Package @reatom/utils

@reatom/utils

Interfaces

AbortError

Defined in: packages/core/src/utils.ts:658

Interface extending DOMException for abort-specific error handling. Used to represent errors triggered by AbortController signal aborts.

See

https://developer.mozilla.org/en-US/docs/Web/API/AbortController

Extends

DOMException

Properties

ABORT_ERR

readonly ABORT_ERR: 20

Defined in: node_modules/.pnpm/typescript@5.9.3/node_modules/typescript/lib/lib.dom.d.ts:8622

Inherited from

DOMException.ABORT_ERR

cause?

optional cause: unknown

Defined in: node_modules/.pnpm/typescript@5.9.3/node_modules/typescript/lib/lib.es2022.error.d.ts:26

Inherited from

DOMException.cause

code

readonly code: number

Defined in: node_modules/.pnpm/typescript@5.9.3/node_modules/typescript/lib/lib.dom.d.ts:8590

The code read-only property of the DOMException interface returns one of the legacy error code constants, or 0 if none match.

Deprecated

MDN Reference

Inherited from

DOMException.code

DATA_CLONE_ERR

readonly DATA_CLONE_ERR: 25

Defined in: node_modules/.pnpm/typescript@5.9.3/node_modules/typescript/lib/lib.dom.d.ts:8627

Inherited from

DOMException.DATA_CLONE_ERR

DOMSTRING_SIZE_ERR

readonly DOMSTRING_SIZE_ERR: 2

Defined in: node_modules/.pnpm/typescript@5.9.3/node_modules/typescript/lib/lib.dom.d.ts:8604

Inherited from

DOMException.DOMSTRING_SIZE_ERR

HIERARCHY_REQUEST_ERR

readonly HIERARCHY_REQUEST_ERR: 3

Defined in: node_modules/.pnpm/typescript@5.9.3/node_modules/typescript/lib/lib.dom.d.ts:8605

Inherited from

DOMException.HIERARCHY_REQUEST_ERR

INDEX_SIZE_ERR

readonly INDEX_SIZE_ERR: 1

Defined in: node_modules/.pnpm/typescript@5.9.3/node_modules/typescript/lib/lib.dom.d.ts:8603

Inherited from

DOMException.INDEX_SIZE_ERR

INUSE_ATTRIBUTE_ERR

readonly INUSE_ATTRIBUTE_ERR: 10

Defined in: node_modules/.pnpm/typescript@5.9.3/node_modules/typescript/lib/lib.dom.d.ts:8612

Inherited from

DOMException.INUSE_ATTRIBUTE_ERR

INVALID_ACCESS_ERR

readonly INVALID_ACCESS_ERR: 15

Defined in: node_modules/.pnpm/typescript@5.9.3/node_modules/typescript/lib/lib.dom.d.ts:8617

Inherited from

DOMException.INVALID_ACCESS_ERR

INVALID_CHARACTER_ERR

readonly INVALID_CHARACTER_ERR: 5

Defined in: node_modules/.pnpm/typescript@5.9.3/node_modules/typescript/lib/lib.dom.d.ts:8607

Inherited from

DOMException.INVALID_CHARACTER_ERR

INVALID_MODIFICATION_ERR

readonly INVALID_MODIFICATION_ERR: 13

Defined in: node_modules/.pnpm/typescript@5.9.3/node_modules/typescript/lib/lib.dom.d.ts:8615

Inherited from

DOMException.INVALID_MODIFICATION_ERR

INVALID_NODE_TYPE_ERR

readonly INVALID_NODE_TYPE_ERR: 24

Defined in: node_modules/.pnpm/typescript@5.9.3/node_modules/typescript/lib/lib.dom.d.ts:8626

Inherited from

DOMException.INVALID_NODE_TYPE_ERR

INVALID_STATE_ERR

readonly INVALID_STATE_ERR: 11

Defined in: node_modules/.pnpm/typescript@5.9.3/node_modules/typescript/lib/lib.dom.d.ts:8613

Inherited from

DOMException.INVALID_STATE_ERR

message

readonly message: string

Defined in: node_modules/.pnpm/typescript@5.9.3/node_modules/typescript/lib/lib.dom.d.ts:8596

The message read-only property of the a message or description associated with the given error name.

