diff --git a/hatmill_test.go b/hatmill_test.go
index 4a0b82e..be5098f 100644
--- a/hatmill_test.go
+++ b/hatmill_test.go
@@ -2,11 +2,16 @@ package hatmill_test
 
 import (
 	"bytes"
+	"fmt"
+	"io"
+    "reflect"
+    "strings"
+	"testing"
+
 	"github.com/leanovate/gopter"
 	"github.com/leanovate/gopter/gen"
 	"github.com/leanovate/gopter/prop"
 	"gitlab.codemonkeysoftware.com/b/hatmill"
-	"testing"
 )
 
 type NopWriter struct{}
@@ -15,33 +20,156 @@ func (NopWriter) Write(p []byte) (n int, err error) {
 	return len(p), nil
 }
 
+func writeToString(wt io.WriterTo) string {
+	var buf bytes.Buffer
+	_, err := wt.WriteTo(&buf)
+	if err != nil {
+		panic(err)
+	}
+	return buf.String()
+}
+
+func checkWrite(wt io.WriterTo, expected string) bool {
+	var buf bytes.Buffer
+	n, err := wt.WriteTo(&buf)
+	return err == nil && n == int64(buf.Len()) && buf.String() == expected
+}
+
 func TestText(t *testing.T) {
 	properties := gopter.NewProperties(nil)
 
-	properties.Property("writing to string is identity", prop.ForAll(
+	properties.Property("WriteTo is correct", prop.ForAll(
 		func(s string) bool {
-			var buf bytes.Buffer
-			hatmill.Text(s).WriteTo(&buf)
-			return buf.String() == s
-		},
-		gen.AnyString(),
-	))
-
-	properties.Property("WriteTo returns correct n", prop.ForAll(
-		func(s string) bool {
-			n, _ := hatmill.Text(s).WriteTo(NopWriter{})
-			return n == int64(len(s))
-		},
-		gen.AnyString(),
-	))
-
-	properties.Property("WriteTo does not generate error", prop.ForAll(
-		func(s string) bool {
-			_, err := hatmill.Text(s).WriteTo(NopWriter{})
-			return err == nil
+			return checkWrite(hatmill.Text(s), s)
 		},
 		gen.AnyString(),
 	))
 
 	properties.TestingRun(t)
 }
+
+var nonEmptyAlphaString = gen.AlphaString().SuchThat(func(v interface{}) bool {
+	return v.(string) != ""
+})
+
+var attribGen = gen.Struct(reflect.TypeOf(hatmill.Attrib{}), map[string]gopter.Gen{
+    "Key": nonEmptyAlphaString,
+    "Value": gen.AlphaString(),
+})
+
+func TestAttrib(t *testing.T) {
+	properties := gopter.NewProperties(nil)
+
+	properties.Property("WriteTo only writes key when value is empty", prop.ForAll(
+		func(key string) bool {
+			attrib := hatmill.Attrib{
+				Key: key,
+			}
+			return checkWrite(attrib, key)
+		},
+		nonEmptyAlphaString,
+	))
+
+	properties.Property("writes key=value when value is not empty", prop.ForAll(
+		func(attrib hatmill.Attrib) bool {
+			expected := fmt.Sprintf("%s='%s'", attrib.Key, attrib.Value)
+			return checkWrite(attrib, expected)
+		},
+        attribGen.SuchThat(func(attrib interface{}) bool {
+            return attrib.(hatmill.Attrib).Value != ""
+        }),
+	))
+
+	properties.TestingRun(t)
+}
+
+func TestEmptyElement(t *testing.T) {
+	properties := gopter.NewProperties(nil)
+
+	properties.Property("WriteTo writes element correctly with no attributes", prop.ForAll(
+		func(tagName string) bool {
+			elem := &hatmill.EmptyElement{
+				TagName: tagName,
+			}
+			expected := "<" + tagName + ">"
+			return checkWrite(elem, expected)
+		},
+		gen.AnyString(),
+	))
+
+	properties.Property("WriteTo writes element correctly with attributes", prop.ForAll(
+        func(tagName string, attribs []hatmill.Attrib) bool {
+            elem := hatmill.EmptyElement{
+                TagName: tagName,
+                Attribs: attribs,
+            }
+
+            var attribStrings []string
+            for _, attrib := range attribs {
+                attribStrings = append(attribStrings, writeToString(attrib))
+            }
+            if len(attribStrings) > 0 {
+                attribStrings[0] = " " + attribStrings[0]
+            }
+
+            expected := "<" + tagName + strings.Join(attribStrings, " ") + ">"
+            return checkWrite(elem, expected)
+        },
+        gen.AnyString(),
+        gen.SliceOf(attribGen),
+    ))
+
+    properties.TestingRun(t)
+}
+
+var htmlTextGen = gen.AnyString().Map(func(s string) hatmill.Html {
+    return hatmill.Text(s)
+})
+
+func TestParentElement(t *testing.T) {
+    properties := gopter.NewProperties(nil)
+
+    properties.Property("WriteTo writes element correctly without children", prop.ForAll(
+        func(tagName string, attribs []hatmill.Attrib) bool {
+            elem := &hatmill.ParentElement {
+                EmptyElement: hatmill.EmptyElement{
+                    TagName: tagName,
+                    Attribs: attribs,
+                },
+            }
+
+            openTag := writeToString(elem.EmptyElement)
+            expected := openTag + "</" + tagName + ">"
+            return checkWrite(elem, expected)
+        },
+        gen.AnyString(),
+        gen.SliceOf(attribGen),
+    ))
+
+    properties.Property("WriteTo writes element correctly with children", prop.ForAll(
+        func(tagName string, attribs []hatmill.Attrib, children []hatmill.Html) bool {
+            elem := &hatmill.ParentElement {
+                EmptyElement: hatmill.EmptyElement{
+                    TagName: tagName,
+                    Attribs: attribs,
+                },
+                Children: children,
+            }
+
+            openTag := writeToString(elem.EmptyElement)
+
+            var childStrings []string
+            for _, child := range children {
+                childStrings = append(childStrings, writeToString(child))
+            }
+
+            expected := openTag + strings.Join(childStrings, "") + "</" + tagName + ">"
+            return checkWrite(elem, expected)
+        },
+        gen.AnyString(),
+        gen.SliceOf(attribGen),
+        gen.SliceOf(htmlTextGen),
+    ))
+
+    properties.TestingRun(t)
+}