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// Copyright 2011 The Go Authors. All rights reserved.
// Use of this source code is governed by a BSD-style
// license that can be found in the LICENSE file.
package template
import (
"bytes"
"encoding/json"
"fmt"
"os"
"strings"
"testing"
"text/template"
"text/template/parse"
)
type badMarshaler struct{}
func (x *badMarshaler) MarshalJSON() ([]byte, error) {
// Keys in valid JSON must be double quoted as must all strings.
return []byte("{ foo: 'not quite valid JSON' }"), nil
}
type goodMarshaler struct{}
func (x *goodMarshaler) MarshalJSON() ([]byte, error) {
return []byte(`{ "<foo>": "O'Reilly" }`), nil
}
func TestEscape(t *testing.T) {
data := struct {
F, T bool
C, G, H string
A, E []string
B, M json.Marshaler
N int
Z *int
W HTML
}{
F: false,
T: true,
C: "<Cincinatti>",
G: "<Goodbye>",
H: "<Hello>",
A: []string{"<a>", "<b>"},
E: []string{},
N: 42,
B: &badMarshaler{},
M: &goodMarshaler{},
Z: nil,
W: HTML(`&iexcl;<b class="foo">Hello</b>, <textarea>O'World</textarea>!`),
}
pdata := &data
tests := []struct {
name string
input string
output string
}{
{
"if",
"{{if .T}}Hello{{end}}, {{.C}}!",
"Hello, &lt;Cincinatti&gt;!",
},
{
"else",
"{{if .F}}{{.H}}{{else}}{{.G}}{{end}}!",
"&lt;Goodbye&gt;!",
},
{
"overescaping1",
"Hello, {{.C | html}}!",
"Hello, &lt;Cincinatti&gt;!",
},
{
"overescaping2",
"Hello, {{html .C}}!",
"Hello, &lt;Cincinatti&gt;!",
},
{
"overescaping3",
"{{with .C}}{{$msg := .}}Hello, {{$msg}}!{{end}}",
"Hello, &lt;Cincinatti&gt;!",
},
{
"assignment",
"{{if $x := .H}}{{$x}}{{end}}",
"&lt;Hello&gt;",
},
{
"withBody",
"{{with .H}}{{.}}{{end}}",
"&lt;Hello&gt;",
},
{
"withElse",
"{{with .E}}{{.}}{{else}}{{.H}}{{end}}",
"&lt;Hello&gt;",
},
{
"rangeBody",
"{{range .A}}{{.}}{{end}}",
"&lt;a&gt;&lt;b&gt;",
},
{
"rangeElse",
"{{range .E}}{{.}}{{else}}{{.H}}{{end}}",
"&lt;Hello&gt;",
},
{
"nonStringValue",
"{{.T}}",
"true",
},
{
"constant",
`<a href="/search?q={{"'a<b'"}}">`,
`<a href="/search?q=%27a%3cb%27">`,
},
{
"multipleAttrs",
"<a b=1 c={{.H}}>",
"<a b=1 c=&lt;Hello&gt;>",
},
{
"urlStartRel",
`<a href='{{"/foo/bar?a=b&c=d"}}'>`,
`<a href='/foo/bar?a=b&amp;c=d'>`,
},
{
"urlStartAbsOk",
`<a href='{{"http://example.com/foo/bar?a=b&c=d"}}'>`,
`<a href='http://example.com/foo/bar?a=b&amp;c=d'>`,
},
{
"protocolRelativeURLStart",
`<a href='{{"//example.com:8000/foo/bar?a=b&c=d"}}'>`,
`<a href='//example.com:8000/foo/bar?a=b&amp;c=d'>`,
},
{
"pathRelativeURLStart",
`<a href="{{"/javascript:80/foo/bar"}}">`,
`<a href="/javascript:80/foo/bar">`,
},
{
"dangerousURLStart",
`<a href='{{"javascript:alert(%22pwned%22)"}}'>`,
`<a href='#ZgotmplZ'>`,
},
{
"dangerousURLStart2",
`<a href=' {{"javascript:alert(%22pwned%22)"}}'>`,
`<a href=' #ZgotmplZ'>`,
},
{
"nonHierURL",
`<a href={{"mailto:Muhammed \"The Greatest\" Ali <m.ali@example.com>"}}>`,
`<a href=mailto:Muhammed%20%22The%20Greatest%22%20Ali%20%3cm.ali@example.com%3e>`,
},
{
"urlPath",
`<a href='http://{{"javascript:80"}}/foo'>`,
`<a href='http://javascript:80/foo'>`,
},
{
"urlQuery",
`<a href='/search?q={{.H}}'>`,
`<a href='/search?q=%3cHello%3e'>`,
},
{
"urlFragment",
`<a href='/faq#{{.H}}'>`,
`<a href='/faq#%3cHello%3e'>`,
},
{
"urlBranch",
`<a href="{{if .F}}/foo?a=b{{else}}/bar{{end}}">`,
`<a href="/bar">`,
},
{
"urlBranchConflictMoot",
`<a href="{{if .T}}/foo?a={{else}}/bar#{{end}}{{.C}}">`,
`<a href="/foo?a=%3cCincinatti%3e">`,
},
{
"jsStrValue",
"<button onclick='alert({{.H}})'>",
`<button onclick='alert(&#34;\u003cHello\u003e&#34;)'>`,
},
{
"jsNumericValue",
"<button onclick='alert({{.N}})'>",
`<button onclick='alert( 42 )'>`,
},
{
"jsBoolValue",
"<button onclick='alert({{.T}})'>",
`<button onclick='alert( true )'>`,
},
{
"jsNilValue",
"<button onclick='alert(typeof{{.Z}})'>",
`<button onclick='alert(typeof null )'>`,
},
{
"jsObjValue",
"<button onclick='alert({{.A}})'>",
`<button onclick='alert([&#34;\u003ca\u003e&#34;,&#34;\u003cb\u003e&#34;])'>`,
},
{
"jsObjValueScript",
"<script>alert({{.A}})</script>",
`<script>alert(["\u003ca\u003e","\u003cb\u003e"])</script>`,
},
{
"jsObjValueNotOverEscaped",
"<button onclick='alert({{.A | html}})'>",
`<button onclick='alert([&#34;\u003ca\u003e&#34;,&#34;\u003cb\u003e&#34;])'>`,
},
{
"jsStr",
"<button onclick='alert(&quot;{{.H}}&quot;)'>",
`<button onclick='alert(&quot;\x3cHello\x3e&quot;)'>`,
},
{
"badMarshaler",
`<button onclick='alert(1/{{.B}}in numbers)'>`,
`<button onclick='alert(1/ /* json: error calling MarshalJSON for type *template.badMarshaler: invalid character &#39;f&#39; looking for beginning of object key string */null in numbers)'>`,
},
{
"jsMarshaler",
`<button onclick='alert({{.M}})'>`,
`<button onclick='alert({&#34;\u003cfoo\u003e&#34;:&#34;O&#39;Reilly&#34;})'>`,
},
{
"jsStrNotUnderEscaped",
"<button onclick='alert({{.C | urlquery}})'>",
// URL escaped, then quoted for JS.