MDN Reference

Inherited from

DOMException.message

name

name: "AbortError"

Defined in: packages/core/src/utils.ts:659

The name read-only property of the one of the strings associated with an error name.

MDN Reference

Overrides

DOMException.name

NAMESPACE_ERR

readonly NAMESPACE_ERR: 14

Defined in: node_modules/.pnpm/typescript@5.9.3/node_modules/typescript/lib/lib.dom.d.ts:8616

Inherited from

DOMException.NAMESPACE_ERR

NETWORK_ERR

readonly NETWORK_ERR: 19

Defined in: node_modules/.pnpm/typescript@5.9.3/node_modules/typescript/lib/lib.dom.d.ts:8621

Inherited from

DOMException.NETWORK_ERR

NO_DATA_ALLOWED_ERR

readonly NO_DATA_ALLOWED_ERR: 6

Defined in: node_modules/.pnpm/typescript@5.9.3/node_modules/typescript/lib/lib.dom.d.ts:8608

Inherited from

DOMException.NO_DATA_ALLOWED_ERR

NO_MODIFICATION_ALLOWED_ERR

readonly NO_MODIFICATION_ALLOWED_ERR: 7

Defined in: node_modules/.pnpm/typescript@5.9.3/node_modules/typescript/lib/lib.dom.d.ts:8609

Inherited from

DOMException.NO_MODIFICATION_ALLOWED_ERR

NOT_FOUND_ERR

readonly NOT_FOUND_ERR: 8

Defined in: node_modules/.pnpm/typescript@5.9.3/node_modules/typescript/lib/lib.dom.d.ts:8610

Inherited from

DOMException.NOT_FOUND_ERR

NOT_SUPPORTED_ERR

readonly NOT_SUPPORTED_ERR: 9

Defined in: node_modules/.pnpm/typescript@5.9.3/node_modules/typescript/lib/lib.dom.d.ts:8611

Inherited from

DOMException.NOT_SUPPORTED_ERR

QUOTA_EXCEEDED_ERR

readonly QUOTA_EXCEEDED_ERR: 22

Defined in: node_modules/.pnpm/typescript@5.9.3/node_modules/typescript/lib/lib.dom.d.ts:8624

Inherited from

DOMException.QUOTA_EXCEEDED_ERR

SECURITY_ERR

readonly SECURITY_ERR: 18

Defined in: node_modules/.pnpm/typescript@5.9.3/node_modules/typescript/lib/lib.dom.d.ts:8620

Inherited from

DOMException.SECURITY_ERR

stack?

optional stack: string

Defined in: node_modules/.pnpm/typescript@5.9.3/node_modules/typescript/lib/lib.es5.d.ts:1078

Inherited from

DOMException.stack

SYNTAX_ERR

readonly SYNTAX_ERR: 12

Defined in: node_modules/.pnpm/typescript@5.9.3/node_modules/typescript/lib/lib.dom.d.ts:8614

Inherited from

DOMException.SYNTAX_ERR

TIMEOUT_ERR

readonly TIMEOUT_ERR: 23

Defined in: node_modules/.pnpm/typescript@5.9.3/node_modules/typescript/lib/lib.dom.d.ts:8625

Inherited from

DOMException.TIMEOUT_ERR

TYPE_MISMATCH_ERR

readonly TYPE_MISMATCH_ERR: 17

Defined in: node_modules/.pnpm/typescript@5.9.3/node_modules/typescript/lib/lib.dom.d.ts:8619

Inherited from

DOMException.TYPE_MISMATCH_ERR

URL_MISMATCH_ERR

readonly URL_MISMATCH_ERR: 21

Defined in: node_modules/.pnpm/typescript@5.9.3/node_modules/typescript/lib/lib.dom.d.ts:8623

Inherited from

DOMException.URL_MISMATCH_ERR

VALIDATION_ERR

readonly VALIDATION_ERR: 16

Defined in: node_modules/.pnpm/typescript@5.9.3/node_modules/typescript/lib/lib.dom.d.ts:8618

Inherited from

DOMException.VALIDATION_ERR

WRONG_DOCUMENT_ERR

readonly WRONG_DOCUMENT_ERR: 4

Defined in: node_modules/.pnpm/typescript@5.9.3/node_modules/typescript/lib/lib.dom.d.ts:8606

Inherited from

DOMException.WRONG_DOCUMENT_ERR

Fn()

Defined in: packages/core/src/utils.ts:8

Generic function type representing any function that takes any parameters and returns any value. Used throughout Reatom for typing function parameters and callbacks.

