Refactor Write (#8)

* fix: reorderColumns execute position

* feat: add Test_writeToChan_emptyptr_sortOrder

* fix: checkSortOrderSlice exec position

* fix: reorderColumns func

* fix: remove unnecessary func

* feat: error handling

decode.go

@@ -141,7 +141,10 @@ func setInnerField(outInner *reflect.Value, outInnerWasPointer bool, index []int
 	if outInnerWasPointer {
 		// initialize nil pointer
 		if oi.IsNil() {
-			setField(oi, "", omitEmpty)
+			err := setField(oi, "", omitEmpty)
+			if err != nil {
+				return err
+			}
 		}
 		oi = outInner.Elem()
 	}

encode.go

@@ -75,15 +75,3 @@ func getInnerField(outInner reflect.Value, outInnerWasPointer bool, index []int)
 	}
 	return getFieldAsString(oi.FieldByIndex(index))
 }
-
-func getPickedFields(fields []fieldInfo, columnFieldsIndexes []int) []fieldInfo {
-	var newFields []fieldInfo
-	if len(columnFieldsIndexes) > 0 {
-		for _, columnFieldsIndex := range columnFieldsIndexes {
-			newFields = append(newFields, fields[columnFieldsIndex])
-		}
-	} else {
-		newFields = fields
-	}
-	return newFields
-}

encode_test.go

@@ -658,7 +658,7 @@ func Test_writeTo_emptyptr_sortOrder(t *testing.T) {
 	}
 
 	xsvWrite := NewXsvWrite[EmbedPtrSample]()
-	xsvWrite.SortOrder = []int{1, 0, 2, 3, 4, 5, 6, 7, 8, 9}
+	xsvWrite.SortOrder = []int{1, 0, 2, 3, 4, 5, 6, 7, 9, 8}
 	if err := xsvWrite.SetWriter(csv.NewWriter(e.out)).Write(s); err != nil {
 		t.Fatal(err)
 	}
@@ -670,6 +670,41 @@ func Test_writeTo_emptyptr_sortOrder(t *testing.T) {
 	if len(lines) != 2 {
 		t.Fatalf("expected 2 lines, got %d", len(lines))
 	}
-	assertLine(t, []string{"foo", "first", "BAR", "Baz", "Quux", "Blah", "SPtr", "Omit", "garply", "last"}, lines[0])
-	assertLine(t, []string{"f", "aaa", "1", "baz", "0.2", "2", "*string", "", "3.141592653589793", "zzz"}, lines[1])
+	assertLine(t, []string{"foo", "first", "BAR", "Baz", "Quux", "Blah", "SPtr", "Omit", "last", "garply"}, lines[0])
+	assertLine(t, []string{"f", "aaa", "1", "baz", "0.2", "2", "*string", "", "zzz", "3.141592653589793"}, lines[1])
+}
+
+func Test_writeToChan_emptyptr_sortOrder(t *testing.T) {
+	b := bytes.Buffer{}
+	e := &encoder{out: &b}
+	sampleChan := make(chan Sample)
+	sptr := "*string"
+	go func() {
+		for i := 0; i < 100; i++ {
+			v := Sample{Foo: "f", Bar: i, Baz: "baz" + strconv.Itoa(i), Frop: float64(i), Blah: nil, SPtr: &sptr}
+			sampleChan <- v
+		}
+		close(sampleChan)
+	}()
+
+	xsvWrite := NewXsvWrite[Sample]()
+	xsvWrite.SortOrder = []int{1, 0, 2, 3, 4, 5, 6}
+	err := xsvWrite.SetWriter(csv.NewWriter(e.out)).WriteFromChan(sampleChan)
+	if err != nil {
+		t.Fatal(err)
+	}
+	lines, err := csv.NewReader(&b).ReadAll()
+	if err != nil {
+		t.Fatal(err)
+	}
+	if len(lines) != 101 {
+		t.Fatalf("expected 100 lines, got %d", len(lines))
+	}
+	for i, l := range lines {
+		if i == 0 {
+			assertLine(t, []string{"BAR", "foo", "Baz", "Quux", "Blah", "SPtr", "Omit"}, l)
+			continue
+		}
+		assertLine(t, []string{strconv.Itoa(i - 1), "f", "baz" + strconv.Itoa(i-1), strconv.FormatFloat(float64(i-1), 'f', -1, 64), "", "*string", ""}, l)
+	}
 }

