Source file src/html/template/escape_test.go

     1  // Copyright 2011 The Go Authors. All rights reserved.
     2  // Use of this source code is governed by a BSD-style
     3  // license that can be found in the LICENSE file.
     4  
     5  package template
     6  
     7  import (
     8  	"bytes"
     9  	"encoding/json"
    10  	"fmt"
    11  	"os"
    12  	"strings"
    13  	"testing"
    14  	"text/template"
    15  	"text/template/parse"
    16  )
    17  
    18  type badMarshaler struct{}
    19  
    20  func (x *badMarshaler) MarshalJSON() ([]byte, error) {
    21  	// Keys in valid JSON must be double quoted as must all strings.
    22  	return []byte("{ foo: 'not quite valid JSON' }"), nil
    23  }
    24  
    25  type goodMarshaler struct{}
    26  
    27  func (x *goodMarshaler) MarshalJSON() ([]byte, error) {
    28  	return []byte(`{ "<foo>": "O'Reilly" }`), nil
    29  }
    30  
    31  func TestEscape(t *testing.T) {
    32  	data := struct {
    33  		F, T    bool
    34  		C, G, H string
    35  		A, E    []string
    36  		B, M    json.Marshaler
    37  		N       int
    38  		U       any  // untyped nil
    39  		Z       *int // typed nil
    40  		W       HTML
    41  	}{
    42  		F: false,
    43  		T: true,
    44  		C: "<Cincinnati>",
    45  		G: "<Goodbye>",
    46  		H: "<Hello>",
    47  		A: []string{"<a>", "<b>"},
    48  		E: []string{},
    49  		N: 42,
    50  		B: &badMarshaler{},
    51  		M: &goodMarshaler{},
    52  		U: nil,
    53  		Z: nil,
    54  		W: HTML(`&iexcl;<b class="foo">Hello</b>, <textarea>O'World</textarea>!`),
    55  	}
    56  	pdata := &data
    57  
    58  	tests := []struct {
    59  		name   string
    60  		input  string
    61  		output string
    62  	}{
    63  		{
    64  			"if",
    65  			"{{if .T}}Hello{{end}}, {{.C}}!",
    66  			"Hello, &lt;Cincinnati&gt;!",
    67  		},
    68  		{
    69  			"else",
    70  			"{{if .F}}{{.H}}{{else}}{{.G}}{{end}}!",
    71  			"&lt;Goodbye&gt;!",
    72  		},
    73  		{
    74  			"overescaping1",
    75  			"Hello, {{.C | html}}!",
    76  			"Hello, &lt;Cincinnati&gt;!",
    77  		},
    78  		{
    79  			"overescaping2",
    80  			"Hello, {{html .C}}!",
    81  			"Hello, &lt;Cincinnati&gt;!",
    82  		},
    83  		{
    84  			"overescaping3",
    85  			"{{with .C}}{{$msg := .}}Hello, {{$msg}}!{{end}}",
    86  			"Hello, &lt;Cincinnati&gt;!",
    87  		},
    88  		{
    89  			"assignment",
    90  			"{{if $x := .H}}{{$x}}{{end}}",
    91  			"&lt;Hello&gt;",
    92  		},
    93  		{
    94  			"withBody",
    95  			"{{with .H}}{{.}}{{end}}",
    96  			"&lt;Hello&gt;",
    97  		},
    98  		{
    99  			"withElse",
   100  			"{{with .E}}{{.}}{{else}}{{.H}}{{end}}",
   101  			"&lt;Hello&gt;",
   102  		},
   103  		{
   104  			"rangeBody",
   105  			"{{range .A}}{{.}}{{end}}",
   106  			"&lt;a&gt;&lt;b&gt;",
   107  		},
   108  		{
   109  			"rangeElse",
   110  			"{{range .E}}{{.}}{{else}}{{.H}}{{end}}",
   111  			"&lt;Hello&gt;",
   112  		},
   113  		{
   114  			"nonStringValue",
   115  			"{{.T}}",
   116  			"true",
   117  		},
   118  		{
   119  			"untypedNilValue",
   120  			"{{.U}}",
   121  			"",
   122  		},
   123  		{
   124  			"typedNilValue",
   125  			"{{.Z}}",
   126  			"&lt;nil&gt;",
   127  		},
   128  		{
   129  			"constant",
   130  			`<a href="/search?q={{"'a<b'"}}">`,
   131  			`<a href="/search?q=%27a%3cb%27">`,
   132  		},
   133  		{
   134  			"multipleAttrs",
   135  			"<a b=1 c={{.H}}>",
   136  			"<a b=1 c=&lt;Hello&gt;>",
   137  		},
   138  		{
   139  			"urlStartRel",
   140  			`<a href='{{"/foo/bar?a=b&c=d"}}'>`,
   141  			`<a href='/foo/bar?a=b&amp;c=d'>`,
   142  		},
   143  		{
   144  			"urlStartAbsOk",
   145  			`<a href='{{"http://example.com/foo/bar?a=b&c=d"}}'>`,
   146  			`<a href='http://example.com/foo/bar?a=b&amp;c=d'>`,
   147  		},
   148  		{
   149  			"protocolRelativeURLStart",
   150  			`<a href='{{"//example.com:8000/foo/bar?a=b&c=d"}}'>`,
   151  			`<a href='//example.com:8000/foo/bar?a=b&amp;c=d'>`,
   152  		},
   153  		{
   154  			"pathRelativeURLStart",
   155  			`<a href="{{"/javascript:80/foo/bar"}}">`,
   156  			`<a href="/javascript:80/foo/bar">`,
   157  		},
   158  		{
   159  			"dangerousURLStart",
   160  			`<a href='{{"javascript:alert(%22pwned%22)"}}'>`,
   161  			`<a href='#ZgotmplZ'>`,
   162  		},
   163  		{
   164  			"dangerousURLStart2",
   165  			`<a href='  {{"javascript:alert(%22pwned%22)"}}'>`,
   166  			`<a href='  #ZgotmplZ'>`,
   167  		},
   168  		{
   169  			"nonHierURL",
   170  			`<a href={{"mailto:Muhammed \"The Greatest\" Ali <m.ali@example.com>"}}>`,
   171  			`<a href=mailto:Muhammed%20%22The%20Greatest%22%20Ali%20%3cm.ali@example.com%3e>`,
   172  		},
   173  		{
   174  			"urlPath",
   175  			`<a href='http://{{"javascript:80"}}/foo'>`,
   176  			`<a href='http://javascript:80/foo'>`,
   177  		},
   178  		{
   179  			"urlQuery",
   180  			`<a href='/search?q={{.H}}'>`,
   181  			`<a href='/search?q=%3cHello%3e'>`,
   182  		},
   183  		{
   184  			"urlFragment",
   185  			`<a href='/faq#{{.H}}'>`,
   186  			`<a href='/faq#%3cHello%3e'>`,
   187  		},
   188  		{
   189  			"urlBranch",
   190  			`<a href="{{if .F}}/foo?a=b{{else}}/bar{{end}}">`,
   191  			`<a href="/bar">`,
   192  		},
   193  		{
   194  			"urlBranchConflictMoot",
   195  			`<a href="{{if .T}}/foo?a={{else}}/bar#{{end}}{{.C}}">`,
   196  			`<a href="/foo?a=%3cCincinnati%3e">`,
   197  		},
   198  		{
   199  			"jsStrValue",
   200  			"<button onclick='alert({{.H}})'>",
   201  			`<button onclick='alert(&#34;\u003cHello\u003e&#34;)'>`,
   202  		},
   203  		{
   204  			"jsNumericValue",
   205  			"<button onclick='alert({{.N}})'>",
   206  			`<button onclick='alert( 42 )'>`,
   207  		},
   208  		{
   209  			"jsBoolValue",
   210  			"<button onclick='alert({{.T}})'>",
   211  			`<button onclick='alert( true )'>`,
   212  		},
   213  		{
   214  			"jsNilValueTyped",
   215  			"<button onclick='alert(typeof{{.Z}})'>",
   216  			`<button onclick='alert(typeof null )'>`,
   217  		},
   218  		{
   219  			"jsNilValueUntyped",
   220  			"<button onclick='alert(typeof{{.U}})'>",
   221  			`<button onclick='alert(typeof null )'>`,
   222  		},
   223  		{
   224  			"jsObjValue",
   225  			"<button onclick='alert({{.A}})'>",
   226  			`<button onclick='alert([&#34;\u003ca\u003e&#34;,&#34;\u003cb\u003e&#34;])'>`,
   227  		},
   228  		{
   229  			"jsObjValueScript",
   230  			"<script>alert({{.A}})</script>",
   231  			`<script>alert(["\u003ca\u003e","\u003cb\u003e"])</script>`,
   232  		},
   233  		{
   234  			"jsObjValueNotOverEscaped",
   235  			"<button onclick='alert({{.A | html}})'>",
   236  			`<button onclick='alert([&#34;\u003ca\u003e&#34;,&#34;\u003cb\u003e&#34;])'>`,
   237  		},
   238  		{
   239  			"jsStr",
   240  			"<button onclick='alert(&quot;{{.H}}&quot;)'>",
   241  			`<button onclick='alert(&quot;\u003cHello\u003e&quot;)'>`,
   242  		},
   243  		{
   244  			"badMarshaler",
   245  			`<button onclick='alert(1/{{.B}}in numbers)'>`,
   246  			`<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)'>`,
   247  		},
   248  		{
   249  			"jsMarshaler",
   250  			`<button onclick='alert({{.M}})'>`,
   251  			`<button onclick='alert({&#34;\u003cfoo\u003e&#34;:&#34;O&#39;Reilly&#34;})'>`,
   252  		},
   253  		{
   254  			"jsStrNotUnderEscaped",
   255  			"<button onclick='alert({{.C | urlquery}})'>",
   256  			// URL escaped, then quoted for JS.
   257  			`<button onclick='alert(&#34;%3CCincinnati%3E&#34;)'>`,
   258  		},
   259  		{
   260  			"jsRe",
   261  			`<button onclick='alert(/{{"foo+bar"}}/.test(""))'>`,
   262  			`<button onclick='alert(/foo\u002bbar/.test(""))'>`,
   263  		},
   264  		{
   265  			"jsReBlank",
   266  			`<script>alert(/{{""}}/.test(""));</script>`,
   267  			`<script>alert(/(?:)/.test(""));</script>`,
   268  		},
   269  		{
   270  			"jsReAmbigOk",
   271  			`<script>{{if true}}var x = 1{{end}}</script>`,
   272  			// The {if} ends in an ambiguous jsCtx but there is
   273  			// no slash following so we shouldn't care.
