Find subsequent changes in the shape (hidden-class) of your Objects which result in unoptimized code
npm install shapeleakRequires Node 6.4+
- Print exact location of the vulnerability.
- Can be applied to Factory, Object-Literal and objects instantiated by new.
- Does not break existing code.
js
const S = require('shapeleak')// new
class A {
constructor(name) {
this.name = name
}
}
A = S(A)
const a = new A('peter')
a.name = 'sandra'
a.name = 1
a.foo = 'bar'
delete a.name
// Factory
function build(name) {
return {
name
}
}
build = S(build)
const b = build('peter')
b.name = 'sandra'
b.name = 1
b.foo = 'bar'
delete b.name
// Object literal
let c = Shaped({
name: 'peter'
})
c.name = 'sandra'
c.name = 1
c.foo = 'bar'
delete b.name
`$3
E:\Repositorys\shaped\example.js
20:8 warn - Property 'name' has change his type from 'string' to 'number'
21:7 error - Property 'foo' was added to shape (name)
22:1 error - Property 'name' was deleted from shape (name,foo)
37:8 warn - Property 'name' has change his type from 'string' to 'number'
38:7 error - Property 'foo' was added to shape (name)
39:1 error - Property 'name' was deleted from shape (name,foo)
50:8 warn - Property 'name' has change his type from 'string' to 'number'
51:7 error - Property 'foo' was added to shape (name)
52:1 error - Property 'name' was deleted from shape (foo)