libgo/go/text/template/exec_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         "errors"
  10         "flag"
  11         "fmt"
  12         "reflect"
  13         "strings"
  14         "testing"
  15 )
  16
  17 var debug = flag.Bool("debug", false, "show the errors produced by the tests")
  18
  19 // T has lots of interesting pieces to use to test execution.
  20 type T struct {
  21         // Basics
  22         True        bool
  23         I           int
  24         U16         uint16
  25         X           string
  26         FloatZero   float64
  27         ComplexZero complex128
  28         // Nested structs.
  29         U *U
  30         // Struct with String method.
  31         V0     V
  32         V1, V2 *V
  33         // Struct with Error method.
  34         W0     W
  35         W1, W2 *W
  36         // Slices
  37         SI      []int
  38         SIEmpty []int
  39         SB      []bool
  40         // Maps
  41         MSI      map[string]int
  42         MSIone   map[string]int // one element, for deterministic output
  43         MSIEmpty map[string]int
  44         MXI      map[interface{}]int
  45         MII      map[int]int
  46         SMSI     []map[string]int
  47         // Empty interfaces; used to see if we can dig inside one.
  48         Empty0 interface{} // nil
  49         Empty1 interface{}
  50         Empty2 interface{}
  51         Empty3 interface{}
  52         Empty4 interface{}
  53         // Non-empty interface.
  54         NonEmptyInterface I
  55         // Stringer.
  56         Str fmt.Stringer
  57         Err error
  58         // Pointers
  59         PI  *int
  60         PS  *string
  61         PSI *[]int
  62         NIL *int
  63         // Function (not method)
  64         BinaryFunc      func(string, string) string
  65         VariadicFunc    func(...string) string
  66         VariadicFuncInt func(int, ...string) string
  67         NilOKFunc       func(*int) bool
  68         ErrFunc         func() (string, error)
  69         // Template to test evaluation of templates.
  70         Tmpl *Template
  71         // Unexported field; cannot be accessed by template.
  72         unexported int
  73 }
  74
  75 type U struct {
  76         V string
  77 }
  78
  79 type V struct {
  80         j int
  81 }
  82
  83 func (v *V) String() string {
  84         if v == nil {
  85                 return "nilV"
  86         }
  87         return fmt.Sprintf("<%d>", v.j)
  88 }
  89
  90 type W struct {
  91         k int
  92 }
  93
  94 func (w *W) Error() string {
  95         if w == nil {
  96                 return "nilW"
  97         }
  98         return fmt.Sprintf("[%d]", w.k)
  99 }
 100
 101 var tVal = &T{
 102         True:   true,
 103         I:      17,
 104         U16:    16,
 105         X:      "x",
 106         U:      &U{"v"},
 107         V0:     V{6666},
 108         V1:     &V{7777}, // leave V2 as nil
 109         W0:     W{888},
 110         W1:     &W{999}, // leave W2 as nil
 111         SI:     []int{3, 4, 5},
 112         SB:     []bool{true, false},
 113         MSI:    map[string]int{"one": 1, "two": 2, "three": 3},
 114         MSIone: map[string]int{"one": 1},
 115         MXI:    map[interface{}]int{"one": 1},
 116         MII:    map[int]int{1: 1},
 117         SMSI: []map[string]int{
 118                 {"one": 1, "two": 2},
 119                 {"eleven": 11, "twelve": 12},
 120         },
 121         Empty1:            3,
 122         Empty2:            "empty2",
 123         Empty3:            []int{7, 8},
 124         Empty4:            &U{"UinEmpty"},
 125         NonEmptyInterface: new(T),
 126         Str:               bytes.NewBuffer([]byte("foozle")),
 127         Err:               errors.New("erroozle"),
 128         PI:                newInt(23),
 129         PS:                newString("a string"),
 130         PSI:               newIntSlice(21, 22, 23),
 131         BinaryFunc:        func(a, b string) string { return fmt.Sprintf("[%s=%s]", a, b) },
 132         VariadicFunc:      func(s ...string) string { return fmt.Sprint("<", strings.Join(s, "+"), ">") },
 133         VariadicFuncInt:   func(a int, s ...string) string { return fmt.Sprint(a, "=<", strings.Join(s, "+"), ">") },
 134         NilOKFunc:         func(s *int) bool { return s == nil },
 135         ErrFunc:           func() (string, error) { return "bla", nil },
 136         Tmpl:              Must(New("x").Parse("test template")), // "x" is the value of .X
 137 }
 138
 139 // A non-empty interface.
 140 type I interface {
 141         Method0() string
 142 }
 143
 144 var iVal I = tVal
 145
 146 // Helpers for creation.