   274  			`<script>var x = 1</script>`,
   275  		},
   276  		{
   277  			"styleBidiKeywordPassed",
   278  			`<p style="dir: {{"ltr"}}">`,
   279  			`<p style="dir: ltr">`,
   280  		},
   281  		{
   282  			"styleBidiPropNamePassed",
   283  			`<p style="border-{{"left"}}: 0; border-{{"right"}}: 1in">`,
   284  			`<p style="border-left: 0; border-right: 1in">`,
   285  		},
   286  		{
   287  			"styleExpressionBlocked",
   288  			`<p style="width: {{"expression(alert(1337))"}}">`,
   289  			`<p style="width: ZgotmplZ">`,
   290  		},
   291  		{
   292  			"styleTagSelectorPassed",
   293  			`<style>{{"p"}} { color: pink }</style>`,
   294  			`<style>p { color: pink }</style>`,
   295  		},
   296  		{
   297  			"styleIDPassed",
   298  			`<style>p{{"#my-ID"}} { font: Arial }</style>`,
   299  			`<style>p#my-ID { font: Arial }</style>`,
   300  		},
   301  		{
   302  			"styleClassPassed",
   303  			`<style>p{{".my_class"}} { font: Arial }</style>`,
   304  			`<style>p.my_class { font: Arial }</style>`,
   305  		},
   306  		{
   307  			"styleQuantityPassed",
   308  			`<a style="left: {{"2em"}}; top: {{0}}">`,
   309  			`<a style="left: 2em; top: 0">`,
   310  		},
   311  		{
   312  			"stylePctPassed",
   313  			`<table style=width:{{"100%"}}>`,
   314  			`<table style=width:100%>`,
   315  		},
   316  		{
   317  			"styleColorPassed",
   318  			`<p style="color: {{"#8ff"}}; background: {{"#000"}}">`,
   319  			`<p style="color: #8ff; background: #000">`,
   320  		},
   321  		{
   322  			"styleObfuscatedExpressionBlocked",
   323  			`<p style="width: {{"  e\\78preS\x00Sio/**/n(alert(1337))"}}">`,
   324  			`<p style="width: ZgotmplZ">`,
   325  		},
   326  		{
   327  			"styleMozBindingBlocked",
   328  			`<p style="{{"-moz-binding(alert(1337))"}}: ...">`,
   329  			`<p style="ZgotmplZ: ...">`,
   330  		},
   331  		{
   332  			"styleObfuscatedMozBindingBlocked",
   333  			`<p style="{{"  -mo\\7a-B\x00I/**/nding(alert(1337))"}}: ...">`,
   334  			`<p style="ZgotmplZ: ...">`,
   335  		},
   336  		{
   337  			"styleFontNameString",
   338  			`<p style='font-family: "{{"Times New Roman"}}"'>`,
   339  			`<p style='font-family: "Times New Roman"'>`,
   340  		},
   341  		{
   342  			"styleFontNameString",
   343  			`<p style='font-family: "{{"Times New Roman"}}", "{{"sans-serif"}}"'>`,
   344  			`<p style='font-family: "Times New Roman", "sans-serif"'>`,
   345  		},
   346  		{
   347  			"styleFontNameUnquoted",
   348  			`<p style='font-family: {{"Times New Roman"}}'>`,
   349  			`<p style='font-family: Times New Roman'>`,
   350  		},
   351  		{
   352  			"styleURLQueryEncoded",
   353  			`<p style="background: url(/img?name={{"O'Reilly Animal(1)<2>.png"}})">`,
   354  			`<p style="background: url(/img?name=O%27Reilly%20Animal%281%29%3c2%3e.png)">`,
   355  		},
   356  		{
   357  			"styleQuotedURLQueryEncoded",
   358  			`<p style="background: url('/img?name={{"O'Reilly Animal(1)<2>.png"}}')">`,
   359  			`<p style="background: url('/img?name=O%27Reilly%20Animal%281%29%3c2%3e.png')">`,
   360  		},
   361  		{
   362  			"styleStrQueryEncoded",
   363  			`<p style="background: '/img?name={{"O'Reilly Animal(1)<2>.png"}}'">`,
   364  			`<p style="background: '/img?name=O%27Reilly%20Animal%281%29%3c2%3e.png'">`,
   365  		},
   366  		{
   367  			"styleURLBadProtocolBlocked",
   368  			`<a style="background: url('{{"javascript:alert(1337)"}}')">`,
   369  			`<a style="background: url('#ZgotmplZ')">`,
   370  		},
   371  		{
   372  			"styleStrBadProtocolBlocked",
   373  			`<a style="background: '{{"vbscript:alert(1337)"}}'">`,
   374  			`<a style="background: '#ZgotmplZ'">`,
   375  		},
   376  		{
   377  			"styleStrEncodedProtocolEncoded",
   378  			`<a style="background: '{{"javascript\\3a alert(1337)"}}'">`,
   379  			// The CSS string 'javascript\\3a alert(1337)' does not contain a colon.
   380  			`<a style="background: 'javascript\\3a alert\28 1337\29 '">`,
   381  		},
   382  		{
   383  			"styleURLGoodProtocolPassed",
   384  			`<a style="background: url('{{"http://oreilly.com/O'Reilly Animals(1)<2>;{}.html"}}')">`,
   385  			`<a style="background: url('http://oreilly.com/O%27Reilly%20Animals%281%29%3c2%3e;%7b%7d.html')">`,
   386  		},
   387  		{
   388  			"styleStrGoodProtocolPassed",
   389  			`<a style="background: '{{"http://oreilly.com/O'Reilly Animals(1)<2>;{}.html"}}'">`,
   390  			`<a style="background: 'http\3a\2f\2foreilly.com\2fO\27Reilly Animals\28 1\29\3c 2\3e\3b\7b\7d.html'">`,
   391  		},
   392  		{
   393  			"styleURLEncodedForHTMLInAttr",
   394  			`<a style="background: url('{{"/search?img=foo&size=icon"}}')">`,
   395  			`<a style="background: url('/search?img=foo&amp;size=icon')">`,
   396  		},
   397  		{
   398  			"styleURLNotEncodedForHTMLInCdata",
   399  			`<style>body { background: url('{{"/search?img=foo&size=icon"}}') }</style>`,
   400  			`<style>body { background: url('/search?img=foo&size=icon') }</style>`,
   401  		},
   402  		{
   403  			"styleURLMixedCase",
   404  			`<p style="background: URL(#{{.H}})">`,
   405  			`<p style="background: URL(#%3cHello%3e)">`,
   406  		},
   407  		{
   408  			"stylePropertyPairPassed",
   409  			`<a style='{{"color: red"}}'>`,
   410  			`<a style='color: red'>`,
   411  		},
   412  		{
   413  			"styleStrSpecialsEncoded",
   414  			`<a style="font-family: '{{"/**/'\";:// \\"}}', &quot;{{"/**/'\";:// \\"}}&quot;">`,
   415  			`<a style="font-family: '\2f**\2f\27\22\3b\3a\2f\2f  \\', &quot;\2f**\2f\27\22\3b\3a\2f\2f  \\&quot;">`,
   416  		},
   417  		{
   418  			"styleURLSpecialsEncoded",
   419  			`<a style="border-image: url({{"/**/'\";:// \\"}}), url(&quot;{{"/**/'\";:// \\"}}&quot;), url('{{"/**/'\";:// \\"}}'), 'http://www.example.com/?q={{"/**/'\";:// \\"}}''">`,
   420  			`<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''">`,
   421  		},
   422  		{
   423  			"HTML comment",
   424  			"<b>Hello, <!-- name of world -->{{.C}}</b>",
   425  			"<b>Hello, &lt;Cincinnati&gt;</b>",
   426  		},
   427  		{
   428  			"HTML comment not first < in text node.",
   429  			"<<!-- -->!--",
   430  			"&lt;!--",
   431  		},
   432  		{
   433  			"HTML normalization 1",
   434  			"a < b",
   435  			"a &lt; b",
   436  		},
   437  		{
   438  			"HTML normalization 2",
   439  			"a << b",
   440  			"a &lt;&lt; b",
   441  		},
   442  		{
   443  			"HTML normalization 3",
   444  			"a<<!-- --><!-- -->b",
   445  			"a&lt;b",
   446  		},
   447  		{
   448  			"HTML doctype not normalized",
   449  			"<!DOCTYPE html>Hello, World!",
   450  			"<!DOCTYPE html>Hello, World!",
   451  		},
   452  		{
   453  			"HTML doctype not case-insensitive",
   454  			"<!doCtYPE htMl>Hello, World!",
   455  			"<!doCtYPE htMl>Hello, World!",
   456  		},
   457  		{
   458  			"No doctype injection",
   459  			`<!{{"DOCTYPE"}}`,
   460  			"&lt;!DOCTYPE",
   461  		},
   462  		{
   463  			"Split HTML comment",
   464  			"<b>Hello, <!-- name of {{if .T}}city -->{{.C}}{{else}}world -->{{.W}}{{end}}</b>",
   465  			"<b>Hello, &lt;Cincinnati&gt;</b>",
   466  		},
   467  		{
   468  			"JS line comment",
   469  			"<script>for (;;) { if (c()) break// foo not a label\n" +
   470  				"foo({{.T}});}</script>",
   471  			"<script>for (;;) { if (c()) break\n" +
   472  				"foo( true );}</script>",
   473  		},
   474  		{
   475  			"JS multiline block comment",
   476  			"<script>for (;;) { if (c()) break/* foo not a label\n" +
   477  				" */foo({{.T}});}</script>",
   478  			// Newline separates break from call. If newline
   479  			// removed, then break will consume label leaving
   480  			// code invalid.
   481  			"<script>for (;;) { if (c()) break\n" +
   482  				"foo( true );}</script>",
   483  		},
   484  		{
   485  			"JS single-line block comment",
   486  			"<script>for (;;) {\n" +
   487  				"if (c()) break/* foo a label */foo;" +
   488  				"x({{.T}});}</script>",
   489  			// Newline separates break from call. If newline
   490  			// removed, then break will consume label leaving
   491  			// code invalid.