`<button onclick='alert(&#34;%3CCincinatti%3E&#34;)'>`,
},
{
"jsRe",
`<button onclick='alert(/{{"foo+bar"}}/.test(""))'>`,
`<button onclick='alert(/foo\x2bbar/.test(""))'>`,
},
{
"jsReBlank",
`<script>alert(/{{""}}/.test(""));</script>`,
`<script>alert(/(?:)/.test(""));</script>`,
},
{
"jsReAmbigOk",
`<script>{{if true}}var x = 1{{end}}</script>`,
// The {if} ends in an ambiguous jsCtx but there is
// no slash following so we shouldn't care.
`<script>var x = 1</script>`,
},
{
"styleBidiKeywordPassed",
`<p style="dir: {{"ltr"}}">`,
`<p style="dir: ltr">`,
},
{
"styleBidiPropNamePassed",
`<p style="border-{{"left"}}: 0; border-{{"right"}}: 1in">`,
`<p style="border-left: 0; border-right: 1in">`,
},
{
"styleExpressionBlocked",
`<p style="width: {{"expression(alert(1337))"}}">`,
`<p style="width: ZgotmplZ">`,
},
{
"styleTagSelectorPassed",
`<style>{{"p"}} { color: pink }</style>`,
`<style>p { color: pink }</style>`,
},
{
"styleIDPassed",
`<style>p{{"#my-ID"}} { font: Arial }</style>`,
`<style>p#my-ID { font: Arial }</style>`,
},
{
"styleClassPassed",
`<style>p{{".my_class"}} { font: Arial }</style>`,
`<style>p.my_class { font: Arial }</style>`,
},
{
"styleQuantityPassed",
`<a style="left: {{"2em"}}; top: {{0}}">`,
`<a style="left: 2em; top: 0">`,
},
{
"stylePctPassed",
`<table style=width:{{"100%"}}>`,
`<table style=width:100%>`,
},
{
"styleColorPassed",
`<p style="color: {{"#8ff"}}; background: {{"#000"}}">`,
`<p style="color: #8ff; background: #000">`,
},
{
"styleObfuscatedExpressionBlocked",
`<p style="width: {{" e\\78preS\x00Sio/**/n(alert(1337))"}}">`,
`<p style="width: ZgotmplZ">`,
},
{
"styleMozBindingBlocked",
`<p style="{{"-moz-binding(alert(1337))"}}: ...">`,
`<p style="ZgotmplZ: ...">`,
},
{
"styleObfuscatedMozBindingBlocked",
`<p style="{{" -mo\\7a-B\x00I/**/nding(alert(1337))"}}: ...">`,
`<p style="ZgotmplZ: ...">`,
},
{
"styleFontNameString",
`<p style='font-family: "{{"Times New Roman"}}"'>`,
`<p style='font-family: "Times New Roman"'>`,
},
{
"styleFontNameString",
`<p style='font-family: "{{"Times New Roman"}}", "{{"sans-serif"}}"'>`,
`<p style='font-family: "Times New Roman", "sans-serif"'>`,
},
{
"styleFontNameUnquoted",
`<p style='font-family: {{"Times New Roman"}}'>`,
`<p style='font-family: Times New Roman'>`,
},
{
"styleURLQueryEncoded",
`<p style="background: url(/img?name={{"O'Reilly Animal(1)<2>.png"}})">`,
`<p style="background: url(/img?name=O%27Reilly%20Animal%281%29%3c2%3e.png)">`,
},
{
"styleQuotedURLQueryEncoded",
`<p style="background: url('/img?name={{"O'Reilly Animal(1)<2>.png"}}')">`,
`<p style="background: url('/img?name=O%27Reilly%20Animal%281%29%3c2%3e.png')">`,
},
{
"styleStrQueryEncoded",
`<p style="background: '/img?name={{"O'Reilly Animal(1)<2>.png"}}'">`,
`<p style="background: '/img?name=O%27Reilly%20Animal%281%29%3c2%3e.png'">`,
},
{
"styleURLBadProtocolBlocked",
`<a style="background: url('{{"javascript:alert(1337)"}}')">`,
`<a style="background: url('#ZgotmplZ')">`,
},
{
"styleStrBadProtocolBlocked",
`<a style="background: '{{"vbscript:alert(1337)"}}'">`,
`<a style="background: '#ZgotmplZ'">`,
},
{
"styleStrEncodedProtocolEncoded",
`<a style="background: '{{"javascript\\3a alert(1337)"}}'">`,
// The CSS string 'javascript\\3a alert(1337)' does not contains a colon.