 147 func newInt(n int) *int {
 148         return &n
 149 }
 150
 151 func newString(s string) *string {
 152         return &s
 153 }
 154
 155 func newIntSlice(n ...int) *[]int {
 156         p := new([]int)
 157         *p = make([]int, len(n))
 158         copy(*p, n)
 159         return p
 160 }
 161
 162 // Simple methods with and without arguments.
 163 func (t *T) Method0() string {
 164         return "M0"
 165 }
 166
 167 func (t *T) Method1(a int) int {
 168         return a
 169 }
 170
 171 func (t *T) Method2(a uint16, b string) string {
 172         return fmt.Sprintf("Method2: %d %s", a, b)
 173 }
 174
 175 func (t *T) Method3(v interface{}) string {
 176         return fmt.Sprintf("Method3: %v", v)
 177 }
 178
 179 func (t *T) MAdd(a int, b []int) []int {
 180         v := make([]int, len(b))
 181         for i, x := range b {
 182                 v[i] = x + a
 183         }
 184         return v
 185 }
 186
 187 var myError = errors.New("my error")
 188
 189 // MyError returns a value and an error according to its argument.
 190 func (t *T) MyError(error bool) (bool, error) {
 191         if error {
 192                 return true, myError
 193         }
 194         return false, nil
 195 }
 196
 197 // A few methods to test chaining.
 198 func (t *T) GetU() *U {
 199         return t.U
 200 }
 201
 202 func (u *U) TrueFalse(b bool) string {
 203         if b {
 204                 return "true"
 205         }
 206         return ""
 207 }
 208
 209 func typeOf(arg interface{}) string {
 210         return fmt.Sprintf("%T", arg)
 211 }
 212
 213 type execTest struct {
 214         name   string
 215         input  string
 216         output string
 217         data   interface{}
 218         ok     bool
 219 }
 220
 221 // bigInt and bigUint are hex string representing numbers either side
 222 // of the max int boundary.
 223 // We do it this way so the test doesn't depend on ints being 32 bits.
 224 var (
 225         bigInt  = fmt.Sprintf("0x%x", int(1<<uint(reflect.TypeOf(0).Bits()-1)-1))
 226         bigUint = fmt.Sprintf("0x%x", uint(1<<uint(reflect.TypeOf(0).Bits()-1)))
 227 )
 228
 229 var execTests = []execTest{
 230         // Trivial cases.
 231         {"empty", "", "", nil, true},
 232         {"text", "some text", "some text", nil, true},
 233         {"nil action", "{{nil}}", "", nil, false},
 234
 235         // Ideal constants.
 236         {"ideal int", "{{typeOf 3}}", "int", 0, true},
 237         {"ideal float", "{{typeOf 1.0}}", "float64", 0, true},
 238         {"ideal exp float", "{{typeOf 1e1}}", "float64", 0, true},
 239         {"ideal complex", "{{typeOf 1i}}", "complex128", 0, true},
 240         {"ideal int", "{{typeOf " + bigInt + "}}", "int", 0, true},
 241         {"ideal too big", "{{typeOf " + bigUint + "}}", "", 0, false},
 242         {"ideal nil without type", "{{nil}}", "", 0, false},
 243
 244         // Fields of structs.
 245         {".X", "-{{.X}}-", "-x-", tVal, true},
 246         {".U.V", "-{{.U.V}}-", "-v-", tVal, true},
 247         {".unexported", "{{.unexported}}", "", tVal, false},
 248
 249         // Fields on maps.
 250         {"map .one", "{{.MSI.one}}", "1", tVal, true},
 251         {"map .two", "{{.MSI.two}}", "2", tVal, true},
 252         {"map .NO", "{{.MSI.NO}}", "<no value>", tVal, true},
 253         {"map .one interface", "{{.MXI.one}}", "1", tVal, true},
 254         {"map .WRONG args", "{{.MSI.one 1}}", "", tVal, false},
 255         {"map .WRONG type", "{{.MII.one}}", "", tVal, false},
 256
 257         // Dots of all kinds to test basic evaluation.
 258         {"dot int", "<{{.}}>", "<13>", 13, true},
 259         {"dot uint", "<{{.}}>", "<14>", uint(14), true},
 260         {"dot float", "<{{.}}>", "<15.1>", 15.1, true},
 261         {"dot bool", "<{{.}}>", "<true>", true, true},
 262         {"dot complex", "<{{.}}>", "<(16.2-17i)>", 16.2 - 17i, true},
 263         {"dot string", "<{{.}}>", "<hello>", "hello", true},
 264         {"dot slice", "<{{.}}>", "<[-1 -2 -3]>", []int{-1, -2, -3}, true},
 265         {"dot map", "<{{.}}>", "<map[two:22]>", map[string]int{"two": 22}, true},
 266         {"dot struct", "<{{.}}>", "<{7 seven}>", struct {
 267                 a int
 268                 b string
 269         }{7, "seven"}, true},
 270
 271         // Variables.
