fundamentool

---

async

Functions

checkNoop()

function checkNoop(): boolean;

Defined in: src/async/checkNoop.ts:9

Default checkFn for async helpers that always allows continuation. Used when no custom check function is provided.

Returns

boolean

true – meaning the loop should continue.

Example

checkNoop(); // => true

---

eachAsync()

function eachAsync<A>(
   collection, 
   iteratee, 
   ctx?, 
checkFn?): Promise<A>;

Defined in: src/async/eachAsync.ts:17

Chooses async iterator (forEach for arrays, forIn for objects) and runs it.

Type Parameters

Type Parameter
A extends any[] | Record<string, any>

Parameters

Parameter	Type	Default value	Description
collection	A	undefined	Array or object to iterate.
iteratee	(this, value, key, collection) => any	undefined	Iteration function.
ctx?	any	undefined	Optional this context.
checkFn?	() => boolean	checkNoop	Optional function to additionally control loop continuation.

Returns

Promise<A>

Promise resolved with the input collection after all items are processed.

Example

await eachAsync([1, 2], async (v) => console.log(v)); // logs 1, 2

---

eachParallel()

function eachParallel<A>(
   collection, 
   iteratee, 
   ctx?, 
   taskLimit?, 
checkFn?): Promise<A>;

Defined in: src/async/parallel/eachParallel.ts:19

Chooses parallel iterator (forEach for arrays, forIn for objects via forInParallel) and runs it. This is a thin facade mirroring the old JS behaviour.

Type Parameters

Type Parameter
A extends any[] | Record<string, any>

Parameters

Parameter	Type	Default value	Description
collection	A	undefined	Source array or object.
iteratee	(this, value, key, collection) => any	undefined	Iteration function.
ctx?	any	undefined	Optional this context.
taskLimit?	number	undefined	Maximum number of concurrent tasks.
checkFn?	() => boolean	checkNoop	Optional function to additionally control loop continuation.

Returns

Promise<A>

Promise resolved with the input collection.

Example

await eachParallel([1, 2, 3], async (v) => process(v), null, 2); // 2 concurrent

---

filterAsync()

function filterAsync<T>(
   items, 
   iteratee, 
   output, 
   ctx?, 
checkFn?): Promise<T[]>;

Defined in: src/async/filterAsync.ts:16

Asynchronously filters items using the provided iteratee.

Type Parameters

Type Parameter
T

Parameters

Parameter	Type	Default value	Description
items	T[]	undefined	Source array-like collection.
iteratee	(this, value, index, items) => any	undefined	Predicate function returning truthy/falsey or a promise.
output	T[]	undefined	Optional array to push accepted items into.
ctx?	any	undefined	Optional this context for the iteratee.
checkFn?	() => boolean	checkNoop	Optional function to additionally control loop continuation.

Returns

Promise<T[]>

Promise-like object resolved with the resulting array.

Example

await filterAsync([1, 2, 3], async (v) => v > 1, null); // => [2, 3]

---

filterInAsync()

function filterInAsync<T>(
   collection, 
   iteratee, 
   output?, 
   ctx?, 
checkFn?): Promise<Record<string, T>>;

Defined in: src/async/filterInAsync.ts:21

Asynchronous filter over array or object.

Unlike the legacy version, this helper expects iteratee to be a function; shorthand/normalize logic is removed.

Type Parameters

Type Parameter
T

Parameters

Parameter	Type	Default value	Description
collection	Record<string, T>	undefined	Source object.
iteratee	(this, value, key, collection) => any	undefined	Predicate function.
output?	Record<string, T>	undefined	Optional output object.
ctx?	any	undefined	Optional this context.
checkFn?	() => boolean	checkNoop	Optional function to additionally control loop continuation.

Returns

Promise<Record<string, T>>

Promise resolved with resulting object.

Example

await filterInAsync({ a: 1, b: 2 }, async (v) => v > 1); // => { b: 2 }

---

filterInParallel()

function filterInParallel<T>(
   collection, 
   iteratee, 
   output?, 
   ctx?, 
   taskLimit?, 
checkFn?): Promise<Record<string, T>>;

Defined in: src/async/parallel/filterInParallel.ts:21

Parallel asynchronous filter over object.

