text/template: add CommentNode to template parse tree
Fixes #34652
Change-Id: Icf6e3eda593fed826736f34f95a9d66f5450cc98
Reviewed-on: https://go-review.googlesource.com/c/go/+/229398
Reviewed-by: Daniel Martí <mvdan@mvdan.cc>
Run-TryBot: Daniel Martí <mvdan@mvdan.cc>
TryBot-Result: Gobot Gobot <gobot@golang.org>
diff --git a/api/next.txt b/api/next.txt
index fe7509b..076f39e 100644
--- a/api/next.txt
+++ b/api/next.txt
@@ -3,3 +3,17 @@
pkg unicode, var Dives_Akuru *RangeTable
pkg unicode, var Khitan_Small_Script *RangeTable
pkg unicode, var Yezidi *RangeTable
+pkg text/template/parse, const NodeComment = 20
+pkg text/template/parse, const NodeComment NodeType
+pkg text/template/parse, const ParseComments = 1
+pkg text/template/parse, const ParseComments Mode
+pkg text/template/parse, method (*CommentNode) Copy() Node
+pkg text/template/parse, method (*CommentNode) String() string
+pkg text/template/parse, method (CommentNode) Position() Pos
+pkg text/template/parse, method (CommentNode) Type() NodeType
+pkg text/template/parse, type CommentNode struct
+pkg text/template/parse, type CommentNode struct, Text string
+pkg text/template/parse, type CommentNode struct, embedded NodeType
+pkg text/template/parse, type CommentNode struct, embedded Pos
+pkg text/template/parse, type Mode uint
+pkg text/template/parse, type Tree struct, Mode Mode
diff --git a/doc/go1.16.html b/doc/go1.16.html
index 805234b..7738cbd 100644
--- a/doc/go1.16.html
+++ b/doc/go1.16.html
@@ -121,6 +121,16 @@
with <code>"use of closed network connection"</code>.
</p>
+
+<h3 id="text/template/parse"><a href="/pkg/text/template/parse/">text/template/parse</a></h3>
+
+<p><!-- CL 229398, golang.org/issue/34652 -->
+ A new <a href="/pkg/text/template/parse/#CommentNode"><code>CommentNode</code></a>
+ was added to the parse tree. The <a href="/pkg/text/template/parse/#Mode"><code>Mode</code></a>
+ field in the <code>parse.Tree</code> enables access to it.
+</p>
+<!-- text/template/parse -->
+
<h3 id="unicode"><a href="/pkg/unicode/">unicode</a></h3>
<p><!-- CL 248765 -->
diff --git a/src/html/template/escape.go b/src/html/template/escape.go
index f12dafa..8739735 100644
--- a/src/html/template/escape.go
+++ b/src/html/template/escape.go
@@ -124,6 +124,8 @@
switch n := n.(type) {
case *parse.ActionNode:
return e.escapeAction(c, n)
+ case *parse.CommentNode:
+ return c
case *parse.IfNode:
return e.escapeBranch(c, &n.BranchNode, "if")
case *parse.ListNode:
diff --git a/src/html/template/template_test.go b/src/html/template/template_test.go
index 86bd4db..1f2c888 100644
--- a/src/html/template/template_test.go
+++ b/src/html/template/template_test.go
@@ -10,6 +10,7 @@
. "html/template"
"strings"
"testing"
+ "text/template/parse"
)
func TestTemplateClone(t *testing.T) {
@@ -160,6 +161,21 @@
}
}
+func TestSkipEscapeComments(t *testing.T) {
+ c := newTestCase(t)
+ tr := parse.New("root")
+ tr.Mode = parse.ParseComments
+ newT, err := tr.Parse("{{/* A comment */}}{{ 1 }}{{/* Another comment */}}", "", "", make(map[string]*parse.Tree))
+ if err != nil {
+ t.Fatalf("Cannot parse template text: %v", err)
+ }
+ c.root, err = c.root.AddParseTree("root", newT)
+ if err != nil {
+ t.Fatalf("Cannot add parse tree to template: %v", err)
+ }
+ c.mustExecute(c.root, nil, "1")
+}
+
type testCase struct {
t *testing.T
root *Template
diff --git a/src/text/template/exec.go b/src/text/template/exec.go
index ac3e741..7ac5175 100644
--- a/src/text/template/exec.go
+++ b/src/text/template/exec.go
@@ -256,6 +256,7 @@
if len(node.Pipe.Decl) == 0 {
s.printValue(node, val)
}
+ case *parse.CommentNode:
case *parse.IfNode:
s.walkIfOrWith(parse.NodeIf, dot, node.Pipe, node.List, node.ElseList)
case *parse.ListNode:
diff --git a/src/text/template/parse/lex.go b/src/text/template/parse/lex.go
index 30371f2..e41373a 100644
--- a/src/text/template/parse/lex.go
+++ b/src/text/template/parse/lex.go
@@ -41,6 +41,7 @@
itemBool // boolean constant
itemChar // printable ASCII character; grab bag for comma etc.
itemCharConstant // character constant
+ itemComment // comment text
itemComplex // complex constant (1+2i); imaginary is just a number
itemAssign // equals ('=') introducing an assignment
itemDeclare // colon-equals (':=') introducing a declaration
@@ -112,6 +113,7 @@
leftDelim string // start of action
rightDelim string // end of action
trimRightDelim string // end of action with trim marker
+ emitComment bool // emit itemComment tokens.
pos Pos // current position in the input
start Pos // start position of this item
width Pos // width of last rune read from input
@@ -203,7 +205,7 @@
}
// lex creates a new scanner for the input string.
