diff --git a/ast.go b/ast.go
index cfcc6a7..081a9af 100644
--- a/ast.go
+++ b/ast.go
@@ -2,6 +2,7 @@ package toml
 
 import (
 	"fmt"
+	"sort"
 	"strings"
 	"time"
 )
@@ -74,13 +75,18 @@ func (parseItem item) String() string {
 		}
 		return fmt.Sprintf("[%s]", strings.Join(items, ", "))
 	case pTable:
-		items := make([]string, len(parseItem.Data))
 		pairs := parseItem.Data[0].(table)
+		keys := make([]string, len(pairs))
 		i := 0
-		for k, v := range pairs {
-			items[i] = fmt.Sprintf("%q: %s", k, v.String())
+		for k := range pairs {
+			keys[i] = k
 			i++
 		}
+		sort.Strings(keys)
+		items := make([]string, len(pairs))
+		for i, k := range keys {
+			items[i] = fmt.Sprintf("%q: %s", k, pairs[k].String())
+		}
 		return fmt.Sprintf("{%s}", strings.Join(items, ", "))
 	case pComment:
 		return fmt.Sprintf("comment(%q)", parseItem.Data[0])
@@ -154,15 +160,15 @@ func (t *parser) setValue(key item, value item) error {
 	return nil
 }
 
-func (t *parser) newTable(key item) (table, error) {
+func (t *parser) openTable(key item) (table, error) {
 	node := t.Root
 	// Go over all requested levels of the key. For all levels, except the last
 	// one, it is okay if a table already exists. For at least the last level,
 	// no table or value must exist, because that would mean we are overwriting
 	// an existing key/value pair, which is not allowed.
-	for i, e := range key.Data {
-		name := e.(string)
-		if subItem, ok := node[name]; ok {
+	for i, value := range key.Data {
+		keyName := value.(string)
+		if subItem, ok := node[keyName]; ok {
 			// You cannot overwrite an already defined key, regardless its value.
 			if subItem.Type != pTable {
 				path := formatKeyPath(key, i)
@@ -178,7 +184,7 @@ func (t *parser) newTable(key item) (table, error) {
 		} else {
 			// Create the subtable.
 			subTable := make(table)
-			node[name] = newItem(pTable, subTable)
+			node[keyName] = newItem(pTable, subTable)
 			node = subTable
 		}
 	}
diff --git a/ast_test.go b/ast_test.go
index d3405bc..245a0d7 100644
--- a/ast_test.go
+++ b/ast_test.go
@@ -1,72 +1,69 @@
 package toml
 
 import (
-	"fmt"
 	"testing"
 )
 
 func TestAST_ConstructStructure(t *testing.T) {
-	p := newParser()
-	p.Root["ding"] = newItem(pInteger, 10)
-	p.Root["dong"] = newItem(pString, "not a song")
-	subTable1, _ := p.newTable(newItem(pKey, "key1", "key2 a"))
-	subTable1["dooh"] = newItem(pBoolean, true)
-	subTable1["dah"] = newItem(pBoolean, false)
-	subTable2, _ := p.newTable(newItem(pKey, "key1", "key2 b"))
-	subTable2["dieh"] = newItem(pFloat, 1.111)
-	subTable2["duhh"] = newItem(pFloat, 1.18e-12)
+	testAST(t, func() (error, *parser) {
+		p := newParser()
+		p.setValue(newItem(pKey, "ding"), newItem(pInteger, 10))
+		p.setValue(newItem(pKey, "dong"), newItem(pString, "not a song"))
+		p.openTable(newItem(pKey, "key1", "key2 a"))
+		p.setValue(newItem(pKey, "dooh"), newItem(pBoolean, true))
+		p.setValue(newItem(pKey, "dah"), newItem(pBoolean, false))
+		p.openTable(newItem(pKey, "key1", "key2 b"))
+		p.setValue(newItem(pKey, "dieh"), newItem(pFloat, 1.111))
+		p.setValue(newItem(pKey, "duh"), newItem(pFloat, 1.18e-12))
+		return nil, p
+	}, "", `{"ding": 10, "dong": "not a song", "key1": {"key2 a": {"dah": false, "dooh": true}, "key2 b": {"dieh": 1.111, "duh": 1.18e-12}}}`)
 }
 
 func TestAST_StoreValueInRootTable(t *testing.T) {
-	testError(t, func() error {
+	testAST(t, func() (error, *parser) {
 		p := newParser()
 		p.setValue(newItem(pKey, "key1"), newItem(pString, "value1"))
-		return p.setValue(newItem(pKey, "key2"), newItem(pString, "value2"))
-	}, "")
+		return p.setValue(newItem(pKey, "key2"), newItem(pString, "value2")), p
+	}, "", `{"key1": "value1", "key2": "value2"}`)
 }
 