   492  			"<script>for (;;) {\n" +
   493  				"if (c()) break foo;" +
   494  				"x( true );}</script>",
   495  		},
   496  		{
   497  			"JS block comment flush with mathematical division",
   498  			"<script>var a/*b*//c\nd</script>",
   499  			"<script>var a /c\nd</script>",
   500  		},
   501  		{
   502  			"JS mixed comments",
   503  			"<script>var a/*b*///c\nd</script>",
   504  			"<script>var a \nd</script>",
   505  		},
   506  		{
   507  			"JS HTML-like comments",
   508  			"<script>before <!-- beep\nbetween\nbefore-->boop\n</script>",
   509  			"<script>before \nbetween\nbefore\n</script>",
   510  		},
   511  		{
   512  			"JS hashbang comment",
   513  			"<script>#! beep\n</script>",
   514  			"<script>\n</script>",
   515  		},
   516  		{
   517  			"Special tags in <script> string literals",
   518  			`<script>var a = "asd < 123 <!-- 456 < fgh <script jkl < 789 </script"</script>`,
   519  			`<script>var a = "asd < 123 \x3C!-- 456 < fgh \x3Cscript jkl < 789 \x3C/script"</script>`,
   520  		},
   521  		{
   522  			"Special tags in <script> string literals (mixed case)",
   523  			`<script>var a = "<!-- <ScripT </ScripT"</script>`,
   524  			`<script>var a = "\x3C!-- \x3CScripT \x3C/ScripT"</script>`,
   525  		},
   526  		{
   527  			"Special tags in <script> regex literals (mixed case)",
   528  			`<script>var a = /<!-- <ScripT </ScripT/</script>`,
   529  			`<script>var a = /\x3C!-- \x3CScripT \x3C/ScripT/</script>`,
   530  		},
   531  		{
   532  			"CSS comments",
   533  			"<style>p// paragraph\n" +
   534  				`{border: 1px/* color */{{"#00f"}}}</style>`,
   535  			"<style>p\n" +
   536  				"{border: 1px #00f}</style>",
   537  		},
   538  		{
   539  			"JS attr block comment",
   540  			`<a onclick="f(&quot;&quot;); /* alert({{.H}}) */">`,
   541  			// Attribute comment tests should pass if the comments
   542  			// are successfully elided.
   543  			`<a onclick="f(&quot;&quot;); /* alert() */">`,
   544  		},
   545  		{
   546  			"JS attr line comment",
   547  			`<a onclick="// alert({{.G}})">`,
   548  			`<a onclick="// alert()">`,
   549  		},
   550  		{
   551  			"CSS attr block comment",
   552  			`<a style="/* color: {{.H}} */">`,
   553  			`<a style="/* color:  */">`,
   554  		},
   555  		{
   556  			"CSS attr line comment",
   557  			`<a style="// color: {{.G}}">`,
   558  			`<a style="// color: ">`,
   559  		},
   560  		{
   561  			"HTML substitution commented out",
   562  			"<p><!-- {{.H}} --></p>",
   563  			"<p></p>",
   564  		},
   565  		{
   566  			"Comment ends flush with start",
   567  			"<!--{{.}}--><script>/*{{.}}*///{{.}}\n</script><style>/*{{.}}*///{{.}}\n</style><a onclick='/*{{.}}*///{{.}}' style='/*{{.}}*///{{.}}'>",
   568  			"<script> \n</script><style> \n</style><a onclick='/**///' style='/**///'>",
   569  		},
   570  		{
   571  			"typed HTML in text",
   572  			`{{.W}}`,
   573  			`&iexcl;<b class="foo">Hello</b>, <textarea>O'World</textarea>!`,
   574  		},
   575  		{
   576  			"typed HTML in attribute",
   577  			`<div title="{{.W}}">`,
   578  			`<div title="&iexcl;Hello, O&#39;World!">`,
   579  		},
   580  		{
   581  			"typed HTML in script",
   582  			`<button onclick="alert({{.W}})">`,
   583  			`<button onclick="alert(&#34;\u0026iexcl;\u003cb class=\&#34;foo\&#34;\u003eHello\u003c/b\u003e, \u003ctextarea\u003eO&#39;World\u003c/textarea\u003e!&#34;)">`,
   584  		},
   585  		{
   586  			"typed HTML in RCDATA",
   587  			`<textarea>{{.W}}</textarea>`,
   588  			`<textarea>&iexcl;&lt;b class=&#34;foo&#34;&gt;Hello&lt;/b&gt;, &lt;textarea&gt;O&#39;World&lt;/textarea&gt;!</textarea>`,
   589  		},
   590  		{
   591  			"range in textarea",
   592  			"<textarea>{{range .A}}{{.}}{{end}}</textarea>",
   593  			"<textarea>&lt;a&gt;&lt;b&gt;</textarea>",
   594  		},
   595  		{
   596  			"No tag injection",
   597  			`{{"10$"}}<{{"script src,evil.org/pwnd.js"}}...`,
   598  			`10$&lt;script src,evil.org/pwnd.js...`,
   599  		},
   600  		{
   601  			"No comment injection",
   602  			`<{{"!--"}}`,
   603  			`&lt;!--`,
   604  		},
   605  		{
   606  			"No RCDATA end tag injection",
   607  			`<textarea><{{"/textarea "}}...</textarea>`,
   608  			`<textarea>&lt;/textarea ...</textarea>`,
   609  		},
   610  		{
   611  			"optional attrs",
   612  			`<img class="{{"iconClass"}}"` +
   613  				`{{if .T}} id="{{"<iconId>"}}"{{end}}` +
   614  				// Double quotes inside if/else.
   615  				` src=` +
   616  				`{{if .T}}"?{{"<iconPath>"}}"` +
   617  				`{{else}}"images/cleardot.gif"{{end}}` +
   618  				// Missing space before title, but it is not a
   619  				// part of the src attribute.
   620  				`{{if .T}}title="{{"<title>"}}"{{end}}` +
   621  				// Quotes outside if/else.
   622  				` alt="` +
   623  				`{{if .T}}{{"<alt>"}}` +
   624  				`{{else}}{{if .F}}{{"<title>"}}{{end}}` +
   625  				`{{end}}"` +
   626  				`>`,
   627  			`<img class="iconClass" id="&lt;iconId&gt;" src="?%3ciconPath%3e"title="&lt;title&gt;" alt="&lt;alt&gt;">`,
   628  		},
   629  		{
   630  			"conditional valueless attr name",
   631  			`<input{{if .T}} checked{{end}} name=n>`,
   632  			`<input checked name=n>`,
   633  		},
   634  		{
   635  			"conditional dynamic valueless attr name 1",
   636  			`<input{{if .T}} {{"checked"}}{{end}} name=n>`,
   637  			`<input checked name=n>`,
   638  		},
   639  		{
   640  			"conditional dynamic valueless attr name 2",
   641  			`<input {{if .T}}{{"checked"}} {{end}}name=n>`,
   642  			`<input checked name=n>`,
   643  		},
   644  		{
   645  			"dynamic attribute name",
   646  			`<img on{{"load"}}="alert({{"loaded"}})">`,
   647  			// Treated as JS since quotes are inserted.
   648  			`<img onload="alert(&#34;loaded&#34;)">`,
   649  		},
   650  		{
   651  			"bad dynamic attribute name 1",
   652  			// Allow checked, selected, disabled, but not JS or
   653  			// CSS attributes.
   654  			`<input {{"onchange"}}="{{"doEvil()"}}">`,
   655  			`<input ZgotmplZ="doEvil()">`,
   656  		},
   657  		{
   658  			"bad dynamic attribute name 2",
   659  			`<div {{"sTyle"}}="{{"color: expression(alert(1337))"}}">`,
   660  			`<div ZgotmplZ="color: expression(alert(1337))">`,
   661  		},
   662  		{
   663  			"bad dynamic attribute name 3",
   664  			// Allow title or alt, but not a URL.
   665  			`<img {{"src"}}="{{"javascript:doEvil()"}}">`,
   666  			`<img ZgotmplZ="javascript:doEvil()">`,
   667  		},
   668  		{
   669  			"bad dynamic attribute name 4",
   670  			// Structure preservation requires values to associate
   671  			// with a consistent attribute.
   672  			`<input checked {{""}}="Whose value am I?">`,
   673  			`<input checked ZgotmplZ="Whose value am I?">`,
   674  		},
   675  		{
   676  			"dynamic element name",
   677  			`<h{{3}}><table><t{{"head"}}>...</h{{3}}>`,
   678  			`<h3><table><thead>...</h3>`,
   679  		},
   680  		{
   681  			"bad dynamic element name",
   682  			// Dynamic element names are typically used to switch
   683  			// between (thead, tfoot, tbody), (ul, ol), (th, td),
   684  			// and other replaceable sets.
   685  			// We do not currently easily support (ul, ol).
   686  			// If we do change to support that, this test should
   687  			// catch failures to filter out special tag names which
   688  			// would violate the structure preservation property --
   689  			// if any special tag name could be substituted, then
   690  			// the content could be raw text/RCDATA for some inputs
   691  			// and regular HTML content for others.
   692  			`<{{"script"}}>{{"doEvil()"}}</{{"script"}}>`,
   693  			`&lt;script>doEvil()&lt;/script>`,
   694  		},
   695  		{
   696  			"srcset bad URL in second position",
   697  			`<img srcset="{{"/not-an-image#,javascript:alert(1)"}}">`,
   698  			// The second URL is also filtered.
   699  			`<img srcset="/not-an-image#,#ZgotmplZ">`,
   700  		},
   701  		{
   702  			"srcset buffer growth",
   703  			`<img srcset={{",,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,"}}>`,
   704  			`<img srcset=,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,>`,
   705  		},
   706  		{
   707  			"unquoted empty attribute value (plaintext)",
   708  			"<p name={{.U}}>",
   709  			"<p name=ZgotmplZ>",
   710  		},
   711  		{
   712  			"unquoted empty attribute value (url)",
   713  			"<p href={{.U}}>",
   714  			"<p href=ZgotmplZ>",
   715  		},
   716  		{
   717  			"quoted empty attribute value",
   718  			"<p name=\"{{.U}}\">",
   719  			"<p name=\"\">",
   720  		},
   721  	}
   722  
   723  	for _, test := range tests {
   724  		t.Run(test.name, func(t *testing.T) {
   725  			tmpl := New(test.name)
   726  			tmpl = Must(tmpl.Parse(test.input))
   727  			// Check for bug 6459: Tree field was not set in Parse.
