Is this value `document.all`, i.e. an object with the [[IsHTMLDDA]] internal slot?

Nanoscale assertion module

Robustly get the byte offset of a Typed Array

ES2015-compliant shim for Object.is - differentiates between -0 and +0

ECMAScript spec abstract operations.

Power Assert feature enhancer for assert function/object

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

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

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

Better assertions for node, reporting the expr, filename, lineno etc

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

Robustly get an object's own property keys (strings and symbols), including non-enumerables when possible

TypeScript definitions for http-assert

Get and robustly cache all JS language-level intrinsics at first require time

Test if a finite numeric value is an odd number.

format power-assert context

ES5 spec-compliant shim for String.prototype.trim

Like a Set, but provides the index of the `key` in the backing array

assertion renderer for power-assert context

Test if a finite double-precision floating-point number is an integer.