@metamask/base-controller
Version:
Provides scaffolding for controllers as well a communication system for all controllers
1 lines • 18.8 kB
Source Map (JSON)
{"version":3,"file":"Messenger.mjs","sourceRoot":"","sources":["../src/Messenger.ts"],"names":[],"mappings":";;;;;;AAAA,OAAO,EAAE,mBAAmB,EAAE,kCAA8B;AAmH5D;;;;;;;;;GASG;AACH,MAAM,OAAO,SAAS;IAAtB;QAIW,6BAAW,IAAI,GAAG,EAA2B,EAAC;QAE9C,4BAAU,IAAI,GAAG,EAA8C,EAAC;QAEzE;;;;WAIG;QACM,gDAA8B,IAAI,GAAG,EAG3C,EAAC;QAEJ;;WAEG;QACM,uCAAqB,IAAI,GAAG,EAGlC,EAAC;IAsTN,CAAC;IApTC;;;;;;;;;;OAUG;IACH,qBAAqB,CACnB,UAAsB,EACtB,OAA0C;QAE1C,IAAI,uBAAA,IAAI,0BAAS,CAAC,GAAG,CAAC,UAAU,CAAC,EAAE;YACjC,MAAM,IAAI,KAAK,CACb,iBAAiB,UAAU,8BAA8B,CAC1D,CAAC;SACH;QACD,uBAAA,IAAI,0BAAS,CAAC,GAAG,CAAC,UAAU,EAAE,OAAO,CAAC,CAAC;IACzC,CAAC;IAED;;;;;;;OAOG;IACH,uBAAuB,CACrB,UAAsB;QAEtB,uBAAA,IAAI,0BAAS,CAAC,MAAM,CAAC,UAAU,CAAC,CAAC;IACnC,CAAC;IAED;;;;OAIG;IACH,YAAY;QACV,uBAAA,IAAI,0BAAS,CAAC,KAAK,EAAE,CAAC;IACxB,CAAC;IAED;;;;;;;;;;;;OAYG;IACH,IAAI,CACF,UAAsB,EACtB,GAAG,MAAmD;QAEtD,MAAM,OAAO,GAAG,uBAAA,IAAI,0BAAS,CAAC,GAAG,CAAC,UAAU,CAG3C,CAAC;QACF,IAAI,CAAC,OAAO,EAAE;YACZ,MAAM,IAAI,KAAK,CAAC,iBAAiB,UAAU,0BAA0B,CAAC,CAAC;SACxE;QACD,OAAO,OAAO,CAAC,GAAG,MAAM,CAAC,CAAC;IAC5B,CAAC;IAED;;;;;;;;;;OAUG;IACH,2BAA2B,CAAkC,EAC3D,SAAS,EACT,UAAU,GAIX;QACC,uBAAA,IAAI,6CAA4B,CAAC,GAAG,CAAC,SAAS,EAAE,UAAU,CAAC,CAAC;IAC9D,CAAC;IAED;;;;;;;;;;;;OAYG;IACH,OAAO,CACL,SAAoB,EACpB,GAAG,OAA8C;QAEjD,MAAM,WAAW,GAAG,uBAAA,IAAI,yBAAQ,CAAC,GAAG,CAAC,SAAS,CAAC,CAAC;QAEhD,IAAI,WAAW,EAAE;YACf,KAAK,MAAM,CAAC,OAAO,EAAE,QAAQ,CAAC,IAAI,WAAW,CAAC,OAAO,EAAE,EAAE;gBACvD,IAAI;oBACF,IAAI,QAAQ,EAAE;wBACZ,MAAM,aAAa,GAAG,uBAAA,IAAI,oCAAmB,CAAC,GAAG,CAAC,OAAO,CAAC,CAAC;wBAC3D,MAAM,QAAQ,GAAG,QAAQ,CAAC,GAAG,OAAO,CAAC,CAAC;wBAEtC,IAAI,QAAQ,KAAK,aAAa,EAAE;4BAC9B,uBAAA,IAAI,oCAAmB,CAAC,GAAG,CAAC,OAAO,EAAE,QAAQ,CAAC,CAAC;4BAC/C,OAAO,CAAC,QAAQ,EAAE,aAAa,CAAC,CAAC;yBAClC;qBACF;yBAAM;wBACJ,OAA+B,CAAC,GAAG,OAAO,CAAC,CAAC;qBAC9C;iBACF;gBAAC,OAAO,KAAK,EAAE;oBACd,qEAAqE;oBACrE,6DAA6D;oBAC7D,UAAU,CAAC,GAAG,EAAE;wBACd,MAAM,KAAK,CAAC;oBACd,CAAC,CAAC,CAAC;iBACJ;aACF;SACF;IACH,CAAC;IAwCD,SAAS,CACP,SAAoB,EACpB,OAA8C,EAC9C,QAAkE;QAElE,IAAI,WAAW,GAAG,uBAAA,IAAI,yBAAQ,CAAC,GAAG,CAAC,SAAS,CAAC,CAAC;QAC9C,IAAI,CAAC,WAAW,EAAE;YAChB,WAAW,GAAG,IAAI,GAAG,EAAE,CAAC;YACxB,uBAAA,IAAI,yBAAQ,CAAC,GAAG,CAAC,SAAS,EAAE,WAAW,CAAC,CAAC;SAC1C;QAED,WAAW,CAAC,GAAG,CAAC,OAAO,EAAE,QAAQ,CAAC,CAAC;QAEnC,IAAI,QAAQ,EAAE;YACZ,MAAM,UAAU,GAAG,uBAAA,IAAI,6CAA4B,CAAC,GAAG,CAAC,SAAS,CAAC,CAAC;YACnE,IAAI,UAAU,EAAE;gBACd,MAAM,YAAY,GAAG,QAAQ,CAAC,GAAG,UAAU,EAAE,CAAC,CAAC;gBAC/C,uBAAA,IAAI,oCAAmB,CAAC,GAAG,CAAC,OAAO,EAAE,YAAY,CAAC,CAAC;aACpD;SACF;IACH,CAAC;IAED;;;;;;;;;OASG;IACH,WAAW,CACT,SAAoB,EACpB,OAA8C;QAE9C,MAAM,WAAW,GAAG,uBAAA,IAAI,yBAAQ,CAAC,GAAG,CAAC,SAAS,CAAC,CAAC;QAEhD,IAAI,CAAC,WAAW,IAAI,CAAC,WAAW,CAAC,GAAG,CAAC,OAAO,CAAC,EAAE;YAC7C,MAAM,IAAI,KAAK,CAAC,qCAAqC,SAAS,EAAE,CAAC,CAAC;SACnE;QAED,MAAM,QAAQ,GAAG,WAAW,CAAC,GAAG,CAAC,OAAO,CAAC,CAAC;QAC1C,IAAI,QAAQ,EAAE;YACZ,uBAAA,IAAI,oCAAmB,CAAC,MAAM,CAAC,OAAO,CAAC,CAAC;SACzC;QAED,WAAW,CAAC,MAAM,CAAC,OAAO,CAAC,CAAC;IAC9B,CAAC;IAED;;;;;;;OAOG;IACH,uBAAuB,CACrB,SAAoB;QAEpB,uBAAA,IAAI,yBAAQ,CAAC,MAAM,CAAC,SAAS,CAAC,CAAC;IACjC,CAAC;IAED;;;;OAIG;IACH,kBAAkB;QAChB,uBAAA,IAAI,yBAAQ,CAAC,KAAK,EAAE,CAAC;IACvB,CAAC;IAED;;;;;;;;;;;;;;;;;;;;;;;;;OAyBG;IACH,aAAa,CAIX,EACA,IAAI,EACJ,cAAc,EACd,aAAa,GAWd;QAQC,OAAO,IAAI,mBAAmB,CAAC;YAC7B,SAAS,EAAE,IAAI;YACf,IAAI;YACJ,cAAc;YACd,aAAa;SACd,CAAC,CAAC;IACL,CAAC;CACF","sourcesContent":["import { RestrictedMessenger } from './RestrictedMessenger';\n\nexport type ActionHandler<\n Action extends ActionConstraint,\n ActionType = Action['type'],\n> = (\n ...args: ExtractActionParameters<Action, ActionType>\n) => ExtractActionResponse<Action, ActionType>;\n\nexport type ExtractActionParameters<\n Action extends ActionConstraint,\n ActionType = Action['type'],\n> = Action extends {\n type: ActionType;\n handler: (...args: infer HandlerArgs) => unknown;\n}\n ? HandlerArgs\n : never;\n\nexport type ExtractActionResponse<\n Action extends ActionConstraint,\n ActionType = Action['type'],\n> = Action extends {\n type: ActionType;\n handler: (...args: infer _) => infer HandlerReturnValue;\n}\n ? HandlerReturnValue\n : never;\n\nexport type ExtractEventHandler<\n Event extends EventConstraint,\n EventType = Event['type'],\n> = Event extends {\n type: EventType;\n payload: infer Payload;\n}\n ? Payload extends unknown[]\n ? (...payload: Payload) => void\n : never\n : never;\n\nexport type ExtractEventPayload<\n Event extends EventConstraint,\n EventType = Event['type'],\n> = Event extends {\n type: EventType;\n payload: infer Payload;\n}\n ? Payload extends unknown[]\n ? Payload\n : never\n : never;\n\nexport type GenericEventHandler = (...args: unknown[]) => void;\n\nexport type SelectorFunction<\n Event extends EventConstraint,\n EventType extends Event['type'],\n ReturnValue,\n> = (...args: ExtractEventPayload<Event, EventType>) => ReturnValue;\nexport type SelectorEventHandler<SelectorReturnValue> = (\n newValue: SelectorReturnValue,\n previousValue: SelectorReturnValue | undefined,\n) => void;\n\nexport type ActionConstraint = {\n type: string;\n handler: ((...args: never) => unknown) | ((...args: never[]) => unknown);\n};\nexport type EventConstraint = {\n type: string;\n payload: unknown[];\n};\n\ntype EventSubscriptionMap<\n Event extends EventConstraint,\n ReturnValue = unknown,\n> = Map<\n GenericEventHandler | SelectorEventHandler<ReturnValue>,\n SelectorFunction<Event, Event['type'], ReturnValue> | undefined\n>;\n\n/**\n * A namespaced string\n *\n * This type verifies that the string Name is prefixed by the string Name followed by a colon.\n *\n * @template Namespace - The namespace we're checking for.\n * @template Name - The full string, including the namespace.\n */\nexport type NamespacedBy<\n Namespace extends string,\n Name extends string,\n> = Name extends `${Namespace}:${string}` ? Name : never;\n\nexport type NotNamespacedBy<\n Namespace extends string,\n Name extends string,\n> = Name extends `${Namespace}:${string}` ? never : Name;\n\nexport type NamespacedName<Namespace extends string = string> =\n `${Namespace}:${string}`;\n\ntype NarrowToNamespace<Name, Namespace extends string> = Name extends {\n type: `${Namespace}:${string}`;\n}\n ? Name\n : never;\n\ntype NarrowToAllowed<Name, Allowed extends string> = Name extends {\n type: Allowed;\n}\n ? Name\n : never;\n\n/**\n * A message broker for \"actions\" and \"events\".\n *\n * The messenger allows registering functions as 'actions' that can be called elsewhere,\n * and it allows publishing and subscribing to events. Both actions and events are identified by\n * unique strings.\n *\n * @template Action - A type union of all Action types.\n * @template Event - A type union of all Event types.\n */\nexport class Messenger<\n Action extends ActionConstraint,\n Event extends EventConstraint,\n> {\n readonly #actions = new Map<Action['type'], unknown>();\n\n readonly #events = new Map<Event['type'], EventSubscriptionMap<Event>>();\n\n /**\n * A map of functions for getting the initial event payload.\n *\n * Used only for events that represent state changes.