-func lex(name, input, left, right string) *lexer {
+func lex(name, input, left, right string, emitComment bool) *lexer {
if left == "" {
left = leftDelim
}
@@ -216,6 +218,7 @@
leftDelim: left,
rightDelim: right,
trimRightDelim: rightTrimMarker + right,
+ emitComment: emitComment,
items: make(chan item),
line: 1,
startLine: 1,
@@ -323,6 +326,9 @@
if !delim {
return l.errorf("comment ends before closing delimiter")
}
+ if l.emitComment {
+ l.emit(itemComment)
+ }
if trimSpace {
l.pos += trimMarkerLen
}
diff --git a/src/text/template/parse/lex_test.go b/src/text/template/parse/lex_test.go
index 563c4fc..f6d5f28 100644
--- a/src/text/template/parse/lex_test.go
+++ b/src/text/template/parse/lex_test.go
@@ -15,6 +15,7 @@
itemBool: "bool",
itemChar: "char",
itemCharConstant: "charconst",
+ itemComment: "comment",
itemComplex: "complex",
itemDeclare: ":=",
itemEOF: "EOF",
@@ -90,6 +91,7 @@
{"text", `now is the time`, []item{mkItem(itemText, "now is the time"), tEOF}},
{"text with comment", "hello-{{/* this is a comment */}}-world", []item{
mkItem(itemText, "hello-"),
+ mkItem(itemComment, "/* this is a comment */"),
mkItem(itemText, "-world"),
tEOF,
}},
@@ -311,6 +313,7 @@
}},
{"trimming spaces before and after comment", "hello- {{- /* hello */ -}} -world", []item{
mkItem(itemText, "hello-"),
+ mkItem(itemComment, "/* hello */"),
mkItem(itemText, "-world"),
tEOF,
}},
@@ -389,7 +392,7 @@
// collect gathers the emitted items into a slice.
func collect(t *lexTest, left, right string) (items []item) {
- l := lex(t.name, t.input, left, right)
+ l := lex(t.name, t.input, left, right, true)
for {
item := l.nextItem()
items = append(items, item)
@@ -529,7 +532,7 @@
func TestShutdown(t *testing.T) {
// We need to duplicate template.Parse here to hold on to the lexer.
const text = "erroneous{{define}}{{else}}1234"
- lexer := lex("foo", text, "{{", "}}")
+ lexer := lex("foo", text, "{{", "}}", false)
_, err := New("root").parseLexer(lexer)
if err == nil {
t.Fatalf("expected error")
diff --git a/src/text/template/parse/node.go b/src/text/template/parse/node.go
index dddc775..177482f 100644
--- a/src/text/template/parse/node.go
+++ b/src/text/template/parse/node.go
@@ -70,6 +70,7 @@
NodeTemplate // A template invocation action.
NodeVariable // A $ variable.
NodeWith // A with action.
+ NodeComment // A comment.
)
// Nodes.
@@ -149,6 +150,38 @@
return &TextNode{tr: t.tr, NodeType: NodeText, Pos: t.Pos, Text: append([]byte{}, t.Text...)}
}
+// CommentNode holds a comment.
+type CommentNode struct {
+ NodeType
+ Pos
+ tr *Tree
+ Text string // Comment text.
+}
+
+func (t *Tree) newComment(pos Pos, text string) *CommentNode {
+ return &CommentNode{tr: t, NodeType: NodeComment, Pos: pos, Text: text}
+}
+
+func (c *CommentNode) String() string {
+ var sb strings.Builder
+ c.writeTo(&sb)
+ return sb.String()
+}
+
+func (c *CommentNode) writeTo(sb *strings.Builder) {
+ sb.WriteString("{{")
+ sb.WriteString(c.Text)
+ sb.WriteString("}}")
+}
+
+func (c *CommentNode) tree() *Tree {
+ return c.tr
+}
+
+func (c *CommentNode) Copy() Node {
+ return &CommentNode{tr: c.tr, NodeType: NodeComment, Pos: c.Pos, Text: c.Text}
+}
+
// PipeNode holds a pipeline with optional declaration
type PipeNode struct {
NodeType
diff --git a/src/text/template/parse/parse.go b/src/text/template/parse/parse.go
index c9b80f4..496d8bf 100644
--- a/src/text/template/parse/parse.go
+++ b/src/text/template/parse/parse.go
@@ -21,6 +21,7 @@
Name string // name of the template represented by the tree.
