add NewDataSetType

go-msg/dataset.go

@@ -16,8 +16,9 @@ func (e errInvalidDataSetType) Error() string {
 
 // Various errors
 var (
-	ErrNilDataSet   = fmt.Errorf("dataset was nil")
-	ErrInvalidField = fmt.Errorf("dataset type does not exist in dataset definition")
+	ErrNilDataSet         = fmt.Errorf("dataset was nil")
+	ErrInvalidField       = fmt.Errorf("dataset type does not exist in dataset definition")
+	ErrInvalidDataSetType = fmt.Errorf("invalid dataset type")
 )
 
 // FieldByType returns one of the field values of a DataSet based on a
@@ -53,3 +54,17 @@ func (m *DataSet) FieldByType(dsType DataSetType) (interface{}, error) {
 	// (case-insensitive) field name
 	return nil, ErrInvalidField
 }
+
+// NewDataSetType returns the cooresponding DataSetType given a string. It is
+// case insensitive.
+func NewDataSetType(name string) (DataSetType, error) {
+	name = strings.ToLower(name)
+
+	for dst, dstName := range DataSetType_name {
+		if name == strings.ToLower(dstName) {
+			return DataSetType(dst), nil
+		}
+	}
+
+	return DataSetType(-1), ErrInvalidDataSetType
+}

go-msg/dataset_test.go

@@ -2,6 +2,7 @@ package msg
 
 import (
 	"fmt"
+	"strings"
 	"testing"
 )
 
@@ -133,3 +134,35 @@ func ExampleDataSet_FieldByType() {
 	fmt.Printf("c == ds.Categorization => %v\n", c == ds.Categorization)
 	// Output: c == ds.Categorization => true
 }
+
+func testDataSetType(t *testing.T, dstValue int32, dstName string) {
+	dst, err := NewDataSetType(strings.ToLower(dstName))
+	if err != nil {
+		t.Error("unexpected error")
+	}
+
+	if DataSetType(dstValue) != dst {
+		t.Error("unexpected dataset type value")
+	}
+}
+
+func TestNewDataSetType(t *testing.T) {
+	for dstValue, dstName := range DataSetType_name {
+		testDataSetType(t, dstValue, dstName)
+		testDataSetType(t, dstValue, strings.ToLower(dstName))
+		testDataSetType(t, dstValue, strings.ToUpper(dstName))
+	}
+
+	dst, err := NewDataSetType("invalid dataset type name")
+	if err == nil {
+		t.Error("NewDataSetType should have returned an error")
+	}
+
+	if err != ErrInvalidDataSetType {
+		t.Error("NewDataSetType returned the wrong error")
+	}
+
+	if dst != DataSetType(-1) {
+		t.Error("NewDataSetType returned wrong response")
+	}
+}