Some improvements

cached_reader.go

@@ -5,45 +5,48 @@ import (
 )
 
 type cachedReader struct {
-	buffer *bufio.Reader
-	cache []byte
-	cacheCap int
-	cacheLen int
+	buffer  *bufio.Reader
+	cache   []byte
 	caching bool
 }
 
 func newCachedReader(r *bufio.Reader) *cachedReader {
 	return &cachedReader{
-		buffer:   r,
-		cache:    make([]byte, 4096),
-		cacheCap: 4096,
-		cacheLen: 0,
-		caching:  false,
+		buffer:  r,
+		cache:   make([]byte, 0, 4096),
+		caching: false,
 	}
 }
 
 func (c *cachedReader) StartCaching() {
-	c.cacheLen = 0
+	c.cache = c.cache[:0]
 	c.caching = true
 }
 
-func (c *cachedReader) ReadByte() (byte, error) {
-	if !c.caching {
-		return c.buffer.ReadByte()
-	}
-	b, err := c.buffer.ReadByte()
+func (c *cachedReader) ReadByte() (b byte, err error) {
+	b, err = c.buffer.ReadByte()
 	if err != nil {
-		return b, err
+		return
 	}
-	if c.cacheLen < c.cacheCap {
-		c.cache[c.cacheLen] = b
-		c.cacheLen++
+	if c.caching {
+		c.cacheByte(b)
 	}
-	return b, err
+	return
 }
 
 func (c *cachedReader) Cache() []byte {
-	return c.cache[:c.cacheLen]
+	return c.cache
+}
+
+func (c *cachedReader) CacheWithLimit(n int) []byte {
+	if n < 1 {
+		return nil
+	}
+	l := len(c.cache)
+	if n > l {
+		n = l
+	}
+	return c.cache[:n]
 }
 
 func (c *cachedReader) StopCaching() {
@@ -55,15 +58,22 @@ func (c *cachedReader) Read(p []byte) (int, error) {
 	if err != nil {
 		return n, err
 	}
-	if c.caching && c.cacheLen < c.cacheCap {
+	if c.caching {
 		for i := 0; i < n; i++ {
-			c.cache[c.cacheLen] = p[i]
-			c.cacheLen++
-			if c.cacheLen >= c.cacheCap {
+			if !c.cacheByte(p[i]) {
 				break
 			}
 		}
 	}
 	return n, err
 }
 
+func (c *cachedReader) cacheByte(b byte) bool {
+	n := len(c.cache)
+	if n == cap(c.cache) {
+		return false
+	}
+	c.cache = c.cache[:n+1]
+	c.cache[n] = b
+	return true
+}

cached_reader_test.go

@@ -39,4 +39,19 @@ func TestCaching(t *testing.T) {
 	if !bytes.Equal(cached, []byte("BCDEF")) {
 		t.Fatalf("Incorrect cached buffer value")
 	}
+
+	cached = cachedReader.CacheWithLimit(-1)
+	if cached != nil {
+		t.Fatalf("Incorrect cached buffer value")
+	}
+
+	cached = cachedReader.CacheWithLimit(3)
+	if !bytes.Equal(cached, []byte("BCD")) {
+		t.Fatalf("Incorrect cached buffer value")
+	}
+
+	cached = cachedReader.CacheWithLimit(1000)
+	if !bytes.Equal(cached, []byte("BCDEF")) {
+		t.Fatalf("Incorrect cached buffer value")
+	}
 }

node.go

@@ -92,6 +92,13 @@ func WithPreserveSpace() OutputOption {
 	}
 }
 
+// WithoutPreserveSpace will not preserve spaces in output
+func WithoutPreserveSpace() OutputOption {
+	return func(oc *outputConfiguration) {
+		oc.preserveSpaces = false
+	}
+}
+
 // WithIndentation sets the indentation string used for formatting the output.
 func WithIndentation(indentation string) OutputOption {
 	return func(oc *outputConfiguration) {
@@ -328,7 +335,9 @@ func (n *Node) Write(writer io.Writer, self bool) error {
 
