Question

I want to use local variables like ‘thisModule’ in scope of the given ‘functionToRun’ without passing them as parameters.

Onsetsu.run = function (functionToRun) {
    var thisModule = Onsetsu.namespace(resolvedModule.moduleName);
    functionToRun();
};

Onsetsu.run(function() {
    /* thisModule should be visible here */
});

Unfortunately ‘thisModule’ is not defined in the scope.
Is there a convinient way to bring ‘thisModule’ into the functions scope?

Answer 1

Define a variable in the closest shared scope of functionToRun and Onsetsu.run. Assign the variable within Onsetsu.run:

var thisModule;
Onsetsu.run = function (functionToRun) {
    thisModule = Onsetsu.namespace(resolvedModule.moduleName);
    functionToRun();
};

Onsetsu.run(function() {
    /* thisModule should be visible here */
});

Assuming your actual code is more complicated than that:

(function(){
    var thisModule;
    var Onsetsu = (function(){
        var resolvedModule = { moduleName: "something" };
        return {
            run: function (functionToRun) {
                thisModule = Onsetsu.namespace(resolvedModule.moduleName);
                functionToRun();
            },
            namespace: function(moduleName){ ... }
        };
    })();
    Onsetsu.run(function() {
        /* thisModule should be visible here */
    });
})();

If Onsetsu is a library that you can’t (or don’t want to) modify, then you are out of luck.

Edit: You could also assign a property on the function itself:

Onsetsu.run = function (functionToRun) {
    var thisModule = Onsetsu.namespace(resolvedModule.moduleName);
    functionToRun.module = thisModule;
    functionToRun();
};

You can access the property from within functionToRun via arguments.callee:

Onsetsu.run(function() {
    var module = arguments.callee.module;
});

Or by giving the function a name:

Onsetsu.run(function fn() {
    var module = fn.module;
});