Check if something is a Node.js stream

Is this value an ES BigInt?

Check if a character is decimal

Check if a character is alphabetical

Check if a character is alphanumerical

Check if a value is an object

Check if a character is hexadecimal

Check if stdout or stderr is interactive

Determine if an object is a Buffer

Determine if a value is an ES6 Symbol or not.

Node is running but you don't know why? why-is-node-running is here to help you.

Check if a value is a plain object

Is this specifier a node.js core module?

Check if the process is running inside a Docker container

Is this value a JS ArrayBuffer?

Determine whether an AST node is a reference

Check whether a string is a URL.

Is this value a JS SharedArrayBuffer?

Determine if a function is a native generator function.

Is this JS value callable? Works with Functions and GeneratorFunctions, despite ES6 @@toStringTag.