 // WriteWithOptions writes xml with given options to given writer.
 func (n *Node) WriteWithOptions(writer io.Writer, opts ...OutputOption) (err error) {
-	config := &outputConfiguration{}
+	config := &outputConfiguration{
+		preserveSpaces: true,
+	}
 	// Set the options
 	for _, opt := range opts {
 		opt(config)
@@ -400,11 +409,7 @@ func AddChild(parent, n *Node) {
 	parent.LastChild = n
 }
 
-// AddSibling adds a new node 'n' as a sibling of a given node 'sibling'.
-// Note it is not necessarily true that the new node 'n' would be added
-// immediately after 'sibling'. If 'sibling' isn't the last child of its
-// parent, then the new node 'n' will be added at the end of the sibling
-// chain of their parent.
+// AddSibling adds a new node 'n' as a last node of sibling chain for a given node 'sibling'.
 func AddSibling(sibling, n *Node) {
 	for t := sibling.NextSibling; t != nil; t = t.NextSibling {
 		sibling = t
@@ -418,6 +423,19 @@ func AddSibling(sibling, n *Node) {
 	}
 }
 
+// AddImmediateSibling adds a new node 'n' as immediate sibling a given node 'sibling'.
+func AddImmediateSibling(sibling, n *Node) {
+	n.Parent = sibling.Parent
+	n.NextSibling = sibling.NextSibling
+	sibling.NextSibling = n
+	n.PrevSibling = sibling
+	if n.NextSibling != nil {
+		n.NextSibling.PrevSibling = n
+	} else if n.Parent != nil {
+		sibling.Parent.LastChild = n
+	}
+}
+
 // RemoveFromTree removes a node and its subtree from the document
 // tree it is in. If the node is the root of the tree, then it's no-op.
 func RemoveFromTree(n *Node) {
@@ -445,3 +463,15 @@ func RemoveFromTree(n *Node) {
 	n.PrevSibling = nil
 	n.NextSibling = nil
 }
+
+// GetRoot returns a root of the tree where 'n' is a node.
+func GetRoot(n *Node) *Node {
+	if n == nil {
+		return nil
+	}
+	root := n
+	for root.Parent != nil {
+		root = root.Parent
+	}
+	return root
+}

node_test.go

@@ -250,7 +250,7 @@ func TestRemoveFromTree(t *testing.T) {
 		testTrue(t, n != nil)
 		RemoveFromTree(n)
 		verifyNodePointers(t, doc)
-		testValue(t, doc.OutputXML(false),
+		testValue(t, doc.OutputXMLWithOptions(WithoutPreserveSpace()),
 			`<?procinst?><!--comment--><aaa><bbb></bbb><ddd></ddd><ggg></ggg></aaa>`)
 	})
 
@@ -260,7 +260,7 @@ func TestRemoveFromTree(t *testing.T) {
 		testTrue(t, n != nil)
 		RemoveFromTree(n)
 		verifyNodePointers(t, doc)
-		testValue(t, doc.OutputXML(false),
+		testValue(t, doc.OutputXMLWithOptions(WithoutPreserveSpace()),
 			`<?procinst?><!--comment--><aaa><ddd><eee><fff></fff></eee></ddd><ggg></ggg></aaa>`)
 	})
 
@@ -270,7 +270,7 @@ func TestRemoveFromTree(t *testing.T) {
 		testTrue(t, n != nil)
 		RemoveFromTree(n)
 		verifyNodePointers(t, doc)
-		testValue(t, doc.OutputXML(false),
+		testValue(t, doc.OutputXMLWithOptions(WithoutPreserveSpace()),
 			`<?procinst?><!--comment--><aaa><bbb></bbb><ggg></ggg></aaa>`)
 	})
 
@@ -280,7 +280,7 @@ func TestRemoveFromTree(t *testing.T) {
 		testTrue(t, n != nil)
 		RemoveFromTree(n)
 		verifyNodePointers(t, doc)
-		testValue(t, doc.OutputXML(false),
+		testValue(t, doc.OutputXMLWithOptions(WithoutPreserveSpace()),
 			`<?procinst?><!--comment--><aaa><bbb></bbb><ddd><eee><fff></fff></eee></ddd></aaa>`)
 	})
 