   728  			if tmpl.Tree != tmpl.text.Tree {
   729  				t.Fatalf("%s: tree not set properly", test.name)
   730  			}
   731  			b := new(strings.Builder)
   732  			if err := tmpl.Execute(b, data); err != nil {
   733  				t.Fatalf("%s: template execution failed: %s", test.name, err)
   734  			}
   735  			if w, g := test.output, b.String(); w != g {
   736  				t.Fatalf("%s: escaped output: want\n\t%q\ngot\n\t%q", test.name, w, g)
   737  			}
   738  			b.Reset()
   739  			if err := tmpl.Execute(b, pdata); err != nil {
   740  				t.Fatalf("%s: template execution failed for pointer: %s", test.name, err)
   741  			}
   742  			if w, g := test.output, b.String(); w != g {
   743  				t.Fatalf("%s: escaped output for pointer: want\n\t%q\ngot\n\t%q", test.name, w, g)
   744  			}
   745  			if tmpl.Tree != tmpl.text.Tree {
   746  				t.Fatalf("%s: tree mismatch", test.name)
   747  			}
   748  		})
   749  	}
   750  }
   751  
   752  func TestEscapeMap(t *testing.T) {
   753  	data := map[string]string{
   754  		"html":     `<h1>Hi!</h1>`,
   755  		"urlquery": `http://www.foo.com/index.html?title=main`,
   756  	}
   757  	for _, test := range [...]struct {
   758  		desc, input, output string
   759  	}{
   760  		// covering issue 20323
   761  		{
   762  			"field with predefined escaper name 1",
   763  			`{{.html | print}}`,
   764  			`&lt;h1&gt;Hi!&lt;/h1&gt;`,
   765  		},
   766  		// covering issue 20323
   767  		{
   768  			"field with predefined escaper name 2",
   769  			`{{.urlquery | print}}`,
   770  			`http://www.foo.com/index.html?title=main`,
   771  		},
   772  	} {
   773  		tmpl := Must(New("").Parse(test.input))
   774  		b := new(strings.Builder)
   775  		if err := tmpl.Execute(b, data); err != nil {
   776  			t.Errorf("%s: template execution failed: %s", test.desc, err)
   777  			continue
   778  		}
   779  		if w, g := test.output, b.String(); w != g {
   780  			t.Errorf("%s: escaped output: want\n\t%q\ngot\n\t%q", test.desc, w, g)
   781  			continue
   782  		}
   783  	}
   784  }
   785  
   786  func TestEscapeSet(t *testing.T) {
   787  	type dataItem struct {
   788  		Children []*dataItem
   789  		X        string
   790  	}
   791  
   792  	data := dataItem{
   793  		Children: []*dataItem{
   794  			{X: "foo"},
   795  			{X: "<bar>"},
   796  			{
   797  				Children: []*dataItem{
   798  					{X: "baz"},
   799  				},
   800  			},
   801  		},
   802  	}
   803  
   804  	tests := []struct {
   805  		inputs map[string]string
   806  		want   string
   807  	}{
   808  		// The trivial set.
   809  		{
   810  			map[string]string{
   811  				"main": ``,
   812  			},
   813  			``,
   814  		},
   815  		// A template called in the start context.
   816  		{
   817  			map[string]string{
   818  				"main": `Hello, {{template "helper"}}!`,
   819  				// Not a valid top level HTML template.
   820  				// "<b" is not a full tag.
   821  				"helper": `{{"<World>"}}`,
   822  			},
   823  			`Hello, &lt;World&gt;!`,
   824  		},
   825  		// A template called in a context other than the start.
   826  		{
   827  			map[string]string{
   828  				"main": `<a onclick='a = {{template "helper"}};'>`,
   829  				// Not a valid top level HTML template.
   830  				// "<b" is not a full tag.
   831  				"helper": `{{"<a>"}}<b`,
   832  			},
   833  			`<a onclick='a = &#34;\u003ca\u003e&#34;<b;'>`,
   834  		},
   835  		// A recursive template that ends in its start context.
   836  		{
   837  			map[string]string{
   838  				"main": `{{range .Children}}{{template "main" .}}{{else}}{{.X}} {{end}}`,
   839  			},
   840  			`foo &lt;bar&gt; baz `,
   841  		},
   842  		// A recursive helper template that ends in its start context.
   843  		{
   844  			map[string]string{
   845  				"main":   `{{template "helper" .}}`,
   846  				"helper": `{{if .Children}}<ul>{{range .Children}}<li>{{template "main" .}}</li>{{end}}</ul>{{else}}{{.X}}{{end}}`,
   847  			},
   848  			`<ul><li>foo</li><li>&lt;bar&gt;</li><li><ul><li>baz</li></ul></li></ul>`,
   849  		},
   850  		// Co-recursive templates that end in its start context.
   851  		{
   852  			map[string]string{
   853  				"main":   `<blockquote>{{range .Children}}{{template "helper" .}}{{end}}</blockquote>`,
   854  				"helper": `{{if .Children}}{{template "main" .}}{{else}}{{.X}}<br>{{end}}`,
   855  			},
   856  			`<blockquote>foo<br>&lt;bar&gt;<br><blockquote>baz<br></blockquote></blockquote>`,
   857  		},
   858  		// A template that is called in two different contexts.
   859  		{
   860  			map[string]string{
   861  				"main":   `<button onclick="title='{{template "helper"}}'; ...">{{template "helper"}}</button>`,
   862  				"helper": `{{11}} of {{"<100>"}}`,
   863  			},
   864  			`<button onclick="title='11 of \u003c100\u003e'; ...">11 of &lt;100&gt;</button>`,
   865  		},
   866  		// A non-recursive template that ends in a different context.
   867  		// helper starts in jsCtxRegexp and ends in jsCtxDivOp.
   868  		{
   869  			map[string]string{
   870  				"main":   `<script>var x={{template "helper"}}/{{"42"}};</script>`,
   871  				"helper": "{{126}}",
   872  			},
   873  			`<script>var x= 126 /"42";</script>`,
   874  		},
   875  		// A recursive template that ends in a similar context.
   876  		{
   877  			map[string]string{
   878  				"main":      `<script>var x=[{{template "countdown" 4}}];</script>`,
   879  				"countdown": `{{.}}{{if .}},{{template "countdown" . | pred}}{{end}}`,
   880  			},
   881  			`<script>var x=[ 4 , 3 , 2 , 1 , 0 ];</script>`,
   882  		},
   883  		// A recursive template that ends in a different context.
   884  		/*
   885  			{
   886  				map[string]string{
   887  					"main":   `<a href="/foo{{template "helper" .}}">`,
   888  					"helper": `{{if .Children}}{{range .Children}}{{template "helper" .}}{{end}}{{else}}?x={{.X}}{{end}}`,
   889  				},
   890  				`<a href="/foo?x=foo?x=%3cbar%3e?x=baz">`,
   891  			},
   892  		*/
   893  	}
   894  
   895  	// pred is a template function that returns the predecessor of a
   896  	// natural number for testing recursive templates.
   897  	fns := FuncMap{"pred": func(a ...any) (any, error) {
   898  		if len(a) == 1 {
   899  			if i, _ := a[0].(int); i > 0 {
   900  				return i - 1, nil
   901  			}
   902  		}
   903  		return nil, fmt.Errorf("undefined pred(%v)", a)
   904  	}}
   905  
   906  	for _, test := range tests {
   907  		source := ""
   908  		for name, body := range test.inputs {
   909  			source += fmt.Sprintf("{{define %q}}%s{{end}} ", name, body)
   910  		}
   911  		tmpl, err := New("root").Funcs(fns).Parse(source)
   912  		if err != nil {
   913  			t.Errorf("error parsing %q: %v", source, err)
   914  			continue
   915  		}
   916  		var b strings.Builder
   917  
   918  		if err := tmpl.ExecuteTemplate(&b, "main", data); err != nil {
   919  			t.Errorf("%q executing %v", err.Error(), tmpl.Lookup("main"))
   920  			continue
   921  		}
   922  		if got := b.String(); test.want != got {
   923  			t.Errorf("want\n\t%q\ngot\n\t%q", test.want, got)
   924  		}
   925  	}
   926  
   927  }
   928  
   929  func TestErrors(t *testing.T) {
   930  	tests := []struct {
   931  		input string
   932  		err   string
   933  	}{
   934  		// Non-error cases.
   935  		{
   936  			"{{if .Cond}}<a>{{else}}<b>{{end}}",
   937  			"",
   938  		},
   939  		{
   940  			"{{if .Cond}}<a>{{end}}",
   941  			"",
   942  		},
   943  		{
   944  			"{{if .Cond}}{{else}}<b>{{end}}",
   945  			"",
   946  		},
   947  		{
   948  			"{{with .Cond}}<div>{{end}}",
   949  			"",
   950  		},
   951  		{
   952  			"{{range .Items}}<a>{{end}}",
   953  			"",
   954  		},
   955  		{
   956  			"<a href='/foo?{{range .Items}}&{{.K}}={{.V}}{{end}}'>",
   957  			"",
   958  		},
   959  		{
   960  			"{{range .Items}}<a{{if .X}}{{end}}>{{end}}",
   961  			"",
   962  		},
   963  		{
   964  			"{{range .Items}}<a{{if .X}}{{end}}>{{continue}}{{end}}",
   965  			"",
   966  		},
   967  		{
   968  			"{{range .Items}}<a{{if .X}}{{end}}>{{break}}{{end}}",
   969  			"",
   970  		},
   971  		{
   972  			"{{range .Items}}<a{{if .X}}{{end}}>{{if .X}}{{break}}{{end}}{{end}}",
   973  			"",
   974  		},
   975  		{
   976  			"<script>var a = `${a+b}`</script>`",
   977  			"",
   978  		},
   979  		// Error cases.
   980  		{
   981  			"{{if .Cond}}<a{{end}}",
   982  			"z:1:5: {{if}} branches",
   983  		},
   984  		{
   985  			"{{if .Cond}}\n{{else}}\n<a{{end}}",
   986  			"z:1:5: {{if}} branches",
   987  		},
   988  		{
   989  			// Missing quote in the else branch.
   990  			`{{if .Cond}}<a href="foo">{{else}}<a href="bar>{{end}}`,
   991  			"z:1:5: {{if}} branches",
   992  		},
   993  		{
   994  			// Different kind of attribute: href implies a URL.
   995  			"<a {{if .Cond}}href='{{else}}title='{{end}}{{.X}}'>",
   996  			"z:1:8: {{if}} branches",
   997  		},
   998  		{
   999  			"\n{{with .X}}<a{{end}}",
  1000  			"z:2:7: {{with}} branches",
  1001  		},
  1002  		{
  1003  			"\n{{with .X}}<a>{{else}}<a{{end}}",
  1004  			"z:2:7: {{with}} branches",
  1005  		},
  1006  		{
  1007  			"{{range .Items}}<a{{end}}",
  1008  			`z:1: on range loop re-entry: "<" in attribute name: "<a"`,
  1009  		},
  1010  		{
  1011  			"\n{{range .Items}} x='<a{{end}}",
  1012  			"z:2:8: on range loop re-entry: {{range}} branches",
  1013  		},
  1014  		{
  1015  			"{{range .Items}}<a{{if .X}}{{break}}{{end}}>{{end}}",
  1016  			"z:1:29: at range loop break: {{range}} branches end in different contexts",
  1017  		},
  1018  		{
  1019  			"{{range .Items}}<a{{if .X}}{{continue}}{{end}}>{{end}}",
  1020  			"z:1:29: at range loop continue: {{range}} branches end in different contexts",
  1021  		},
  1022  		{
  1023  			"<a b=1 c={{.H}}",
  1024  			"z: ends in a non-text context: {stateAttr delimSpaceOrTagEnd",
  1025  		},
  1026  		{
  1027  			"<script>foo();",
  1028  			"z: ends in a non-text context: {stateJS",
  1029  		},
  1030  		{
  1031  			`<a href="{{if .F}}/foo?a={{else}}/bar/{{end}}{{.H}}">`,
  1032  			"z:1:47: {{.H}} appears in an ambiguous context within a URL",
  1033  		},
  1034  		{
  1035  			`<a onclick="alert('Hello \`,
  1036  			`unfinished escape sequence in JS string: "Hello \\"`,
  1037  		},
  1038  		{
  1039  			`<a onclick='alert("Hello\, World\`,
  1040  			`unfinished escape sequence in JS string: "Hello\\, World\\"`,
  1041  		},
  1042  		{
  1043  			`<a onclick='alert(/x+\`,
  1044  			`unfinished escape sequence in JS string: "x+\\"`,
  1045  		},
  1046  		{
  1047  			`<a onclick="/foo[\]/`,
  1048  			`unfinished JS regexp charset: "foo[\\]/"`,
  1049  		},
  1050  		{
  1051  			// It is ambiguous whether 1.5 should be 1\.5 or 1.5.
