I am trying to get the file and line location of a function I saved in an object. If I am logging the object to the Chrome Dev Tools I see this:
Can I somehow from inside the code access [[FunctionLocation]]? Or is this something the Chrome Dev Tools add to the object? If so, is it possible to retrieve the function location when I am developing a Chrome Dev Tools extension or a Chrome extension?
You still cannot access the internal properties through JavaScript.
The information is exposed through the Chrome DevTools Protocol, as an InternalPropertyDescriptor. This is observable through for example Node.js:
global.a = () => { /* test function */ };
const s = new (require('inspector').Session)();
s.connect();
let objectId;
s.post('Runtime.evaluate', { expression: 'a' }, (err, { result }) => {
objectId = result.objectId;
});
s.post('Runtime.getProperties', { objectId }, (err, { internalProperties }) => {
console.log(internalProperties);
});
yields
[
{
name: '[[FunctionLocation]]',
value: {
type: 'object',
subtype: 'internal#location',
value: [Object],
description: 'Object'
}
},
{
name: '[[Scopes]]',
value: {
type: 'object',
subtype: 'internal#scopeList',
className: 'Array',
description: 'Scopes[2]',
objectId: '{"injectedScriptId":1,"id":24}'
}
}
]
with Node.js v12.3.1.
Chrome extensions may interact with the Chrome DevTools protocol through chrome.debugger. I am not familiar with how DevTools extensions work, but you may find the Integrating with DevTools page to be insightful.
