Inspect JS

Does the JS environment support named capture groups in regexes?

Determine if the JS environment has private fields (`class { #x; }`) support.

Determine if the JS environment has `Symbol.toStringTag` support. Supports spec, or shams.

Returns true if a value has the characteristics of a valid JavaScript accessor descriptor.

Is this an arguments object? It's a harder question than you think.

Is this specifier a node.js core module?

What is the type of this builtin JS value?

node's assert.deepEqual algorithm

Is this an ES6 Symbol value?

string representations of objects in node and the browser

Which regular expression flags does the current environment support?

Returns an array of Typed Array names that are available in the current environment.

Does the current JS environment have strict mode? ES5+ should; but let's not assume.

.github repo for inspect-js org

Info about node `exports` field support: version ranges, categories, etc.

No description provided.

Is this value a JS WeakRef? This module works cross-realm/iframe, and despite ES6 @@toStringTag.

Is this value a JS Boolean? This module works cross-realm/iframe, and despite ES6 @@toStringTag.

Get the ArrayBuffer out of a TypedArray, robustly.

Which kind of Typed Array is this JavaScript value? Works cross-realm, without `instanceof`, and despite Symbol.toStringTag.

Get the byte length of an ArrayBuffer, even in engines without a `.byteLength` method.

Does the given package have TypeScript types?

Which kind of Collection (Map, Set, WeakMap, WeakSet) is this JavaScript value? Works cross-realm, without `instanceof`, and despite Symbol.toStringTag.

Is this value a well-known Symbol?

Is this value a JS WeakSet? This module works cross-realm/iframe, and despite ES6 @@toStringTag.

Is this value a JS WeakMap? This module works cross-realm/iframe, and despite ES6 @@toStringTag.

Is this value a JS SharedArrayBuffer? This module works cross-realm/iframe, does not depend on `instanceof` or mutable properties, and despite ES6 Symbol.toStringTag.

Is this value a JS Set? This module works cross-realm/iframe, and despite ES6 @@toStringTag.

Does this environment have the ability to set the [[Prototype]] of an object on creation with `__proto__`?

Does the environment have full property descriptor support? Handles IE 8's broken defineProperty/gOPD.