Fn(…params): any

Defined in: packages/core/src/utils.ts:9

Generic function type representing any function that takes any parameters and returns any value. Used throughout Reatom for typing function parameters and callbacks.

Parameters

params

…any[]

Returns

any

Newable<ReturnType>

Defined in: packages/core/src/utils.ts:99

Represents a constructor function that can be instantiated with the new operator.

Type Parameters

ReturnType

ReturnType

The type of object that will be created when instantiated

Constructors

Constructor

new Newable(…params): ReturnType

Defined in: packages/core/src/utils.ts:100

Parameters

params

…any[]

Returns

ReturnType

Unsubscribe()

Defined in: packages/core/src/utils.ts:24

Function interface for unsubscribing from subscriptions. Used consistently throughout Reatom for cleanup functions.

Unsubscribe(): void

Defined in: packages/core/src/utils.ts:25

Function interface for unsubscribing from subscriptions. Used consistently throughout Reatom for cleanup functions.

Returns

void

Type Aliases

Assign<T1, T2, T3, T4>

Assign<T1, T2, T3, T4> = Plain<T1 extends (…params) => infer O ? (…params) => O : object & Omit<T1, keyof T2 | keyof T3 | keyof T4> & Omit<T2, keyof T3 | keyof T4> & Omit<T3, keyof T4> & T4>

Defined in: packages/core/src/utils.ts:380

Type utility for merging up to four types with proper type safety. Properties from later types override properties from earlier types. Preserves function signatures from T1 if it’s a function type.

Type Parameters

T1

T1

First type to merge

T2

T2

Second type to merge, overrides T1 properties

T3

T3 = { }

Optional third type to merge, overrides T1 and T2 properties

T4

T4 = { }

Optional fourth type to merge, overrides T1, T2, and T3 properties

Constructor()<T>

Constructor<T> = (…args) => T

Defined in: packages/core/src/utils.ts:773

Represents a constructor function that can be instantiated with the new operator.

Type Parameters

T

T

The type of object that will be created when instantiated

Parameters

args

…any[]

Returns

T

Falsy

Falsy = false | 0 | "" | null | undefined

Defined in: packages/core/src/utils.ts:56

Union type of all JavaScript falsy values except for NaN. Includes: false, 0, empty string, null, and undefined.

See

https://stackoverflow.com/a/51390763

MaybeUnsubscribe

MaybeUnsubscribe = void | Unsubscribe | { unsubscribe: Unsubscribe; }

Defined in: packages/core/src/utils.ts:33

Type representing different possible return values from observable subscription methods. Supports both function-based unsubscribers and objects with unsubscribe methods.

OmitValues<T, V>

OmitValues<T, V> = { [K in OmitValuesKeys<T, V>]: T[K] }

Defined in: packages/core/src/utils.ts:128

Creates a type with all properties from T except those with values extending V.

Type Parameters

T

T

The object type to filter properties from

V

V

The value type to exclude

OmitValuesKeys<T, V>

OmitValuesKeys<T, V> = Values<{ [K in keyof T]: T[K] extends V ? never : K }>

Defined in: packages/core/src/utils.ts:117

Extracts keys from type T where the corresponding value does not extend type V.

Type Parameters

T

T

The object type to extract keys from

V

V

The value type to exclude

OverloadParameters<T>

OverloadParameters<T> = Parameters<Overloads<T>>

Defined in: packages/core/src/utils.ts:190

Extracts the parameters type from an overloaded function. Returns a union of all possible parameter tuples.

Type Parameters

T

T

The overloaded function type to extract parameters from

Overloads<T>

Overloads<T> = T extends {(…params): Return1; (…params): Return2; (…params): Return3; (…params): Return4; (…params): Return5; } ? (…params) => Return1 | Return2 | Return3 | Return4 | Return5 : never

Defined in: packages/core/src/utils.ts:160

Flattens a function type with up to 5 overloads into a single function signature. This creates a union of the parameter types and return types.

Useful for generic type handling of overloaded functions.