  1052  			// Either `var x = 1/- 1.5 /i.test(x)`
  1053  			// where `i.test(x)` is a method call of reference i,
  1054  			// or `/-1\.5/i.test(x)` which is a method call on a
  1055  			// case insensitive regular expression.
  1056  			`<script>{{if false}}var x = 1{{end}}/-{{"1.5"}}/i.test(x)</script>`,
  1057  			`'/' could start a division or regexp: "/-"`,
  1058  		},
  1059  		{
  1060  			`{{template "foo"}}`,
  1061  			"z:1:11: no such template \"foo\"",
  1062  		},
  1063  		{
  1064  			`<div{{template "y"}}>` +
  1065  				// Illegal starting in stateTag but not in stateText.
  1066  				`{{define "y"}} foo<b{{end}}`,
  1067  			`"<" in attribute name: " foo<b"`,
  1068  		},
  1069  		{
  1070  			`<script>reverseList = [{{template "t"}}]</script>` +
  1071  				// Missing " after recursive call.
  1072  				`{{define "t"}}{{if .Tail}}{{template "t" .Tail}}{{end}}{{.Head}}",{{end}}`,
  1073  			`: cannot compute output context for template t$htmltemplate_stateJS_elementScript`,
  1074  		},
  1075  		{
  1076  			`<input type=button value=onclick=>`,
  1077  			`html/template:z: "=" in unquoted attr: "onclick="`,
  1078  		},
  1079  		{
  1080  			`<input type=button value= onclick=>`,
  1081  			`html/template:z: "=" in unquoted attr: "onclick="`,
  1082  		},
  1083  		{
  1084  			`<input type=button value= 1+1=2>`,
  1085  			`html/template:z: "=" in unquoted attr: "1+1=2"`,
  1086  		},
  1087  		{
  1088  			"<a class=`foo>",
  1089  			"html/template:z: \"`\" in unquoted attr: \"`foo\"",
  1090  		},
  1091  		{
  1092  			`<a style=font:'Arial'>`,
  1093  			`html/template:z: "'" in unquoted attr: "font:'Arial'"`,
  1094  		},
  1095  		{
  1096  			`<a=foo>`,
  1097  			`: expected space, attr name, or end of tag, but got "=foo>"`,
  1098  		},
  1099  		{
  1100  			`Hello, {{. | urlquery | print}}!`,
  1101  			// urlquery is disallowed if it is not the last command in the pipeline.
  1102  			`predefined escaper "urlquery" disallowed in template`,
  1103  		},
  1104  		{
  1105  			`Hello, {{. | html | print}}!`,
  1106  			// html is disallowed if it is not the last command in the pipeline.
  1107  			`predefined escaper "html" disallowed in template`,
  1108  		},
  1109  		{
  1110  			`Hello, {{html . | print}}!`,
  1111  			// A direct call to html is disallowed if it is not the last command in the pipeline.
  1112  			`predefined escaper "html" disallowed in template`,
  1113  		},
  1114  		{
  1115  			`<div class={{. | html}}>Hello<div>`,
  1116  			// html is disallowed in a pipeline that is in an unquoted attribute context,
  1117  			// even if it is the last command in the pipeline.
  1118  			`predefined escaper "html" disallowed in template`,
  1119  		},
  1120  		{
  1121  			`Hello, {{. | urlquery | html}}!`,
  1122  			// html is allowed since it is the last command in the pipeline, but urlquery is not.
  1123  			`predefined escaper "urlquery" disallowed in template`,
  1124  		},
  1125  		{
  1126  			"<script>var tmpl = `asd {{.}}`;</script>",
  1127  			`{{.}} appears in a JS template literal`,
  1128  		},
  1129  	}
  1130  	for _, test := range tests {
  1131  		buf := new(bytes.Buffer)
  1132  		tmpl, err := New("z").Parse(test.input)
  1133  		if err != nil {
  1134  			t.Errorf("input=%q: unexpected parse error %s\n", test.input, err)
  1135  			continue
  1136  		}
  1137  		err = tmpl.Execute(buf, nil)
  1138  		var got string
  1139  		if err != nil {
  1140  			got = err.Error()
  1141  		}
  1142  		if test.err == "" {
  1143  			if got != "" {
  1144  				t.Errorf("input=%q: unexpected error %q", test.input, got)
  1145  			}
  1146  			continue
  1147  		}
  1148  		if !strings.Contains(got, test.err) {
  1149  			t.Errorf("input=%q: error\n\t%q\ndoes not contain expected string\n\t%q", test.input, got, test.err)
  1150  			continue
  1151  		}
  1152  		// Check that we get the same error if we call Execute again.
  1153  		if err := tmpl.Execute(buf, nil); err == nil || err.Error() != got {
  1154  			t.Errorf("input=%q: unexpected error on second call %q", test.input, err)
  1155  
  1156  		}
  1157  	}
  1158  }
  1159  
  1160  func TestEscapeText(t *testing.T) {
  1161  	tests := []struct {
  1162  		input  string
  1163  		output context
  1164  	}{
  1165  		{
  1166  			``,
  1167  			context{},
  1168  		},
  1169  		{
  1170  			`Hello, World!`,
  1171  			context{},
  1172  		},
  1173  		{
  1174  			// An orphaned "<" is OK.
  1175  			`I <3 Ponies!`,
  1176  			context{},
  1177  		},
  1178  		{
  1179  			`<a`,
  1180  			context{state: stateTag},
  1181  		},
  1182  		{
  1183  			`<a `,
  1184  			context{state: stateTag},
  1185  		},
  1186  		{
  1187  			`<a>`,
  1188  			context{state: stateText},
  1189  		},
  1190  		{
  1191  			`<a href`,
  1192  			context{state: stateAttrName, attr: attrURL},
  1193  		},
  1194  		{
  1195  			`<a on`,
  1196  			context{state: stateAttrName, attr: attrScript},
  1197  		},
  1198  		{
  1199  			`<a href `,
  1200  			context{state: stateAfterName, attr: attrURL},
  1201  		},
  1202  		{
  1203  			`<a style  =  `,
  1204  			context{state: stateBeforeValue, attr: attrStyle},
  1205  		},
  1206  		{
  1207  			`<a href=`,
  1208  			context{state: stateBeforeValue, attr: attrURL},
  1209  		},
  1210  		{
  1211  			`<a href=x`,
  1212  			context{state: stateURL, delim: delimSpaceOrTagEnd, urlPart: urlPartPreQuery, attr: attrURL},
  1213  		},
  1214  		{
  1215  			`<a href=x `,
  1216  			context{state: stateTag},
  1217  		},
  1218  		{
  1219  			`<a href=>`,
  1220  			context{state: stateText},
  1221  		},
  1222  		{
  1223  			`<a href=x>`,
  1224  			context{state: stateText},
  1225  		},
  1226  		{
  1227  			`<a href ='`,
  1228  			context{state: stateURL, delim: delimSingleQuote, attr: attrURL},
  1229  		},
  1230  		{
  1231  			`<a href=''`,
  1232  			context{state: stateTag},
  1233  		},
  1234  		{
  1235  			`<a href= "`,
  1236  			context{state: stateURL, delim: delimDoubleQuote, attr: attrURL},
  1237  		},
  1238  		{
  1239  			`<a href=""`,
  1240  			context{state: stateTag},
  1241  		},
  1242  		{
  1243  			`<a title="`,
  1244  			context{state: stateAttr, delim: delimDoubleQuote},
  1245  		},
  1246  		{
  1247  			`<a HREF='http:`,
  1248  			context{state: stateURL, delim: delimSingleQuote, urlPart: urlPartPreQuery, attr: attrURL},
  1249  		},
  1250  		{
  1251  			`<a Href='/`,
  1252  			context{state: stateURL, delim: delimSingleQuote, urlPart: urlPartPreQuery, attr: attrURL},
  1253  		},
  1254  		{
  1255  			`<a href='"`,
  1256  			context{state: stateURL, delim: delimSingleQuote, urlPart: urlPartPreQuery, attr: attrURL},
  1257  		},
  1258  		{
  1259  			`<a href="'`,
  1260  			context{state: stateURL, delim: delimDoubleQuote, urlPart: urlPartPreQuery, attr: attrURL},
  1261  		},
  1262  		{
  1263  			`<a href='&apos;`,
  1264  			context{state: stateURL, delim: delimSingleQuote, urlPart: urlPartPreQuery, attr: attrURL},
  1265  		},
  1266  		{
  1267  			`<a href="&quot;`,
  1268  			context{state: stateURL, delim: delimDoubleQuote, urlPart: urlPartPreQuery, attr: attrURL},
  1269  		},
  1270  		{
  1271  			`<a href="&#34;`,
  1272  			context{state: stateURL, delim: delimDoubleQuote, urlPart: urlPartPreQuery, attr: attrURL},
  1273  		},
  1274  		{
  1275  			`<a href=&quot;`,
  1276  			context{state: stateURL, delim: delimSpaceOrTagEnd, urlPart: urlPartPreQuery, attr: attrURL},
  1277  		},
  1278  		{
  1279  			`<img alt="1">`,
  1280  			context{state: stateText},
  1281  		},
  1282  		{
  1283  			`<img alt="1>"`,
  1284  			context{state: stateTag},
  1285  		},
  1286  		{
  1287  			`<img alt="1>">`,
  1288  			context{state: stateText},
  1289  		},
  1290  		{
  1291  			`<input checked type="checkbox"`,
  1292  			context{state: stateTag},
  1293  		},
  1294  		{
  1295  			`<a onclick="`,
  1296  			context{state: stateJS, delim: delimDoubleQuote, attr: attrScript},
  1297  		},
  1298  		{
  1299  			`<a onclick="//foo`,
  1300  			context{state: stateJSLineCmt, delim: delimDoubleQuote, attr: attrScript},
  1301  		},
  1302  		{
  1303  			"<a onclick='//\n",
  1304  			context{state: stateJS, delim: delimSingleQuote, attr: attrScript},
  1305  		},
  1306  		{
  1307  			"<a onclick='//\r\n",
  1308  			context{state: stateJS, delim: delimSingleQuote, attr: attrScript},
  1309  		},
  1310  		{
  1311  			"<a onclick='//\u2028",