`<a style="background: 'javascript\\3a alert\28 1337\29 '">`,
},
{
"styleURLGoodProtocolPassed",
`<a style="background: url('{{"http://oreilly.com/O'Reilly Animals(1)<2>;{}.html"}}')">`,
`<a style="background: url('http://oreilly.com/O%27Reilly%20Animals%281%29%3c2%3e;%7b%7d.html')">`,
},
{
"styleStrGoodProtocolPassed",
`<a style="background: '{{"http://oreilly.com/O'Reilly Animals(1)<2>;{}.html"}}'">`,
`<a style="background: 'http\3a\2f\2foreilly.com\2fO\27Reilly Animals\28 1\29\3c 2\3e\3b\7b\7d.html'">`,
},
{
"styleURLEncodedForHTMLInAttr",
`<a style="background: url('{{"/search?img=foo&size=icon"}}')">`,
`<a style="background: url('/search?img=foo&amp;size=icon')">`,
},
{
"styleURLNotEncodedForHTMLInCdata",
`<style>body { background: url('{{"/search?img=foo&size=icon"}}') }</style>`,
`<style>body { background: url('/search?img=foo&size=icon') }</style>`,
},
{
"styleURLMixedCase",
`<p style="background: URL(#{{.H}})">`,
`<p style="background: URL(#%3cHello%3e)">`,
},
{
"stylePropertyPairPassed",
`<a style='{{"color: red"}}'>`,
`<a style='color: red'>`,
},
{
"styleStrSpecialsEncoded",
`<a style="font-family: '{{"/**/'\";:// \\"}}', &quot;{{"/**/'\";:// \\"}}&quot;">`,
`<a style="font-family: '\2f**\2f\27\22\3b\3a\2f\2f \\', &quot;\2f**\2f\27\22\3b\3a\2f\2f \\&quot;">`,
},
{
"styleURLSpecialsEncoded",
`<a style="border-image: url({{"/**/'\";:// \\"}}), url(&quot;{{"/**/'\";:// \\"}}&quot;), url('{{"/**/'\";:// \\"}}'), 'http://www.example.com/?q={{"/**/'\";:// \\"}}''">`,
`<a style="border-image: url(/**/%27%22;://%20%5c), url(&quot;/**/%27%22;://%20%5c&quot;), url('/**/%27%22;://%20%5c'), 'http://www.example.com/?q=%2f%2a%2a%2f%27%22%3b%3a%2f%2f%20%5c''">`,
},
{
"HTML comment",
"<b>Hello, <!-- name of world -->{{.C}}</b>",
"<b>Hello, &lt;Cincinatti&gt;</b>",
},
{
"HTML comment not first < in text node.",
"<<!-- -->!--",
"&lt;!--",
},
{
"HTML normalization 1",
"a < b",
"a &lt; b",
},
{
"HTML normalization 2",
"a << b",
"a &lt;&lt; b",
},
{
"HTML normalization 3",
"a<<!-- --><!-- -->b",
"a&lt;b",
},
{
"HTML doctype not normalized",
"<!DOCTYPE html>Hello, World!",
"<!DOCTYPE html>Hello, World!",
},
{
"HTML doctype not case-insensitive",
"<!doCtYPE htMl>Hello, World!",
"<!doCtYPE htMl>Hello, World!",
},
{
"No doctype injection",
`<!{{"DOCTYPE"}}`,
"&lt;!DOCTYPE",
},
{
"Split HTML comment",
"<b>Hello, <!-- name of {{if .T}}city -->{{.C}}{{else}}world -->{{.W}}{{end}}</b>",
"<b>Hello, &lt;Cincinatti&gt;</b>",
},
{
"JS line comment",
"<script>for (;;) { if (c()) break// foo not a label\n" +
"foo({{.T}});}</script>",
"<script>for (;;) { if (c()) break\n" +
"foo( true );}</script>",
},
{
"JS multiline block comment",
"<script>for (;;) { if (c()) break/* foo not a label\n" +
" */foo({{.T}});}</script>",
// Newline separates break from call. If newline
// removed, then break will consume label leaving
// code invalid.
"<script>for (;;) { if (c()) break\n" +
"foo( true );}</script>",
},
{
"JS single-line block comment",
"<script>for (;;) {\n" +
"if (c()) break/* foo a label */foo;" +
"x({{.T}});}</script>",
// Newline separates break from call. If newline
// removed, then break will consume label leaving
// code invalid.
"<script>for (;;) {\n" +
"if (c()) break foo;" +
"x( true );}</script>",
},
{
"JS block comment flush with mathematical division",
"<script>var a/*b*//c\nd</script>",
"<script>var a /c\nd</script>",
},
{
"JS mixed comments",
"<script>var a/*b*///c\nd</script>",
"<script>var a \nd</script>",
},
{
"CSS comments",
"<style>p// paragraph\n" +
`{border: 1px/* color */{{"#00f"}}}</style>`,
"<style>p\n" +
"{border: 1px #00f}</style>",
},
{
"JS attr block comment",
`<a onclick="f(&quot;&quot;); /* alert({{.H}}) */">`,
// Attribute comment tests should pass if the comments
// are successfully elided.
`<a onclick="f(&quot;&quot;); /* alert() */">`,
},
{
"JS attr line comment",
`<a onclick="// alert({{.G}})">`,
`<a onclick="// alert()">`,
},
{
"CSS attr block comment",
`<a style="/* color: {{.H}} */">`,
`<a style="/* color: */">`,
},
{
"CSS attr line comment",
`<a style="// color: {{.G}}">`,
`<a style="// color: ">`,
},
{
"HTML substitution commented out",
"<p><!-- {{.H}} --></p>",
"<p></p>",
},
{
"Comment ends flush with start",
"<!--{{.}}--><script>/*{{.}}*///{{.}}\n</script><style>/*{{.}}*///{{.}}\n</style><a onclick='/*{{.}}*///{{.}}' style='/*{{.}}*///{{.}}'>",
"<script> \n</script><style> \n</style><a onclick='/**///' style='/**///'>",
},
{
"typed HTML in text",
`{{.W}}`,
`&iexcl;<b class="foo">Hello</b>, <textarea>O'World</textarea>!`,
},
{
"typed HTML in attribute",
`<div title="{{.W}}">`,
`<div title="&iexcl;Hello, O&#39;World!">`,
},
{
"typed HTML in script",
`<button onclick="alert({{.W}})">`,
`<button onclick="alert(&#34;\u0026iexcl;\u003cb class=\&#34;foo\&#34;\u003eHello\u003c/b\u003e, \u003ctextarea\u003eO&#39;World\u003c/textarea\u003e!&#34;)">`,
},
{
"typed HTML in RCDATA",
`<textarea>{{.W}}</textarea>`,
`<textarea>&iexcl;&lt;b class=&#34;foo&#34;&gt;Hello&lt;/b&gt;, &lt;textarea&gt;O&#39;World&lt;/textarea&gt;!</textarea>`,
},
{
"range in textarea",
"<textarea>{{range .A}}{{.}}{{end}}</textarea>",
"<textarea>&lt;a&gt;&lt;b&gt;</textarea>",
},
{
"No tag injection",
`{{"10$"}}<{{"script src,evil.org/pwnd.js"}}...`,
`10$&lt;script src,evil.org/pwnd.js...`,
},
{
"No comment injection",
`<{{"!--"}}`,
`&lt;!--`,
},
{
"No RCDATA end tag injection",
`<textarea><{{"/textarea "}}...</textarea>`,
`<textarea>&lt;/textarea ...</textarea>`,
},
{
"optional attrs",
`<img class="{{"iconClass"}}"` +
`{{if .T}} id="{{"<iconId>"}}"{{end}}` +
// Double quotes inside if/else.
