padSpec.js

describe('Launchpad', function(){
    function cartesianProduct(as, bs) {
        return as.map(function(a){
            return bs.map(function(b){
                return [a, b]
            });
        }).reduce(function(result, partialProduct){
            return result.concat(partialProduct);
        }, []);
    };

    var ANY_CHANNEL = 144;
    var ANY_NOTE = 0;
    var mockMidiAdapter;

    beforeEach(function(){
        mockMidiAdapter = new launchpad.Observable();
        mockMidiAdapter.send = function(){
            this.arguments = Array.prototype.slice.call(arguments);
        };
    });

    it('should be Observable', function(){
        var pad = new launchpad.Launchpad(mockMidiAdapter);

        expect(pad instanceof launchpad.Observable).toBe(true);
    });

    describe('on [*, *, 127] midi message', function(){
        it('pad should emit \'press\'', function(){
            var pad = new launchpad.Launchpad(mockMidiAdapter);
            var notified = false;
            pad.on('press', function(){ notified = true; });

            mockMidiAdapter.emit('input', ANY_CHANNEL, ANY_NOTE, 127);

            expect(notified).toBe(true);
        });

        it('should emit corresponding button', function(){
            var pad = new launchpad.Launchpad(mockMidiAdapter);
            var button;
            pad.on('press', function(aButton){ button = aButton; });

            mockMidiAdapter.emit('input', ANY_CHANNEL, ANY_NOTE, 127);

            expect(button).toBeDefined();
            expect(button instanceof launchpad.Button).toBe(true);
            expect(button.channel).toBe(ANY_CHANNEL);
            expect(button.note).toBe(ANY_NOTE);
        });
    });

    describe('on [*, *, 0] midi message', function(){
        it('pad should emit \'release\'', function(){
            var pad = new launchpad.Launchpad(mockMidiAdapter);
            var notified = false;
            pad.on('release', function(){ notified = true; });

            mockMidiAdapter.emit('input', ANY_CHANNEL, ANY_NOTE, 0);

            expect(notified).toBe(true);
        });

        it('should emit corresponding button', function(){
            var pad = new launchpad.Launchpad(mockMidiAdapter);
            var button;
            pad.on('release', function(aButton){ button = aButton; });

            mockMidiAdapter.emit('input', ANY_CHANNEL, ANY_NOTE, 0);

            expect(button).toBeDefined();
            expect(button instanceof launchpad.Button).toBe(true);
            expect(button.channel).toBe(ANY_CHANNEL);
            expect(button.note).toBe(ANY_NOTE);
        });
    });

    describe('clear', function(){
        it('should send [176, 0, 0] to midiAdapter', function(){
            var pad = new launchpad.Launchpad(mockMidiAdapter);

            pad.clear();

            expect(mockMidiAdapter.arguments).toEqual([176, 0, 0]);
        });
    });

    describe('button', function(){
        it('should return a Button by regular button id', function(){
            var pad = new launchpad.Launchpad(mockMidiAdapter);

            [0, 1, 2, 3, 4, 5, 6, 7]
                .map(function(n){ return 16*n; })
                .map(function(m){
                    return [0, 1, 2, 3, 4, 5, 6, 7, 8].map(function(n){ return m + n; });
                })
                .reduce(function(result, ids){ return result.concat(ids); },[])
                .map(function(id){ return { 'id': id, 'note': id }; })
                .forEach(function(data){
                    var button = pad.button(data.id);

                    expect(button.channel).toBe(144);
                    expect(button.note).toBe(data.note);
                });
        });

        it('should return a Button by coordinates', function(){
            var pad = new launchpad.Launchpad(mockMidiAdapter);

            cartesianProduct([0, 1, 2, 3, 4, 5, 6, 7], [0, 1, 2, 3, 4, 5, 6, 7, 8])
                .map(function(product){
                    return {
                        'x': product[0],
                        'y': product[1]
                    }
                })
                .forEach(function(coordinates){
                    var button = pad.button(coordinates.x, coordinates.y);

                    expect(button.channel).toBe(144);
                    expect(button.note).toBe(coordinates.x + 16 * coordinates.y);
                });
        });
    });

    describe('controlButton', function(){
        it('should return a Button by control button id', function(){
            var pad = new launchpad.Launchpad(mockMidiAdapter);

            [0, 1, 2, 3, 4, 5, 6, 7]
                .map(function(id){ return { 'id': id, 'note': 104 + id }; })
                .forEach(function(data){
                    var button = pad.controlButton(data.id);

                    expect(button.channel).toBe(176);
                    expect(button.note).toBe(data.note);
                });
        });
    });
});