Refactor RecordConfig: Add getters/setters (#314)

* Replace RecordConfig.Name and .NameFQDN with getters and setters.
* Replace RecordConfig.Target with getters and setters.
* Eliminate the CombinedTarget concept.
* Add RecordConfig.PopulateFromString to reduce code in all providers.
* encode and decode name.com txt records (#315)
* Replace fmt.Errorf with errors.Errorf

providers/namedotcom/records_test.go

@@ -0,0 +1,51 @@
+package namedotcom
+
+import (
+	"strings"
+	"testing"
+)
+
+var txtData = []struct {
+	decoded []string
+	encoded string
+}{
+	{[]string{`simple`}, `simple`},
+	{[]string{`changed`}, `changed`},
+	{[]string{`with spaces`}, `with spaces`},
+	{[]string{`with whitespace`}, `with whitespace`},
+	{[]string{"one", "two"}, `"one""two"`},
+	{[]string{"eh", "bee", "cee"}, `"eh""bee""cee"`},
+	{[]string{"o\"ne", "tw\"o"}, `"o\"ne""tw\"o"`},
+	{[]string{"dimple"}, `dimple`},
+	{[]string{"fun", "two"}, `"fun""two"`},
+	{[]string{"eh", "bzz", "cee"}, `"eh""bzz""cee"`},
+}
+
+func TestEncodeTxt(t *testing.T) {
+	// Test encoded the lists of strings into a string:
+	for i, test := range txtData {
+		enc := encodeTxt(test.decoded)
+		if enc != test.encoded {
+			t.Errorf("%v: txt\n    data: []string{%v}\nexpected: %s\n     got: %s",
+				i, "`"+strings.Join(test.decoded, "`, `")+"`", test.encoded, enc)
+		}
+	}
+}
+
+func TestDecodeTxt(t *testing.T) {
+	// Test decoded a string into the list of strings:
+	for i, test := range txtData {
+		data := test.encoded
+		got := decodeTxt(data)
+		wanted := test.decoded
+		if len(got) != len(wanted) {
+			t.Errorf("%v: txt\n  decode: %v\nexpected: `%v`\n     got: `%v`\n", i, data, strings.Join(wanted, "`, `"), strings.Join(got, "`, `"))
+		} else {
+			for j := range got {
+				if got[j] != wanted[j] {
+					t.Errorf("%v: txt\n  decode: %v\nexpected: `%v`\n     got: `%v`\n", i, data, strings.Join(wanted, "`, `"), strings.Join(got, "`, `"))
+				}
+			}
+		}
+	}
+}