xsv_writer.go

@@ -34,16 +34,16 @@ func (xw *XsvWriter[T]) Write(data []T) error {
 
 	fieldInfos := getFieldInfos(inInnerType, []int{}, []string{}, xw.TagName, xw.TagSeparator, xw.nameNormalizer) // Get the inner struct info to get CSV annotations
 	fieldInfos = xw.getSelectedFieldInfos(fieldInfos)
+	if err := xw.checkSortOrderSlice(len(fieldInfos)); err != nil {
+		return err
+	}
+	fieldInfos = reorderColumns[fieldInfo](fieldInfos, xw.SortOrder)
 	inInnerStructInfo := &structInfo{fieldInfos}
 
 	csvHeadersLabels := make([]string, len(inInnerStructInfo.Fields))
 	for i, fieldInfo := range inInnerStructInfo.Fields { // Used to write the header (first line) in CSV
 		csvHeadersLabels[i] = fieldInfo.getFirstKey()
 	}
-	if err := xw.checkSortOrderSlice(len(fieldInfos)); err != nil {
-		return err
-	}
-	csvHeadersLabels = reorderColumns(csvHeadersLabels, xw.SortOrder)
 	if !xw.OmitHeaders {
 		if err := xw.writer.Write(csvHeadersLabels); err != nil {
 			return err
@@ -59,7 +59,6 @@ func (xw *XsvWriter[T]) Write(data []T) error {
 			}
 			csvHeadersLabels[j] = inInnerFieldValue
 		}
-		csvHeadersLabels = reorderColumns(csvHeadersLabels, xw.SortOrder)
 		if err := xw.writer.Write(csvHeadersLabels); err != nil {
 			return err
 		}
@@ -81,16 +80,16 @@ func (xw *XsvWriter[T]) WriteFromChan(dataChan chan T) error {
 	inInnerWasPointer := inType.Kind() == reflect.Ptr
 	fieldInfos := getFieldInfos(inType, []int{}, []string{}, xw.TagName, xw.TagSeparator, xw.nameNormalizer) // Get the inner struct info to get CSV annotations
 	fieldInfos = xw.getSelectedFieldInfos(fieldInfos)
+	if err := xw.checkSortOrderSlice(len(fieldInfos)); err != nil {
+		return err
+	}
+	fieldInfos = reorderColumns[fieldInfo](fieldInfos, xw.SortOrder)
 	inInnerStructInfo := &structInfo{fieldInfos}
 	csvHeadersLabels := make([]string, len(inInnerStructInfo.Fields))
 	for i, fieldInfo := range inInnerStructInfo.Fields { // Used to Write the header (first line) in CSV
 		csvHeadersLabels[i] = fieldInfo.getFirstKey()
 	}
 
-	if err := xw.checkSortOrderSlice(len(fieldInfos)); err != nil {
-		return err
-	}
-	csvHeadersLabels = reorderColumns(csvHeadersLabels, xw.SortOrder)
 	if !xw.OmitHeaders {
 		if err := xw.writer.Write(csvHeadersLabels); err != nil {
 			return err
@@ -104,7 +103,6 @@ func (xw *XsvWriter[T]) WriteFromChan(dataChan chan T) error {
 				return err
 			}
 			csvHeadersLabels[j] = inInnerFieldValue
-			csvHeadersLabels = reorderColumns(csvHeadersLabels, xw.SortOrder)
 		}
 		if err := xw.writer.Write(csvHeadersLabels); err != nil {
 			return err
@@ -127,9 +125,9 @@ func (xw *XsvWriter[T]) WriteFromChan(dataChan chan T) error {
 	return xw.writer.Error()
 }
 
-func reorderColumns(row []string, sortOrder []int) []string {
-	if len(sortOrder) > 0 {
-		newLine := make([]string, len(row))
+func reorderColumns[T any](row []T, sortOrder []int) []T {
+	if len(sortOrder) > 1 {
+		newLine := make([]T, len(row))
 		for from, to := range sortOrder {
 			newLine[to] = row[from]
 		}