{ strong-type }

Complete API reference

201 validators.
One searchable table set.

Every public validator is listed exactly once, with what passes, an important edge, its runtime, and a runnable example.

183 · Isomorphic core

Browser-safe and Node-safe validators.

Every method exists in every runtime. A guarded type that the host does not provide throws in strict mode and returns false in non-strict mode—never a missing-global ReferenceError.

11 · Core and extension methods

Build checks in the same style.

Unions

Accept one of several named validators.

JavaScript
is.union('type','string|number');
is.union(42,['string','number']);

// Spaces are trimmed. Custom and Node validators work.
nodeIs.union(Buffer.from('type'),'buffer|string');
Validator names are resolved only from the strong-type prototype chain. Inherited Object methods such as toString and multi-argument helper methods are rejected.

18 · Node adapter

Node precision stays opt-in.

The adapter extends the same Is class. It imports only Node built-ins. The browser playground intentionally never loads it.

Node JavaScript
import IsNode from 'strong-type/node';

const is=new IsNode;

is.buffer(Buffer.from('type'));
is.proxy(new Proxy({},{}));
is.nodeReadable(process.stdin);

Runtime labels

Stable methods. Guarded capabilities.

Runtime availability rules
LabelAvailabilityWhen unavailable
SharedStandard JavaScript across supported Node and modern browsers.Not normally applicable.
Guarded standardA newer ECMAScript or Intl capability.Strict throws TypeError; non-strict returns false.
Guarded Web APIA host API that may exist in browsers, workers, or newer Node versions.Strict throws TypeError; non-strict returns false.
NodeAvailable only through strong-type/node.The root import never loads Node built-ins.
object(null) remains true because JavaScript reports typeof null === 'object'. Use nonNullObject for the common non-null meaning.