 272         {"$ int", "{{$}}", "123", 123, true},
 273         {"$.I", "{{$.I}}", "17", tVal, true},
 274         {"$.U.V", "{{$.U.V}}", "v", tVal, true},
 275         {"declare in action", "{{$x := $.U.V}}{{$x}}", "v", tVal, true},
 276
 277         // Type with String method.
 278         {"V{6666}.String()", "-{{.V0}}-", "-<6666>-", tVal, true},
 279         {"&V{7777}.String()", "-{{.V1}}-", "-<7777>-", tVal, true},
 280         {"(*V)(nil).String()", "-{{.V2}}-", "-nilV-", tVal, true},
 281
 282         // Type with Error method.
 283         {"W{888}.Error()", "-{{.W0}}-", "-[888]-", tVal, true},
 284         {"&W{999}.Error()", "-{{.W1}}-", "-[999]-", tVal, true},
 285         {"(*W)(nil).Error()", "-{{.W2}}-", "-nilW-", tVal, true},
 286
 287         // Pointers.
 288         {"*int", "{{.PI}}", "23", tVal, true},
 289         {"*string", "{{.PS}}", "a string", tVal, true},
 290         {"*[]int", "{{.PSI}}", "[21 22 23]", tVal, true},
 291         {"*[]int[1]", "{{index .PSI 1}}", "22", tVal, true},
 292         {"NIL", "{{.NIL}}", "<nil>", tVal, true},
 293
 294         // Empty interfaces holding values.
 295         {"empty nil", "{{.Empty0}}", "<no value>", tVal, true},
 296         {"empty with int", "{{.Empty1}}", "3", tVal, true},
 297         {"empty with string", "{{.Empty2}}", "empty2", tVal, true},
 298         {"empty with slice", "{{.Empty3}}", "[7 8]", tVal, true},
 299         {"empty with struct", "{{.Empty4}}", "{UinEmpty}", tVal, true},
 300         {"empty with struct, field", "{{.Empty4.V}}", "UinEmpty", tVal, true},
 301
 302         // Method calls.
 303         {".Method0", "-{{.Method0}}-", "-M0-", tVal, true},
 304         {".Method1(1234)", "-{{.Method1 1234}}-", "-1234-", tVal, true},
 305         {".Method1(.I)", "-{{.Method1 .I}}-", "-17-", tVal, true},
 306         {".Method2(3, .X)", "-{{.Method2 3 .X}}-", "-Method2: 3 x-", tVal, true},
 307         {".Method2(.U16, `str`)", "-{{.Method2 .U16 `str`}}-", "-Method2: 16 str-", tVal, true},
 308         {".Method2(.U16, $x)", "{{if $x := .X}}-{{.Method2 .U16 $x}}{{end}}-", "-Method2: 16 x-", tVal, true},
 309         {".Method3(nil constant)", "-{{.Method3 nil}}-", "-Method3: <nil>-", tVal, true},
 310         {".Method3(nil value)", "-{{.Method3 .MXI.unset}}-", "-Method3: <nil>-", tVal, true},
 311         {"method on var", "{{if $x := .}}-{{$x.Method2 .U16 $x.X}}{{end}}-", "-Method2: 16 x-", tVal, true},
 312         {"method on chained var",
 313                 "{{range .MSIone}}{{if $.U.TrueFalse $.True}}{{$.U.TrueFalse $.True}}{{else}}WRONG{{end}}{{end}}",
 314                 "true", tVal, true},
 315         {"chained method",
 316                 "{{range .MSIone}}{{if $.GetU.TrueFalse $.True}}{{$.U.TrueFalse $.True}}{{else}}WRONG{{end}}{{end}}",
 317                 "true", tVal, true},
 318         {"chained method on variable",
 319                 "{{with $x := .}}{{with .SI}}{{$.GetU.TrueFalse $.True}}{{end}}{{end}}",
 320                 "true", tVal, true},
 321         {".NilOKFunc not nil", "{{call .NilOKFunc .PI}}", "false", tVal, true},
 322         {".NilOKFunc nil", "{{call .NilOKFunc nil}}", "true", tVal, true},
 323
 324         // Function call builtin.
