js_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  	"errors"
     9  	"math"
    10  	"strings"
    11  	"testing"
    12  )
    13  
    14  func TestNextJsCtx(t *testing.T) {
    15  	tests := []struct {
    16  		jsCtx jsCtx
    17  		s     string
    18  	}{
    19  		// Statement terminators precede regexps.
    20  		{jsCtxRegexp, ";"},
    21  		// This is not airtight.
    22  		//     ({ valueOf: function () { return 1 } } / 2)
    23  		// is valid JavaScript but in practice, devs do not do this.
    24  		// A block followed by a statement starting with a RegExp is
    25  		// much more common:
    26  		//     while (x) {...} /foo/.test(x) || panic()
    27  		{jsCtxRegexp, "}"},
    28  		// But member, call, grouping, and array expression terminators
    29  		// precede div ops.
    30  		{jsCtxDivOp, ")"},
    31  		{jsCtxDivOp, "]"},
    32  		// At the start of a primary expression, array, or expression
    33  		// statement, expect a regexp.
    34  		{jsCtxRegexp, "("},
    35  		{jsCtxRegexp, "["},
    36  		{jsCtxRegexp, "{"},
    37  		// Assignment operators precede regexps as do all exclusively
    38  		// prefix and binary operators.
    39  		{jsCtxRegexp, "="},
    40  		{jsCtxRegexp, "+="},
    41  		{jsCtxRegexp, "*="},
    42  		{jsCtxRegexp, "*"},
    43  		{jsCtxRegexp, "!"},
    44  		// Whether the + or - is infix or prefix, it cannot precede a
    45  		// div op.
    46  		{jsCtxRegexp, "+"},
    47  		{jsCtxRegexp, "-"},
    48  		// An incr/decr op precedes a div operator.
    49  		// This is not airtight. In (g = ++/h/i) a regexp follows a
    50  		// pre-increment operator, but in practice devs do not try to
    51  		// increment or decrement regular expressions.
    52  		// (g++/h/i) where ++ is a postfix operator on g is much more
    53  		// common.
    54  		{jsCtxDivOp, "--"},
    55  		{jsCtxDivOp, "++"},
    56  		{jsCtxDivOp, "x--"},
    57  		// When we have many dashes or pluses, then they are grouped
    58  		// left to right.
    59  		{jsCtxRegexp, "x---"}, // A postfix -- then a -.
    60  		// return followed by a slash returns the regexp literal or the
    61  		// slash starts a regexp literal in an expression statement that
    62  		// is dead code.
    63  		{jsCtxRegexp, "return"},
    64  		{jsCtxRegexp, "return "},
    65  		{jsCtxRegexp, "return\t"},
    66  		{jsCtxRegexp, "return\n"},
    67  		{jsCtxRegexp, "return\u2028"},
    68  		// Identifiers can be divided and cannot validly be preceded by
    69  		// a regular expressions. Semicolon insertion cannot happen
    70  		// between an identifier and a regular expression on a new line
    71  		// because the one token lookahead for semicolon insertion has
    72  		// to conclude that it could be a div binary op and treat it as
    73  		// such.
    74  		{jsCtxDivOp, "x"},
    75  		{jsCtxDivOp, "x "},
    76  		{jsCtxDivOp, "x\t"},
    77  		{jsCtxDivOp, "x\n"},
    78  		{jsCtxDivOp, "x\u2028"},
    79  		{jsCtxDivOp, "preturn"},
    80  		// Numbers precede div ops.
    81  		{jsCtxDivOp, "0"},
    82  		// Dots that are part of a number are div preceders.
    83  		{jsCtxDivOp, "0."},
    84  		// Some JS interpreters treat NBSP as a normal space, so
    85  		// we must too in order to properly escape things.