Expects iteratee to be a function; shorthand/normalize logic is removed.

Type Parameters

Type Parameter
T

Parameters

Parameter	Type	Default value	Description
collection	Record<string, T>	undefined	Source object.
iteratee	(this, value, key, collection) => any	undefined	Predicate function.
output?	Record<string, T>	undefined	Optional output object.
ctx?	any	undefined	Optional this context.
taskLimit?	number	undefined	Maximum number of concurrent tasks.
checkFn?	() => boolean	checkNoop	Optional function to additionally control loop continuation.

Returns

Promise<Record<string, T>>

Promise resolved with resulting object.

Example

await filterInParallel({ a: 1, b: 2 }, async (v) => v > 1, null, null, 2); // => { b: 2 }

---

filterParallel()

function filterParallel<T>(
   items, 
   iteratee, 
   output, 
   ctx?, 
   taskLimit?, 
checkFn?): Promise<T[]>;

Defined in: src/async/parallel/filterParallel.ts:21

Parallel asynchronous filter over items.

First phase evaluates predicate in parallel and stores boolean flags, then reuses generic filterEach to build resulting array.

Type Parameters

Type Parameter
T

Parameters

Parameter	Type	Default value	Description
items	T[]	undefined	Source array-like collection.
iteratee	(this, value, index, items) => any	undefined	Predicate function.
output	T[]	undefined	Optional output array.
ctx?	any	undefined	Optional this context.
taskLimit?	number	undefined	Maximum concurrent tasks.
checkFn?	() => boolean	checkNoop	Optional function to additionally control loop continuation.

Returns

Promise<T[]>

Promise resolved with resulting array.

Example

await filterParallel([1, 2, 3], async (v) => v > 1, null, null, 2); // => [2, 3]

---

findAsync()

function findAsync<T>(
   items, 
   iteratee, 
   ctx?, 
checkFn?): Promise<T>;

Defined in: src/async/findAsync.ts:15

Asynchronously finds first item that matches iteratee.

Type Parameters

Type Parameter
T

Parameters

Parameter	Type	Default value	Description
items	T[]	undefined	Source array-like collection.
iteratee	(this, value, index, items) => any	undefined	Predicate function returning truthy/falsey or a promise.
ctx?	any	undefined	Optional this context for the iteratee.
checkFn?	() => boolean	checkNoop	Optional function to additionally control loop continuation.

Returns

Promise<T>

Promise-like object resolved with the found item or undefined.

Example

await findAsync([1, 2, 3], async (v) => v === 2); // => 2

---

findInAsync()

function findInAsync<T>(
   collection, 
   iteratee, 
   ctx?, 
checkFn?): Promise<T>;

Defined in: src/async/findInAsync.ts:18

Asynchronous find over array or object.

Expects iteratee to be a function; shorthand/normalize logic is removed.

Type Parameters

Type Parameter
T

Parameters

Parameter	Type	Default value	Description
collection	Record<string, T>	undefined	Source array-like collection.
iteratee	(this, value, key, collection) => any	undefined	Predicate function.
ctx?	any	undefined	Optional this context.
checkFn?	() => boolean	checkNoop	Optional function to additionally control loop continuation.

Returns

Promise<T>

Promise resolved with the found item or undefined.

Example

await findInAsync({ a: 1, b: 2 }, async (v) => v === 2); // => 2

---

findInParallel()

function findInParallel<T>(
   collection, 
   iteratee, 
   ctx?, 
   taskLimit?, 
checkFn?): Promise<T>;

Defined in: src/async/parallel/findInParallel.ts:19

Parallel asynchronous find over object.

Expects iteratee to be a function; shorthand/normalize logic is removed.

Type Parameters

Type Parameter
T

Parameters

Parameter	Type	Default value	Description
collection	Record<string, T>	undefined	Source object.
iteratee	(this, value, key, collection) => any	undefined	Predicate function.
ctx?	any	undefined	Optional this context.
taskLimit?	number	undefined	Maximum number of concurrent tasks.
checkFn?	() => boolean	checkNoop	Optional function to additionally control loop continuation.