 325         {".BinaryFunc", "{{call .BinaryFunc `1` `2`}}", "[1=2]", tVal, true},
 326         {".VariadicFunc0", "{{call .VariadicFunc}}", "<>", tVal, true},
 327         {".VariadicFunc2", "{{call .VariadicFunc `he` `llo`}}", "<he+llo>", tVal, true},
 328         {".VariadicFuncInt", "{{call .VariadicFuncInt 33 `he` `llo`}}", "33=<he+llo>", tVal, true},
 329         {"if .BinaryFunc call", "{{ if .BinaryFunc}}{{call .BinaryFunc `1` `2`}}{{end}}", "[1=2]", tVal, true},
 330         {"if not .BinaryFunc call", "{{ if not .BinaryFunc}}{{call .BinaryFunc `1` `2`}}{{else}}No{{end}}", "No", tVal, true},
 331         {"Interface Call", `{{stringer .S}}`, "foozle", map[string]interface{}{"S": bytes.NewBufferString("foozle")}, true},
 332         {".ErrFunc", "{{call .ErrFunc}}", "bla", tVal, true},
 333
 334         // Erroneous function calls (check args).
 335         {".BinaryFuncTooFew", "{{call .BinaryFunc `1`}}", "", tVal, false},
 336         {".BinaryFuncTooMany", "{{call .BinaryFunc `1` `2` `3`}}", "", tVal, false},
 337         {".BinaryFuncBad0", "{{call .BinaryFunc 1 3}}", "", tVal, false},
 338         {".BinaryFuncBad1", "{{call .BinaryFunc `1` 3}}", "", tVal, false},
 339         {".VariadicFuncBad0", "{{call .VariadicFunc 3}}", "", tVal, false},
 340         {".VariadicFuncIntBad0", "{{call .VariadicFuncInt}}", "", tVal, false},
 341         {".VariadicFuncIntBad`", "{{call .VariadicFuncInt `x`}}", "", tVal, false},
 342         {".VariadicFuncNilBad", "{{call .VariadicFunc nil}}", "", tVal, false},
 343
 344         // Pipelines.
 345         {"pipeline", "-{{.Method0 | .Method2 .U16}}-", "-Method2: 16 M0-", tVal, true},
 346         {"pipeline func", "-{{call .VariadicFunc `llo` | call .VariadicFunc `he` }}-", "-<he+<llo>>-", tVal, true},
 347
 348         // Parenthesized expressions
 349         {"parens in pipeline", "{{printf `%d %d %d` (1) (2 | add 3) (add 4 (add 5 6))}}", "1 5 15", tVal, true},
 350
 351         // Parenthesized expressions with field accesses
 352         {"parens: $ in paren", "{{($).X}}", "x", tVal, true},
 353         {"parens: $.GetU in paren", "{{($.GetU).V}}", "v", tVal, true},
 354         {"parens: $ in paren in pipe", "{{($ | echo).X}}", "x", tVal, true},
 355         {"parens: spaces and args", `{{(makemap "up" "down" "left" "right").left}}`, "right", tVal, true},
 356
 357         // If.
 358         {"if true", "{{if true}}TRUE{{end}}", "TRUE", tVal, true},
 359         {"if false", "{{if false}}TRUE{{else}}FALSE{{end}}", "FALSE", tVal, true},
 360         {"if nil", "{{if nil}}TRUE{{end}}", "", tVal, false},
 361         {"if 1", "{{if 1}}NON-ZERO{{else}}ZERO{{end}}", "NON-ZERO", tVal, true},
 362         {"if 0", "{{if 0}}NON-ZERO{{else}}ZERO{{end}}", "ZERO", tVal, true},
 363         {"if 1.5", "{{if 1.5}}NON-ZERO{{else}}ZERO{{end}}", "NON-ZERO", tVal, true},
 364         {"if 0.0", "{{if .FloatZero}}NON-ZERO{{else}}ZERO{{end}}", "ZERO", tVal, true},
 365         {"if 1.5i", "{{if 1.5i}}NON-ZERO{{else}}ZERO{{end}}", "NON-ZERO", tVal, true},
 366         {"if 0.0i", "{{if .ComplexZero}}NON-ZERO{{else}}ZERO{{end}}", "ZERO", tVal, true},
 367         {"if emptystring", "{{if ``}}NON-EMPTY{{else}}EMPTY{{end}}", "EMPTY", tVal, true},
 368         {"if string", "{{if `notempty`}}NON-EMPTY{{else}}EMPTY{{end}}", "NON-EMPTY", tVal, true},
 369         {"if emptyslice", "{{if .SIEmpty}}NON-EMPTY{{else}}EMPTY{{end}}", "EMPTY", tVal, true},
 370         {"if slice", "{{if .SI}}NON-EMPTY{{else}}EMPTY{{end}}", "NON-EMPTY", tVal, true},
 371         {"if emptymap", "{{if .MSIEmpty}}NON-EMPTY{{else}}EMPTY{{end}}", "EMPTY", tVal, true},
 372         {"if map", "{{if .MSI}}NON-EMPTY{{else}}EMPTY{{end}}", "NON-EMPTY", tVal, true},
 373         {"if map unset", "{{if .MXI.none}}NON-ZERO{{else}}ZERO{{end}}", "ZERO", tVal, true},
 374         {"if map not unset", "{{if not .MXI.none}}ZERO{{else}}NON-ZERO{{end}}", "ZERO", tVal, true},
 375         {"if $x with $y int", "{{if $x := true}}{{with $y := .I}}{{$x}},{{$y}}{{end}}{{end}}", "true,17", tVal, true},
 376         {"if $x with $x int", "{{if $x := true}}{{with $x := .I}}{{$x}},{{end}}{{$x}}{{end}}", "17,true", tVal, true},
 377         {"if else if", "{{if false}}FALSE{{else if true}}TRUE{{end}}", "TRUE", tVal, true},
 378         {"if else chain", "{{if eq 1 3}}1{{else if eq 2 3}}2{{else if eq 3 3}}3{{end}}", "3", tVal, true},
 379
 380         // Print etc.