    86  		{jsCtxRegexp, "=\u00A0"},
    87  	}
    88  
    89  	for _, test := range tests {
    90  		if ctx := nextJSCtx([]byte(test.s), jsCtxRegexp); ctx != test.jsCtx {
    91  			t.Errorf("%q: want %s got %s", test.s, test.jsCtx, ctx)
    92  		}
    93  		if ctx := nextJSCtx([]byte(test.s), jsCtxDivOp); ctx != test.jsCtx {
    94  			t.Errorf("%q: want %s got %s", test.s, test.jsCtx, ctx)
    95  		}
    96  	}
    97  
    98  	if nextJSCtx([]byte("   "), jsCtxRegexp) != jsCtxRegexp {
    99  		t.Error("Blank tokens")
   100  	}
   101  
   102  	if nextJSCtx([]byte("   "), jsCtxDivOp) != jsCtxDivOp {
   103  		t.Error("Blank tokens")
   104  	}
   105  }
   106  
   107  type jsonErrType struct{}
   108  
   109  func (e *jsonErrType) MarshalJSON() ([]byte, error) {
   110  	return nil, errors.New("beep */ boop </script blip <!--")
   111  }
   112  
   113  func TestJSValEscaper(t *testing.T) {
   114  	tests := []struct {
   115  		x        any
   116  		js       string
   117  		skipNest bool
   118  	}{
   119  		{int(42), " 42 ", false},
   120  		{uint(42), " 42 ", false},
   121  		{int16(42), " 42 ", false},
   122  		{uint16(42), " 42 ", false},
   123  		{int32(-42), " -42 ", false},
   124  		{uint32(42), " 42 ", false},
   125  		{int16(-42), " -42 ", false},
   126  		{uint16(42), " 42 ", false},
   127  		{int64(-42), " -42 ", false},
   128  		{uint64(42), " 42 ", false},
   129  		{uint64(1) << 53, " 9007199254740992 ", false},
   130  		// ulp(1 << 53) > 1 so this loses precision in JS
   131  		// but it is still a representable integer literal.
   132  		{uint64(1)<<53 + 1, " 9007199254740993 ", false},
   133  		{float32(1.0), " 1 ", false},
   134  		{float32(-1.0), " -1 ", false},
   135  		{float32(0.5), " 0.5 ", false},
   136  		{float32(-0.5), " -0.5 ", false},
   137  		{float32(1.0) / float32(256), " 0.00390625 ", false},
   138  		{float32(0), " 0 ", false},
   139  		{math.Copysign(0, -1), " -0 ", false},
   140  		{float64(1.0), " 1 ", false},
   141  		{float64(-1.0), " -1 ", false},
   142  		{float64(0.5), " 0.5 ", false},
   143  		{float64(-0.5), " -0.5 ", false},
   144  		{float64(0), " 0 ", false},
   145  		{math.Copysign(0, -1), " -0 ", false},
   146  		{"", `""`, false},
   147  		{"foo", `"foo"`, false},
   148  		// Newlines.
   149  		{"\r\n\u2028\u2029", `"\r\n\u2028\u2029"`, false},
   150  		// "\v" == "v" on IE 6 so use "\u000b" instead.
   151  		{"\t\x0b", `"\t\u000b"`, false},
   152  		{struct{ X, Y int }{1, 2}, `{"X":1,"Y":2}`, false},
   153  		{[]any{}, "[]", false},
   154  		{[]any{42, "foo", nil}, `[42,"foo",null]`, false},
   155  		{[]string{"<!--", "</script>", "-->"}, `["\u003c!--","\u003c/script\u003e","--\u003e"]`, false},
   156  		{"<!--", `"\u003c!--"`, false},
   157  		{"-->", `"--\u003e"`, false},
   158  		{"<![CDATA[", `"\u003c![CDATA["`, false},
   159  		{"]]>", `"]]\u003e"`, false},
   160  		{"</script", `"\u003c/script"`, false},
   161  		{"\U0001D11E", "\"\U0001D11E\"", false}, // or "\uD834\uDD1E"
   162  		{nil, " null ", false},
   163  		{&jsonErrType{}, " /* json: error calling MarshalJSON for type *template.jsonErrType: beep * / boop \\x3C/script blip \\x3C!-- */null ", true},
   164  	}
   165  
   166  	for _, test := range tests {
   167  		if js := jsValEscaper(test.x); js != test.js {
   168  			t.Errorf("%+v: want\n\t%q\ngot\n\t%q", test.x, test.js, js)
   169  		}
   170  		if test.skipNest {
   171  			continue
   172  		}
   173  		// Make sure that escaping corner cases are not broken
   174  		// by nesting.