\n */\n readonly #initialEventPayloadGetters = new Map<\n Event['type'],\n () => ExtractEventPayload<Event, Event['type']>\n >();\n\n /**\n * A cache of selector return values for their respective handlers.\n */\n readonly #eventPayloadCache = new Map<\n GenericEventHandler,\n unknown | undefined\n >();\n\n /**\n * Register an action handler.\n *\n * This will make the registered function available to call via the `call` method.\n *\n * @param actionType - The action type. This is a unqiue identifier for this action.\n * @param handler - The action handler. This function gets called when the `call` method is\n * invoked with the given action type.\n * @throws Will throw when a handler has been registered for this action type already.\n * @template ActionType - A type union of Action type strings.\n */\n registerActionHandler<ActionType extends Action['type']>(\n actionType: ActionType,\n handler: ActionHandler<Action, ActionType>,\n ) {\n if (this.#actions.has(actionType)) {\n throw new Error(\n `A handler for ${actionType} has already been registered`,\n );\n }\n this.#actions.set(actionType, handler);\n }\n\n /**\n * Unregister an action handler.\n *\n * This will prevent this action from being called.\n *\n * @param actionType - The action type. This is a unqiue identifier for this action.\n * @template ActionType - A type union of Action type strings.\n */\n unregisterActionHandler<ActionType extends Action['type']>(\n actionType: ActionType,\n ) {\n this.#actions.delete(actionType);\n }\n\n /**\n * Unregister all action handlers.\n *\n * This prevents all actions from being called.\n */\n clearActions() {\n this.#actions.clear();\n }\n\n /**\n * Call an action.\n *\n * This function will call the action handler corresponding to the given action type, passing\n * along any parameters given.\n *\n * @param actionType - The action type. This is a unqiue identifier for this action.\n * @param params - The action parameters. These must match the type of the parameters of the\n * registered action handler.\n * @throws Will throw when no handler has been registered for the given type.\n * @template ActionType - A type union of Action type strings.\n * @returns The action return value.\n */\n call<ActionType extends Action['type']>(\n actionType: ActionType,\n ...params: ExtractActionParameters<Action, ActionType>\n ): ExtractActionResponse<Action, ActionType> {\n const handler = this.#actions.get(actionType) as ActionHandler<\n Action,\n ActionType\n >;\n if (!handler) {\n throw new Error(`A handler for ${actionType} has not been registered`);\n }\n return handler(...params);\n }\n\n /**\n * Register a function for getting the initial payload for an event.\n *\n * This is used for events that represent a state change, where the payload is the state.\n * Registering a function for getting the payload allows event selectors to have a point of\n * comparison the first time state changes.\n *\n * @param args - The arguments to this function\n * @param args.eventType - The event type to register a payload for.\n * @param args.getPayload - A function for retrieving the event payload.\n */\n registerInitialEventPayload<EventType extends Event['type']>({\n eventType,\n getPayload,\n }: {\n eventType: EventType;\n getPayload: () => ExtractEventPayload<Event, EventType>;\n }) {\n this.#initialEventPayloadGetters.set(eventType, getPayload);\n }\n\n /**\n * Publish an event.\n *\n * Publishes the given payload to all subscribers of the given event type.\n *\n * Note that this method should never throw directly. Any errors from\n * subscribers are captured and re-thrown in a timeout handler.\n *\n * @param eventType - The event type. This is a unique identifier for this event.