html/template: improve ErrBadHTML error report #19408
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The path to resolution is known, but the work has not been done.
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bradfitz
added
the
NeedsDecision
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@robpike, thoughts on line numbers in error messages? |
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This is html/template, which I no longer maintain. The Nodes have the information, so line numbers could be added. They are present in messages from text/template/parse, and so delivered in parse errors. The html/package needs to use them in its own messages. Should be easy. |
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Anyone is welcome to do this (for Go 1.10; Go 1.9 is closed). |
rsc
added
NeedsFix
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CL https://golang.org/cl/49990 mentions this issue. |
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For Go 1.11, I think we could consider the following, which threads the current parse.Node into the code where that error is generated. Then the location information is for the start of the surrounding text node, which maybe is better or maybe is not. But it is probably the best we can do. CL 49990 is too invasive. |
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I've encountered a similar issue while using Current patch is here: diff --git a/src/html/template/escape.go b/src/html/template/escape.go
index 5963194be6..feb2705279 100644
--- a/src/html/template/escape.go
+++ b/src/html/template/escape.go
@@ -656,7 +656,7 @@ var doctypeBytes = []byte("<!DOCTYPE")
func (e *escaper) escapeText(c context, n *parse.TextNode) context {
s, written, i, b := n.Text, 0, 0, new(bytes.Buffer)
for i != len(s) {
- c1, nread := contextAfterText(c, s[i:])
+ c1, nread := contextAfterText(n, c, s[i:])
i1 := i + nread
if c.state == stateText || c.state == stateRCDATA {
end := i1
@@ -722,16 +722,16 @@ func (e *escaper) escapeText(c context, n *parse.TextNode) context {
// contextAfterText starts in context c, consumes some tokens from the front of
// s, then returns the context after those tokens and the unprocessed suffix.
-func contextAfterText(c context, s []byte) (context, int) {
+func contextAfterText(n parse.Node, c context, s []byte) (context, int) {
if c.delim == delimNone {
- c1, i := tSpecialTagEnd(c, s)
+ c1, i := tSpecialTagEnd(n, c, s)
if i == 0 {
// A special end tag (`</script>`) has been seen and
// all content preceding it has been consumed.
return c1, 0
}
// Consider all content up to any end tag.
- return transitionFunc[c.state](c, s[:i])
+ return transitionFunc[c.state](n, c, s[:i])
}
// We are at the beginning of an attribute value.
@@ -761,7 +761,7 @@ func contextAfterText(c context, s []byte) (context, int) {
// <button onclick="alert("Hi!")">
// without having to entity decode token boundaries.
for u := []byte(html.UnescapeString(string(s))); len(u) != 0; {
- c1, i1 := transitionFunc[c.state](c, u)
+ c1, i1 := transitionFunc[c.state](n, c, u)
c, u = c1, u[i1:]
}
return c, len(s)
diff --git a/src/html/template/escape_test.go b/src/html/template/escape_test.go
index 55f808ccba..431f8d8cee 100644
--- a/src/html/template/escape_test.go
+++ b/src/html/template/escape_test.go
@@ -927,7 +927,7 @@ func TestErrors(t *testing.T) {
},
{
"{{range .Items}}<a{{end}}",
- `z:1: on range loop re-entry: "<" in attribute name: "<a"`,
+ `z:1:16: on range loop re-entry: "<" in attribute name: "<a"`,
},
{
"\n{{range .Items}} x='<a{{end}}",
diff --git a/src/html/template/html.go b/src/html/template/html.go
index de4aa4abb2..b1eae7c24b 100644
--- a/src/html/template/html.go
+++ b/src/html/template/html.go
@@ -179,7 +179,7 @@ func stripTags(html string) string {
if c.element != elementNone && !isInTag(st) {
st = stateRCDATA
}
- d, nread := transitionFunc[st](c, s[i:])
+ d, nread := transitionFunc[st](nil, c, s[i:])
i1 := i + nread
if c.state == stateText || c.state == stateRCDATA {
// Emit text up to the start of the tag or comment.
diff --git a/src/html/template/transition.go b/src/html/template/transition.go
index c72cf1ea60..d050936a83 100644
--- a/src/html/template/transition.go
+++ b/src/html/template/transition.go
@@ -7,13 +7,14 @@ package template
import (
"bytes"
"strings"
+ "text/template/parse"
)
// transitionFunc is the array of context transition functions for text nodes.
// A transition function takes a context and template text input, and returns
// the updated context and the number of bytes consumed from the front of the
// input.