 381         {"print", `{{print "hello, print"}}`, "hello, print", tVal, true},
 382         {"print 123", `{{print 1 2 3}}`, "1 2 3", tVal, true},
 383         {"print nil", `{{print nil}}`, "<nil>", tVal, true},
 384         {"println", `{{println 1 2 3}}`, "1 2 3\n", tVal, true},
 385         {"printf int", `{{printf "%04x" 127}}`, "007f", tVal, true},
 386         {"printf float", `{{printf "%g" 3.5}}`, "3.5", tVal, true},
 387         {"printf complex", `{{printf "%g" 1+7i}}`, "(1+7i)", tVal, true},
 388         {"printf string", `{{printf "%s" "hello"}}`, "hello", tVal, true},
 389         {"printf function", `{{printf "%#q" zeroArgs}}`, "`zeroArgs`", tVal, true},
 390         {"printf field", `{{printf "%s" .U.V}}`, "v", tVal, true},
 391         {"printf method", `{{printf "%s" .Method0}}`, "M0", tVal, true},
 392         {"printf dot", `{{with .I}}{{printf "%d" .}}{{end}}`, "17", tVal, true},
 393         {"printf var", `{{with $x := .I}}{{printf "%d" $x}}{{end}}`, "17", tVal, true},
 394         {"printf lots", `{{printf "%d %s %g %s" 127 "hello" 7-3i .Method0}}`, "127 hello (7-3i) M0", tVal, true},
 395
 396         // HTML.
 397         {"html", `{{html "<script>alert(\"XSS\");</script>"}}`,
 398                 "&lt;script&gt;alert(&#34;XSS&#34;);&lt;/script&gt;", nil, true},
 399         {"html pipeline", `{{printf "<script>alert(\"XSS\");</script>" | html}}`,
 400                 "&lt;script&gt;alert(&#34;XSS&#34;);&lt;/script&gt;", nil, true},
 401         {"html", `{{html .PS}}`, "a string", tVal, true},
 402
 403         // JavaScript.
 404         {"js", `{{js .}}`, `It\'d be nice.`, `It'd be nice.`, true},
 405
 406         // URL query.
 407         {"urlquery", `{{"http://www.example.org/"|urlquery}}`, "http%3A%2F%2Fwww.example.org%2F", nil, true},
 408
 409         // Booleans
 410         {"not", "{{not true}} {{not false}}", "false true", nil, true},
 411         {"and", "{{and false 0}} {{and 1 0}} {{and 0 true}} {{and 1 1}}", "false 0 0 1", nil, true},
 412         {"or", "{{or 0 0}} {{or 1 0}} {{or 0 true}} {{or 1 1}}", "0 1 true 1", nil, true},
 413         {"boolean if", "{{if and true 1 `hi`}}TRUE{{else}}FALSE{{end}}", "TRUE", tVal, true},
 414         {"boolean if not", "{{if and true 1 `hi` | not}}TRUE{{else}}FALSE{{end}}", "FALSE", nil, true},
 415
 416         // Indexing.
 417         {"slice[0]", "{{index .SI 0}}", "3", tVal, true},
 418         {"slice[1]", "{{index .SI 1}}", "4", tVal, true},
 419         {"slice[HUGE]", "{{index .SI 10}}", "", tVal, false},
 420         {"slice[WRONG]", "{{index .SI `hello`}}", "", tVal, false},
 421         {"map[one]", "{{index .MSI `one`}}", "1", tVal, true},
 422         {"map[two]", "{{index .MSI `two`}}", "2", tVal, true},
 423         {"map[NO]", "{{index .MSI `XXX`}}", "0", tVal, true},
 424         {"map[nil]", "{{index .MSI nil}}", "0", tVal, true},
 425         {"map[WRONG]", "{{index .MSI 10}}", "", tVal, false},
 426         {"double index", "{{index .SMSI 1 `eleven`}}", "11", tVal, true},
 427
 428         // Len.