Returns

Promise<T>

Promise resolved with the found item or undefined.

Example

await findInParallel({ a: 1, b: 2 }, async (v) => v === 2, null, 2); // => 2

---

findParallel()

function findParallel<T>(
   items, 
   iteratee, 
   ctx?, 
   taskLimit?, 
checkFn?): Promise<T>;

Defined in: src/async/parallel/findParallel.ts:16

Parallel asynchronous find over array.

Type Parameters

Type Parameter
T

Parameters

Parameter	Type	Default value	Description
items	T[]	undefined	Source array.
iteratee	(this, value, index, items) => any	undefined	Predicate function.
ctx?	any	undefined	Optional this context.
taskLimit?	number	undefined	Maximum concurrent tasks.
checkFn?	() => boolean	checkNoop	Optional function to additionally control loop continuation.

Returns

Promise<T>

Promise resolved with the found item or undefined.

Example

await findParallel([1, 2, 3], async (v) => v === 2, null, 2); // => 2

---

forEachAsync()

function forEachAsync<T>(
   items, 
   iteratee, 
   ctx?, 
checkFn?): Promise<T[]>;

Defined in: src/async/forEachAsync.ts:15

Asynchronously iterates over an array-like items.

Type Parameters

Type Parameter
T

Parameters

Parameter	Type	Default value	Description
items	T[]	undefined	Source array-like collection.
iteratee	(this, value, index, items) => any	undefined	Iteration function, may return a value or a promise.
ctx?	any	undefined	Optional this context for the iteratee.
checkFn?	() => boolean	checkNoop	Optional function to additionally control loop continuation.

Returns

Promise<T[]>

Promise resolved with the original items array when the loop completes.

Example

await forEachAsync([1, 2], async (v) => console.log(v)); // logs 1, 2

---

forEachParallel()

function forEachParallel<T>(
   items, 
   fn, 
   ctx?, 
   taskLimit?, 
checkFn?): Promise<T[]>;

Defined in: src/async/parallel/forEachParallel.ts:16

Parallel asynchronous forEach over array.

Type Parameters

Type Parameter
T

Parameters

Parameter	Type	Default value	Description
items	T[]	undefined	Source array-like collection.
fn	(this, value, index, items) => any	undefined	Iteration function.
ctx?	any	undefined	Optional this context.
taskLimit?	number	undefined	Maximum number of concurrent tasks.
checkFn?	() => boolean	checkNoop	Optional function to additionally control loop continuation.

Returns

Promise<T[]>

Promise resolved with the original items array.

Example

await forEachParallel([1, 2, 3], async (v) => process(v), null, 2); // 2 concurrent

---

forInAsync()

function forInAsync<T>(
   collection, 
   iteratee, 
   ctx?, 
checkFn?): Promise<Record<string, T>>;

Defined in: src/async/forInAsync.ts:16

Asynchronously iterates over object properties using entries.

Type Parameters

Type Parameter
T

Parameters

Parameter	Type	Default value	Description
collection	Record<string, T>	undefined	Source object.
iteratee	(this, value, key, collection) => any	undefined	-
ctx?	any	undefined	Optional this context.
checkFn?	() => boolean	checkNoop	Optional function to additionally control loop continuation.

Returns

Promise<Record<string, T>>

Promise resolved with the original collection when the loop completes.

Example

await forInAsync({ a: 1 }, async (v, k) => console.log(k, v)); // logs 'a', 1

---

forInParallel()

function forInParallel<T>(
   collection, 
   fn, 
   ctx?, 
   taskLimit?, 
checkFn?): Promise<Record<string, T>>;

Defined in: src/async/parallel/forInParallel.ts:17

Parallel asynchronous iteration over object properties.

Type Parameters

Type Parameter
T

Parameters

Parameter	Type	Default value	Description
collection	Record<string, T>	undefined	Source object.
fn	(this, value, key, collection) => any	undefined	Iteration function receiving (value, key, collection).
ctx?	any	undefined	Optional this context.
taskLimit?	number	undefined	Maximum number of concurrent tasks.
checkFn?	() => boolean	checkNoop	Optional function to additionally control loop continuation.

