func TestDecode(t *testing.T) {
for i, test := range decodeTests {
t.Logf("\ntest %d: %s", i, test.name)
data := undump(test.data)
p, err := drum.Decode(bytes.NewReader(data))
if test.expectError != "" {
if err == nil {
t.Fatalf("got no error; expected error matching %q", test.expectError)
}
ok, err1 := regexp.MatchString("^("+test.expectError+")$", err.Error())
if err1 != nil {
t.Fatalf("bad error pattern in test: %v", err1)
}
if !ok {
t.Fatalf("got unexpected error %q; want %q", err.Error(), test.expectError)
}
if p != nil {
t.Fatalf("non-nil return from error-returning Decode")
}
continue
}
if err != nil {
t.Fatalf("unexpected error when decoding: %v", err)
}
output := p.String()
if output != test.expectOutput {
t.Fatalf("unexpected output\nGot\n%s\nWant\n%s\n", output, test.expectOutput)
}
// Test that it round-trips OK through MarshalBinary
data, err = p.MarshalBinary()
if err != nil {
t.Fatalf("cannot marshal binary: %v", err)
}
p1, err := drum.Decode(bytes.NewReader(data))
if err != nil {
t.Fatalf("cannot decode round-tripped binary: %v", err)
}
output = p1.String()
if output != test.expectOutput {
t.Fatalf("round trip gave unexpected output\nGot\n%s\nWant\n%s\n", output, test.expectOutput)
}
}
}
func Example_cowbell() {
// This example demonstrates how to add more cowbell to
// a drum machine pattern.
p, err := drum.Decode(bytes.NewReader(cowbellExampleData))
if err != nil {
panic(err)
}
var cowbellTrack *drum.Track
maxChan := 0
for i := range p.Tracks {
tr := &p.Tracks[i]
if tr.Name == "cowbell" {
cowbellTrack = tr
break
}
if tr.Channel > maxChan {
maxChan = tr.Channel
}
}
if cowbellTrack == nil {
p.Tracks = append(p.Tracks, drum.Track{
Channel: maxChan + 1,
Name: "cowbell",
})
cowbellTrack = &p.Tracks[len(p.Tracks)-1]
}
for i := range cowbellTrack.Beats {
if i%2 == 0 {
cowbellTrack.Beats[i] = true
}
}
fmt.Print(p)
data, err := p.MarshalBinary()
if err != nil {
panic(err)
}
// To save the file, write data to a new file.
_ = data
// Output: Saved with HW Version: 0.808-alpha
//Tempo: 120
//(0) kick |x---|x---|x---|x---|
//(1) snare |----|x---|----|x---|
//(2) clap |----|x-x-|----|----|
//(3) hh-open |--x-|--x-|x-x-|--x-|
//(4) hh-close |x---|x---|----|x--x|
//(5) cowbell |x-x-|x-x-|x-x-|x-x-|
}
func TestMarshalBinaryWithNoVersion(t *testing.T) {
p := &drum.Pattern{
Tempo: 120,
}
data, err := p.MarshalBinary()
if err != nil {
t.Fatalf("cannot marshal: %v", err)
}
p1, err := drum.Decode(bytes.NewReader(data))
if err != nil {
t.Fatalf("error decoding: %v", err)
}
want := "1.0"
if p1.Version != want {
t.Fatalf("bad version, got %q; want %q", p1.Version, want)
}
}