\n * @param payload - The event payload. The type of the parameters for each event handler must\n * match the type of this payload.\n * @template EventType - A type union of Event type strings.\n */\n publish<EventType extends Event['type']>(\n eventType: EventType,\n ...payload: ExtractEventPayload<Event, EventType>\n ) {\n const subscribers = this.#events.get(eventType);\n\n if (subscribers) {\n for (const [handler, selector] of subscribers.entries()) {\n try {\n if (selector) {\n const previousValue = this.#eventPayloadCache.get(handler);\n const newValue = selector(...payload);\n\n if (newValue !== previousValue) {\n this.#eventPayloadCache.set(handler, newValue);\n handler(newValue, previousValue);\n }\n } else {\n (handler as GenericEventHandler)(...payload);\n }\n } catch (error) {\n // Throw error after timeout so that it is capured as a console error\n // (and by Sentry) without interrupting the event publishing.\n setTimeout(() => {\n throw error;\n });\n }\n }\n }\n }\n\n /**\n * Subscribe to an event.\n *\n * Registers the given function as an event handler for the given event type.\n *\n * @param eventType - The event type. This is a unique identifier for this event.\n * @param handler - The event handler. The type of the parameters for this event handler must\n * match the type of the payload for this event type.\n * @template EventType - A type union of Event type strings.\n */\n subscribe<EventType extends Event['type']>(\n eventType: EventType,\n handler: ExtractEventHandler<Event, EventType>,\n ): void;\n\n /**\n * Subscribe to an event, with a selector.\n *\n * Registers the given handler function as an event handler for the given\n * event type. When an event is published, its payload is first passed to the\n * selector. The event handler is only called if the selector's return value\n * differs from its last known return value.\n *\n * @param eventType - The event type. This is a unique identifier for this event.\n * @param handler - The event handler. The type of the parameters for this event\n * handler must match the return type of the selector.\n * @param selector - The selector function used to select relevant data from\n * the event payload. The type of the parameters for this selector must match\n * the type of the payload for this event type.\n * @template EventType - A type union of Event type strings.\n * @template SelectorReturnValue - The selector return value.\n */\n subscribe<EventType extends Event['type'], SelectorReturnValue>(\n eventType: EventType,\n handler: SelectorEventHandler<SelectorReturnValue>,\n selector: SelectorFunction<Event, EventType, SelectorReturnValue>,\n ): void;\n\n subscribe<EventType extends Event['type'], SelectorReturnValue>(\n eventType: EventType,\n handler: ExtractEventHandler<Event, EventType>,\n selector?: SelectorFunction<Event, EventType, SelectorReturnValue>,\n ): void {\n let subscribers = this.#events.get(eventType);\n if (!subscribers) {\n subscribers = new Map();\n this.#events.set(eventType, subscribers);\n }\n\n subscribers.set(handler, selector);\n\n if (selector) {\n const getPayload = this.#initialEventPayloadGetters.get(eventType);\n if (getPayload) {\n const initialValue = selector(...getPayload());\n this.#eventPayloadCache.set(handler, initialValue);\n }\n }\n }\n\n /**\n * Unsubscribe from an event.\n *\n * Unregisters the given function as an event handler for the given event.\n *\n * @param eventType - The event type. This is a unique identifier for this event.\n * @param handler - The event handler to unregister.