 429         {"slice", "{{len .SI}}", "3", tVal, true},
 430         {"map", "{{len .MSI }}", "3", tVal, true},
 431         {"len of int", "{{len 3}}", "", tVal, false},
 432         {"len of nothing", "{{len .Empty0}}", "", tVal, false},
 433
 434         // With.
 435         {"with true", "{{with true}}{{.}}{{end}}", "true", tVal, true},
 436         {"with false", "{{with false}}{{.}}{{else}}FALSE{{end}}", "FALSE", tVal, true},
 437         {"with 1", "{{with 1}}{{.}}{{else}}ZERO{{end}}", "1", tVal, true},
 438         {"with 0", "{{with 0}}{{.}}{{else}}ZERO{{end}}", "ZERO", tVal, true},
 439         {"with 1.5", "{{with 1.5}}{{.}}{{else}}ZERO{{end}}", "1.5", tVal, true},
 440         {"with 0.0", "{{with .FloatZero}}{{.}}{{else}}ZERO{{end}}", "ZERO", tVal, true},
 441         {"with 1.5i", "{{with 1.5i}}{{.}}{{else}}ZERO{{end}}", "(0+1.5i)", tVal, true},
 442         {"with 0.0i", "{{with .ComplexZero}}{{.}}{{else}}ZERO{{end}}", "ZERO", tVal, true},
 443         {"with emptystring", "{{with ``}}{{.}}{{else}}EMPTY{{end}}", "EMPTY", tVal, true},
 444         {"with string", "{{with `notempty`}}{{.}}{{else}}EMPTY{{end}}", "notempty", tVal, true},
 445         {"with emptyslice", "{{with .SIEmpty}}{{.}}{{else}}EMPTY{{end}}", "EMPTY", tVal, true},
 446         {"with slice", "{{with .SI}}{{.}}{{else}}EMPTY{{end}}", "[3 4 5]", tVal, true},
 447         {"with emptymap", "{{with .MSIEmpty}}{{.}}{{else}}EMPTY{{end}}", "EMPTY", tVal, true},
 448         {"with map", "{{with .MSIone}}{{.}}{{else}}EMPTY{{end}}", "map[one:1]", tVal, true},
 449         {"with empty interface, struct field", "{{with .Empty4}}{{.V}}{{end}}", "UinEmpty", tVal, true},
 450         {"with $x int", "{{with $x := .I}}{{$x}}{{end}}", "17", tVal, true},
 451         {"with $x struct.U.V", "{{with $x := $}}{{$x.U.V}}{{end}}", "v", tVal, true},
 452         {"with variable and action", "{{with $x := $}}{{$y := $.U.V}}{{$y}}{{end}}", "v", tVal, true},
 453
 454         // Range.
 455         {"range []int", "{{range .SI}}-{{.}}-{{end}}", "-3--4--5-", tVal, true},
 456         {"range empty no else", "{{range .SIEmpty}}-{{.}}-{{end}}", "", tVal, true},
 457         {"range []int else", "{{range .SI}}-{{.}}-{{else}}EMPTY{{end}}", "-3--4--5-", tVal, true},
 458         {"range empty else", "{{range .SIEmpty}}-{{.}}-{{else}}EMPTY{{end}}", "EMPTY", tVal, true},
 459         {"range []bool", "{{range .SB}}-{{.}}-{{end}}", "-true--false-", tVal, true},
 460         {"range []int method", "{{range .SI | .MAdd .I}}-{{.}}-{{end}}", "-20--21--22-", tVal, true},
 461         {"range map", "{{range .MSI}}-{{.}}-{{end}}", "-1--3--2-", tVal, true},
 462         {"range empty map no else", "{{range .MSIEmpty}}-{{.}}-{{end}}", "", tVal, true},
 463         {"range map else", "{{range .MSI}}-{{.}}-{{else}}EMPTY{{end}}", "-1--3--2-", tVal, true},
 464         {"range empty map else", "{{range .MSIEmpty}}-{{.}}-{{else}}EMPTY{{end}}", "EMPTY", tVal, true},
 465         {"range empty interface", "{{range .Empty3}}-{{.}}-{{else}}EMPTY{{end}}", "-7--8-", tVal, true},
 466         {"range empty nil", "{{range .Empty0}}-{{.}}-{{end}}", "", tVal, true},
 467         {"range $x SI", "{{range $x := .SI}}<{{$x}}>{{end}}", "<3><4><5>", tVal, true},
 468         {"range $x $y SI", "{{range $x, $y := .SI}}<{{$x}}={{$y}}>{{end}}", "<0=3><1=4><2=5>", tVal, true},
 469         {"range $x MSIone", "{{range $x := .MSIone}}<{{$x}}>{{end}}", "<1>", tVal, true},
 470         {"range $x $y MSIone", "{{range $x, $y := .MSIone}}<{{$x}}={{$y}}>{{end}}", "<one=1>", tVal, true},
 471         {"range $x PSI", "{{range $x := .PSI}}<{{$x}}>{{end}}", "<21><22><23>", tVal, true},
 472         {"declare in range", "{{range $x := .PSI}}<{{$foo:=$x}}{{$x}}>{{end}}", "<21><22><23>", tVal, true},
 473         {"range count", `{{range $i, $x := count 5}}[{{$i}}]{{$x}}{{end}}`, "[0]a[1]b[2]c[3]d[4]e", tVal, true},
 474         {"range nil count", `{{range $i, $x := count 0}}{{else}}empty{{end}}`, "empty", tVal, true},
 475
 476         // Cute examples.
