Add test for data reset

Author: Richard Artoul

go/arrow/array/data_test.go

@@ -0,0 +1,35 @@
+package array
+
+import (
+	"testing"
+
+	"github.com/apache/arrow/go/arrow"
+	"github.com/apache/arrow/go/arrow/memory"
+	"github.com/stretchr/testify/assert"
+)
+
+func TestDataReset(t *testing.T) {
+	var (
+		buffers1 = make([]*memory.Buffer, 0, 3)
+		buffers2 = make([]*memory.Buffer, 0, 3)
+	)
+	for i := 0; i < cap(buffers1); i++ {
+		buffers1 = append(buffers1, memory.NewBufferBytes([]byte("some-bytes1")))
+		buffers2 = append(buffers2, memory.NewBufferBytes([]byte("some-bytes2")))
+	}
+
+	data := NewData(&arrow.StringType{}, 10, buffers1, nil, 0, 0)
+	data.Reset(&arrow.Int64Type{}, 5, buffers2, nil, 1, 2)
+
+	for i := 0; i < 2; i++ {
+		assert.Equal(t, buffers2, data.Buffers())
+		assert.Equal(t, &arrow.Int64Type{}, data.DataType())
+		assert.Equal(t, 1, data.NullN())
+		assert.Equal(t, 2, data.Offset())
+		assert.Equal(t, 5, data.Len())
+
+		// Make sure it works when resetting the data with its own buffers (new buffers are retained
+		// before old ones are released.)
+		data.Reset(&arrow.Int64Type{}, 5, data.Buffers(), nil, 1, 2)
+	}
+}