@mrpelz/misc-utils

Miscellaneous TypeScript helpers.

data

Miscellaneous data conversion helpers.

$3

Empty/zero-length Buffer.

$3

One-byte 0 Buffer.

$3

One-byte 1 Buffer.

$3

``ts
const arrayCompare = <
A extends Array,
B extends Array,
>(
a: A,
b: B,
): b is B
`

Returns true if all elements of array a strict-equal array b.

$3

`ts
const arrayPadLeft = (
input: T[],
length: number,
value: T = null as unknown as T,
): T[]
`

Inserts length-n of value at the start of array input.
Modifies array in-place and returns it.

$3

`ts
const arrayPadRight = (
input: T[],
length: number,
value: T = null as unknown as T,
): T[]
`

Inserts length-n of value at the end of array input.
Modifies array in-place and returns it.

$3

`ts
const bufferChunks = (input: Buffer, chunkSize = 1): Buffer[]
`

Splits Buffer input into chunks of size chunkSize each.
Returns array of Buffer chunks. Throws if input Buffer is smaller than chunkSize.

$3

`ts
const concatBytes = (input: number[]): Buffer
`

Concatenates number-array as bytes and returns as Buffer.

$3

`ts
const humanPayload = (input: Buffer): string
`

Pretty-prints Buffer input’s binary contents in a human readable format, represented as binary, decimal and hexadecimal:

`txt
0b00000000 | 0b00000001 | 0b00000010 | 0b00001111 | 0b00010000
0 | 1 | 2 | 15 | 16
0x00 | 0x01 | 0x02 | 0x0f | 0x10
`

Returns pre-formatted multi-line string.

$3

`ts
const jsonParseGuarded = (input: unknown): T | Error
`

Guarded JSON-parse. Tries to parse _anything_ in input, returns JSON.parse result. Returns Error if input is not a string. If parsing of the string fails, catches the Error and returns it. Error is returned instead of thrown to ease implementation of fallback code paths.

$3

`ts
const numberToDigits = (
input: number,
pad = 0,
radix = 10,
): number[]
`

Splits number in input into single digits and returns them as number-array. Throws if input is not an integer.

$3

`ts
const readNumber = (input: Buffer, bytes = 1): number
`

Read number value from Buffer input with number of bytes. Throws if the buffer isn’t long enough to fit the desired byte count.

* bytes = 1 → UInt8
* bytes = 2 → UInt16LE
* bytes = 4 → UInt32LE

Throws otherwise.

$3

`ts
const booleanToBuffer = (input: boolean): Buffer
`

Turns boolean input into trueBuffer or falseBuffer respectively.

$3

`ts
const bufferToBoolean = (input: Buffer): boolean
`

Turns Buffer input into boolean. A buffer whose first byte is zero is considered false, everything else is considered true. Throws if Buffer isn’t long enough.

$3

`ts
const swapByte = (input: number): number
`

Bitwise-invert the the input value. Use for single byte values.

$3

`ts
const writeNumber = (input: number, bytes = 1): Buffer
`

Write number value from input with number of bytes into Buffer. Throws if the number cannot be represented using the desired byte count.

* bytes = 1 → UInt8
* bytes = 2 → UInt16LE
* bytes = 4 → UInt32LE

Throws otherwise.

number

$3

`ts
const bitRange = (count: number): number
`

Returns the number bit range of given bit length in count, e.g.

* 4 → 15
* 8 → 255
* 16 → 65535

$3

`ts
const byteRange = (count: number): number
`

Returns the number range of given byte length in count`, e.g. 4 → 4294967295.