error-callsites

error-callsites

Yet another module for extracting callsites (a.k.a. stack-frames) from Node.js Error objects.

Installation

npm install error-callsites

Usage

var callsites = require('error-callsites')

var err = new Error('foo')
var stack = callsites(err)

console.log('Error occurred on line', stack[0].getLineNumber())

API

The module exposes a single function which expects an Error object as the first arguemnt:

var arr = callsites(err)

The function returns an array of callsite objects - one for each frame in the stack trace.

Callsite object

Each element in the returned array is a V8 callsite object and in turn reponds to the following V8 functions:

• callsite.getThis() - returns the value of this
• callsite.getTypeName() - returns the type of this as a string. This is the name of the function stored in the constructor field of this, if available, otherwise the object's [[Class]] internal property.
• callsite.getFunction() - returns the current function
• callsite.getFunctionName() - returns the name of the current function, typically its name property. If a name property is not available an attempt will be made to try to infer a name from the function's context.
• callsite.getMethodName() - returns the name of the property of this or one of its prototypes that holds the current function
• callsite.getFileName() - if this function was defined in a script returns the name of the script
• callsite.getLineNumber() - if this function was defined in a script returns the current line number
• callsite.getColumnNumber() - if this function was defined in a script returns the current column number
• callsite.getEvalOrigin() - if this function was created using a call to eval returns a CallSite object representing the location where eval was called
• callsite.isToplevel() - is this a toplevel invocation, that is, is this the global object?
• callsite.isEval() - does this call take place in code defined by a call to eval?
• callsite.isNative() - is this call in native V8 code?
• callsite.isConstructor() - is this a constructor call?

License

MIT