callsite-tracker
v1.0.16
Published
callsite-based information tool
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Readme
callsite-tracker
V8 stacktrace API-based information tool.
install
npm install callsite-tracker
example
var tracker = require('callsite-tracker');
describe('tracker', function (){
it('should give me info!', function origin(){
tracked = tracker(3, origin);
should(tracked.module).be('mocha');
console.log(tracked);
})
})
// Of course! this is a mocha test file!
// its just to illustrate things better.
which will output
{
module: 'mocha',
scope: 'mocha/lib',
path: '/home/jcm/npm/lib/node_modules/mocha/lib/runner.js',
isCore: false,
isNative: false,
site:
[ { receiver: [Object], fun: [Function: callFn], pos: 5274 },
{ receiver: [Object], fun: [Function], pos: 5169 },
{ receiver: [Object], fun: [Function], pos: 7711 } ] }
documentation
var tracker = require('callsite-tracker')([frames, origin])
frames
if specified should be aninteger
bigger than0
orInfinity
.origin
if specified should be a function.- if no arguments, the default number of
frames
is2
so theorigin
is the module itself. The returned stack is sliced by one.
The instance returned can walk through the recorded stack on a simple manner
var tracker = require('callsite-tracker');
var tracked = tracker(3); // <- creates the `tracker` instance
tracked // looks the same as the above output given
tracked.get(1) // will move to the second element of the sites array
// and get the same information overriding
// whatever value the properties had
tracker properties
Each tracker instance has attached the stack trace with the callsites. I called each "step" of the stack
a frame. So if you had
callFn (/home/jcm/npm/lib/node_modules/mocha/lib/runnable.js:249:21)
Test.Runnable.run (/home/jcm/npm/lib/node_modules/mocha/lib/runnable.js:242:7)
Runner.runTest (/home/jcm/npm/lib/node_modules/mocha/lib/runner.js:373:10)
each line represents in my head a callsite
frame. The first frame would be
that of the caller
.
module
: the module from which that frame comes from.scope
: the module's module (thats why is called scope you know).path
:__filename
of the frame.isCore
: was themodule
anode
's core module?isNative
: was a nativev8
module?sites
: an array of callsites.
All tracker.sites
elements are callsites so they have their own api
. Go and see the avaliable methods of the V8 stack trace api like:
getLineNumber
getFileName
getEvalOrigin
- etc.
on that link.
why
You want to know stuff.
By default two frames are recorded, though you can even lower it to one providing a function from which start.
inspirated and based on
It serves for the same use cases implemented on this cool modules
I've been using those a lot.
test
npm test