Returns

Promise<Record<string, T>>

Promise resolved with the resulting object.

Example

await forInParallel({ a: 1, b: 2 }, async (v, k) => process(k, v), null, 2);

---

intervalAsync()

function intervalAsync(
   fn, 
   delayMs?, 
   args?, 
   self?): () => void;

Defined in: src/async/intervalAsync.ts:20

Runs fn periodically with the given delay.

If fn returns a promise, the next tick is scheduled after it settles. Returns a cancel function that stops subsequent executions.

Parameters

Parameter	Type	Default value	Description
fn	(...args) => any	undefined	Function to execute periodically.
delayMs	number	0	Delay in milliseconds.
args?	ArrayLike<any>	undefined	Arguments to pass to the function.
self?	any	undefined	Optional this context.

Returns

A cancel function that stops subsequent executions.

() => void

Example

const stop = intervalAsync(() => fetch('/ping'), 5000);
stop(); // cancels further executions

---

loopAsync()

function loopAsync(checkFn, statementFn): Promise<void>;

Defined in: src/async/loopAsync.ts:13

Asynchronous loop helper that repeatedly calls statementFn while checkFn is true.

Parameters

Parameter	Type	Description
checkFn	() => boolean	Function to check if the loop should continue.
statementFn	() => any	Function to execute on each iteration.

Returns

Promise<void>

Promise resolved when the loop completes.

Example

let i = 0;
await loopAsync(() => i < 3, async () => { i++; }); // i === 3

---

loopParallel()

function loopParallel(
   checkFn, 
   statementFn, 
taskLimit?): Promise<any[]>;

Defined in: src/async/parallel/loopParallel.ts:17

Runs statementFn in parallel with a maximum of taskLimit concurrent tasks, advancing while checkFn returns true.

Parameters

Parameter	Type	Default value	Description
checkFn	() => boolean	undefined	Function to check if the loop should continue.
statementFn	() => any	undefined	Function to execute on each iteration.
taskLimit	number	1	Maximum number of concurrent tasks.

Returns

Promise<any[]>

Promise resolved when the loop completes.

Example

let i = 0;
await loopParallel(() => i < 6, async () => { i++; }, 3); // 3 concurrent tasks

---

mapAsync()

function mapAsync<T, R>(
   items, 
   iteratee, 
   ctx?, 
checkFn?): Promise<R[]>;

Defined in: src/async/mapAsync.ts:15

Asynchronously maps an array-like items using iteratee.

Type Parameters

Type Parameter
T
R

Parameters

Parameter	Type	Default value	Description
items	T[]	undefined	Source array-like collection.
iteratee	(this, value, index, items) => R | Promise<R>	undefined	Mapping function, may return a value or a promise.
ctx?	any	undefined	Optional this context for the iteratee.
checkFn?	() => boolean	checkNoop	Optional function to additionally control loop continuation.

Returns

Promise<R[]>

Promise resolved with the resulting array.

Example

await mapAsync([1, 2], async (v) => v * 2); // => [2, 4]

---

mapInAsync()

function mapInAsync<T>(
   collection, 
   iteratee, 
   ctx?, 
checkFn?): Promise<Record<string, T>>;

Defined in: src/async/mapInAsync.ts:19

Asynchronous map over object.

Expects iteratee to be a function; shorthand/normalize logic is removed.

Type Parameters

Type Parameter
T

Parameters

Parameter	Type	Default value	Description
collection	Record<string, T>	undefined	Source object.
iteratee	(this, value, key, collection) => T | Promise<T>	undefined	Mapping function.
ctx?	any	undefined	Optional this context.
checkFn?	() => boolean	checkNoop	Optional function to additionally control loop continuation.

Returns

Promise<Record<string, T>>

Promise resolved with resulting object.

Example

await mapInAsync({ a: 1 }, async (v) => v * 2); // => { a: 2 }

---

mapInParallel()

function mapInParallel<T>(
   collection, 
   iteratee, 
   ctx?, 
   taskLimit?, 
checkFn?): Promise<Record<string, T>>;

Defined in: src/async/parallel/mapInParallel.ts:18

Parallel asynchronous map over array or object.