   175  		a := []any{test.x}
   176  		want := "[" + strings.TrimSpace(test.js) + "]"
   177  		if js := jsValEscaper(a); js != want {
   178  			t.Errorf("%+v: want\n\t%q\ngot\n\t%q", a, want, js)
   179  		}
   180  	}
   181  }
   182  
   183  func TestJSStrEscaper(t *testing.T) {
   184  	tests := []struct {
   185  		x   any
   186  		esc string
   187  	}{
   188  		{"", ``},
   189  		{"foo", `foo`},
   190  		{"\u0000", `\u0000`},
   191  		{"\t", `\t`},
   192  		{"\n", `\n`},
   193  		{"\r", `\r`},
   194  		{"\u2028", `\u2028`},
   195  		{"\u2029", `\u2029`},
   196  		{"\\", `\\`},
   197  		{"\\n", `\\n`},
   198  		{"foo\r\nbar", `foo\r\nbar`},
   199  		// Preserve attribute boundaries.
   200  		{`"`, `\u0022`},
   201  		{`'`, `\u0027`},
   202  		// Allow embedding in HTML without further escaping.
   203  		{`&amp;`, `\u0026amp;`},
   204  		// Prevent breaking out of text node and element boundaries.
   205  		{"</script>", `\u003c\/script\u003e`},
   206  		{"<![CDATA[", `\u003c![CDATA[`},
   207  		{"]]>", `]]\u003e`},
   208  		// https://dev.w3.org/html5/markup/aria/syntax.html#escaping-text-span
   209  		//   "The text in style, script, title, and textarea elements
   210  		//   must not have an escaping text span start that is not
   211  		//   followed by an escaping text span end."
   212  		// Furthermore, spoofing an escaping text span end could lead
   213  		// to different interpretation of a </script> sequence otherwise
   214  		// masked by the escaping text span, and spoofing a start could
   215  		// allow regular text content to be interpreted as script
   216  		// allowing script execution via a combination of a JS string
   217  		// injection followed by an HTML text injection.
   218  		{"<!--", `\u003c!--`},
   219  		{"-->", `--\u003e`},
   220  		// From https://code.google.com/p/doctype/wiki/ArticleUtf7
   221  		{"+ADw-script+AD4-alert(1)+ADw-/script+AD4-",
   222  			`\u002bADw-script\u002bAD4-alert(1)\u002bADw-\/script\u002bAD4-`,
   223  		},
   224  		// Invalid UTF-8 sequence
   225  		{"foo\xA0bar", "foo\xA0bar"},
   226  		// Invalid unicode scalar value.
   227  		{"foo\xed\xa0\x80bar", "foo\xed\xa0\x80bar"},
   228  	}
   229  
   230  	for _, test := range tests {
   231  		esc := jsStrEscaper(test.x)
   232  		if esc != test.esc {
   233  			t.Errorf("%q: want %q got %q", test.x, test.esc, esc)
   234  		}
   235  	}
   236  }
   237  
   238  func TestJSRegexpEscaper(t *testing.T) {
   239  	tests := []struct {
   240  		x   any
   241  		esc string
   242  	}{
   243  		{"", `(?:)`},
   244  		{"foo", `foo`},
   245  		{"\u0000", `\u0000`},
   246  		{"\t", `\t`},
   247  		{"\n", `\n`},
   248  		{"\r", `\r`},
   249  		{"\u2028", `\u2028`},
   250  		{"\u2029", `\u2029`},
   251  		{"\\", `\\`},
   252  		{"\\n", `\\n`},
   253  		{"foo\r\nbar", `foo\r\nbar`},
   254  		// Preserve attribute boundaries.
   255  		{`"`, `\u0022`},
   256  		{`'`, `\u0027`},
   257  		// Allow embedding in HTML without further escaping.
   258  		{`&amp;`, `\u0026amp;`},
   259  		// Prevent breaking out of text node and element boundaries.
