module.provider.js

module.provider('greeter3', function() {
    var salutation = 'Hello';
    this.setSalutation = function(s) {
        salutation = s;
    }

    function Greeter(a) {
        this.greet = function() {
            return salutation + ' ' + a;
        }
    }

    this.$get = function(a) {
        return new Greeter(a);
    };
});

//later

module('abc', []).config(function(greeter2Provider) {
    greeter2Provider.setSalutation('Halo');
});

function Controller(greeter2) {
    expect(greeter2.greet()).toEqual('Halo 123');
}