Type Parameters

Type Parameter
T

Parameters

Parameter	Type	Default value	Description
collection	Record<string, T>	undefined	Source object.
iteratee	(this, value, key, collection) => T | Promise<T>	undefined	Mapping function.
ctx?	any	undefined	Optional this context.
taskLimit?	number	undefined	Maximum number of concurrent tasks.
checkFn?	() => boolean	checkNoop	Optional function to additionally control loop continuation.

Returns

Promise<Record<string, T>>

Promise resolved with resulting object.

Example

await mapInParallel({ a: 1, b: 2 }, async (v) => v * 2, null, 2); // => { a: 2, b: 4 }

---

mapParallel()

function mapParallel<T, R>(
   items, 
   iteratee, 
   ctx?, 
   taskLimit?, 
checkFn?): Promise<R[]>;

Defined in: src/async/parallel/mapParallel.ts:16

Parallel asynchronous map over items.

Type Parameters

Type Parameter
T
R

Parameters

Parameter	Type	Default value	Description
items	T[]	undefined	Source array-like collection.
iteratee	(this, value, index, items) => R | Promise<R>	undefined	Mapping function, may return a value or a promise.
ctx?	any	undefined	Optional this context for the iteratee.
taskLimit?	number	undefined	Maximum number of concurrent tasks.
checkFn?	() => boolean	checkNoop	Optional function to additionally control loop continuation.

Returns

Promise<R[]>

Promise resolved with resulting array.

Example

await mapParallel([1, 2, 3], async (v) => v * 2, null, 2); // => [2, 4, 6]

---

reduceAsync()

function reduceAsync<T, A>(
   items, 
   iteratee, 
   accumulator, 
   ctx?, 
checkFn?): Promise<A>;

Defined in: src/async/reduceAsync.ts:18

Asynchronously reduces an array-like items from left to right.

Expects iteratee to be a function; shorthand/normalize logic is removed.

Type Parameters

Type Parameter
T
A

Parameters

Parameter	Type	Default value	Description
items	T[]	undefined	Source array-like collection.
iteratee	(this, acc, value, index, items) => A | Promise<A>	undefined	Reducer function, may return a value or a promise.
accumulator	A	undefined	Initial accumulator value.
ctx?	any	undefined	Optional this context for the iteratee.
checkFn?	() => boolean	checkNoop	Optional function to additionally control loop continuation.

Returns

Promise<A>

Promise resolved with the final accumulator.

Example

await reduceAsync([1, 2, 3], async (acc, v) => acc + v, 0); // => 6

---

reduceInAsync()

function reduceInAsync<T, A>(
   collection, 
   iteratee, 
   accumulator, 
   ctx?, 
checkFn?): Promise<A>;

Defined in: src/async/reduceInAsync.ts:19

Asynchronous reduce over object.

Expects iteratee to be a function; shorthand/normalize logic is removed.

Type Parameters

Type Parameter
T
A

Parameters

Parameter	Type	Default value	Description
collection	Record<string, T>	undefined	Array or object to reduce.
iteratee	(this, acc, value, key, collection) => A | Promise<A>	undefined	Async-friendly reducer function.
accumulator	A	undefined	Initial accumulator value.
ctx?	any	undefined	Optional this context for the iteratee.
checkFn?	() => boolean	checkNoop	Optional function to additionally control loop continuation.

Returns

Promise<A>

Promise resolved with the final accumulator.

Example

await reduceInAsync({ a: 1, b: 2 }, async (acc, v) => acc + v, 0); // => 3

---

reduceInParallel()

function reduceInParallel<T, A>(
   collection, 
   iteratee, 
   accumulator, 
   ctx?, 
   taskLimit?, 
checkFn?): Promise<A>;

Defined in: src/async/parallel/reduceInParallel.ts:18

Parallel asynchronous reduce over array or object.

Type Parameters

Type Parameter
T
A

Parameters

Parameter	Type	Default value	Description
collection	Record<string, T>	undefined	Source object.
iteratee	(this, acc, value, key, collection) => A | Promise<A>	undefined	Reducer function.
accumulator	A	undefined	Initial accumulator value.
ctx?	any	undefined	Optional this context for the iteratee.
taskLimit?	number	undefined	Maximum number of concurrent tasks.
checkFn?	() => boolean	checkNoop	Optional function to additionally control loop continuation.