` src=` +
`{{if .T}}"?{{"<iconPath>"}}"` +
`{{else}}"images/cleardot.gif"{{end}}` +
// Missing space before title, but it is not a
// part of the src attribute.
`{{if .T}}title="{{"<title>"}}"{{end}}` +
// Quotes outside if/else.
` alt="` +
`{{if .T}}{{"<alt>"}}` +
`{{else}}{{if .F}}{{"<title>"}}{{end}}` +
`{{end}}"` +
`>`,
`<img class="iconClass" id="&lt;iconId&gt;" src="?%3ciconPath%3e"title="&lt;title&gt;" alt="&lt;alt&gt;">`,
},
{
"conditional valueless attr name",
`<input{{if .T}} checked{{end}} name=n>`,
`<input checked name=n>`,
},
{
"conditional dynamic valueless attr name 1",
`<input{{if .T}} {{"checked"}}{{end}} name=n>`,
`<input checked name=n>`,
},
{
"conditional dynamic valueless attr name 2",
`<input {{if .T}}{{"checked"}} {{end}}name=n>`,
`<input checked name=n>`,
},
{
"dynamic attribute name",
`<img on{{"load"}}="alert({{"loaded"}})">`,
// Treated as JS since quotes are inserted.
`<img onload="alert(&#34;loaded&#34;)">`,
},
{
"bad dynamic attribute name 1",
// Allow checked, selected, disabled, but not JS or
// CSS attributes.
`<input {{"onchange"}}="{{"doEvil()"}}">`,
`<input ZgotmplZ="doEvil()">`,
},
{
"bad dynamic attribute name 2",
`<div {{"sTyle"}}="{{"color: expression(alert(1337))"}}">`,
`<div ZgotmplZ="color: expression(alert(1337))">`,
},
{
"bad dynamic attribute name 3",
// Allow title or alt, but not a URL.
`<img {{"src"}}="{{"javascript:doEvil()"}}">`,
`<img ZgotmplZ="javascript:doEvil()">`,
},
{
"bad dynamic attribute name 4",
// Structure preservation requires values to associate
// with a consistent attribute.
`<input checked {{""}}="Whose value am I?">`,
`<input checked ZgotmplZ="Whose value am I?">`,
},
{
"dynamic element name",
`<h{{3}}><table><t{{"head"}}>...</h{{3}}>`,
`<h3><table><thead>...</h3>`,
},
{
"bad dynamic element name",
// Dynamic element names are typically used to switch
// between (thead, tfoot, tbody), (ul, ol), (th, td),
// and other replaceable sets.
// We do not currently easily support (ul, ol).
// If we do change to support that, this test should
// catch failures to filter out special tag names which
// would violate the structure preservation property --
// if any special tag name could be substituted, then
// the content could be raw text/RCDATA for some inputs
// and regular HTML content for others.
`<{{"script"}}>{{"doEvil()"}}</{{"script"}}>`,
`&lt;script>doEvil()&lt;/script>`,
},
}
for _, test := range tests {
tmpl := New(test.name)
tmpl = Must(tmpl.Parse(test.input))
// Check for bug 6459: Tree field was not set in Parse.
if tmpl.Tree != tmpl.text.Tree {
t.Errorf("%s: tree not set properly", test.name)
continue
}
b := new(bytes.Buffer)
if err := tmpl.Execute(b, data); err != nil {
t.Errorf("%s: template execution failed: %s", test.name, err)
continue
}
if w, g := test.output, b.String(); w != g {
t.Errorf("%s: escaped output: want\n\t%q\ngot\n\t%q", test.name, w, g)
continue
}
b.Reset()
if err := tmpl.Execute(b, pdata); err != nil {
t.Errorf("%s: template execution failed for pointer: %s", test.name, err)
continue
}
if w, g := test.output, b.String(); w != g {
t.Errorf("%s: escaped output for pointer: want\n\t%q\ngot\n\t%q", test.name, w, g)
continue
}
if tmpl.Tree != tmpl.text.Tree {
t.Errorf("%s: tree mismatch", test.name)
continue
}
}
}
func TestEscapeSet(t *testing.T) {
type dataItem struct {
Children []*dataItem
X string
}
data := dataItem{
Children: []*dataItem{
{X: "foo"},
{X: "<bar>"},
{
Children: []*dataItem{
{X: "baz"},
},
},
},
}
tests := []struct {
inputs map[string]string
want string
}{
// The trivial set.
{
map[string]string{
"main": ``,
},
``,
},
// A template called in the start context.
{
map[string]string{
"main": `Hello, {{template "helper"}}!`,
// Not a valid top level HTML template.
// "<b" is not a full tag.
"helper": `{{"<World>"}}`,
},
`Hello, &lt;World&gt;!`,
},
// A template called in a context other than the start.
{
map[string]string{
"main": `<a onclick='a = {{template "helper"}};'>`,
// Not a valid top level HTML template.
// "<b" is not a full tag.
"helper": `{{"<a>"}}<b`,
},
`<a onclick='a = &#34;\u003ca\u003e&#34;<b;'>`,
},
// A recursive template that ends in its start context.
{
map[string]string{
"main": `{{range .Children}}{{template "main" .}}{{else}}{{.X}} {{end}}`,
},
`foo &lt;bar&gt; baz `,
},
// A recursive helper template that ends in its start context.
{
map[string]string{
"main": `{{template "helper" .}}`,
"helper": `{{if .Children}}<ul>{{range .Children}}<li>{{template "main" .}}</li>{{end}}</ul>{{else}}{{.X}}{{end}}`,
},
`<ul><li>foo</li><li>&lt;bar&gt;</li><li><ul><li>baz</li></ul></li></ul>`,
},
// Co-recursive templates that end in its start context.
{
map[string]string{
"main": `<blockquote>{{range .Children}}{{template "helper" .}}{{end}}</blockquote>`,
"helper": `{{if .Children}}{{template "main" .}}{{else}}{{.X}}<br>{{end}}`,
},
`<blockquote>foo<br>&lt;bar&gt;<br><blockquote>baz<br></blockquote></blockquote>`,
},
// A template that is called in two different contexts.