   260  		{"</script>", `\u003c\/script\u003e`},
   261  		{"<![CDATA[", `\u003c!\[CDATA\[`},
   262  		{"]]>", `\]\]\u003e`},
   263  		// Escaping text spans.
   264  		{"<!--", `\u003c!\-\-`},
   265  		{"-->", `\-\-\u003e`},
   266  		{"*", `\*`},
   267  		{"+", `\u002b`},
   268  		{"?", `\?`},
   269  		{"[](){}", `\[\]\(\)\{\}`},
   270  		{"$foo|x.y", `\$foo\|x\.y`},
   271  		{"x^y", `x\^y`},
   272  	}
   273  
   274  	for _, test := range tests {
   275  		esc := jsRegexpEscaper(test.x)
   276  		if esc != test.esc {
   277  			t.Errorf("%q: want %q got %q", test.x, test.esc, esc)
   278  		}
   279  	}
   280  }
   281  
   282  func TestEscapersOnLower7AndSelectHighCodepoints(t *testing.T) {
   283  	input := ("\x00\x01\x02\x03\x04\x05\x06\x07\x08\t\n\x0b\x0c\r\x0e\x0f" +
   284  		"\x10\x11\x12\x13\x14\x15\x16\x17\x18\x19\x1a\x1b\x1c\x1d\x1e\x1f" +
   285  		` !"#$%&'()*+,-./` +
   286  		`0123456789:;<=>?` +
   287  		`@ABCDEFGHIJKLMNO` +
   288  		`PQRSTUVWXYZ[\]^_` +
   289  		"`abcdefghijklmno" +
   290  		"pqrstuvwxyz{|}~\x7f" +
   291  		"\u00A0\u0100\u2028\u2029\ufeff\U0001D11E")
   292  
   293  	tests := []struct {
   294  		name    string
   295  		escaper func(...any) string
   296  		escaped string
   297  	}{
   298  		{
   299  			"jsStrEscaper",
   300  			jsStrEscaper,
   301  			`\u0000\u0001\u0002\u0003\u0004\u0005\u0006\u0007` +
   302  				`\u0008\t\n\u000b\f\r\u000e\u000f` +
   303  				`\u0010\u0011\u0012\u0013\u0014\u0015\u0016\u0017` +
   304  				`\u0018\u0019\u001a\u001b\u001c\u001d\u001e\u001f` +
   305  				` !\u0022#$%\u0026\u0027()*\u002b,-.\/` +
   306  				`0123456789:;\u003c=\u003e?` +
   307  				`@ABCDEFGHIJKLMNO` +
   308  				`PQRSTUVWXYZ[\\]^_` +
   309  				"\\u0060abcdefghijklmno" +
   310  				"pqrstuvwxyz{|}~\u007f" +
   311  				"\u00A0\u0100\\u2028\\u2029\ufeff\U0001D11E",
   312  		},
   313  		{
   314  			"jsRegexpEscaper",
   315  			jsRegexpEscaper,
   316  			`\u0000\u0001\u0002\u0003\u0004\u0005\u0006\u0007` +
   317  				`\u0008\t\n\u000b\f\r\u000e\u000f` +
   318  				`\u0010\u0011\u0012\u0013\u0014\u0015\u0016\u0017` +
   319  				`\u0018\u0019\u001a\u001b\u001c\u001d\u001e\u001f` +
   320  				` !\u0022#\$%\u0026\u0027\(\)\*\u002b,\-\.\/` +
   321  				`0123456789:;\u003c=\u003e\?` +
   322  				`@ABCDEFGHIJKLMNO` +
   323  				`PQRSTUVWXYZ\[\\\]\^_` +
   324  				"`abcdefghijklmno" +
   325  				`pqrstuvwxyz\{\|\}~` + "\u007f" +
   326  				"\u00A0\u0100\\u2028\\u2029\ufeff\U0001D11E",
   327  		},
   328  	}
   329  
   330  	for _, test := range tests {
   331  		if s := test.escaper(input); s != test.escaped {
   332  			t.Errorf("%s once: want\n\t%q\ngot\n\t%q", test.name, test.escaped, s)
   333  			continue
   334  		}
   335  
   336  		// Escape it rune by rune to make sure that any
   337  		// fast-path checking does not break escaping.