\n * @throws Will throw when the given event handler is not registered for this event.\n * @template EventType - A type union of Event type strings.\n */\n unsubscribe<EventType extends Event['type']>(\n eventType: EventType,\n handler: ExtractEventHandler<Event, EventType>,\n ) {\n const subscribers = this.#events.get(eventType);\n\n if (!subscribers || !subscribers.has(handler)) {\n throw new Error(`Subscription not found for event: ${eventType}`);\n }\n\n const selector = subscribers.get(handler);\n if (selector) {\n this.#eventPayloadCache.delete(handler);\n }\n\n subscribers.delete(handler);\n }\n\n /**\n * Clear subscriptions for a specific event.\n *\n * This will remove all subscribed handlers for this event.\n *\n * @param eventType - The event type. This is a unique identifier for this event.\n * @template EventType - A type union of Event type strings.\n */\n clearEventSubscriptions<EventType extends Event['type']>(\n eventType: EventType,\n ) {\n this.#events.delete(eventType);\n }\n\n /**\n * Clear all subscriptions.\n *\n * This will remove all subscribed handlers for all events.\n */\n clearSubscriptions() {\n this.#events.clear();\n }\n\n /**\n * Get a restricted messenger\n *\n * Returns a wrapper around the messenger instance that restricts access to actions and events.\n * The provided allowlists grant the ability to call the listed actions and subscribe to the\n * listed events. The \"name\" provided grants ownership of any actions and events under that\n * namespace. Ownership allows registering actions and publishing events, as well as\n * unregistering actions and clearing event subscriptions.\n *\n * @param options - Messenger options.\n * @param options.name - The name of the thing this messenger will be handed to (e.g. the\n * controller name). This grants \"ownership\" of actions and events under this namespace to the\n * restricted messenger returned.\n * @param options.allowedActions - The list of actions that this restricted messenger should be\n * allowed to call.\n * @param options.allowedEvents - The list of events that this restricted messenger should be\n * allowed to subscribe to.\n * @template Namespace - The namespace for this messenger. Typically this is the name of the\n * module that this messenger has been created for. The authority to publish events and register\n * actions under this namespace is granted to this restricted messenger instance.\n * @template AllowedAction - A type union of the 'type' string for any allowed actions.\n * This must not include internal actions that are in the messenger's namespace.\n * @template AllowedEvent - A type union of the 'type' string for any allowed events.\n * This must not include internal events that are in the messenger's namespace.\n * @returns The restricted messenger.\n */\n getRestricted<\n Namespace extends string,\n AllowedAction extends NotNamespacedBy<Namespace, Action['type']> = never,\n AllowedEvent extends NotNamespacedBy<Namespace, Event['type']> = never,\n >({\n name,\n allowedActions,\n allowedEvents,\n }: {\n name: Namespace;\n allowedActions: NotNamespacedBy<\n Namespace,\n Extract<Action['type'], AllowedAction>\n >[];\n allowedEvents: NotNamespacedBy<\n Namespace,\n Extract<Event['type'], AllowedEvent>\n >[];\n }): RestrictedMessenger<\n Namespace,\n | NarrowToNamespace<Action, Namespace>\n | NarrowToAllowed<Action, AllowedAction>,\n NarrowToNamespace<Event, Namespace> | NarrowToAllowed<Event, AllowedEvent>,\n AllowedAction,\n AllowedEvent\n > {\n return new RestrictedMessenger({\n messenger: this,\n name,\n allowedActions,\n allowedEvents,\n });\n }\n}\n"]}