{
map[string]string{
"main": `<button onclick="title='{{template "helper"}}'; ...">{{template "helper"}}</button>`,
"helper": `{{11}} of {{"<100>"}}`,
},
`<button onclick="title='11 of \x3c100\x3e'; ...">11 of &lt;100&gt;</button>`,
},
// A non-recursive template that ends in a different context.
// helper starts in jsCtxRegexp and ends in jsCtxDivOp.
{
map[string]string{
"main": `<script>var x={{template "helper"}}/{{"42"}};</script>`,
"helper": "{{126}}",
},
`<script>var x= 126 /"42";</script>`,
},
// A recursive template that ends in a similar context.
{
map[string]string{
"main": `<script>var x=[{{template "countdown" 4}}];</script>`,
"countdown": `{{.}}{{if .}},{{template "countdown" . | pred}}{{end}}`,
},
`<script>var x=[ 4 , 3 , 2 , 1 , 0 ];</script>`,
},
// A recursive template that ends in a different context.
/*
{
map[string]string{
"main": `<a href="/foo{{template "helper" .}}">`,
"helper": `{{if .Children}}{{range .Children}}{{template "helper" .}}{{end}}{{else}}?x={{.X}}{{end}}`,
},
`<a href="/foo?x=foo?x=%3cbar%3e?x=baz">`,
},
*/
}
// pred is a template function that returns the predecessor of a
// natural number for testing recursive templates.
fns := FuncMap{"pred": func(a ...interface{}) (interface{}, error) {
if len(a) == 1 {
if i, _ := a[0].(int); i > 0 {
return i - 1, nil
}
}
return nil, fmt.Errorf("undefined pred(%v)", a)
}}
for _, test := range tests {
source := ""
for name, body := range test.inputs {
source += fmt.Sprintf("{{define %q}}%s{{end}} ", name, body)
}
tmpl, err := New("root").Funcs(fns).Parse(source)
if err != nil {
t.Errorf("error parsing %q: %v", source, err)
continue
}
var b bytes.Buffer
if err := tmpl.ExecuteTemplate(&b, "main", data); err != nil {
t.Errorf("%q executing %v", err.Error(), tmpl.Lookup("main"))
continue
}
if got := b.String(); test.want != got {
t.Errorf("want\n\t%q\ngot\n\t%q", test.want, got)
}
}
}
func TestErrors(t *testing.T) {
tests := []struct {
input string
err string
}{
// Non-error cases.
{
"{{if .Cond}}<a>{{else}}<b>{{end}}",
"",
},
{
"{{if .Cond}}<a>{{end}}",
"",
},
{
"{{if .Cond}}{{else}}<b>{{end}}",
"",
},
{
"{{with .Cond}}<div>{{end}}",
"",
},
{
"{{range .Items}}<a>{{end}}",
"",
},
{
"<a href='/foo?{{range .Items}}&{{.K}}={{.V}}{{end}}'>",
"",
},
// Error cases.
{
"{{if .Cond}}<a{{end}}",
"z:1: {{if}} branches",
},
{
"{{if .Cond}}\n{{else}}\n<a{{end}}",
"z:1: {{if}} branches",
},
{
// Missing quote in the else branch.
`{{if .Cond}}<a href="foo">{{else}}<a href="bar>{{end}}`,
"z:1: {{if}} branches",
},
{
// Different kind of attribute: href implies a URL.
"<a {{if .Cond}}href='{{else}}title='{{end}}{{.X}}'>",
"z:1: {{if}} branches",
},
{
"\n{{with .X}}<a{{end}}",
"z:2: {{with}} branches",
},
{
"\n{{with .X}}<a>{{else}}<a{{end}}",
"z:2: {{with}} branches",
},
{
"{{range .Items}}<a{{end}}",
`z:1: on range loop re-entry: "<" in attribute name: "<a"`,
},
{
"\n{{range .Items}} x='<a{{end}}",
"z:2: on range loop re-entry: {{range}} branches",
},
{
"<a b=1 c={{.H}}",
"z: ends in a non-text context: {stateAttr delimSpaceOrTagEnd",
},
{
"<script>foo();",
"z: ends in a non-text context: {stateJS",
},
{
`<a href="{{if .F}}/foo?a={{else}}/bar/{{end}}{{.H}}">`,
"z:1: {{.H}} appears in an ambiguous URL context",
},
{
`<a onclick="alert('Hello \`,
`unfinished escape sequence in JS string: "Hello \\"`,
},
{
`<a onclick='alert("Hello\, World\`,
`unfinished escape sequence in JS string: "Hello\\, World\\"`,
},
{
`<a onclick='alert(/x+\`,
`unfinished escape sequence in JS string: "x+\\"`,
},
{
`<a onclick="/foo[\]/`,
`unfinished JS regexp charset: "foo[\\]/"`,
},
{
// It is ambiguous whether 1.5 should be 1\.5 or 1.5.
// Either `var x = 1/- 1.5 /i.test(x)`
// where `i.test(x)` is a method call of reference i,
// or `/-1\.5/i.test(x)` which is a method call on a
// case insensitive regular expression.
`<script>{{if false}}var x = 1{{end}}/-{{"1.5"}}/i.test(x)</script>`,
`'/' could start a division or regexp: "/-"`,
},
{
`{{template "foo"}}`,
"z:1: no such template \"foo\"",
},
{
`<div{{template "y"}}>` +
// Illegal starting in stateTag but not in stateText.
`{{define "y"}} foo<b{{end}}`,
`"<" in attribute name: " foo<b"`,
},
{
`<script>reverseList = [{{template "t"}}]</script>` +
// Missing " after recursive call.