@@ -290,7 +290,7 @@ func TestRemoveFromTree(t *testing.T) {
 		testValue(t, procInst.Type, DeclarationNode)
 		RemoveFromTree(procInst)
 		verifyNodePointers(t, doc)
-		testValue(t, doc.OutputXML(false),
+		testValue(t, doc.OutputXMLWithOptions(WithoutPreserveSpace()),
 			`<!--comment--><aaa><bbb></bbb><ddd><eee><fff></fff></eee></ddd><ggg></ggg></aaa>`)
 	})
 
@@ -300,19 +300,44 @@ func TestRemoveFromTree(t *testing.T) {
 		testValue(t, commentNode.Type, CommentNode)
 		RemoveFromTree(commentNode)
 		verifyNodePointers(t, doc)
-		testValue(t, doc.OutputXML(false),
+		testValue(t, doc.OutputXMLWithOptions(WithoutPreserveSpace()),
 			`<?procinst?><aaa><bbb></bbb><ddd><eee><fff></fff></eee></ddd><ggg></ggg></aaa>`)
 	})
 
 	t.Run("remove call on root does nothing", func(t *testing.T) {
 		doc := parseXML()
 		RemoveFromTree(doc)
 		verifyNodePointers(t, doc)
-		testValue(t, doc.OutputXML(false),
+		testValue(t, doc.OutputXMLWithOptions(WithoutPreserveSpace()),
 			`<?procinst?><!--comment--><aaa><bbb></bbb><ddd><eee><fff></fff></eee></ddd><ggg></ggg></aaa>`)
 	})
 }
 
+func TestAddImmediateSibling(t *testing.T) {
+	s := `<?xml version="1.0" encoding="UTF-8"?>
+    <AAA>
+        <BBB id="1"/>
+        <CCC id="2">
+            <DDD/>
+        </CCC>
+		<CCC id="3">
+            <DDD/>
+        </CCC>
+     </AAA>`
+	root, err := Parse(strings.NewReader(s))
+	if err != nil {
+		t.Error(err)
+	}
+
+	aaa := findNode(root, "AAA")
+	n := aaa.SelectElement("BBB")
+	if n == nil {
+		t.Fatalf("n is nil")
+	}
+	AddImmediateSibling(n, &Node{Type: ElementNode, Data: "r"})
+	testValue(t, root.OutputXMLWithOptions(WithoutPreserveSpace()), `<?xml version="1.0" encoding="UTF-8"?><AAA><BBB id="1"></BBB><r></r><CCC id="2"><DDD></DDD></CCC><CCC id="3"><DDD></DDD></CCC></AAA>`)
+}
+
 func TestSelectElement(t *testing.T) {
 	s := `<?xml version="1.0" encoding="UTF-8"?>
     <AAA>
@@ -497,7 +522,6 @@ func TestWriteWithNamespacePrefix(t *testing.T) {
 	}
 }
 
-
 func TestQueryWithPrefix(t *testing.T) {
 	s := `<?xml version="1.0" encoding="UTF-8"?><S:Envelope xmlns:S="http://schemas.xmlsoap.org/soap/envelope/"><S:Body test="1"><ns2:Fault xmlns:ns2="http://schemas.xmlsoap.org/soap/envelope/" xmlns:ns3="http://www.w3.org/2003/05/soap-envelope"><faultcode>ns2:Client</faultcode><faultstring>This is a client fault</faultstring></ns2:Fault></S:Body></S:Envelope>`
 	doc, _ := Parse(strings.NewReader(s))
@@ -582,7 +606,7 @@ func TestOutputXMLWithSpaceDirect(t *testing.T) {
 		t.Errorf(`expected "%s", obtained "%s"`, expected, g)
 	}
 