Type Parameters

T

T

The overloaded function type to flatten

PickValues<T, V>

PickValues<T, V> = { [K in PickValuesKeys<T, V>]: T[K] }

Defined in: packages/core/src/utils.ts:148

Creates a type with only properties from T with values extending V.

Type Parameters

T

T

The object type to filter properties from

V

V

The value type to include

PickValuesKeys<T, V>

PickValuesKeys<T, V> = Values<{ [K in keyof T]: T[K] extends V ? K : never }>

Defined in: packages/core/src/utils.ts:138

Extracts keys from type T where the corresponding value extends type V.

Type Parameters

T

T

The object type to extract keys from

V

V

The value type to include

Plain<Intersection>

Plain<Intersection> = Intersection extends (…params) => infer O ? (…params) => O & { [Key in keyof Intersection]: Intersection[Key] } : Intersection extends (…params) => any ? Intersection : Intersection extends object ? { [Key in keyof Intersection]: Intersection[Key] } : Intersection

Defined in: packages/core/src/utils.ts:68

Removes named generics to produce a plain type representation. Preserves function signatures and object structure while eliminating generic parameter names.

This is useful for presenting cleaner types in documentation and error messages.

Type Parameters

Intersection

Intersection

The type to convert to a plain representation

Rec<T>

Rec<T> = Record<string, T>

Defined in: packages/core/src/utils.ts:18

Type alias for Record<string, T> for brevity. Represents an object with string keys and values of type T.

Type Parameters

T

T = any

The type of values in the record (defaults to any)

Shallow<T>

Shallow<T> = { [K in keyof T]: T[K] } & object

Defined in: packages/core/src/utils.ts:88

Creates a shallow clone type of T. Useful for creating a new type that has the same shape but is a distinct type.

Type Parameters

T

T

The type to create a shallow clone of

UndefinedToOptional<T>

UndefinedToOptional<T> = Partial<T> & PickValues<T, { } | null>

Defined in: packages/core/src/utils.ts:47

Utility type that converts properties with undefined values to optional properties. Makes properties with object or null values required, while making other properties optional.

Type Parameters

T

T extends object

The object type to transform

Values<T>

Values<T> = T[keyof T]

Defined in: packages/core/src/utils.ts:108

Extracts the union type of all values in an object type.

Type Parameters

T

T

The object type to extract values from

Variables

assign()

const assign: {<T1, T2>(a1, a2): Plain<T1 extends (…params) => O ? (…params) => O : object & Omit<T1, keyof T2> & Omit<T2, never> & Omit<{ }, never>>; <T1, T2, T3>(a1, a2, a3?): Plain<T1 extends (…params) => O ? (…params) => O : object & Omit<T1, keyof T2 | keyof T3> & Omit<T2, keyof T3> & Omit<T3, never>>; <T1, T2, T3, T4>(a1, a2, a3?, a4?): Plain<T1 extends (…params) => O ? (…params) => O : object & Omit<T1, keyof T2 | keyof T3 | keyof T4> & Omit<T2, keyof T3 | keyof T4> & Omit<T3, keyof T4> & T4>; } = Object.assign

Defined in: packages/core/src/utils.ts:399

Type-safe version of Object.assign that properly handles type merging. Unlike standard Object.assign typing, properties with the same name are replaced rather than becoming a union type.

Call Signature

<T1, T2>(a1, a2): Plain<T1 extends (…params) => O ? (…params) => O : object & Omit<T1, keyof T2> & Omit<T2, never> & Omit<{ }, never>>

Type Parameters

T1

T1

T2

T2

Parameters

a1

T1

a2

T2

Returns

Plain<T1 extends (…params) => O ? (…params) => O : object & Omit<T1, keyof T2> & Omit<T2, never> & Omit<{ }, never>>

Call Signature

<T1, T2, T3>(a1, a2, a3?): Plain<T1 extends (…params) => O ? (…params) => O : object & Omit<T1, keyof T2 | keyof T3> & Omit<T2, keyof T3> & Omit<T3, never>>

Type Parameters

T1

T1

T2

T2

T3

T3 = { }

Parameters

a1

T1

a2

T2

a3?

