isWorkletFunction

Available from 0.1.0

isWorkletFunction checks if a function is a worklet function. It only works with Worklets Babel plugin enabled. Unless you are doing something with internals of the Worklets library you shouldn't need to use this function.

Reference

Both checks run on the RN Runtime. Checking a function doesn't execute it or schedule it on another thread.

Code

Code

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1function workletFunction() {

2 'worklet';

3 return 1;

4}

5

6function nonWorkletFunction() {

7 return 1;

8}

9

10const isWorklet = isWorkletFunction(workletFunction);

11console.log(isWorklet); // true

12

13const isNonWorklet = isWorkletFunction(nonWorkletFunction);

14console.log(isNonWorklet); // false

Type definitions

type WorkletClosure = unknown[];

export type WorkletStackDetails = [
  error: Error,
  lineOffset: number,
  columnOffset: number,
];

interface WorkletInitData {
  /** Only when bytecode isn't toggled. */
  code?: string;
  /** Only in production builds and explicitly toggled. */
  bytecode?: ArrayBuffer;
  /** Only in dev builds. */
  location?: string;
  /** Only in dev builds. */
  sourceMap?: string;
}

interface WorkletProps {
  __closure?: WorkletClosure;
  __workletHash: number;
  /** Only in Legacy Eval Mode. */
  __initData?: WorkletInitData;
  /** `__stackDetails` is removed after parsing. */
  __stackDetails?: WorkletStackDetails;
  /** Only in dev builds. */
  __pluginVersion?: string;
}

type WorkletFunction<
  TArgs extends unknown[] = unknown[],
  TReturn = unknown,
> = ((...args: TArgs) => TReturn) & WorkletProps;

function isWorkletFunction<
  Args extends unknown[] = unknown[],
  ReturnValue = unknown,
>(value: unknown): value is WorkletFunction<Args, ReturnValue>;

Arguments

value

A function to check if it is a worklet function.

Returns

isWorkletFunction returns a boolean value.

Remarks

• Do not call it before the worklet function is declared, as it will always return false then.

  isWorkletFunction(myWorklet); // Will always return false.
  
  function myWorklet() {
    'worklet';
  }