`{{define "t"}}{{if .Tail}}{{template "t" .Tail}}{{end}}{{.Head}}",{{end}}`,
`: cannot compute output context for template t$htmltemplate_stateJS_elementScript`,
},
{
`<input type=button value=onclick=>`,
`html/template:z: "=" in unquoted attr: "onclick="`,
},
{
`<input type=button value= onclick=>`,
`html/template:z: "=" in unquoted attr: "onclick="`,
},
{
`<input type=button value= 1+1=2>`,
`html/template:z: "=" in unquoted attr: "1+1=2"`,
},
{
"<a class=`foo>",
"html/template:z: \"`\" in unquoted attr: \"`foo\"",
},
{
`<a style=font:'Arial'>`,
`html/template:z: "'" in unquoted attr: "font:'Arial'"`,
},
{
`<a=foo>`,
`: expected space, attr name, or end of tag, but got "=foo>"`,
},
}
for _, test := range tests {
buf := new(bytes.Buffer)
tmpl, err := New("z").Parse(test.input)
if err != nil {
t.Errorf("input=%q: unexpected parse error %s\n", test.input, err)
continue
}
err = tmpl.Execute(buf, nil)
var got string
if err != nil {
got = err.Error()
}
if test.err == "" {
if got != "" {
t.Errorf("input=%q: unexpected error %q", test.input, got)
}
continue
}
if strings.Index(got, test.err) == -1 {
t.Errorf("input=%q: error\n\t%q\ndoes not contain expected string\n\t%q", test.input, got, test.err)
continue
}
}
}
func TestEscapeText(t *testing.T) {
tests := []struct {
input string
output context
}{
{
``,
context{},
},
{
`Hello, World!`,
context{},
},
{
// An orphaned "<" is OK.
`I <3 Ponies!`,
context{},
},
{
`<a`,
context{state: stateTag},
},
{
`<a `,
context{state: stateTag},
},
{
`<a>`,
context{state: stateText},
},
{
`<a href`,
context{state: stateAttrName, attr: attrURL},
},
{
`<a on`,
context{state: stateAttrName, attr: attrScript},
},
{
`<a href `,
context{state: stateAfterName, attr: attrURL},
},
{
`<a style = `,
context{state: stateBeforeValue, attr: attrStyle},
},
{
`<a href=`,
context{state: stateBeforeValue, attr: attrURL},
},
{
`<a href=x`,
context{state: stateURL, delim: delimSpaceOrTagEnd, urlPart: urlPartPreQuery},
},
{
`<a href=x `,
context{state: stateTag},
},
{
`<a href=>`,
context{state: stateText},
},
{
`<a href=x>`,
context{state: stateText},
},
{
`<a href ='`,
context{state: stateURL, delim: delimSingleQuote},
},
{
`<a href=''`,
context{state: stateTag},
},
{
`<a href= "`,
context{state: stateURL, delim: delimDoubleQuote},
},
{
`<a href=""`,
context{state: stateTag},
},
{
`<a title="`,
context{state: stateAttr, delim: delimDoubleQuote},
},
{
`<a HREF='http:`,
context{state: stateURL, delim: delimSingleQuote, urlPart: urlPartPreQuery},
},
{
`<a Href='/`,
context{state: stateURL, delim: delimSingleQuote, urlPart: urlPartPreQuery},
},
{
`<a href='"`,
context{state: stateURL, delim: delimSingleQuote, urlPart: urlPartPreQuery},
},
{
`<a href="'`,
context{state: stateURL, delim: delimDoubleQuote, urlPart: urlPartPreQuery},
},
{
`<a href='&apos;`,
context{state: stateURL, delim: delimSingleQuote, urlPart: urlPartPreQuery},
},
{
`<a href="&quot;`,
context{state: stateURL, delim: delimDoubleQuote, urlPart: urlPartPreQuery},
},
{
`<a href="&#34;`,
context{state: stateURL, delim: delimDoubleQuote, urlPart: urlPartPreQuery},
},
{
`<a href=&quot;`,
context{state: stateURL, delim: delimSpaceOrTagEnd, urlPart: urlPartPreQuery},
},
{
`<img alt="1">`,
context{state: stateText},
},
{
`<img alt="1>"`,
context{state: stateTag},
},
{
`<img alt="1>">`,
context{state: stateText},
},
{
`<input checked type="checkbox"`,
context{state: stateTag},
},
{
`<a onclick="`,
context{state: stateJS, delim: delimDoubleQuote},
},
{
`<a onclick="//foo`,
context{state: stateJSLineCmt, delim: delimDoubleQuote},
},
{
"<a onclick='//\n",
context{state: stateJS, delim: delimSingleQuote},
},
{
"<a onclick='//\r\n",
context{state: stateJS, delim: delimSingleQuote},
},
{
"<a onclick='//\u2028",
context{state: stateJS, delim: delimSingleQuote},
},
{
`<a onclick="/*`,
context{state: stateJSBlockCmt, delim: delimDoubleQuote},
},
{
`<a onclick="/*/`,
context{state: stateJSBlockCmt, delim: delimDoubleQuote},
},
{
`<a onclick="/**/`,
context{state: stateJS, delim: delimDoubleQuote},
},
{
`<a onkeypress="&quot;`,
context{state: stateJSDqStr, delim: delimDoubleQuote},
},
{
`<a onclick='&quot;foo&quot;`,
context{state: stateJS, delim: delimSingleQuote, jsCtx: jsCtxDivOp},
},
{
`<a onclick=&#39;foo&#39;`,
context{state: stateJS, delim: delimSpaceOrTagEnd, jsCtx: jsCtxDivOp},
},
{
`<a onclick=&#39;foo`,
context{state: stateJSSqStr, delim: delimSpaceOrTagEnd},
},
{
`<a onclick="&quot;foo'`,
context{state: stateJSDqStr, delim: delimDoubleQuote},
},
{
`<a onclick="'foo&quot;`,
context{state: stateJSSqStr, delim: delimDoubleQuote},
},
{
`<A ONCLICK="'`,
context{state: stateJSSqStr, delim: delimDoubleQuote},
},
{
`<a onclick="/`,
context{state: stateJSRegexp, delim: delimDoubleQuote},
},
{
`<a onclick="'foo'`,
context{state: stateJS, delim: delimDoubleQuote, jsCtx: jsCtxDivOp},
},
{
`<a onclick="'foo\'`,
context{state: stateJSSqStr, delim: delimDoubleQuote},
},
{
`<a onclick="'foo\'`,
context{state: stateJSSqStr, delim: delimDoubleQuote},
},
{
`<a onclick="/foo/`,
context{state: stateJS, delim: delimDoubleQuote, jsCtx: jsCtxDivOp},
},
{
`<script>/foo/ /=`,
