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@NV /Readme.md
Last active Oct 23, 2017

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Prepend the debugger statement to a function as easy as stopBefore('Element.prototype.removeChild'). Works in Chrome DevTools and Safari Inspector, doesn’t work in Firebug‘s and Firefox Developer Tools‘ console (I don’t know why). Works as a standalone script everywhere.

stopBefore.js

2min screencast

Examples

stopBefore(document, 'getElementById')
stopBefore('document.getElementById') // the same as the previous
stopBefore(Element.prototype, 'removeChild')

stopAfter(Element.prototype, 'querySelectorAll')

Element.prototype.querySelectorAll.removeBreakpoint()
(function() {
window.stopBefore = function stopBefore(object, methodName) {
// stopBefore('Element.prototype.removeChild')
if (typeof methodName == 'undefined' && typeof object == 'string') {
var temp = resolvePath(object);
object = temp.object;
methodName = temp.methodName;
}
var originalMethod = object[methodName];
object[methodName] = function patched() {
debugger;
var result = originalMethod.apply(this, arguments);
return result;
};
object[methodName].removeBreakpoint = function() {
object[methodName] = originalMethod;
};
object[methodName].__original = originalMethod;
};
window.stopAfter = function stopAfter(object, methodName) {
// stopAfter('jQuery.fn.html')
if (typeof methodName == 'undefined') {
var temp = resolvePath(object);
object = temp.object;
methodName = temp.methodName;
}
var originalMethod = object[methodName];
object[methodName] = function patched() {
var result = originalMethod.apply(this, arguments);
debugger;
return result;
};
object[methodName].removeBreakpoint = function() {
object[methodName] = originalMethod;
};
object[methodName].__original = originalMethod;
};
function resolvePath(path) {
var object = this;
var parts = path.split('.');
for (var i = 0, ii = parts.length - 1; i < ii; i++) {
object = object[parts[i]];
}
return {
object: object,
methodName: parts[ii]
}
}
})();
@azproduction

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azproduction commented Apr 13, 2013

It works fine as "normal script" http://jsfiddle.net/4RGfa/ but in Firebug console it is broken as Firebug console itself.

@NV

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Owner

NV commented Apr 13, 2013

@azproduction good to know, thanks!

@johan

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johan commented Apr 24, 2013

Great idea! I consolidated the code a bit and added logBefore, logAfter, logAround and logCount too: https://gist.github.com/johan/5436827

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