   338  		var buf strings.Builder
   339  		for _, c := range input {
   340  			buf.WriteString(test.escaper(string(c)))
   341  		}
   342  
   343  		if s := buf.String(); s != test.escaped {
   344  			t.Errorf("%s rune-wise: want\n\t%q\ngot\n\t%q", test.name, test.escaped, s)
   345  			continue
   346  		}
   347  	}
   348  }
   349  
   350  func TestIsJsMimeType(t *testing.T) {
   351  	tests := []struct {
   352  		in  string
   353  		out bool
   354  	}{
   355  		{"application/javascript;version=1.8", true},
   356  		{"application/javascript;version=1.8;foo=bar", true},
   357  		{"application/javascript/version=1.8", false},
   358  		{"text/javascript", true},
   359  		{"application/json", true},
   360  		{"application/ld+json", true},
   361  		{"module", true},
   362  	}
   363  
   364  	for _, test := range tests {
   365  		if isJSType(test.in) != test.out {
   366  			t.Errorf("isJSType(%q) = %v, want %v", test.in, !test.out, test.out)
   367  		}
   368  	}
   369  }
   370  
   371  func BenchmarkJSValEscaperWithNum(b *testing.B) {
   372  	for i := 0; i < b.N; i++ {
   373  		jsValEscaper(3.141592654)
   374  	}
   375  }
   376  
   377  func BenchmarkJSValEscaperWithStr(b *testing.B) {
   378  	for i := 0; i < b.N; i++ {
   379  		jsValEscaper("The <i>quick</i>,\r\n<span style='color:brown'>brown</span> fox jumps\u2028over the <canine class=\"lazy\">dog</canine>")
   380  	}
   381  }
   382  
   383  func BenchmarkJSValEscaperWithStrNoSpecials(b *testing.B) {
   384  	for i := 0; i < b.N; i++ {
   385  		jsValEscaper("The quick, brown fox jumps over the lazy dog")
   386  	}
   387  }
   388  
   389  func BenchmarkJSValEscaperWithObj(b *testing.B) {
   390  	o := struct {
   391  		S string
   392  		N int
   393  	}{
   394  		"The <i>quick</i>,\r\n<span style='color:brown'>brown</span> fox jumps\u2028over the <canine class=\"lazy\">dog</canine>\u2028",
   395  		42,
   396  	}
   397  	for i := 0; i < b.N; i++ {
   398  		jsValEscaper(o)
   399  	}
   400  }
   401  
   402  func BenchmarkJSValEscaperWithObjNoSpecials(b *testing.B) {
   403  	o := struct {
   404  		S string
   405  		N int
   406  	}{
   407  		"The quick, brown fox jumps over the lazy dog",
   408  		42,
   409  	}
   410  	for i := 0; i < b.N; i++ {
   411  		jsValEscaper(o)
   412  	}
   413  }
   414  
   415  func BenchmarkJSStrEscaperNoSpecials(b *testing.B) {
   416  	for i := 0; i < b.N; i++ {
   417  		jsStrEscaper("The quick, brown fox jumps over the lazy dog.")
   418  	}
   419  }
   420  
   421  func BenchmarkJSStrEscaper(b *testing.B) {
   422  	for i := 0; i < b.N; i++ {
   423  		jsStrEscaper("The <i>quick</i>,\r\n<span style='color:brown'>brown</span> fox jumps\u2028over the <canine class=\"lazy\">dog</canine>")
   424  	}
   425  }
   426  
   427  func BenchmarkJSRegexpEscaperNoSpecials(b *testing.B) {
   428  	for i := 0; i < b.N; i++ {
   429  		jsRegexpEscaper("The quick, brown fox jumps over the lazy dog")
   430  	}
   431  }
   432  
   433  func BenchmarkJSRegexpEscaper(b *testing.B) {
   434  	for i := 0; i < b.N; i++ {
   435  		jsRegexpEscaper("The <i>quick</i>,\r\n<span style='color:brown'>brown</span> fox jumps\u2028over the <canine class=\"lazy\">dog</canine>")
   436  	}
   437  }
   438
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