Move mock datastore to tests package

tests/mock_artist_repo.go

@@ -0,0 +1,48 @@
+package tests
+
+import (
+	"errors"
+
+	"github.com/deluan/navidrome/model"
+)
+
+func CreateMockArtistRepo() *MockArtist {
+	return &MockArtist{}
+}
+
+type MockArtist struct {
+	model.ArtistRepository
+	data map[string]model.Artist
+	err  bool
+}
+
+func (m *MockArtist) SetError(err bool) {
+	m.err = err
+}
+
+func (m *MockArtist) SetData(artists model.Artists) {
+	m.data = make(map[string]model.Artist)
+	for _, a := range artists {
+		m.data[a.ID] = a
+	}
+}
+
+func (m *MockArtist) Exists(id string) (bool, error) {
+	if m.err {
+		return false, errors.New("Error!")
+	}
+	_, found := m.data[id]
+	return found, nil
+}
+
+func (m *MockArtist) Get(id string) (*model.Artist, error) {
+	if m.err {
+		return nil, errors.New("Error!")
+	}
+	if d, ok := m.data[id]; ok {
+		return &d, nil
+	}
+	return nil, model.ErrNotFound
+}
+
+var _ model.ArtistRepository = (*MockArtist)(nil)