context{state: stateJS, element: elementScript},
},
{
`<a onclick="1 /foo`,
context{state: stateJS, delim: delimDoubleQuote, jsCtx: jsCtxDivOp},
},
{
`<a onclick="1 /*c*/ /foo`,
context{state: stateJS, delim: delimDoubleQuote, jsCtx: jsCtxDivOp},
},
{
`<a onclick="/foo[/]`,
context{state: stateJSRegexp, delim: delimDoubleQuote},
},
{
`<a onclick="/foo\/`,
context{state: stateJSRegexp, delim: delimDoubleQuote},
},
{
`<a onclick="/foo/`,
context{state: stateJS, delim: delimDoubleQuote, jsCtx: jsCtxDivOp},
},
{
`<input checked style="`,
context{state: stateCSS, delim: delimDoubleQuote},
},
{
`<a style="//`,
context{state: stateCSSLineCmt, delim: delimDoubleQuote},
},
{
`<a style="//</script>`,
context{state: stateCSSLineCmt, delim: delimDoubleQuote},
},
{
"<a style='//\n",
context{state: stateCSS, delim: delimSingleQuote},
},
{
"<a style='//\r",
context{state: stateCSS, delim: delimSingleQuote},
},
{
`<a style="/*`,
context{state: stateCSSBlockCmt, delim: delimDoubleQuote},
},
{
`<a style="/*/`,
context{state: stateCSSBlockCmt, delim: delimDoubleQuote},
},
{
`<a style="/**/`,
context{state: stateCSS, delim: delimDoubleQuote},
},
{
`<a style="background: '`,
context{state: stateCSSSqStr, delim: delimDoubleQuote},
},
{
`<a style="background: &quot;`,
context{state: stateCSSDqStr, delim: delimDoubleQuote},
},
{
`<a style="background: '/foo?img=`,
context{state: stateCSSSqStr, delim: delimDoubleQuote, urlPart: urlPartQueryOrFrag},
},
{
`<a style="background: '/`,
context{state: stateCSSSqStr, delim: delimDoubleQuote, urlPart: urlPartPreQuery},
},
{
`<a style="background: url(&#x22;/`,
context{state: stateCSSDqURL, delim: delimDoubleQuote, urlPart: urlPartPreQuery},
},
{
`<a style="background: url('/`,
context{state: stateCSSSqURL, delim: delimDoubleQuote, urlPart: urlPartPreQuery},
},
{
`<a style="background: url('/)`,
context{state: stateCSSSqURL, delim: delimDoubleQuote, urlPart: urlPartPreQuery},
},
{
`<a style="background: url('/ `,
context{state: stateCSSSqURL, delim: delimDoubleQuote, urlPart: urlPartPreQuery},
},
{
`<a style="background: url(/`,
context{state: stateCSSURL, delim: delimDoubleQuote, urlPart: urlPartPreQuery},
},
{
`<a style="background: url( `,
context{state: stateCSSURL, delim: delimDoubleQuote},
},
{
`<a style="background: url( /image?name=`,
context{state: stateCSSURL, delim: delimDoubleQuote, urlPart: urlPartQueryOrFrag},
},
{
`<a style="background: url(x)`,
context{state: stateCSS, delim: delimDoubleQuote},
},
{
`<a style="background: url('x'`,
context{state: stateCSS, delim: delimDoubleQuote},
},
{
`<a style="background: url( x `,
context{state: stateCSS, delim: delimDoubleQuote},
},
{
`<!-- foo`,
context{state: stateHTMLCmt},
},
{
`<!-->`,
context{state: stateHTMLCmt},
},
{
`<!--->`,
context{state: stateHTMLCmt},
},
{
`<!-- foo -->`,
context{state: stateText},
},
{
`<script`,
context{state: stateTag, element: elementScript},
},
{
`<script `,
context{state: stateTag, element: elementScript},
},
{
`<script src="foo.js" `,
context{state: stateTag, element: elementScript},
},
{
`<script src='foo.js' `,
context{state: stateTag, element: elementScript},
},
{
`<script type=text/javascript `,
context{state: stateTag, element: elementScript},
},
{
`<script>foo`,
context{state: stateJS, jsCtx: jsCtxDivOp, element: elementScript},
},
{
`<script>foo</script>`,
context{state: stateText},
},
{
`<script>foo</script><!--`,
context{state: stateHTMLCmt},
},
{
`<script>document.write("<p>foo</p>");`,
context{state: stateJS, element: elementScript},
},
{
`<script>document.write("<p>foo<\/script>");`,
context{state: stateJS, element: elementScript},
},
{
`<script>document.write("<script>alert(1)</script>");`,
context{state: stateText},
},
{
`<Script>`,
context{state: stateJS, element: elementScript},
},
{
`<SCRIPT>foo`,
context{state: stateJS, jsCtx: jsCtxDivOp, element: elementScript},
},
{
`<textarea>value`,
context{state: stateRCDATA, element: elementTextarea},
},
{
`<textarea>value</TEXTAREA>`,
context{state: stateText},
},
{
`<textarea name=html><b`,
context{state: stateRCDATA, element: elementTextarea},
},
{
`<title>value`,
context{state: stateRCDATA, element: elementTitle},
},
{
`<style>value`,
context{state: stateCSS, element: elementStyle},
},
{
`<a xlink:href`,
context{state: stateAttrName, attr: attrURL},
},
{
`<a xmlns`,
context{state: stateAttrName, attr: attrURL},
},
{
`<a xmlns:foo`,
context{state: stateAttrName, attr: attrURL},
},
{
`<a xmlnsxyz`,
context{state: stateAttrName},
},
{
`<a data-url`,
context{state: stateAttrName, attr: attrURL},
},
{
`<a data-iconUri`,
context{state: stateAttrName, attr: attrURL},
},
{
`<a data-urlItem`,
context{state: stateAttrName, attr: attrURL},
},
{
`<a g:`,
context{state: stateAttrName},
},
{
`<a g:url`,
context{state: stateAttrName, attr: attrURL},
},
{
`<a g:iconUri`,
context{state: stateAttrName, attr: attrURL},
},
{
`<a g:urlItem`,
context{state: stateAttrName, attr: attrURL},
},
{
`<a g:value`,
context{state: stateAttrName},
},
{
`<a svg:style='`,
context{state: stateCSS, delim: delimSingleQuote},
},
{
`<svg:font-face`,
context{state: stateTag},
