JavaScript bug question.

bindFunction.js

/*

bindFunctions as implemented below has a bug.

1.  What is the bug?
2.  How do you fix it?

All functions have the args:

functionList:  list of functions
context:  an object that should be used as the 'this' of those functions

*/

function bindFunctions0(functionlist,context) {
    var i,cmd;
    for (i = 0; i < functionlist.length; i++) {
        cmd = functionlist[i];
        context[cmd.name] = function(){ return cmd.apply(context, arguments); };
    }
    return context;
}


function test(bindingfn) {
    var somecmnds = [function oner(v){return [this.a, v, 1]}, function twoer(y){return [this.a, y, 2]}];
    var mycontext = bindingfn(somecmnds,{'a':'AA'});
    console.log(mycontext.oner('Q'));
    console.log(mycontext.twoer('Q'));
}; 

test(bindFunctions0);


/* Solutions 

Recall the block scoping rules for JS!


*/

/* solution 1, add another closure */
function bindFunctions1(functionlist,context) {
    var i,cmd;
    for (i = 0; i < functionlist.length; i++) {
        cmd = functionlist[i];
        context[cmd.name] = (function(cmd){return function(){return cmd.apply(context,arguments)} })(cmd);
    }
    return context;
}

test(bindFunctions1);

/* solution 2, 'let' keyword, available in recent js (such as FF web console */
function bindFunctions2(functionlist,context) {
    var i,cmd;
    for (i = 0; i < functionlist.length; i++) {
        let cmd = functionlist[i];
        context[cmd.name] = function(){ return cmd.apply(context, arguments); };
    }
    return context;
}

test(bindFunctions2);