Types

Every value that exists inside a StaticJs sandbox is a StaticJsValue. The type system mirrors JavaScript's own primitives and objects, but wraps them so the host can inspect, create, and manipulate sandbox values safely without executing untrusted code directly.

All types carry a realm reference and implement the StaticJsPrimitive base interface. Object-like types additionally implement StaticJsObject, which provides the full ECMAScript internal-method API ([[Get]], [[Set]], [[DefineOwnProperty]], etc.) as async/sync/evaluator triplets.

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Inheritance diagram

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Union types

Two union types group related concrete types for type-narrowing purposes:

StaticJsValue

StaticJsValue is a type representing every possible StaticJs value. Use isStaticJsValue to check, or the more specific guards below to narrow further.

StaticJsValue = StaticJsScalar | StaticJsPlainObject | StaticJsArray | StaticJsFunction | ...

StaticJsScalar

StaticJsScalar covers the non-compound types. All StaticJsScalar types include a .value property reflecting the native, non-sandbox value. Use isStaticJsScalar to narrow to any scalar.

StaticJsScalar = StaticJsString | StaticJsNumber | StaticJsBoolean
               | StaticJsNull | StaticJsUndefined | StaticJsSymbol

Symbols are dual-classified

StaticJsSymbol appears in both the StaticJsScalar union (it is a primitive in JavaScript) and extends StaticJsObject in the interface hierarchy (so the sandbox can support Symbol.prototype method access internally). isStaticJsScalar returns true for symbols; isStaticJsObject also returns true for them.

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Type reference

Type	Type guard	.value
StaticJsValue	isStaticJsValue	—
StaticJsPrimitive		—
StaticJsScalar	isStaticJsScalar	string | number | boolean | null | undefined | symbol
StaticJsObject	isStaticJsObject	—
StaticJsCallable	isStaticJsCallable	—
StaticJsString	isStaticJsString	string
StaticJsNumber	isStaticJsNumber	number
StaticJsBoolean	isStaticJsBoolean	boolean
StaticJsNull	isStaticJsNull	null
StaticJsUndefined	isStaticJsUndefined	undefined
StaticJsSymbol	isStaticJsSymbol	symbol
StaticJsPlainObject	isStaticJsPlainObject	—
StaticJsArray	isStaticJsArray	—
StaticJsFunction	isStaticJsFunction	—
StaticJsProxy	isStaticJsProxy	—
StaticJsMap	isStaticJsMap	—
StaticJsSet	isStaticJsSet	—
StaticJsPromise	isStaticJsPromise	—
StaticJsIterator	isStaticJsIterator	—
StaticJsAsyncGenerator	isStaticJsAsyncGenerator	—
StaticJsGenerator	isStaticJsGenerator	—

All type guards and types are importable from @suntime-js/core.