotes \" with escaped single quotes \' inside HTML tags.

j_.replaceHtmlAttributeQuotes('<div class=\\"test\\">') // => '<div class=\'test\'>'

educateQuotes

Converts straight quotes to smart/curly quotes.

j_.educateQuotes('"Hello"') // => '“Hello”'

straightenQuotes

Converts smart/curly quotes to straight quotes.

j_.straightenQuotes('“Hello”') // => '"Hello"'

quoteIfString

Wraps input in single quotes if it is a string.

j_.quoteIfString('test') // => "'test'"
j_.quoteIfString(1) // => 1

backtickIfString

Wraps input in backticks if it is a string.

j_.backtickIfString('test') // => "`test`"

escapeQuotes

Escapes quotes and backslashes in a string.

j_.escapeQuotes('It\'s "ok"') // => 'It\\\'s \\"ok\\"'

quoteAndEscapeQuotesIfString

Combines quoting and escaping.

j_.quoteAndEscapeQuotesIfString('It\'s') // => "'It\\\'s'"

quoteAndEducateQuotesIfString

Combines quoting and smart quoting.

j_.quoteAndEducateQuotesIfString('"Hi"') // => "'“Hi”'"

addAdditionalSingleQuoteIfString

Doubles single quotes (often for SQL).

j_.addAdditionalSingleQuoteIfString("It's") // => "It''s"

Random Operations

randomInteger

Returns a random integer between min and max (inclusive).

j_.randomInteger(1, 10)

randomAlphaNumeric

Returns a random alphanumeric string of specified length.

j_.randomAlphaNumeric(8)

randomCrayolaColor

Returns a random Crayola color name.

j_.randomCrayolaColor()

randomColor

Alias for randomCrayolaColor.

j_.randomColor()

randomHexColor

Returns a random hex color code.

j_.randomHexColor() // => "#f3a2b1"

randomAnimal

Returns a random animal name.

j_.randomAnimal()

uaid

Generates a unique ID: Letter_Timestamp_Random_Animal.

j_.uaid('A')

ucid

Generates a unique ID: Letter_Timestamp_Random_Color.

j_.ucid('B')

uniqID

Generates a complex unique ID.

j_.uniqID('prefix')

id

Generates a simple random ID with prefix.

j_.id('user') // => "userx7d8s9..."

randomLoadingMessage

Returns a random funny loading message.

j_.randomLoadingMessage()

randomSuccessQuote

Returns a random motivational quote.

j_.randomSuccessQuote()

Validation Operations

validEmailAddress

Validates standard email format.

j_.validEmailAddress('[email protected]') // => true

validEmailAddressNonLatin

Validates email allowing non-latin characters.

j_.validEmailAddressNonLatin('[email protected]')

luhnCheck

Validates numbers using the Luhn algorithm (credit cards, IMEIs).

j_.luhnCheck('79927398713') // => true

Misc Operations

openCleanWindow

Opens a new browser window with specific dimensions and settings.

j_.openCleanWindow('http://google.com')

fillCleanWindowWithHTML

Opens a window and populates it with HTML content.

j_.fillCleanWindowWithHTML('myWindow')

secondsToHms

Converts seconds to HH:MM:SS format.

j_.secondsToHms(3665) // => "01:01:05"

hmsToSeconds

Converts HH:MM:SS to seconds.

j_.hmsToSeconds("01:01:05") // => 3665

timeAgo

Returns a human-readable string for how long ago a date was.

j_.timeAgo(new Date(Date.now() - 600000)) // => "10 minutes ago"

formatMonthYear

Formats strings like "MM-YYYY" to "MM/YY".

j_.formatMonthYear('12-2023') // => "12/23"

decodeHtmlEntity

Decodes numeric HTML entities.

j_.decodeHtmlEntity('A') // => "A"

decodeHTML

Same as decodeHtmlEntity.

j_.decodeHTML('A') // => "A"

naturalSorter

Comparator for natural sort order (e.g. "File 2" before "File 10").

['f10', 'f2'].sort(j_.naturalSorter) // => ['f2', 'f10']

trueFalse

Evaluates "truthiness" including handling empty objects as false.

j_.trueFalse({}) // => false
j_.trueFalse({ a: 1 }) // => true

tf

Alias for trueFalse.

j_.tf(someVal)

sleep

Returns a promise that resolves after N milliseconds.

await j_.sleep(1000)