Returns

Promise<A>

Promise resolved with the final accumulator.

Example

await reduceInParallel({ a: 1, b: 2 }, async (acc, v) => acc + v, 0, null, 2); // => 3

---

reduceParallel()

function reduceParallel<T, A>(
   input, 
   iteratee, 
   accumulator, 
   ctx?, 
   taskLimit?, 
checkFn?): Promise<A>;

Defined in: src/async/parallel/reduceParallel.ts:19

Parallel asynchronous reduce over an array-like input.

Iterations are scheduled in parallel with a configurable taskLimit.

Type Parameters

Type Parameter
T
A

Parameters

Parameter	Type	Default value	Description
input	T[]	undefined	Source array-like collection.
iteratee	(this, acc, value, index, input) => A | Promise<A>	undefined	Function called for each item.
accumulator	A	undefined	Initial accumulator value.
ctx?	any	undefined	Optional this context for the iteratee.
taskLimit?	number	undefined	Maximum number of concurrent tasks.
checkFn?	() => boolean	checkNoop	Optional function to additionally control loop continuation.

Returns

Promise<A>

A promise resolved with the final accumulator.

Example

await reduceParallel([1, 2, 3], async (acc, v) => acc + v, 0, null, 2); // => 6

---

sequence()

function sequence<T>(fn, ctx?): (...args) => Promise<ReturnType<T>>;

Defined in: src/async/sequence.ts:13

Wraps function so that calls are executed sequentially: each waits for the previous.

Type Parameters

Type Parameter
T extends (...args) => any

Parameters

Parameter	Type	Description
fn	T	Function to wrap.
ctx?	any	Optional this context for the function.

Returns

Wrapped function that returns a Promise.

(...args) => Promise<ReturnType<T>>

Example

const seq = sequence(fetchData);
seq(); // first call starts immediately
seq(); // waits for first to finish, then runs

---

sequenceDelay()

function sequenceDelay<T>(
   fn, 
   delayMs, 
ctx?): (...args) => Promise<ReturnType<T>>;

Defined in: src/async/sequenceDelay.ts:15

Like sequence, but adds a delay before each execution.

Type Parameters

Type Parameter
T extends (...args) => any

Parameters

Parameter	Type	Description
fn	T	Function to wrap.
delayMs	number	Delay in milliseconds.
ctx?	any	Optional this context for the function.

Returns

Wrapped function that returns a Promise.

(...args) => Promise<ReturnType<T>>

Example

const delayedSave = sequenceDelay(save, 300);
delayedSave(); // waits 300ms before executing, queues subsequent calls

---

withDelayAsync()

function withDelayAsync<T>(
   fn, 
   delayMs, 
ctx?): (...args) => Promise<ReturnType<T>>;

Defined in: src/async/withDelayAsync.ts:13

Debounced async wrapper: schedules function execution after delayMs. Returns a promise resolved with the last call result.

Type Parameters

Type Parameter
T extends (...args) => any

Parameters

Parameter	Type	Description
fn	T	Function to wrap.
delayMs	number	Delay in milliseconds.
ctx?	any	Optional this context for the function.

Returns

Wrapped debounced function that returns a Promise.

(...args) => Promise<ReturnType<T>>

Example

const debounced = withDelayAsync(search, 300);
debounced('query'); // => Promise, resolves after 300ms

---

withLatencyProvider()

function withLatencyProvider(requestLatency): <T>(fn, args, ctx) => Promise<T>;

Defined in: src/async/withLatencyProvider.ts:15

Ensures that calls to fn take at least requestLatency ms. Useful for smoothing UI latency so fast responses don't cause visual flicker.

Parameters

Parameter	Type	Description
requestLatency	number	Minimum response time in milliseconds.

Returns

A function that runs fn with the given minimum latency.

<T>(fn, args, ctx) => Promise<T>

Example

const run = withLatencyProvider(500);
await run(fetchData, [], ctx); // always takes at least 500ms