  1312  			context{state: stateJS, delim: delimSingleQuote, attr: attrScript},
  1313  		},
  1314  		{
  1315  			`<a onclick="/*`,
  1316  			context{state: stateJSBlockCmt, delim: delimDoubleQuote, attr: attrScript},
  1317  		},
  1318  		{
  1319  			`<a onclick="/*/`,
  1320  			context{state: stateJSBlockCmt, delim: delimDoubleQuote, attr: attrScript},
  1321  		},
  1322  		{
  1323  			`<a onclick="/**/`,
  1324  			context{state: stateJS, delim: delimDoubleQuote, attr: attrScript},
  1325  		},
  1326  		{
  1327  			`<a onkeypress="&quot;`,
  1328  			context{state: stateJSDqStr, delim: delimDoubleQuote, attr: attrScript},
  1329  		},
  1330  		{
  1331  			`<a onclick='&quot;foo&quot;`,
  1332  			context{state: stateJS, delim: delimSingleQuote, jsCtx: jsCtxDivOp, attr: attrScript},
  1333  		},
  1334  		{
  1335  			`<a onclick=&#39;foo&#39;`,
  1336  			context{state: stateJS, delim: delimSpaceOrTagEnd, jsCtx: jsCtxDivOp, attr: attrScript},
  1337  		},
  1338  		{
  1339  			`<a onclick=&#39;foo`,
  1340  			context{state: stateJSSqStr, delim: delimSpaceOrTagEnd, attr: attrScript},
  1341  		},
  1342  		{
  1343  			`<a onclick="&quot;foo'`,
  1344  			context{state: stateJSDqStr, delim: delimDoubleQuote, attr: attrScript},
  1345  		},
  1346  		{
  1347  			`<a onclick="'foo&quot;`,
  1348  			context{state: stateJSSqStr, delim: delimDoubleQuote, attr: attrScript},
  1349  		},
  1350  		{
  1351  			"<a onclick=\"`foo",
  1352  			context{state: stateJSBqStr, delim: delimDoubleQuote, attr: attrScript},
  1353  		},
  1354  		{
  1355  			`<A ONCLICK="'`,
  1356  			context{state: stateJSSqStr, delim: delimDoubleQuote, attr: attrScript},
  1357  		},
  1358  		{
  1359  			`<a onclick="/`,
  1360  			context{state: stateJSRegexp, delim: delimDoubleQuote, attr: attrScript},
  1361  		},
  1362  		{
  1363  			`<a onclick="'foo'`,
  1364  			context{state: stateJS, delim: delimDoubleQuote, jsCtx: jsCtxDivOp, attr: attrScript},
  1365  		},
  1366  		{
  1367  			`<a onclick="'foo\'`,
  1368  			context{state: stateJSSqStr, delim: delimDoubleQuote, attr: attrScript},
  1369  		},
  1370  		{
  1371  			`<a onclick="'foo\'`,
  1372  			context{state: stateJSSqStr, delim: delimDoubleQuote, attr: attrScript},
  1373  		},
  1374  		{
  1375  			`<a onclick="/foo/`,
  1376  			context{state: stateJS, delim: delimDoubleQuote, jsCtx: jsCtxDivOp, attr: attrScript},
  1377  		},
  1378  		{
  1379  			`<script>/foo/ /=`,
  1380  			context{state: stateJS, element: elementScript},
  1381  		},
  1382  		{
  1383  			`<a onclick="1 /foo`,
  1384  			context{state: stateJS, delim: delimDoubleQuote, jsCtx: jsCtxDivOp, attr: attrScript},
  1385  		},
  1386  		{
  1387  			`<a onclick="1 /*c*/ /foo`,
  1388  			context{state: stateJS, delim: delimDoubleQuote, jsCtx: jsCtxDivOp, attr: attrScript},
  1389  		},
  1390  		{
  1391  			`<a onclick="/foo[/]`,
  1392  			context{state: stateJSRegexp, delim: delimDoubleQuote, attr: attrScript},
  1393  		},
  1394  		{
  1395  			`<a onclick="/foo\/`,
  1396  			context{state: stateJSRegexp, delim: delimDoubleQuote, attr: attrScript},
  1397  		},
  1398  		{
  1399  			`<a onclick="/foo/`,
  1400  			context{state: stateJS, delim: delimDoubleQuote, jsCtx: jsCtxDivOp, attr: attrScript},
  1401  		},
  1402  		{
  1403  			`<input checked style="`,
  1404  			context{state: stateCSS, delim: delimDoubleQuote, attr: attrStyle},
  1405  		},
  1406  		{
  1407  			`<a style="//`,
  1408  			context{state: stateCSSLineCmt, delim: delimDoubleQuote, attr: attrStyle},
  1409  		},
  1410  		{
  1411  			`<a style="//</script>`,
  1412  			context{state: stateCSSLineCmt, delim: delimDoubleQuote, attr: attrStyle},
  1413  		},
  1414  		{
  1415  			"<a style='//\n",
  1416  			context{state: stateCSS, delim: delimSingleQuote, attr: attrStyle},
  1417  		},
  1418  		{
  1419  			"<a style='//\r",
  1420  			context{state: stateCSS, delim: delimSingleQuote, attr: attrStyle},
  1421  		},
  1422  		{
  1423  			`<a style="/*`,
  1424  			context{state: stateCSSBlockCmt, delim: delimDoubleQuote, attr: attrStyle},
  1425  		},
  1426  		{
  1427  			`<a style="/*/`,
  1428  			context{state: stateCSSBlockCmt, delim: delimDoubleQuote, attr: attrStyle},
  1429  		},
  1430  		{
  1431  			`<a style="/**/`,
  1432  			context{state: stateCSS, delim: delimDoubleQuote, attr: attrStyle},
  1433  		},
  1434  		{
  1435  			`<a style="background: '`,
  1436  			context{state: stateCSSSqStr, delim: delimDoubleQuote, attr: attrStyle},
  1437  		},
  1438  		{
  1439  			`<a style="background: &quot;`,
  1440  			context{state: stateCSSDqStr, delim: delimDoubleQuote, attr: attrStyle},
  1441  		},
  1442  		{
  1443  			`<a style="background: '/foo?img=`,
  1444  			context{state: stateCSSSqStr, delim: delimDoubleQuote, urlPart: urlPartQueryOrFrag, attr: attrStyle},
  1445  		},
  1446  		{
  1447  			`<a style="background: '/`,
  1448  			context{state: stateCSSSqStr, delim: delimDoubleQuote, urlPart: urlPartPreQuery, attr: attrStyle},
  1449  		},
  1450  		{
  1451  			`<a style="background: url(&#x22;/`,
  1452  			context{state: stateCSSDqURL, delim: delimDoubleQuote, urlPart: urlPartPreQuery, attr: attrStyle},
  1453  		},
  1454  		{
  1455  			`<a style="background: url('/`,
  1456  			context{state: stateCSSSqURL, delim: delimDoubleQuote, urlPart: urlPartPreQuery, attr: attrStyle},
  1457  		},
  1458  		{
  1459  			`<a style="background: url('/)`,
  1460  			context{state: stateCSSSqURL, delim: delimDoubleQuote, urlPart: urlPartPreQuery, attr: attrStyle},
  1461  		},
  1462  		{
  1463  			`<a style="background: url('/ `,
  1464  			context{state: stateCSSSqURL, delim: delimDoubleQuote, urlPart: urlPartPreQuery, attr: attrStyle},
  1465  		},
  1466  		{
  1467  			`<a style="background: url(/`,
  1468  			context{state: stateCSSURL, delim: delimDoubleQuote, urlPart: urlPartPreQuery, attr: attrStyle},
  1469  		},
  1470  		{
  1471  			`<a style="background: url( `,
  1472  			context{state: stateCSSURL, delim: delimDoubleQuote, attr: attrStyle},
  1473  		},
  1474  		{
  1475  			`<a style="background: url( /image?name=`,
  1476  			context{state: stateCSSURL, delim: delimDoubleQuote, urlPart: urlPartQueryOrFrag, attr: attrStyle},
  1477  		},
  1478  		{
  1479  			`<a style="background: url(x)`,
  1480  			context{state: stateCSS, delim: delimDoubleQuote, attr: attrStyle},
  1481  		},
  1482  		{
  1483  			`<a style="background: url('x'`,
  1484  			context{state: stateCSS, delim: delimDoubleQuote, attr: attrStyle},
  1485  		},
  1486  		{
  1487  			`<a style="background: url( x `,
  1488  			context{state: stateCSS, delim: delimDoubleQuote, attr: attrStyle},
  1489  		},
  1490  		{
  1491  			`<!-- foo`,
  1492  			context{state: stateHTMLCmt},
  1493  		},
  1494  		{
  1495  			`<!-->`,
  1496  			context{state: stateHTMLCmt},
  1497  		},
  1498  		{
  1499  			`<!--->`,
  1500  			context{state: stateHTMLCmt},
  1501  		},
  1502  		{
  1503  			`<!-- foo -->`,
  1504  			context{state: stateText},
  1505  		},
  1506  		{
  1507  			`<script`,
  1508  			context{state: stateTag, element: elementScript},
  1509  		},
  1510  		{
  1511  			`<script `,
  1512  			context{state: stateTag, element: elementScript},
  1513  		},
  1514  		{
  1515  			`<script src="foo.js" `,
  1516  			context{state: stateTag, element: elementScript},
  1517  		},
  1518  		{
  1519  			`<script src='foo.js' `,
  1520  			context{state: stateTag, element: elementScript},
  1521  		},
  1522  		{
  1523  			`<script type=text/javascript `,
  1524  			context{state: stateTag, element: elementScript},
  1525  		},
  1526  		{
  1527  			`<script>`,
  1528  			context{state: stateJS, jsCtx: jsCtxRegexp, element: elementScript},
  1529  		},
  1530  		{
  1531  			`<script>foo`,
  1532  			context{state: stateJS, jsCtx: jsCtxDivOp, element: elementScript},
  1533  		},
  1534  		{
  1535  			`<script>foo</script>`,
  1536  			context{state: stateText},
  1537  		},
  1538  		{
  1539  			`<script>foo</script><!--`,
  1540  			context{state: stateHTMLCmt},
  1541  		},
  1542  		{
  1543  			`<script>document.write("<p>foo</p>");`,
  1544  			context{state: stateJS, element: elementScript},
  1545  		},
  1546  		{
  1547  			`<script>document.write("<p>foo<\/script>");`,
  1548  			context{state: stateJS, element: elementScript},
  1549  		},
  1550  		{
  1551  			// <script and </script tags are escaped, so </script> should not
  1552  			// cause us to exit the JS state.
