Merge pull request #798 from gobuffalo/empty-slice

fixed empty slice bug on slices.Float

slices/float.go

@@ -27,8 +27,9 @@ func (f *Float) Scan(src interface{}) error {
 	default:
 		return fmt.Errorf("scan source was not []byte nor string but %T", src)
 	}
-	*f = strToFloat(str)
-	return nil
+	v, err := strToFloat(str)
+	*f = v
+	return err
 }
 
 // Value implements the driver.Valuer interface.
@@ -56,12 +57,22 @@ func (f *Float) UnmarshalText(text []byte) error {
 	return nil
 }
 
-func strToFloat(s string) []float64 {
+func strToFloat(s string) ([]float64, error) {
 	r := strings.Trim(s, "{}")
 	a := make([]float64, 0, 10)
-	for _, t := range strings.Split(r, ",") {
-		i, _ := strconv.ParseFloat(t, 64)
-		a = append(a, i)
+
+	elems := strings.Split(r, ",")
+	if len(elems) == 1 && elems[0] == "" {
+		return a, nil
 	}
-	return a
+
+	for _, t := range elems {
+		f, err := strconv.ParseFloat(t, 64)
+		if err != nil {
+			return nil, err
+		}
+		a = append(a, f)
+	}
+
+	return a, nil
 }

slices/float_test.go

@@ -0,0 +1,30 @@
+package slices
+
+import (
+	"testing"
+
+	"github.com/stretchr/testify/require"
+)
+
+func Test_Float_Scan(t *testing.T) {
+	r := require.New(t)
+	t.Run("empty slice", func(t *testing.T) {
+		in := "{}"
+		v := &Float{}
+		r.NoError(v.Scan(in))
+		r.Len(*v, 0)
+	})
+
+	t.Run("non-empty slice", func(t *testing.T) {
+		in := "{3.14,9.999}"
+		v := &Float{}
+		r.NoError(v.Scan(in))
+		r.Equal([]float64(*v), []float64{3.14, 9.999})
+	})
+
+	t.Run("invalid entry", func(t *testing.T) {
+		in := "{44,word}"
+		v := &Float{}
+		r.Error(v.Scan(in))
+	})
+}

slices_test.go

@@ -44,6 +44,7 @@ func (s *PostgreSQLSuite) Test_Int() {
 		err = tx.Reload(c)
 		r.NoError(err)
 		r.Equal(slices.Int{1, 2, 3}, c.Int)
+		r.Equal(slices.Float{}, c.Float)
 	})
 }
 
@@ -59,6 +60,7 @@ func (s *PostgreSQLSuite) Test_Float() {
 
 		err = tx.Reload(c)
 		r.NoError(err)
+		r.Equal(slices.Int{}, c.Int)
 		r.Equal(slices.Float{1.0, 2.1, 3.2}, c.Float)
 	})
 }