ParseName string // name of the top-level template during parsing, for error messages.
Root *ListNode // top-level root of the tree.
+ Mode Mode // parsing mode.
text string // text parsed to create the template (or its parent)
// Parsing only; cleared after parse.
funcs []map[string]interface{}
@@ -29,8 +30,16 @@
peekCount int
vars []string // variables defined at the moment.
treeSet map[string]*Tree
+ mode Mode
}
+// A mode value is a set of flags (or 0). Modes control parser behavior.
+type Mode uint
+
+const (
+ ParseComments Mode = 1 << iota // parse comments and add them to AST
+)
+
// Copy returns a copy of the Tree. Any parsing state is discarded.
func (t *Tree) Copy() *Tree {
if t == nil {
@@ -220,7 +229,8 @@
func (t *Tree) Parse(text, leftDelim, rightDelim string, treeSet map[string]*Tree, funcs ...map[string]interface{}) (tree *Tree, err error) {
defer t.recover(&err)
t.ParseName = t.Name
- t.startParse(funcs, lex(t.Name, text, leftDelim, rightDelim), treeSet)
+ emitComment := t.Mode&ParseComments != 0
+ t.startParse(funcs, lex(t.Name, text, leftDelim, rightDelim, emitComment), treeSet)
t.text = text
t.parse()
t.add()
@@ -240,12 +250,14 @@
}
}
-// IsEmptyTree reports whether this tree (node) is empty of everything but space.
+// IsEmptyTree reports whether this tree (node) is empty of everything but space or comments.
func IsEmptyTree(n Node) bool {
switch n := n.(type) {
case nil:
return true
case *ActionNode:
+ case *CommentNode:
+ return true
case *IfNode:
case *ListNode:
for _, node := range n.Nodes {
@@ -276,6 +288,7 @@
if t.nextNonSpace().typ == itemDefine {
newT := New("definition") // name will be updated once we know it.
newT.text = t.text
+ newT.Mode = t.Mode
newT.ParseName = t.ParseName
newT.startParse(t.funcs, t.lex, t.treeSet)
newT.parseDefinition()
@@ -331,13 +344,15 @@
}
// textOrAction:
-// text | action
+// text | comment | action
func (t *Tree) textOrAction() Node {
switch token := t.nextNonSpace(); token.typ {
case itemText:
return t.newText(token.pos, token.val)
case itemLeftDelim:
return t.action()
+ case itemComment:
+ return t.newComment(token.pos, token.val)
default:
t.unexpected(token, "input")
}
@@ -539,6 +554,7 @@
block := New(name) // name will be updated once we know it.
block.text = t.text
+ block.Mode = t.Mode
block.ParseName = t.ParseName
block.startParse(t.funcs, t.lex, t.treeSet)
var end Node
diff --git a/src/text/template/parse/parse_test.go b/src/text/template/parse/parse_test.go
index 4e09a78..d9c13c5 100644
--- a/src/text/template/parse/parse_test.go
+++ b/src/text/template/parse/parse_test.go
@@ -348,6 +348,30 @@
testParse(true, t)
}
+func TestParseWithComments(t *testing.T) {
+ textFormat = "%q"
+ defer func() { textFormat = "%s" }()
+ tests := [...]parseTest{
+ {"comment", "{{/*\n\n\n*/}}", noError, "{{/*\n\n\n*/}}"},
+ {"comment trim left", "x \r\n\t{{- /* hi */}}", noError, `"x"{{/* hi */}}`},
+ {"comment trim right", "{{/* hi */ -}}\n\n\ty", noError, `{{/* hi */}}"y"`},
+ {"comment trim left and right", "x \r\n\t{{- /* */ -}}\n\n\ty", noError, `"x"{{/* */}}"y"`},
+ }
+ for _, test := range tests {
+ t.Run(test.name, func(t *testing.T) {
+ tr := New(test.name)
+ tr.Mode = ParseComments
+ tmpl, err := tr.Parse(test.input, "", "", make(map[string]*Tree))
+ if err != nil {
+ t.Errorf("%q: expected error; got none", test.name)
+ }
+ if result := tmpl.Root.String(); result != test.result {
+ t.Errorf("%s=(%q): got\n\t%v\nexpected\n\t%v", test.name, test.input, result, test.result)
+ }
+ })
+ }
+}
+
type isEmptyTest struct {
name string
input string
@@ -358,6 +382,7 @@
{"empty", ``, true},
{"nonempty", `hello`, false},
{"spaces only", " \t\n \t\n", true},
+ {"comment only", "{{/* comment */}}", true},
{"definition", `{{define "x"}}something{{end}}`, true},
{"definitions and space", "{{define `x`}}something{{end}}\n\n{{define `y`}}something{{end}}\n\n", true},
{"definitions and text", "{{define `x`}}something{{end}}\nx\n{{define `y`}}something{{end}}\ny\n", false},