  1553  			`<script>document.write("<script>alert(1)</script>");`,
  1554  			context{state: stateJS, element: elementScript},
  1555  		},
  1556  		{
  1557  			`<script>document.write("<script>`,
  1558  			context{state: stateJSDqStr, element: elementScript},
  1559  		},
  1560  		{
  1561  			`<script>document.write("<script>alert(1)</script>`,
  1562  			context{state: stateJSDqStr, element: elementScript},
  1563  		},
  1564  		{
  1565  			`<script>document.write("<script>alert(1)<!--`,
  1566  			context{state: stateJSDqStr, element: elementScript},
  1567  		},
  1568  		{
  1569  			`<script>document.write("<script>alert(1)</Script>");`,
  1570  			context{state: stateJS, element: elementScript},
  1571  		},
  1572  		{
  1573  			`<script>document.write("<!--");`,
  1574  			context{state: stateJS, element: elementScript},
  1575  		},
  1576  		{
  1577  			`<script>let a = /</script`,
  1578  			context{state: stateJSRegexp, element: elementScript},
  1579  		},
  1580  		{
  1581  			`<script>let a = /</script/`,
  1582  			context{state: stateJS, element: elementScript, jsCtx: jsCtxDivOp},
  1583  		},
  1584  		{
  1585  			`<script type="text/template">`,
  1586  			context{state: stateText},
  1587  		},
  1588  		// covering issue 19968
  1589  		{
  1590  			`<script type="TEXT/JAVASCRIPT">`,
  1591  			context{state: stateJS, element: elementScript},
  1592  		},
  1593  		// covering issue 19965
  1594  		{
  1595  			`<script TYPE="text/template">`,
  1596  			context{state: stateText},
  1597  		},
  1598  		{
  1599  			`<script type="notjs">`,
  1600  			context{state: stateText},
  1601  		},
  1602  		{
  1603  			`<Script>`,
  1604  			context{state: stateJS, element: elementScript},
  1605  		},
  1606  		{
  1607  			`<SCRIPT>foo`,
  1608  			context{state: stateJS, jsCtx: jsCtxDivOp, element: elementScript},
  1609  		},
  1610  		{
  1611  			`<textarea>value`,
  1612  			context{state: stateRCDATA, element: elementTextarea},
  1613  		},
  1614  		{
  1615  			`<textarea>value</TEXTAREA>`,
  1616  			context{state: stateText},
  1617  		},
  1618  		{
  1619  			`<textarea name=html><b`,
  1620  			context{state: stateRCDATA, element: elementTextarea},
  1621  		},
  1622  		{
  1623  			`<title>value`,
  1624  			context{state: stateRCDATA, element: elementTitle},
  1625  		},
  1626  		{
  1627  			`<style>value`,
  1628  			context{state: stateCSS, element: elementStyle},
  1629  		},
  1630  		{
  1631  			`<a xlink:href`,
  1632  			context{state: stateAttrName, attr: attrURL},
  1633  		},
  1634  		{
  1635  			`<a xmlns`,
  1636  			context{state: stateAttrName, attr: attrURL},
  1637  		},
  1638  		{
  1639  			`<a xmlns:foo`,
  1640  			context{state: stateAttrName, attr: attrURL},
  1641  		},
  1642  		{
  1643  			`<a xmlnsxyz`,
  1644  			context{state: stateAttrName},
  1645  		},
  1646  		{
  1647  			`<a data-url`,
  1648  			context{state: stateAttrName, attr: attrURL},
  1649  		},
  1650  		{
  1651  			`<a data-iconUri`,
  1652  			context{state: stateAttrName, attr: attrURL},
  1653  		},
  1654  		{
  1655  			`<a data-urlItem`,
  1656  			context{state: stateAttrName, attr: attrURL},
  1657  		},
  1658  		{
  1659  			`<a g:`,
  1660  			context{state: stateAttrName},
  1661  		},
  1662  		{
  1663  			`<a g:url`,
  1664  			context{state: stateAttrName, attr: attrURL},
  1665  		},
  1666  		{
  1667  			`<a g:iconUri`,
  1668  			context{state: stateAttrName, attr: attrURL},
  1669  		},
  1670  		{
  1671  			`<a g:urlItem`,
  1672  			context{state: stateAttrName, attr: attrURL},
  1673  		},
  1674  		{
  1675  			`<a g:value`,
  1676  			context{state: stateAttrName},
  1677  		},
  1678  		{
  1679  			`<a svg:style='`,
  1680  			context{state: stateCSS, delim: delimSingleQuote, attr: attrStyle},
  1681  		},
  1682  		{
  1683  			`<svg:font-face`,
  1684  			context{state: stateTag},
  1685  		},
  1686  		{
  1687  			`<svg:a svg:onclick="`,
  1688  			context{state: stateJS, delim: delimDoubleQuote, attr: attrScript},
  1689  		},
  1690  		{
  1691  			`<svg:a svg:onclick="x()">`,
  1692  			context{},
  1693  		},
  1694  	}
  1695  
  1696  	for _, test := range tests {
  1697  		b, e := []byte(test.input), makeEscaper(nil)
  1698  		c := e.escapeText(context{}, &parse.TextNode{NodeType: parse.NodeText, Text: b})
  1699  		if !test.output.eq(c) {
  1700  			t.Errorf("input %q: want context\n\t%v\ngot\n\t%v", test.input, test.output, c)
  1701  			continue
  1702  		}
  1703  		if test.input != string(b) {
  1704  			t.Errorf("input %q: text node was modified: want %q got %q", test.input, test.input, b)
  1705  			continue
  1706  		}
  1707  	}
  1708  }
  1709  
  1710  func TestEnsurePipelineContains(t *testing.T) {
  1711  	tests := []struct {
  1712  		input, output string
  1713  		ids           []string
  1714  	}{
  1715  		{
  1716  			"{{.X}}",
  1717  			".X",
  1718  			[]string{},
  1719  		},
  1720  		{
  1721  			"{{.X | html}}",
  1722  			".X | html",
  1723  			[]string{},
  1724  		},
  1725  		{
  1726  			"{{.X}}",
  1727  			".X | html",
  1728  			[]string{"html"},
  1729  		},
  1730  		{
  1731  			"{{html .X}}",
  1732  			"_eval_args_ .X | html | urlquery",
  1733  			[]string{"html", "urlquery"},
  1734  		},
  1735  		{
  1736  			"{{html .X .Y .Z}}",
  1737  			"_eval_args_ .X .Y .Z | html | urlquery",
  1738  			[]string{"html", "urlquery"},
  1739  		},
  1740  		{
  1741  			"{{.X | print}}",
  1742  			".X | print | urlquery",
  1743  			[]string{"urlquery"},
  1744  		},
  1745  		{
  1746  			"{{.X | print | urlquery}}",
  1747  			".X | print | urlquery",
  1748  			[]string{"urlquery"},
  1749  		},
  1750  		{
  1751  			"{{.X | urlquery}}",
  1752  			".X | html | urlquery",
  1753  			[]string{"html", "urlquery"},
  1754  		},
  1755  		{
  1756  			"{{.X | print 2 | .f 3}}",
  1757  			".X | print 2 | .f 3 | urlquery | html",
  1758  			[]string{"urlquery", "html"},
  1759  		},
  1760  		{
  1761  			// covering issue 10801
  1762  			"{{.X | println.x }}",
  1763  			".X | println.x | urlquery | html",
  1764  			[]string{"urlquery", "html"},
  1765  		},
  1766  		{
  1767  			// covering issue 10801
  1768  			"{{.X | (print 12 | println).x }}",
  1769  			".X | (print 12 | println).x | urlquery | html",
  1770  			[]string{"urlquery", "html"},
  1771  		},
  1772  		// The following test cases ensure that the merging of internal escapers
  1773  		// with the predefined "html" and "urlquery" escapers is correct.
