tuning changes

Author: er-davo

fingerboard.go

@@ -2,87 +2,18 @@ package guitar
 
 import (
 	"errors"
-	"strings"
 )
 
-type TuningType int
-
-const (
-	StandardTuning TuningType = iota
-)
-
-type Tuning []Note
-
-func (t *Tuning) NoteNames() []string {
-	names := make([]string, len(*t))
-	for i := range *t {
-		names[i] = (*t)[i].Name
-	}
-	names[0] = strings.ToLower(names[0])
-	return names
-}
-
-func GetTuning(t TuningType) (Tuning, error) {
-	switch t {
-	case StandardTuning:
-		return Tuning{
-			{
-				Name:   "E",
-				Octave: 4,
-				Fret:   0,
-				String: 0,
-			},
-			{
-				Name:   "B",
-				Octave: 3,
-				Fret:   0,
-				String: 1,
-			},
-			{
-				Name:   "G",
-				Octave: 3,
-				Fret:   0,
-				String: 2,
-			},
-			{
-				Name:   "D",
-				Octave: 3,
-				Fret:   0,
-				String: 3,
-			},
-			{
-				Name:   "A",
-				Octave: 2,
-				Fret:   0,
-				String: 4,
-			},
-			{
-				Name:   "E",
-				Octave: 2,
-				Fret:   0,
-				String: 5,
-			},
-		}, nil
-	default:
-		return Tuning{}, errors.ErrUnsupported
-	}
-}
-
 type FingerBoard struct {
 	tuning Tuning
 	frets  int
 }
 
-func NewFingerBoard(tuningType TuningType, frets int) (*FingerBoard, error) {
+func NewFingerBoard(tun Tuning, frets int) (*FingerBoard, error) {
 	if frets < 0 {
 		return nil, errors.New("frets value can not be negative")
 	}
 
-	tun, err := GetTuning(tuningType)
-	if err != nil {
-		return nil, err
-	}
-
 	return &FingerBoard{
 		tuning: tun,
 		frets:  frets,

fingerboard_test.go

@@ -1,32 +1,28 @@
 package guitar
 
 import (
-	"errors"
 	"testing"
 
 	"github.com/stretchr/testify/assert"
 )
 
 func TestNewFingerBoard(t *testing.T) {
+	standardTun, _ := GetTuning(StandardTuning, GuitarType)
 	t.Run("valid frets", func(t *testing.T) {
-		fb, err := NewFingerBoard(StandardTuning, 24)
+		fb, err := NewFingerBoard(standardTun, 24)
 		assert.NoError(t, err)
 		assert.Equal(t, 24, fb.frets)
 	})
 
 	t.Run("negative frets", func(t *testing.T) {
-		_, err := NewFingerBoard(StandardTuning, -5)
+		_, err := NewFingerBoard(standardTun, -5)
 		assert.ErrorContains(t, err, "frets value can not be negative")
 	})
-
-	t.Run("invalid tuning", func(t *testing.T) {
-		_, err := NewFingerBoard(TuningType(99), 12)
-		assert.ErrorIs(t, err, errors.ErrUnsupported)
-	})
 }
 
 func TestGetNotes(t *testing.T) {
-	fb, _ := NewFingerBoard(StandardTuning, 24)
+	standardTun, _ := GetTuning(StandardTuning, GuitarType)
+	fb, _ := NewFingerBoard(standardTun, 24)
 
 	testCases := []struct {
 		name         string

tab_test.go

@@ -7,7 +7,7 @@ import (
 )
 
 func TestWriteNotes(t *testing.T) {
-	tun, _ := GetTuning(StandardTuning)
+	tun, _ := GetTuning(StandardTuning, GuitarType)
 	tuningNotes := tun.NoteNames()
 
 	testCases := []struct {

tuning.go

@@ -0,0 +1,94 @@
+package guitar
+
+import (
+	"errors"
+	"fmt"
+	"strings"
+)
+
+type TuningType int
+
+const (
+	StandardTuning TuningType = iota
+)
+
+type Tuning []Note
+
+func (t *Tuning) NoteNames() []string {
+	names := make([]string, len(*t))
+	for i := range *t {
+		names[i] = (*t)[i].Name
+	}
+	names[0] = strings.ToLower(names[0])
+	return names
+}
+
+func NewTuning(t []Note, instrument InstrumentType) (Tuning, error) {
+	for i := range t {
+		if !noteIsValid(t[i]) {
+			return Tuning{}, fmt.Errorf("invalid note %+v", t[i])
+		}
+	}
+
+	switch instrument {
+	case GuitarType:
+		if len(t) != 6 {
+			return Tuning{}, fmt.Errorf("invalid tuning for guitar! must be 6 notes")
+		}
+	default:
+		return Tuning{}, fmt.Errorf("unsupported instrument")
+	}
+
+	return append(Tuning{}, t...), nil
+}
+
+func GetTuning(t TuningType, instrumentType InstrumentType) (Tuning, error) {
+	switch instrumentType {
+	case GuitarType:
+		switch t {
+		case StandardTuning:
+			return Tuning{
+				{
+					Name:   "E",
+					Octave: 4,
+					Fret:   0,
+					String: 0,
+				},
+				{
+					Name:   "B",
+					Octave: 3,
+					Fret:   0,
+					String: 1,
+				},
+				{
+					Name:   "G",
+					Octave: 3,
+					Fret:   0,
+					String: 2,
+				},
+				{
+					Name:   "D",
+					Octave: 3,
+					Fret:   0,
+					String: 3,
+				},
+				{
+					Name:   "A",
+					Octave: 2,
+					Fret:   0,
+					String: 4,
+				},
+				{
+					Name:   "E",
+					Octave: 2,
+					Fret:   0,
+					String: 5,
+				},
+			}, nil
+		default:
+			return Tuning{}, errors.ErrUnsupported
+		}
+	default:
+		return Tuning{}, errors.ErrUnsupported
+	}
+}