-var transitionFunc = [...]func(context, []byte) (context, int){
+var transitionFunc = [...]func(parse.Node, context, []byte) (context, int){
stateText: tText,
stateTag: tTag,
stateAttrName: tAttrName,
@@ -45,7 +46,7 @@ var commentStart = []byte("<!--")
var commentEnd = []byte("-->")
// tText is the context transition function for the text state.
-func tText(c context, s []byte) (context, int) {
+func tText(n parse.Node, c context, s []byte) (context, int) {
k := 0
for {
i := k + bytes.IndexByte(s[k:], '<')
@@ -83,7 +84,7 @@ var elementContentType = [...]state{
}
// tTag is the context transition function for the tag state.
-func tTag(c context, s []byte) (context, int) {
+func tTag(n parse.Node, c context, s []byte) (context, int) {
// Find the attribute name.
i := eatWhiteSpace(s, 0)
if i == len(s) {
@@ -95,7 +96,7 @@ func tTag(c context, s []byte) (context, int) {
element: c.element,
}, i + 1
}
- j, err := eatAttrName(s, i)
+ j, err := eatAttrName(n, s, i)
if err != nil {
return context{state: stateError, err: err}, len(s)
}
@@ -132,8 +133,8 @@ func tTag(c context, s []byte) (context, int) {
}
// tAttrName is the context transition function for stateAttrName.
-func tAttrName(c context, s []byte) (context, int) {
- i, err := eatAttrName(s, 0)
+func tAttrName(n parse.Node, c context, s []byte) (context, int) {
+ i, err := eatAttrName(n, s, 0)
if err != nil {
return context{state: stateError, err: err}, len(s)
} else if i != len(s) {
@@ -143,7 +144,7 @@ func tAttrName(c context, s []byte) (context, int) {
}
// tAfterName is the context transition function for stateAfterName.
-func tAfterName(c context, s []byte) (context, int) {
+func tAfterName(n parse.Node, c context, s []byte) (context, int) {
// Look for the start of the value.
i := eatWhiteSpace(s, 0)
if i == len(s) {
@@ -168,7 +169,7 @@ var attrStartStates = [...]state{
}
// tBeforeValue is the context transition function for stateBeforeValue.
-func tBeforeValue(c context, s []byte) (context, int) {
+func tBeforeValue(n parse.Node, c context, s []byte) (context, int) {
i := eatWhiteSpace(s, 0)
if i == len(s) {
return c, len(s)
@@ -186,7 +187,7 @@ func tBeforeValue(c context, s []byte) (context, int) {
}
// tHTMLCmt is the context transition function for stateHTMLCmt.
-func tHTMLCmt(c context, s []byte) (context, int) {
+func tHTMLCmt(n parse.Node, c context, s []byte) (context, int) {
if i := bytes.Index(s, commentEnd); i != -1 {
return context{}, i + 3
}
@@ -209,7 +210,7 @@ var (
// tSpecialTagEnd is the context transition function for raw text and RCDATA
// element states.
-func tSpecialTagEnd(c context, s []byte) (context, int) {
+func tSpecialTagEnd(n parse.Node, c context, s []byte) (context, int) {
if c.element != elementNone {
if i := indexTagEnd(s, specialTagEndMarkers[c.element]); i != -1 {
return context{}, i
@@ -244,12 +245,12 @@ func indexTagEnd(s []byte, tag []byte) int {
}
// tAttr is the context transition function for the attribute state.
-func tAttr(c context, s []byte) (context, int) {
+func tAttr(n parse.Node, c context, s []byte) (context, int) {
return c, len(s)
}
// tURL is the context transition function for the URL state.
-func tURL(c context, s []byte) (context, int) {
+func tURL(n parse.Node, c context, s []byte) (context, int) {
if bytes.ContainsAny(s, "#?") {
c.urlPart = urlPartQueryOrFrag
} else if len(s) != eatWhiteSpace(s, 0) && c.urlPart == urlPartNone {
@@ -261,7 +262,7 @@ func tURL(c context, s []byte) (context, int) {
}
// tJS is the context transition function for the JS state.
-func tJS(c context, s []byte) (context, int) {
+func tJS(n parse.Node, c context, s []byte) (context, int) {
i := bytes.IndexAny(s, `"'/`)
if i == -1 {
// Entire input is non string, comment, regexp tokens.