 477         {"or as if true", `{{or .SI "slice is empty"}}`, "[3 4 5]", tVal, true},
 478         {"or as if false", `{{or .SIEmpty "slice is empty"}}`, "slice is empty", tVal, true},
 479
 480         // Error handling.
 481         {"error method, error", "{{.MyError true}}", "", tVal, false},
 482         {"error method, no error", "{{.MyError false}}", "false", tVal, true},
 483
 484         // Fixed bugs.
 485         // Must separate dot and receiver; otherwise args are evaluated with dot set to variable.
 486         {"bug0", "{{range .MSIone}}{{if $.Method1 .}}X{{end}}{{end}}", "X", tVal, true},
 487         // Do not loop endlessly in indirect for non-empty interfaces.
 488         // The bug appears with *interface only; looped forever.
 489         {"bug1", "{{.Method0}}", "M0", &iVal, true},
 490         // Was taking address of interface field, so method set was empty.
 491         {"bug2", "{{$.NonEmptyInterface.Method0}}", "M0", tVal, true},
 492         // Struct values were not legal in with - mere oversight.
 493         {"bug3", "{{with $}}{{.Method0}}{{end}}", "M0", tVal, true},
 494         // Nil interface values in if.
 495         {"bug4", "{{if .Empty0}}non-nil{{else}}nil{{end}}", "nil", tVal, true},
 496         // Stringer.
 497         {"bug5", "{{.Str}}", "foozle", tVal, true},
 498         {"bug5a", "{{.Err}}", "erroozle", tVal, true},
 499         // Args need to be indirected and dereferenced sometimes.
 500         {"bug6a", "{{vfunc .V0 .V1}}", "vfunc", tVal, true},
 501         {"bug6b", "{{vfunc .V0 .V0}}", "vfunc", tVal, true},
 502         {"bug6c", "{{vfunc .V1 .V0}}", "vfunc", tVal, true},
 503         {"bug6d", "{{vfunc .V1 .V1}}", "vfunc", tVal, true},
 504         // Legal parse but illegal execution: non-function should have no arguments.
 505         {"bug7a", "{{3 2}}", "", tVal, false},
 506         {"bug7b", "{{$x := 1}}{{$x 2}}", "", tVal, false},
 507         {"bug7c", "{{$x := 1}}{{3 | $x}}", "", tVal, false},
 508         // Pipelined arg was not being type-checked.
 509         {"bug8a", "{{3|oneArg}}", "", tVal, false},
 510         {"bug8b", "{{4|dddArg 3}}", "", tVal, false},
 511         // A bug was introduced that broke map lookups for lower-case names.
 512         {"bug9", "{{.cause}}", "neglect", map[string]string{"cause": "neglect"}, true},
 513         // Field chain starting with function did not work.
 514         {"bug10", "{{mapOfThree.three}}-{{(mapOfThree).three}}", "3-3", 0, true},
 515         // Dereferencing nil pointer while evaluating function arguments should not panic. Issue 7333.
 516         {"bug11", "{{valueString .PS}}", "", T{}, false},
 517 }
 518
 519 func zeroArgs() string {
 520         return "zeroArgs"
 521 }
 522
 523 func oneArg(a string) string {
 524         return "oneArg=" + a
 525 }
 526
 527 func dddArg(a int, b ...string) string {
 528         return fmt.Sprintln(a, b)
 529 }
 530
 531 // count returns a channel that will deliver n sequential 1-letter strings starting at "a"
 532 func count(n int) chan string {
 533         if n == 0 {
 534                 return nil
 535         }
 536         c := make(chan string)
 537         go func() {
 538                 for i := 0; i < n; i++ {
 539                         c <- "abcdefghijklmnop"[i : i+1]
 540                 }
 541                 close(c)
 542         }()
 543         return c
 544 }
 545
 546 // vfunc takes a *V and a V
 547 func vfunc(V, *V) string {
 548         return "vfunc"
 549 }
 550
 551 // valueString takes a string, not a pointer.