T3

Returns

Plain<T1 extends (…params) => O ? (…params) => O : object & Omit<T1, keyof T2 | keyof T3> & Omit<T2, keyof T3> & Omit<T3, never>>

Call Signature

<T1, T2, T3, T4>(a1, a2, a3?, a4?): Plain<T1 extends (…params) => O ? (…params) => O : object & Omit<T1, keyof T2 | keyof T3 | keyof T4> & Omit<T2, keyof T3 | keyof T4> & Omit<T3, keyof T4> & T4>

Type Parameters

T1

T1

T2

T2

T3

T3 = { }

T4

T4 = { }

Parameters

a1

T1

a2

T2

a3?

T3

a4?

T4

Returns

Plain<T1 extends (…params) => O ? (…params) => O : object & Omit<T1, keyof T2 | keyof T3 | keyof T4> & Omit<T2, keyof T3 | keyof T4> & Omit<T3, keyof T4> & T4>

Template

Type of the target object

Template

Type of the first source object

Template

Type of the optional second source object

Template

Type of the optional third source object

Returns

A new object with merged properties

entries()

const entries: <T>(thing) => [keyof T, T[keyof T]][] = Object.entries

Defined in: packages/core/src/utils.ts:444

Type-safe version of Object.entries that preserves key and value type information. Returns an array of key-value pairs with correct types.

Type Parameters

T

T extends object

The object type

Parameters

thing

T

The object to get entries from

Returns

[keyof T, T[keyof T]][]

An array of [key, value] pairs with proper typing

keys()

const keys: <T>(thing) => keyof T[] = Object.keys

Defined in: packages/core/src/utils.ts:432

Type-safe version of Object.keys that preserves the key type information. Returns an array of keys with the correct type for the object.

Type Parameters

T

T extends object

The object type

Parameters

thing

T

The object to get keys from

Returns

keyof T[]

An array of the object’s keys with proper typing

MAX_SAFE_TIMEOUT

const MAX_SAFE_TIMEOUT: number

Defined in: packages/core/src/utils.ts:765

Maximum safe integer value for setTimeout delay. Any timeout value larger than this may cause overflow issues in some browsers.

See

https://developer.mozilla.org/en-US/docs/Web/API/setTimeout#maximum_delay_value

merge

const merge: typeof assign

Defined in: packages/core/src/utils.ts:421

Creates a new object with merged properties from all provided objects. Similar to Object.assign but always creates a new object rather than mutating the first argument.

Example

// Creates a new object: { a: 1, b: 2, c: 3 }
  const obj = merge({ a: 1 }, { b: 2 }, { c: 3 })

Returns

A new object with all properties from the provided objects

noop()

const noop: (…params) => any

Defined in: packages/core/src/utils.ts:224

No-operation function that accepts any parameters and returns undefined. Useful as a default callback or for stubbing functionality.

Parameters

params

…any[]

Returns

any

random

const random: typeof _random

Defined in: packages/core/src/utils.ts:522

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

Param

The minimum integer value (defaults to 0)

Param

The maximum integer value (defaults to Number.MAX_SAFE_INTEGER - 1)

Returns

A random integer between min and max

setTimeout

const setTimeout: SetTimeout

Defined in: packages/core/src/utils.ts:747

Enhanced version of the global setTimeout function. Ensures consistent behavior across different environments by handling both numeric and object timeout IDs. Adds a toJSON method to object timeout IDs for serialization.

Param

The function to call after the timeout

Param

The time in milliseconds to wait before calling the handler

Param

Optional arguments to pass to the handler function

Returns

A timeout ID that can be used with clearTimeout

Functions

assert()

assert(value, message, ErrorConstructor): asserts value

Defined in: packages/core/src/utils.ts:212

Asserts that a value is truthy, throwing an error if it’s falsy. This is a TypeScript type assertion function that helps with type narrowing.

Parameters

value

unknown

The value to check

message

string

The error message to use if the assertion fails

ErrorConstructor

Newable<Error> = Error

Optional custom error constructor to use (defaults to Error)

Returns

asserts value

Throws

Throws an error with the provided message if value is falsy

identity()

identity<T>(value, …a): T

Defined in: packages/core/src/utils.ts:234

Identity function that returns the first argument unchanged. Can accept additional parameters but ignores them.

Type Parameters

T

T

The type of value being passed through

Parameters

value

T

The value to return

a

…any[]

Returns

T

The same value that was passed in

isAbort()

isAbort(thing): thing is AbortError

Defined in: packages/core/src/utils.ts:717

Type guard that checks if a value is an AbortError.