},
{
`<svg:a svg:onclick="`,
context{state: stateJS, delim: delimDoubleQuote},
},
}
for _, test := range tests {
b, e := []byte(test.input), newEscaper(nil)
c := e.escapeText(context{}, &parse.TextNode{NodeType: parse.NodeText, Text: b})
if !test.output.eq(c) {
t.Errorf("input %q: want context\n\t%v\ngot\n\t%v", test.input, test.output, c)
continue
}
if test.input != string(b) {
t.Errorf("input %q: text node was modified: want %q got %q", test.input, test.input, b)
continue
}
}
}
func TestEnsurePipelineContains(t *testing.T) {
tests := []struct {
input, output string
ids []string
}{
{
"{{.X}}",
".X",
[]string{},
},
{
"{{.X | html}}",
".X | html",
[]string{},
},
{
"{{.X}}",
".X | html",
[]string{"html"},
},
{
"{{.X | html}}",
".X | html | urlquery",
[]string{"urlquery"},
},
{
"{{.X | html | urlquery}}",
".X | html | urlquery",
[]string{"urlquery"},
},
{
"{{.X | html | urlquery}}",
".X | html | urlquery",
[]string{"html", "urlquery"},
},
{
"{{.X | html | urlquery}}",
".X | html | urlquery",
[]string{"html"},
},
{
"{{.X | urlquery}}",
".X | html | urlquery",
[]string{"html", "urlquery"},
},
{
"{{.X | html | print}}",
".X | urlquery | html | print",
[]string{"urlquery", "html"},
},
{
"{{($).X | html | print}}",
"($).X | urlquery | html | print",
[]string{"urlquery", "html"},
},
}
for i, test := range tests {
tmpl := template.Must(template.New("test").Parse(test.input))
action, ok := (tmpl.Tree.Root.Nodes[0].(*parse.ActionNode))
if !ok {
t.Errorf("#%d: First node is not an action: %s", i, test.input)
continue
}
pipe := action.Pipe
ensurePipelineContains(pipe, test.ids)
got := pipe.String()
if got != test.output {
t.Errorf("#%d: %s, %v: want\n\t%s\ngot\n\t%s", i, test.input, test.ids, test.output, got)
}
}
}
func TestEscapeErrorsNotIgnorable(t *testing.T) {
var b bytes.Buffer
tmpl, _ := New("dangerous").Parse("<a")
err := tmpl.Execute(&b, nil)
if err == nil {
t.Errorf("Expected error")
} else if b.Len() != 0 {
t.Errorf("Emitted output despite escaping failure")
}
}
func TestEscapeSetErrorsNotIgnorable(t *testing.T) {
var b bytes.Buffer
tmpl, err := New("root").Parse(`{{define "t"}}<a{{end}}`)
if err != nil {
t.Errorf("failed to parse set: %q", err)
}
err = tmpl.ExecuteTemplate(&b, "t", nil)
if err == nil {
t.Errorf("Expected error")
} else if b.Len() != 0 {
t.Errorf("Emitted output despite escaping failure")
}
}
func TestRedundantFuncs(t *testing.T) {
inputs := []interface{}{
"\x00\x01\x02\x03\x04\x05\x06\x07\x08\t\n\x0b\x0c\r\x0e\x0f" +
"\x10\x11\x12\x13\x14\x15\x16\x17\x18\x19\x1a\x1b\x1c\x1d\x1e\x1f" +
` !"#$%&'()*+,-./` +
`0123456789:;<=>?` +
`@ABCDEFGHIJKLMNO` +
`PQRSTUVWXYZ[\]^_` +
"`abcdefghijklmno" +
"pqrstuvwxyz{|}~\x7f" +
"\u00A0\u0100\u2028\u2029\ufeff\ufdec\ufffd\uffff\U0001D11E" +
"&amp;%22\\",
CSS(`a[href =~ "//example.com"]#foo`),
HTML(`Hello, <b>World</b> &amp;tc!`),
HTMLAttr(` dir="ltr"`),
JS(`c && alert("Hello, World!");`),
JSStr(`Hello, World & O'Reilly\x21`),
URL(`greeting=H%69&addressee=(World)`),
}
for n0, m := range redundantFuncs {
f0 := funcMap[n0].(func(...interface{}) string)
for n1 := range m {
f1 := funcMap[n1].(func(...interface{}) string)
for _, input := range inputs {
want := f0(input)
if got := f1(want); want != got {
t.Errorf("%s %s with %T %q: want\n\t%q,\ngot\n\t%q", n0, n1, input, input, want, got)
}
}
}
}
}
func TestIndirectPrint(t *testing.T) {
a := 3
ap := &a
b := "hello"
bp := &b
bpp := &bp
tmpl := Must(New("t").Parse(`{{.}}`))
var buf bytes.Buffer
err := tmpl.Execute(&buf, ap)
if err != nil {
t.Errorf("Unexpected error: %s", err)
} else if buf.String() != "3" {
t.Errorf(`Expected "3"; got %q`, buf.String())
}
buf.Reset()
err = tmpl.Execute(&buf, bpp)
if err != nil {
t.Errorf("Unexpected error: %s", err)
} else if buf.String() != "hello" {
t.Errorf(`Expected "hello"; got %q`, buf.String())
}
}
// This is a test for issue 3272.
func TestEmptyTemplate(t *testing.T) {
page := Must(New("page").ParseFiles(os.DevNull))
if err := page.ExecuteTemplate(os.Stdout, "page", "nothing"); err == nil {
t.Fatal("expected error")
}
}
type Issue7379 int
func (Issue7379) SomeMethod(x int) string {
return fmt.Sprintf("<%d>", x)
}
// This is a test for issue 7379: type assertion error caused panic, and then
// the code to handle the panic breaks escaping. It's hard to see the second
// problem once the first is fixed, but its fix is trivial so we let that go. See
// the discussion for issue 7379.
func TestPipeToMethodIsEscaped(t *testing.T) {
tmpl := Must(New("x").Parse("<html>{{0 | .SomeMethod}}</html>\n"))
tryExec := func() string {
defer func() {
panicValue := recover()
if panicValue != nil {
t.Errorf("panicked: %v\n", panicValue)
}
}()
var b bytes.Buffer
tmpl.Execute(&b, Issue7379(0))
return b.String()
}
for i := 0; i < 3; i++ {
str := tryExec()
const expect = "<html>&lt;0&gt;</html>\n"
if str != expect {
t.Errorf("expected %q got %q", expect, str)
}
}
}
func BenchmarkEscapedExecute(b *testing.B) {
tmpl := Must(New("t").Parse(`<a onclick="alert('{{.}}')">{{.}}</a>`))
var buf bytes.Buffer
b.ResetTimer()
for i := 0; i < b.N; i++ {
tmpl.Execute(&buf, "foo & 'bar' & baz")
buf.Reset()
}
}