-	output := html.UnescapeString(doc.OutputXML(true))
+	output := html.UnescapeString(doc.OutputXMLWithOptions(WithOutputSelf(), WithoutPreserveSpace()))
 	if strings.Contains(output, "\n") {
 		t.Errorf("the outputted xml contains newlines")
 	}
@@ -606,7 +630,7 @@ func TestOutputXMLWithSpaceOverwrittenToPreserve(t *testing.T) {
 		t.Errorf(`expected "%s", obtained "%s"`, expected, g)
 	}
 
-	output := html.UnescapeString(doc.OutputXML(true))
+	output := html.UnescapeString(doc.OutputXMLWithOptions(WithOutputSelf(), WithoutPreserveSpace()))
 	if strings.Contains(output, "\n") {
 		t.Errorf("the outputted xml contains newlines")
 	}
@@ -680,8 +704,8 @@ func TestOutputXMLWithPreserveSpaceOption(t *testing.T) {
 		</student>
 	</class_list>`
 	doc, _ := Parse(strings.NewReader(s))
-	resultWithSpace := doc.OutputXMLWithOptions(WithPreserveSpace())
-	resultWithoutSpace := doc.OutputXMLWithOptions()
+	resultWithSpace := doc.OutputXMLWithOptions()
+	resultWithoutSpace := doc.OutputXMLWithOptions(WithoutPreserveSpace())
 	if !strings.Contains(resultWithSpace, "> Robert <") {
 		t.Errorf("output was not expected. expected %v but got %v", " Robert ", resultWithSpace)
 	}

parse.go

@@ -2,6 +2,7 @@ package xmlquery
 
 import (
 	"bufio"
+	"bytes"
 	"encoding/xml"
 	"fmt"
 	"io"
@@ -39,15 +40,31 @@ func Parse(r io.Reader) (*Node, error) {
 func ParseWithOptions(r io.Reader, options ParserOptions) (*Node, error) {
 	p := createParser(r)
 	options.apply(p)
-	for {
-		_, err := p.parse()
-		if err == io.EOF {
-			return p.doc, nil
+	var err error
+	for err == nil {
+		_, err = p.parse()
+	}
+
+	if err == io.EOF {
+		// additional check for validity
+		// according to: https://www.w3.org/TR/xml
+		// the document MUST contain at least ONE element
+		valid := false
+		for doc := p.doc; doc != nil; doc = doc.NextSibling {
+			for node := doc.FirstChild; node != nil; node = node.NextSibling {
+				if node.Type == ElementNode {
+					valid = true
+					break
+				}
+			}
 		}
-		if err != nil {
-			return nil, err
+		if !valid {
+			return nil, fmt.Errorf("xmlquery: invalid XML document")
 		}
+		return p.doc, nil
 	}
+
+	return nil, err
 }
 
 type parser struct {
@@ -168,7 +185,7 @@ func (p *parser) parse() (*Node, error) {
 
 			if node.NamespaceURI != "" {
 				if v, ok := p.space2prefix[node.NamespaceURI]; ok {
-					cached := string(p.reader.Cache())
+					cached := string(p.reader.CacheWithLimit(len(v.name) + len(node.Data) + 2))
 					if strings.HasPrefix(cached, fmt.Sprintf("%s:%s", v.name, node.Data)) || strings.HasPrefix(cached, fmt.Sprintf("<%s:%s", v.name, node.Data)) {
 						node.Prefix = v.name
 					}
@@ -228,12 +245,11 @@ func (p *parser) parse() (*Node, error) {
 			}
 		case xml.CharData:
 			// First, normalize the cache...
-			cached := strings.ToUpper(string(p.reader.Cache()))
+			cached := bytes.ToUpper(p.reader.CacheWithLimit(9))
 			nodeType := TextNode
-			if strings.HasPrefix(cached, "<![CDATA[") || strings.HasPrefix(cached, "![CDATA[") {
+			if bytes.HasPrefix(cached, []byte("<![CDATA[")) || bytes.HasPrefix(cached, []byte("![CDATA[")) {
 				nodeType = CharDataNode
 			}
-
 			node := &Node{Type: nodeType, Data: string(tok), level: p.level}
 			if p.level == p.prev.level {
 				AddSibling(p.prev, node)