xstate
Version:
Finite State Machines and Statecharts for the Modern Web.
129 lines (128 loc) • 5.24 kB
TypeScript
import type { EventObject, StateValue, MachineContext, ParameterizedObject, AnyMachineSnapshot, NoRequiredParams, WithDynamicParams, Identity, Elements, DoNotInfer } from "./types.js";
type SingleGuardArg<TContext extends MachineContext, TExpressionEvent extends EventObject, TParams extends ParameterizedObject['params'] | undefined, TGuardArg> = [TGuardArg] extends [{
type: string;
}] ? Identity<TGuardArg> : [TGuardArg] extends [string] ? TGuardArg : GuardPredicate<TContext, TExpressionEvent, TParams, ParameterizedObject>;
type NormalizeGuardArg<TGuardArg> = TGuardArg extends {
type: string;
} ? Identity<TGuardArg> & {
params: unknown;
} : TGuardArg extends string ? {
type: TGuardArg;
params: undefined;
} : '_out_TGuard' extends keyof TGuardArg ? TGuardArg['_out_TGuard'] & ParameterizedObject : never;
type NormalizeGuardArgArray<TArg extends unknown[]> = Elements<{
[K in keyof TArg]: NormalizeGuardArg<TArg[K]>;
}>;
export type GuardPredicate<TContext extends MachineContext, TExpressionEvent extends EventObject, TParams extends ParameterizedObject['params'] | undefined, TGuard extends ParameterizedObject> = {
(args: GuardArgs<TContext, TExpressionEvent>, params: TParams): boolean;
_out_TGuard?: TGuard;
};
export interface GuardArgs<TContext extends MachineContext, TExpressionEvent extends EventObject> {
context: TContext;
event: TExpressionEvent;
}
export type Guard<TContext extends MachineContext, TExpressionEvent extends EventObject, TParams extends ParameterizedObject['params'] | undefined, TGuard extends ParameterizedObject> = NoRequiredParams<TGuard> | WithDynamicParams<TContext, TExpressionEvent, TGuard> | GuardPredicate<TContext, TExpressionEvent, TParams, TGuard>;
export type UnknownGuard = UnknownReferencedGuard | UnknownInlineGuard;
type UnknownReferencedGuard = Guard<MachineContext, EventObject, ParameterizedObject['params'], ParameterizedObject>;
type UnknownInlineGuard = Guard<MachineContext, EventObject, undefined, ParameterizedObject>;
export declare function stateIn<TContext extends MachineContext, TExpressionEvent extends EventObject, TParams extends ParameterizedObject['params'] | undefined>(stateValue: StateValue): GuardPredicate<TContext, TExpressionEvent, TParams, any>;
/**
* Higher-order guard that evaluates to `true` if the `guard` passed to it
* evaluates to `false`.
*
* @category Guards
* @example
*
* ```ts
* import { setup, not } from 'xstate';
*
* const machine = setup({
* guards: {
* someNamedGuard: () => false
* }
* }).createMachine({
* on: {
* someEvent: {
* guard: not('someNamedGuard'),
* actions: () => {
* // will be executed if guard in `not(...)`
* // evaluates to `false`
* }
* }
* }
* });
* ```
*
* @returns A guard
*/
export declare function not<TContext extends MachineContext, TExpressionEvent extends EventObject, TArg>(guard: SingleGuardArg<TContext, TExpressionEvent, unknown, TArg>): GuardPredicate<TContext, TExpressionEvent, unknown, NormalizeGuardArg<DoNotInfer<TArg>>>;
/**
* Higher-order guard that evaluates to `true` if all `guards` passed to it
* evaluate to `true`.
*
* @category Guards
* @example
*
* ```ts
* import { setup, and } from 'xstate';
*
* const machine = setup({
* guards: {
* someNamedGuard: () => true
* }
* }).createMachine({
* on: {
* someEvent: {
* guard: and([({ context }) => context.value > 0, 'someNamedGuard']),
* actions: () => {
* // will be executed if all guards in `and(...)`
* // evaluate to true
* }
* }
* }
* });
* ```
*
* @returns A guard action object
*/
export declare function and<TContext extends MachineContext, TExpressionEvent extends EventObject, TArg extends unknown[]>(guards: readonly [
...{
[K in keyof TArg]: SingleGuardArg<TContext, TExpressionEvent, unknown, TArg[K]>;
}
]): GuardPredicate<TContext, TExpressionEvent, unknown, NormalizeGuardArgArray<DoNotInfer<TArg>>>;
/**
* Higher-order guard that evaluates to `true` if any of the `guards` passed to
* it evaluate to `true`.
*
* @category Guards
* @example
*
* ```ts
* import { setup, or } from 'xstate';
*
* const machine = setup({
* guards: {
* someNamedGuard: () => true
* }
* }).createMachine({
* on: {
* someEvent: {
* guard: or([({ context }) => context.value > 0, 'someNamedGuard']),
* actions: () => {
* // will be executed if any of the guards in `or(...)`
* // evaluate to true
* }
* }
* }
* });
* ```
*
* @returns A guard action object
*/
export declare function or<TContext extends MachineContext, TExpressionEvent extends EventObject, TArg extends unknown[]>(guards: readonly [
...{
[K in keyof TArg]: SingleGuardArg<TContext, TExpressionEvent, unknown, TArg[K]>;
}
]): GuardPredicate<TContext, TExpressionEvent, unknown, NormalizeGuardArgArray<DoNotInfer<TArg>>>;
export declare function evaluateGuard<TContext extends MachineContext, TExpressionEvent extends EventObject>(guard: UnknownGuard | UnknownInlineGuard, context: TContext, event: TExpressionEvent, snapshot: AnyMachineSnapshot): boolean;
export {};