Parameters

thing

any

The value to check

Returns

thing is AbortError

True if the value is an AbortError, false otherwise

isBrowser()

isBrowser(): boolean

Defined in: packages/core/src/utils.ts:781

Detects whether the code is running in a browser environment. Checks for the existence of window and document objects.

Returns

boolean

True if running in a browser environment, false otherwise

isDeepEqual()

isDeepEqual(a, b): any

Defined in: packages/core/src/utils.ts:355

Performs a deep equality comparison between two values. Recursively compares nested objects and arrays while properly handling cyclic references.

Handles primitives, objects, dates, regular expressions, arrays, maps, and sets. Uses a WeakMap to track visited objects to avoid infinite recursion with circular references.

Parameters

a

any

First value to compare

b

any

Second value to compare

Returns

any

True if the values are deeply equal, false otherwise

isObject()

isObject<T>(thing): thing is T extends Record<string | number | symbol, unknown> ? T<T> : Record<string | number | symbol, unknown>

Defined in: packages/core/src/utils.ts:258

Type guard that checks if a value is an object (non-null and typeof ‘object’). Provides advanced type narrowing to either the original object type or a generic object type.

Type Parameters

T

T

The type of value being checked

Parameters

thing

T

The value to check

Returns

thing is T extends Record<string | number | symbol, unknown> ? T<T> : Record<string | number | symbol, unknown>

True if the value is a non-null object, false otherwise

isRec()

isRec(thing): thing is Record<string, unknown>

Defined in: packages/core/src/utils.ts:274

Type guard that checks if a value is a plain object (a simple object literal or created with Object.create(null)). Verifies that the object either has no prototype or its prototype is Object.prototype.

Parameters

thing

unknown

The value to check

Returns

thing is Record<string, unknown>

True if the value is a plain object, false otherwise

isShallowEqual()

isShallowEqual(a, b, is): any

Defined in: packages/core/src/utils.ts:298

Performs a shallow equality comparison between two values. Handles primitives, objects, dates, regular expressions, arrays, maps, and sets.

For iterables, compares each item in sequence for equality. For objects, compares direct property values but not nested objects deeply.

Parameters

a

any

First value to compare

b

any

Second value to compare

is

(value1, value2) => boolean

Optional comparison function to use for individual values (defaults to Object.is)

Returns

any

True if the values are shallowly equal, false otherwise

jsonClone()

jsonClone<T>(value): T

Defined in: packages/core/src/utils.ts:509

Creates a deep clone of a value using JSON serialization/deserialization. This is a type-safe shortcut to JSON.parse(JSON.stringify(value)).

Note: This has limitations with circular references, functions, symbols, and special objects like Date (converts to string). Consider using the native structuredClone when available.

Type Parameters

T

T

The type of value being cloned

Parameters

value

T

The value to clone

Returns

T

A deep clone of the input value

See

https://developer.mozilla.org/en-US/docs/Web/API/structuredClone

mockRandom()

mockRandom(fn): () => void

Defined in: packages/core/src/utils.ts:538

Replaces the default random number generator with a custom implementation. Useful for testing to provide deterministic “random” values.

Parameters

fn

(min, max) => number

The custom random function to use

Returns

A restore function that reverts to the original random implementation when called

(): void

Returns

void

Example

// Set up deterministic random values for testing
  const restore = mockRandom(() => 42)
  console.log(random()) // Always returns 42
  restore() // Back to normal random behavior

nonNullable()

nonNullable<T>(value, message?): NonNullable<T>

Defined in: packages/core/src/utils.ts:560

Asserts that a value is not null or undefined. Throws a TypeError if the value is null or undefined. Also serves as a type guard to narrow the type to non-nullable.

Type Parameters

T

T

The type of value to check

Parameters

value

T

The value to check

message?

string

Optional custom error message

Returns

NonNullable<T>

The input value if it’s not null or undefined

Example

const name = nonNullable(user.name) // TypeScript knows name is not null or undefined

Throws

If the value is null or undefined

omit()

omit<T, K>(target, keys): Plain<Omit<T, K>>

Defined in: packages/core/src/utils.ts:485

Creates a new object excluding the specified keys from the original object.