 func TestAST_StoreValueWithMultipartKey_CreatesTableHierarchy(t *testing.T) {
-	testError(t, func() error {
+	testAST(t, func() (error, *parser) {
 		p := newParser()
-		return p.setValue(newItem(pKey, "key1", "key2", "key3"), newItem(pString, "value"))
-	}, "")
-	// TODO an actual test assertion
+		return p.setValue(newItem(pKey, "key1", "key2", "key3"), newItem(pString, "value")), p
+	}, "", `{"key1": {"key2": {"key3": "value"}}}`)
 }
 
 func TestAST_StoreValueWithMultipartKey_UnderSubtable_CreatesTableHierarchy(t *testing.T) {
-	testError(t, func() error {
+	testAST(t, func() (error, *parser) {
 		p := newParser()
-		p.newTable(newItem(pKey, "subkey1", "subkey2"))
-		err := p.setValue(newItem(pKey, "key1", "key2", "key3"), newItem(pString, "value"))
-		fmt.Printf("%s", p.Root)
-		return err
-	}, "")
-	t.Fail()
-	// TODO an actual test assertion
+		p.openTable(newItem(pKey, "tablekey1", "tablekey2"))
+		return p.setValue(newItem(pKey, "valuekey1", "valuekey2", "valuekey3"), newItem(pString, "value")), p
+	}, "", `{"tablekey1": {"tablekey2": {"valuekey1": {"valuekey2": {"valuekey3": "value"}}}}}`)
 }
 
 func TestAST_StoreDuplicateKeyInRootTable_ReturnsError(t *testing.T) {
-	testError(t, func() error {
+	testAST(t, func() (error, *parser) {
 		p := newParser()
 		p.setValue(newItem(pKey, "key"), newItem(pString, "value"))
-		return p.setValue(newItem(pKey, "key"), newItem(pInteger, 321))
-	}, `Cannot store value: string item already exists at key "key"`)
+		return p.setValue(newItem(pKey, "key"), newItem(pInteger, 321)), p
+	}, `Cannot store value: string item already exists at key "key"`, "")
 }
 
 func TestAST_GivenExistingTableAtKey_CreatingTableAtSameKey_ReturnsError(t *testing.T) {
-	testError(t, func() error {
+	testAST(t, func() (error, *parser) {
 		p := newParser()
-		p.newTable(newItem(pKey, "key1", "key2"))
-		_, err := p.newTable(newItem(pKey, "key1", "key2"))
-		return err
-	}, `Cannot create table: table for key "key1"."key2" already exists`)
+		p.openTable(newItem(pKey, "key1", "key2"))
+		_, err := p.openTable(newItem(pKey, "key1", "key2"))
+		return err, p
+	}, `Cannot create table: table for key "key1"."key2" already exists`, "")
 }
 
 func TestAST_GivenExistingItemAtKey_CreatingTableAtSameKey_ReturnsError(t *testing.T) {
-	testError(t, func() error {
+	testAST(t, func() (error, *parser) {
 		p := newParser()
 		p.Root["key"] = newItem(pString, "value")
-		_, err := p.newTable(newItem(pKey, "key"))
-		return err
-	}, `Cannot create table: string item already exists at key "key"`)
+		_, err := p.openTable(newItem(pKey, "key"))
+		return err, p
+	}, `Cannot create table: string item already exists at key "key"`, "")
 }
diff --git a/helpers_test.go b/helpers_test.go
index 9f76c0e..eaa5094 100644
--- a/helpers_test.go
+++ b/helpers_test.go
@@ -54,17 +54,23 @@ func testParseHandler(t *testing.T, p *parser, handler parse.Handler, test parse
 	err = parse.New(handler)(test.input)
 }
 
-func testError(t *testing.T, code func() error, expected string) {
-	err := code()
-	if expected == "" {
+func testAST(t *testing.T, code func() (error, *parser), expectedError string, expectedData string) {
+	err, p := code()
+	if expectedError == "" {
 		if err != nil {
 			t.Fatalf("Unexpected error: %s", err)
 		}
 	} else {
 		if err == nil {
 			t.Fatalf("An error was expected, but no error was returned")
-		} else if err.Error() != expected {
-			t.Fatalf("Unexpected error:\nexpected: %s\nactual: %s\n", expected, err.Error())
+		} else if err.Error() != expectedError {
+			t.Fatalf("Unexpected error:\nexpected: %s\nactual: %s\n", expectedError, err.Error())
 		}
 	}
+	if expectedData == "" {
+		return
+	}
+	if expectedData != p.Root.String() {
+		t.Fatalf("Unexpected data after parsing:\nexpected: %s\nactual: %s\n", expectedData, p.Root.String())
+	}
 }
diff --git a/value_table.go b/value_table.go
index b66800f..4e17265 100644
--- a/value_table.go
+++ b/value_table.go
@@ -107,5 +107,5 @@ func (t *parser) startPlainTable(p *parse.API) {
 	}
 	key := t.Items[0]
 	t.Items = t.Items[1:]
-	t.newTable(key)
+	t.openTable(key)
 }