  1774  		{
  1775  			"{{.X | urlquery}}",
  1776  			".X | _html_template_urlfilter | urlquery",
  1777  			[]string{"_html_template_urlfilter", "_html_template_urlnormalizer"},
  1778  		},
  1779  		{
  1780  			"{{.X | urlquery}}",
  1781  			".X | urlquery | _html_template_urlfilter | _html_template_cssescaper",
  1782  			[]string{"_html_template_urlfilter", "_html_template_cssescaper"},
  1783  		},
  1784  		{
  1785  			"{{.X | urlquery}}",
  1786  			".X | urlquery",
  1787  			[]string{"_html_template_urlnormalizer"},
  1788  		},
  1789  		{
  1790  			"{{.X | urlquery}}",
  1791  			".X | urlquery",
  1792  			[]string{"_html_template_urlescaper"},
  1793  		},
  1794  		{
  1795  			"{{.X | html}}",
  1796  			".X | html",
  1797  			[]string{"_html_template_htmlescaper"},
  1798  		},
  1799  		{
  1800  			"{{.X | html}}",
  1801  			".X | html",
  1802  			[]string{"_html_template_rcdataescaper"},
  1803  		},
  1804  	}
  1805  	for i, test := range tests {
  1806  		tmpl := template.Must(template.New("test").Parse(test.input))
  1807  		action, ok := (tmpl.Tree.Root.Nodes[0].(*parse.ActionNode))
  1808  		if !ok {
  1809  			t.Errorf("First node is not an action: %s", test.input)
  1810  			continue
  1811  		}
  1812  		pipe := action.Pipe
  1813  		originalIDs := make([]string, len(test.ids))
  1814  		copy(originalIDs, test.ids)
  1815  		ensurePipelineContains(pipe, test.ids)
  1816  		got := pipe.String()
  1817  		if got != test.output {
  1818  			t.Errorf("#%d: %s, %v: want\n\t%s\ngot\n\t%s", i, test.input, originalIDs, test.output, got)
  1819  		}
  1820  	}
  1821  }
  1822  
  1823  func TestEscapeMalformedPipelines(t *testing.T) {
  1824  	tests := []string{
  1825  		"{{ 0 | $ }}",
  1826  		"{{ 0 | $ | urlquery }}",
  1827  		"{{ 0 | (nil) }}",
  1828  		"{{ 0 | (nil) | html }}",
  1829  	}
  1830  	for _, test := range tests {
  1831  		var b bytes.Buffer
  1832  		tmpl, err := New("test").Parse(test)
  1833  		if err != nil {
  1834  			t.Errorf("failed to parse set: %q", err)
  1835  		}
  1836  		err = tmpl.Execute(&b, nil)
  1837  		if err == nil {
  1838  			t.Errorf("Expected error for %q", test)
  1839  		}
  1840  	}
  1841  }
  1842  
  1843  func TestEscapeErrorsNotIgnorable(t *testing.T) {
  1844  	var b bytes.Buffer
  1845  	tmpl, _ := New("dangerous").Parse("<a")
  1846  	err := tmpl.Execute(&b, nil)
  1847  	if err == nil {
  1848  		t.Errorf("Expected error")
  1849  	} else if b.Len() != 0 {
  1850  		t.Errorf("Emitted output despite escaping failure")
  1851  	}
  1852  }
  1853  
  1854  func TestEscapeSetErrorsNotIgnorable(t *testing.T) {
  1855  	var b bytes.Buffer
  1856  	tmpl, err := New("root").Parse(`{{define "t"}}<a{{end}}`)
  1857  	if err != nil {
  1858  		t.Errorf("failed to parse set: %q", err)
  1859  	}
  1860  	err = tmpl.ExecuteTemplate(&b, "t", nil)
  1861  	if err == nil {
  1862  		t.Errorf("Expected error")
  1863  	} else if b.Len() != 0 {
  1864  		t.Errorf("Emitted output despite escaping failure")
  1865  	}
  1866  }
  1867  
  1868  func TestRedundantFuncs(t *testing.T) {
  1869  	inputs := []any{
  1870  		"\x00\x01\x02\x03\x04\x05\x06\x07\x08\t\n\x0b\x0c\r\x0e\x0f" +
  1871  			"\x10\x11\x12\x13\x14\x15\x16\x17\x18\x19\x1a\x1b\x1c\x1d\x1e\x1f" +
  1872  			` !"#$%&'()*+,-./` +
  1873  			`0123456789:;<=>?` +
  1874  			`@ABCDEFGHIJKLMNO` +
  1875  			`PQRSTUVWXYZ[\]^_` +
  1876  			"`abcdefghijklmno" +
  1877  			"pqrstuvwxyz{|}~\x7f" +
  1878  			"\u00A0\u0100\u2028\u2029\ufeff\ufdec\ufffd\uffff\U0001D11E" +
  1879  			"&amp;%22\\",
  1880  		CSS(`a[href =~ "//example.com"]#foo`),
  1881  		HTML(`Hello, <b>World</b> &amp;tc!`),
  1882  		HTMLAttr(` dir="ltr"`),
  1883  		JS(`c && alert("Hello, World!");`),
  1884  		JSStr(`Hello, World & O'Reilly\x21`),
  1885  		URL(`greeting=H%69&addressee=(World)`),
  1886  	}
  1887  
  1888  	for n0, m := range redundantFuncs {
  1889  		f0 := funcMap[n0].(func(...any) string)
  1890  		for n1 := range m {
  1891  			f1 := funcMap[n1].(func(...any) string)
  1892  			for _, input := range inputs {
  1893  				want := f0(input)
  1894  				if got := f1(want); want != got {
  1895  					t.Errorf("%s %s with %T %q: want\n\t%q,\ngot\n\t%q", n0, n1, input, input, want, got)
  1896  				}
  1897  			}
  1898  		}
  1899  	}
  1900  }
  1901  
  1902  func TestIndirectPrint(t *testing.T) {
  1903  	a := 3
  1904  	ap := &a
  1905  	b := "hello"
  1906  	bp := &b
  1907  	bpp := &bp
  1908  	tmpl := Must(New("t").Parse(`{{.}}`))
  1909  	var buf strings.Builder
  1910  	err := tmpl.Execute(&buf, ap)
  1911  	if err != nil {
  1912  		t.Errorf("Unexpected error: %s", err)
  1913  	} else if buf.String() != "3" {
  1914  		t.Errorf(`Expected "3"; got %q`, buf.String())
  1915  	}
  1916  	buf.Reset()
  1917  	err = tmpl.Execute(&buf, bpp)
  1918  	if err != nil {
  1919  		t.Errorf("Unexpected error: %s", err)
  1920  	} else if buf.String() != "hello" {
  1921  		t.Errorf(`Expected "hello"; got %q`, buf.String())
  1922  	}
  1923  }
  1924  
  1925  // This is a test for issue 3272.
  1926  func TestEmptyTemplateHTML(t *testing.T) {
  1927  	page := Must(New("page").ParseFiles(os.DevNull))
  1928  	if err := page.ExecuteTemplate(os.Stdout, "page", "nothing"); err == nil {
  1929  		t.Fatal("expected error")
  1930  	}
  1931  }
  1932  
  1933  type Issue7379 int
  1934  
  1935  func (Issue7379) SomeMethod(x int) string {
  1936  	return fmt.Sprintf("<%d>", x)
  1937  }
  1938  
  1939  // This is a test for issue 7379: type assertion error caused panic, and then
  1940  // the code to handle the panic breaks escaping. It's hard to see the second
  1941  // problem once the first is fixed, but its fix is trivial so we let that go. See
  1942  // the discussion for issue 7379.
  1943  func TestPipeToMethodIsEscaped(t *testing.T) {
  1944  	tmpl := Must(New("x").Parse("<html>{{0 | .SomeMethod}}</html>\n"))
  1945  	tryExec := func() string {
  1946  		defer func() {
  1947  			panicValue := recover()
  1948  			if panicValue != nil {
  1949  				t.Errorf("panicked: %v\n", panicValue)
  1950  			}
  1951  		}()
  1952  		var b strings.Builder
  1953  		tmpl.Execute(&b, Issue7379(0))
  1954  		return b.String()
  1955  	}
  1956  	for i := 0; i < 3; i++ {
  1957  		str := tryExec()
  1958  		const expect = "<html>&lt;0&gt;</html>\n"
  1959  		if str != expect {
  1960  			t.Errorf("expected %q got %q", expect, str)
  1961  		}
  1962  	}
  1963  }
  1964  
  1965  // Unlike text/template, html/template crashed if given an incomplete
  1966  // template, that is, a template that had been named but not given any content.
  1967  // This is issue #10204.
  1968  func TestErrorOnUndefined(t *testing.T) {
  1969  	tmpl := New("undefined")
  1970  
  1971  	err := tmpl.Execute(nil, nil)
  1972  	if err == nil {
  1973  		t.Error("expected error")
  1974  	} else if !strings.Contains(err.Error(), "incomplete") {
  1975  		t.Errorf("expected error about incomplete template; got %s", err)
  1976  	}
  1977  }
  1978  
  1979  // This covers issue #20842.
  1980  func TestIdempotentExecute(t *testing.T) {
  1981  	tmpl := Must(New("").
  1982  		Parse(`{{define "main"}}<body>{{template "hello"}}</body>{{end}}`))
  1983  	Must(tmpl.
  1984  		Parse(`{{define "hello"}}Hello, {{"Ladies & Gentlemen!"}}{{end}}`))
  1985  	got := new(strings.Builder)
  1986  	var err error
  1987  	// Ensure that "hello" produces the same output when executed twice.
  1988  	want := "Hello, Ladies &amp; Gentlemen!"
  1989  	for i := 0; i < 2; i++ {
  1990  		err = tmpl.ExecuteTemplate(got, "hello", nil)
  1991  		if err != nil {
  1992  			t.Errorf("unexpected error: %s", err)
  1993  		}
  1994  		if got.String() != want {
  1995  			t.Errorf("after executing template \"hello\", got:\n\t%q\nwant:\n\t%q\n", got.String(), want)
  1996  		}
  1997  		got.Reset()
  1998  	}
  1999  	// Ensure that the implicit re-execution of "hello" during the execution of
  2000  	// "main" does not cause the output of "hello" to change.
  2001  	err = tmpl.ExecuteTemplate(got, "main", nil)
  2002  	if err != nil {
  2003  		t.Errorf("unexpected error: %s", err)
  2004  	}
  2005  	// If the HTML escaper is added again to the action {{"Ladies & Gentlemen!"}},
  2006  	// we would expected to see the ampersand overescaped to "&amp;amp;".
  2007  	want = "<body>Hello, Ladies &amp; Gentlemen!</body>"
  2008  	if got.String() != want {
  2009  		t.Errorf("after executing template \"main\", got:\n\t%q\nwant:\n\t%q\n", got.String(), want)
  2010  	}
  2011  }
  2012  
  2013  func BenchmarkEscapedExecute(b *testing.B) {
  2014  	tmpl := Must(New("t").Parse(`<a onclick="alert('{{.}}')">{{.}}</a>`))
  2015  	var buf bytes.Buffer
  2016  	b.ResetTimer()
  2017  	for i := 0; i < b.N; i++ {
  2018  		tmpl.Execute(&buf, "foo & 'bar' & baz")
  2019  		buf.Reset()
  2020  	}
  2021  }
  2022  
  2023  // Covers issue 22780.
  2024  func TestOrphanedTemplate(t *testing.T) {
  2025  	t1 := Must(New("foo").Parse(`<a href="{{.}}">link1</a>`))
  2026  	t2 := Must(t1.New("foo").Parse(`bar`))
  2027  
  2028  	var b strings.Builder
  2029  	const wantError = `template: "foo" is an incomplete or empty template`
  2030  	if err := t1.Execute(&b, "javascript:alert(1)"); err == nil {
  2031  		t.Fatal("expected error executing t1")
  2032  	} else if gotError := err.Error(); gotError != wantError {
  2033  		t.Fatalf("got t1 execution error:\n\t%s\nwant:\n\t%s", gotError, wantError)
  2034  	}
  2035  	b.Reset()
  2036  	if err := t2.Execute(&b, nil); err != nil {
  2037  		t.Fatalf("error executing t2: %s", err)
  2038  	}
  2039  	const want = "bar"
  2040  	if got := b.String(); got != want {
  2041  		t.Fatalf("t2 rendered %q, want %q", got, want)
  2042  	}
  2043  }
  2044  
  2045  // Covers issue 21844.
  2046  func TestAliasedParseTreeDoesNotOverescape(t *testing.T) {
  2047  	const (
  2048  		tmplText = `{{.}}`
  2049  		data     = `<baz>`
  2050  		want     = `&lt;baz&gt;`
  2051  	)
  2052  	// Templates "foo" and "bar" both alias the same underlying parse tree.
  2053  	tpl := Must(New("foo").Parse(tmplText))
  2054  	if _, err := tpl.AddParseTree("bar", tpl.Tree); err != nil {
  2055  		t.Fatalf("AddParseTree error: %v", err)
  2056  	}
  2057  	var b1, b2 strings.Builder
  2058  	if err := tpl.ExecuteTemplate(&b1, "foo", data); err != nil {
  2059  		t.Fatalf(`ExecuteTemplate failed for "foo": %v`, err)
  2060  	}
  2061  	if err := tpl.ExecuteTemplate(&b2, "bar", data); err != nil {
  2062  		t.Fatalf(`ExecuteTemplate failed for "foo": %v`, err)
  2063  	}
  2064  	got1, got2 := b1.String(), b2.String()
  2065  	if got1 != want {
  2066  		t.Fatalf(`Template "foo" rendered %q, want %q`, got1, want)
  2067  	}
  2068  	if got1 != got2 {
  2069  		t.Fatalf(`Template "foo" and "bar" rendered %q and %q respectively, expected equal values`, got1, got2)
  2070  	}
  2071  }
  2072  

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