scope

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Small, framework-independent ownership scopes for TypeScript.

@kayahr/scope provides disposable ownership scopes, cleanup registration, parent/child scope trees, and typed scope-local values.

Installation

npm install @kayahr/scope

TypeScript consumers currently need a compatible lib configuration including esnext.disposable.

Runtimes without native Symbol.dispose need a polyfill before importing @kayahr/scope, for example from core-js:

import "core-js/proposals/explicit-resource-management";

Basic Usage

Create a scope, activate it while constructing owned resources, and dispose it later as one unit:

import { createScope, onDispose } from "@kayahr/scope";

const scope = createScope();

scope.run(() => {
    const interval = setInterval(() => {
        console.log("tick");
    }, 1000);

    onDispose(() => {
        clearInterval(interval);
    });
});

// ...
scope.dispose();

createScope() creates a scope. Without an explicit parent, it uses the current active scope as parent, or the shared root scope when no scope is active. createScope(scope => ...) is shorthand for creating a scope and running a callback inside it. Only the synchronous execution of scope.run(...) or createScope(scope => ...) belongs to the scope. Work created after an await is outside that scope. If the callback returns a promise, that promise is returned as-is and is not awaited.

getRootScope() returns the shared root scope. It is not active by default, but scopes created without an active scope are attached to it. resetRootScope() clears the shared root scope without replacing it.

Documentation

• Scopes
• Scope Slots