fix(arreflect): hasViewableType accepts all view/large-list/view-typed variants; add idempotency regression test

Author: zeroshade

arrow/array/arreflect/reflect_infer.go

@@ -284,7 +284,9 @@ func applyViewOpts(dt arrow.DataType) arrow.DataType {
 
 func hasViewableType(dt arrow.DataType) bool {
 	switch dt.ID() {
-	case arrow.STRING, arrow.BINARY, arrow.LARGE_STRING, arrow.LARGE_BINARY, arrow.LIST:
+	case arrow.STRING, arrow.BINARY, arrow.LARGE_STRING, arrow.LARGE_BINARY,
+		arrow.STRING_VIEW, arrow.BINARY_VIEW,
+		arrow.LIST, arrow.LIST_VIEW, arrow.LARGE_LIST, arrow.LARGE_LIST_VIEW:
 		return true
 	case arrow.STRUCT:
 		st := dt.(*arrow.StructType)

arrow/array/arreflect/reflect_infer_test.go

@@ -851,4 +851,19 @@ func TestHasViewableType(t *testing.T) {
 	t.Run("large_binary is true", func(t *testing.T) {
 		assert.True(t, hasViewableType(arrow.BinaryTypes.LargeBinary))
 	})
+	t.Run("string_view is true", func(t *testing.T) {
+		assert.True(t, hasViewableType(arrow.BinaryTypes.StringView))
+	})
+	t.Run("binary_view is true", func(t *testing.T) {
+		assert.True(t, hasViewableType(arrow.BinaryTypes.BinaryView))
+	})
+	t.Run("list_view is true", func(t *testing.T) {
+		assert.True(t, hasViewableType(arrow.ListViewOf(arrow.PrimitiveTypes.Int64)))
+	})
+	t.Run("large_list is true", func(t *testing.T) {
+		assert.True(t, hasViewableType(arrow.LargeListOf(arrow.PrimitiveTypes.Int64)))
+	})
+	t.Run("large_list_view is true", func(t *testing.T) {
+		assert.True(t, hasViewableType(arrow.LargeListViewOf(arrow.PrimitiveTypes.Int64)))
+	})
 }

arrow/array/arreflect/reflect_public_test.go

@@ -798,4 +798,23 @@ func TestWithViewRoundTrip(t *testing.T) {
 		require.Error(t, err)
 		assert.ErrorIs(t, err, ErrUnsupportedType)
 	})
+
+	t.Run("struct with view-tagged fields via WithView is idempotent", func(t *testing.T) {
+		// Fields already tagged ,view infer to STRING_VIEW; WithView() should still
+		// accept the struct and the top-level applyViewOpts walk is a no-op on views.
+		type Row struct {
+			Name string `arrow:"name,view"`
+			Code int32  `arrow:"code"`
+		}
+		input := []Row{{"click", 1}, {"view", 2}}
+		arr, err := FromSlice(input, mem, WithView())
+		require.NoError(t, err)
+		defer arr.Release()
+		sa := arr.(*array.Struct)
+		assert.Equal(t, arrow.STRING_VIEW, sa.Field(0).DataType().ID())
+
+		got, err := ToSlice[Row](arr)
+		require.NoError(t, err)
+		assert.Equal(t, input, got)
+	})
 }