FuzzedDataProvider

import { FuzzedDataProvider } from "@vitiate/fuzzed-data-provider";

FuzzedDataProvider consumes bytes from a fuzzer-generated buffer and produces typed values. It follows the same design as LLVM’s FuzzedDataProvider.

Constructor

new FuzzedDataProvider(data: Uint8Array)

Creates a provider that consumes bytes from data. A Buffer (which extends Uint8Array) can be passed directly.

Properties

Property	Type	Description
`remainingBytes`	`number`	Number of unconsumed bytes remaining

Boolean

Method	Return Type	Description
`consumeBoolean()`	`boolean`	Consume one byte as a boolean
`consumeBooleans(maxLength)`	`boolean[]`	Consume up to `maxLength` bytes, interpreting each byte’s LSB as a boolean

Integers

Method	Return Type	Description
`consumeIntegral(maxNumBytes, isSigned?)`	`number`	Consume up to `maxNumBytes` (1-6) as an integer. `isSigned` defaults to `false`.
`consumeIntegralInRange(min, max)`	`number`	Consume an integer uniformly distributed in `[min, max]`
`consumeIntegrals(maxLength, numBytesPerIntegral, isSigned?)`	`number[]`	Consume an array of integers

BigInts

Method	Return Type	Description
`consumeBigIntegral(maxNumBytes, isSigned?)`	`bigint`	Consume up to `maxNumBytes` as a BigInt
`consumeBigIntegralInRange(min, max)`	`bigint`	Consume a BigInt in `[min, max]`
`consumeBigIntegrals(maxLength, numBytesPerIntegral, isSigned?)`	`bigint[]`	Consume an array of BigInts

Floating Point

Method	Return Type	Description
`consumeNumber()`	`number`	Consume 8 bytes as a `number` (double)
`consumeNumberInRange(min, max)`	`number`	Consume a number in `[min, max]`
`consumeFloat()`	`number`	Consume 4 bytes as a float
`consumeFloatInRange(min, max)`	`number`	Consume a float in `[min, max]`
`consumeDouble()`	`number`	Alias for `consumeNumber()`
`consumeDoubleInRange(min, max)`	`number`	Alias for `consumeNumberInRange()`
`consumeNumbers(maxLength)`	`number[]`	Consume an array of doubles
`consumeProbabilityFloat()`	`number`	Consume a float in `[0.0, 1.0]`
`consumeProbabilityDouble()`	`number`	Consume a double in `[0.0, 1.0]`

Bytes

Method	Return Type	Description
`consumeBytes(maxLength)`	`Uint8Array`	Consume up to `maxLength` bytes
`consumeRemainingAsBytes()`	`Uint8Array`	Consume all remaining bytes

Strings

Method	Return Type	Description
`consumeString(maxLength, options?)`	`string`	Consume up to `maxLength` characters
`consumeRemainingAsString(options?)`	`string`	Consume all remaining bytes as a string
`consumeStringArray(maxArrayLength, maxStringLength, options?)`	`string[]`	Consume an array of strings

StringOptions

Field	Type	Default	Description
`encoding`	`string`	`"utf-8"`	String encoding
`printable`	`boolean`	`false`	Restrict to printable ASCII characters

The string methods take an options object. Passing a positional encoding or printable argument (as jazzer.js does) throws a TypeError rather than being silently ignored.

Element Picking

Method	Return Type	Description
`pickValue<T>(array)`	`T`	Pick a random element from the array
`pickValues<T>(array, numValues)`	`T[]`	Pick `numValues` elements (with replacement)

Behavior When Empty

When no bytes remain, consume methods return zero-values: 0 for numbers, false for booleans, "" for strings, empty arrays for array methods. They do not throw.