Type Parameters

T

T

The source object type

K

K extends string | number | symbol

The keys to omit from the object

Parameters

target

T

The source object

keys

K[]

Array of keys to exclude from the result

Returns

Plain<Omit<T, K>>

A new object containing all keys except the specified ones

Example

const user = { id: 1, name: 'Alice', password: 'secret' }
  const safeUser = omit(user, ['password'])
  // Result: { id: 1, name: 'Alice' }

pick()

pick<T, K>(target, keys): Plain<Pick<T, K>>

Defined in: packages/core/src/utils.ts:462

Creates a new object with only the specified keys from the original object.

Type Parameters

T

T

The source object type

K

K extends string | number | symbol

The keys to pick from the object

Parameters

target

T

The source object

keys

K[]

Array of keys to include in the result

Returns

Plain<Pick<T, K>>

A new object containing only the specified keys and their values

Example

const user = { id: 1, name: 'Alice', email: 'alice@example.com' }
  const userInfo = pick(user, ['name', 'email'])
  // Result: { name: 'Alice', email: 'alice@example.com' }

sleep()

sleep(ms): Promise<unknown>

Defined in: packages/core/src/utils.ts:247

Creates a promise that resolves after the specified number of milliseconds. Useful for creating delays in async functions.

Parameters

ms

number = 0

The number of milliseconds to sleep (defaults to 0)

Returns

Promise<unknown>

A promise that resolves after the specified delay

throwAbort()

throwAbort(message, controller?): never

Defined in: packages/core/src/utils.ts:728

Creates and throws an AbortError with the provided message. Optionally aborts the provided controller with the same error.

Parameters

message

string = ''

The error message

controller?

AbortController

Optional AbortController to abort

Returns

never

Throws

Always throws the created AbortError

throwIfAborted()

throwIfAborted(controller?): void

Defined in: packages/core/src/utils.ts:705

Checks if an AbortController is aborted and throws an AbortError if it is. Useful for quick abort checks at the beginning of async operations.

Parameters

controller?

The AbortController to check (can be undefined, null or void)

null | void | AbortController

Returns

void

Throws

If the controller’s signal is aborted

toAbortError()

toAbortError(reason): AbortError

Defined in: packages/core/src/utils.ts:674

Converts any value to an AbortError. If the value is already an AbortError, it will be returned as is. Otherwise, creates a new AbortError with appropriate information.

Handles different environments by using DOMException when available or falling back to regular Error with name set to ‘AbortError’.

Parameters

reason

any

The value to convert to an AbortError

Returns

AbortError

An AbortError instance

toStringKey()

toStringKey(thing, immutable): string

Defined in: packages/core/src/utils.ts:598

Converts any JavaScript value to a stable string representation. Handles complex data structures and edge cases that JSON.stringify cannot manage.

Provides special handling for:

Circular references
Maps and Sets
Symbols
Functions
Custom class instances
Regular objects (with sorted keys for stability)

Parameters

thing

any

The value to convert to a string

immutable

boolean = true

Whether to memoize results for complex objects (defaults to true)

Returns

string

A string representation of the value

Example

// Handles circular references
  const obj = { name: 'test' }
  obj.self = obj
  const key = toStringKey(obj) // No infinite recursion!

  // Stable representation of objects (key order doesn't matter)
  toStringKey({ a: 1, b: 2 }) === toStringKey({ b: 2, a: 1 }) // true

withResolvers()

withResolvers<T>(): object

Defined in: packages/core/src/utils.ts:814

Creates a Promise and returns it along with its resolve and reject functions. This utility is similar to the upcoming Promise.withResolvers() static method. It allows for manual control over a Promise’s settlement from outside its constructor.

Type Parameters

T

T

The type of the value the promise will resolve with.

Returns

object

An object containing the promise, and its resolve and reject functions.

promise

promise: Promise<T>

reject()

reject: (reason?) => void

Parameters

reason?

any

Returns

void

resolve()

resolve: (value) => void

Parameters

value

T

Returns

void

Example

const { promise, resolve, reject } = withResolvers<string>()

  promise
    .then((value) => console.log('Resolved:', value))
    .catch((error) => console.error('Rejected:', error))

  // Sometime later, or in a different part of the code:
  if (Math.random() > 0.5) {
    resolve('Success!')
  } else {
    reject(new Error('Failed!'))
  }