@@ -298,7 +299,7 @@ func tJS(c context, s []byte) (context, int) {
// tJSDelimited is the context transition function for the JS string and regexp
// states.
-func tJSDelimited(c context, s []byte) (context, int) {
+func tJSDelimited(n parse.Node, c context, s []byte) (context, int) {
specials := `\"`
switch c.state {
case stateJSSqStr:
@@ -351,7 +352,7 @@ func tJSDelimited(c context, s []byte) (context, int) {
var blockCommentEnd = []byte("*/")
// tBlockCmt is the context transition function for /*comment*/ states.
-func tBlockCmt(c context, s []byte) (context, int) {
+func tBlockCmt(n parse.Node, c context, s []byte) (context, int) {
i := bytes.Index(s, blockCommentEnd)
if i == -1 {
return c, len(s)
@@ -368,7 +369,7 @@ func tBlockCmt(c context, s []byte) (context, int) {
}
// tLineCmt is the context transition function for //comment states.
-func tLineCmt(c context, s []byte) (context, int) {
+func tLineCmt(n parse.Node, c context, s []byte) (context, int) {
var lineTerminators string
var endState state
switch c.state {
@@ -401,7 +402,7 @@ func tLineCmt(c context, s []byte) (context, int) {
}
// tCSS is the context transition function for the CSS state.
-func tCSS(c context, s []byte) (context, int) {
+func tCSS(n parse.Node, c context, s []byte) (context, int) {
// CSS quoted strings are almost never used except for:
// (1) URLs as in background: "/foo.png"
// (2) Multiword font-names as in font-family: "Times New Roman"
@@ -474,7 +475,7 @@ func tCSS(c context, s []byte) (context, int) {
}
// tCSSStr is the context transition function for the CSS string and URL states.
-func tCSSStr(c context, s []byte) (context, int) {
+func tCSSStr(n parse.Node, c context, s []byte) (context, int) {
var endAndEsc string
switch c.state {
case stateCSSDqStr, stateCSSDqURL:
@@ -493,7 +494,7 @@ func tCSSStr(c context, s []byte) (context, int) {
for {
i := k + bytes.IndexAny(s[k:], endAndEsc)
if i < k {
- c, nread := tURL(c, decodeCSS(s[k:]))
+ c, nread := tURL(n, c, decodeCSS(s[k:]))
return c, k + nread
}
if s[i] == '\\' {
@@ -508,13 +509,13 @@ func tCSSStr(c context, s []byte) (context, int) {
c.state = stateCSS
return c, i + 1
}
- c, _ = tURL(c, decodeCSS(s[:i+1]))
+ c, _ = tURL(n, c, decodeCSS(s[:i+1]))
k = i + 1
}
}
// tError is the context transition function for the error state.
-func tError(c context, s []byte) (context, int) {
+func tError(n parse.Node, c context, s []byte) (context, int) {
return c, len(s)
}
@@ -522,7 +523,7 @@ func tError(c context, s []byte) (context, int) {
// It returns an error if s[i:] does not look like it begins with an
// attribute name, such as encountering a quote mark without a preceding
// equals sign.
-func eatAttrName(s []byte, i int) (int, *Error) {
+func eatAttrName(n parse.Node, s []byte, i int) (int, *Error) {
for j := i; j < len(s); j++ {
switch s[j] {
case ' ', '\t', '\n', '\f', '\r', '=', '>':
@@ -531,7 +532,7 @@ func eatAttrName(s []byte, i int) (int, *Error) {
// These result in a parse warning in HTML5 and are
// indicative of serious problems if seen in an attr
// name in a template.
- return -1, errorf(ErrBadHTML, nil, 0, "%q in attribute name: %.32q", s[j:j+1], s)
+ return -1, errorf(ErrBadHTML, n, 0, "%q in attribute name: %.32q", s[j:j+1], s)
default:
// No-op.
} |
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Change https://golang.org/cl/96955 mentions this issue: |
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Only semi-related but I noticed the above patch includes: This is a lot of extra Is there any chance for a new |
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Please answer these questions before submitting your issue. Thanks!
What did you do?
Recently I got the
ErrBadHTMLerror 2-3 times, and and each time it took longer than expected to fix the typo, since there was no line reported in the error message.Here is an example:
https://play.golang.org/p/syrtLCXWeE
What did you expect to see?
The error message should report the line were the error was found.
What did you see instead?
The error message only reports
but this does not help when searching for the error in a big template.
Looking at the source code, it is possible that this issue does not only affect ErrBadHTML but also other errors.
System details
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