Q:

anonymous functions javascript, how to access source code?

I got some JS Code that gets inside a random Anonymous js function.
I want that code (for example alert('hello') ) to dump/alert 
the entire script block/object which it was injected into. 
kinda like document.body.innerHTML but for the anonymous function block 
result should be like :
Function()({ somecode; MyAlert(...) } )()

or
Try { some code; mycode; } catch(e) { }

A:

Mind your terms. "(browser) script block" literally means script element's code by the spec.
Use "javascript block" or "javascript object" to mean a block or an object.
Do not create confusing new terms; do read and research.
Blocks are not objects; they are language statements.
Just like you cannot "get the code/variables of current line", you cannot "get the code/variables of current block", try block or not.
Stepping back, for now you can use Function.caller to get the function calling your code:

var mycode = function me(){ if ( me.caller ) alert( me.caller.toString() ); };
(function(){ var some = 'code'; mycode(); })();
// Alert "function(){ var some = 'code'; mycode(); }", even when it is anonymous

Note that you get the whole function's code, not the function block's code which excludes parameters and function name.

Function.caller may be removed in future, like arguments.caller. (Both are troubles. What if a cross origin function on the call stack contains private api key code? How should js engines inline your code?)
When the time comes, or when caller is null (when it is global code), you may still be able to get textual stacktrace (new Error().stack) and current script element (document.currentScript), but their capabilities are pretty limited.
You can get a script element's code - if any - with its textContent or innerHTML property.
Your question sounds like an XY Problem.  You want to do something that no modern language is meant to do, but never say for what purpose.
Try to describe your real problem.