 552 func valueString(v string) string {
 553         return "value is ignored"
 554 }
 555
 556 func add(args ...int) int {
 557         sum := 0
 558         for _, x := range args {
 559                 sum += x
 560         }
 561         return sum
 562 }
 563
 564 func echo(arg interface{}) interface{} {
 565         return arg
 566 }
 567
 568 func makemap(arg ...string) map[string]string {
 569         if len(arg)%2 != 0 {
 570                 panic("bad makemap")
 571         }
 572         m := make(map[string]string)
 573         for i := 0; i < len(arg); i += 2 {
 574                 m[arg[i]] = arg[i+1]
 575         }
 576         return m
 577 }
 578
 579 func stringer(s fmt.Stringer) string {
 580         return s.String()
 581 }
 582
 583 func mapOfThree() interface{} {
 584         return map[string]int{"three": 3}
 585 }
 586
 587 func testExecute(execTests []execTest, template *Template, t *testing.T) {
 588         b := new(bytes.Buffer)
 589         funcs := FuncMap{
 590                 "add":         add,
 591                 "count":       count,
 592                 "dddArg":      dddArg,
 593                 "echo":        echo,
 594                 "makemap":     makemap,
 595                 "mapOfThree":  mapOfThree,
 596                 "oneArg":      oneArg,
 597                 "stringer":    stringer,
 598                 "typeOf":      typeOf,
 599                 "valueString": valueString,
 600                 "vfunc":       vfunc,
 601                 "zeroArgs":    zeroArgs,
 602         }
 603         for _, test := range execTests {
 604                 var tmpl *Template
 605                 var err error
 606                 if template == nil {
 607                         tmpl, err = New(test.name).Funcs(funcs).Parse(test.input)
 608                 } else {
 609                         tmpl, err = template.New(test.name).Funcs(funcs).Parse(test.input)
 610                 }
 611                 if err != nil {
 612                         t.Errorf("%s: parse error: %s", test.name, err)
 613                         continue
 614                 }
 615                 b.Reset()
 616                 err = tmpl.Execute(b, test.data)
 617                 switch {
 618                 case !test.ok && err == nil:
 619                         t.Errorf("%s: expected error; got none", test.name)
 620                         continue
 621                 case test.ok && err != nil:
 622                         t.Errorf("%s: unexpected execute error: %s", test.name, err)
 623                         continue
 624                 case !test.ok && err != nil:
 625                         // expected error, got one
 626                         if *debug {
 627                                 fmt.Printf("%s: %s\n\t%s\n", test.name, test.input, err)
 628                         }
 629                 }
 630                 result := b.String()
 631                 if result != test.output {
 632                         t.Errorf("%s: expected\n\t%q\ngot\n\t%q", test.name, test.output, result)
 633                 }
 634         }
 635 }
 636
 637 func TestExecute(t *testing.T) {
 638         testExecute(execTests, nil, t)
 639 }
 640
 641 var delimPairs = []string{
 642         "", "", // default
 643         "{{", "}}", // same as default
 644         "<<", ">>", // distinct
 645         "|", "|", // same
 646         "(日)", "(本)", // peculiar
 647 }
 648
 649 func TestDelims(t *testing.T) {
 650         const hello = "Hello, world"
 651         var value = struct{ Str string }{hello}
 652         for i := 0; i < len(delimPairs); i += 2 {
 653                 text := ".Str"
 654                 left := delimPairs[i+0]
 655                 trueLeft := left
 656                 right := delimPairs[i+1]
 657                 trueRight := right
 658                 if left == "" { // default case
 659                         trueLeft = "{{"
 660                 }
 661                 if right == "" { // default case
 662                         trueRight = "}}"
 663                 }
 664                 text = trueLeft + text + trueRight
 665                 // Now add a comment
 666                 text += trueLeft + "/*comment*/" + trueRight
 667                 // Now add  an action containing a string.
 668                 text += trueLeft + `"` + trueLeft + `"` + trueRight
 669                 // At this point text looks like `{{.Str}}{{/*comment*/}}{{"{{"}}`.
 670                 tmpl, err := New("delims").Delims(left, right).Parse(text)
 671                 if err != nil {
 672                         t.Fatalf("delim %q text %q parse err %s", left, text, err)
 673                 }
 674                 var b = new(bytes.Buffer)
 675                 err = tmpl.Execute(b, value)
 676                 if err != nil {
 677                         t.Fatalf("delim %q exec err %s", left, err)
 678                 }
 679                 if b.String() != hello+trueLeft {
 680                         t.Errorf("expected %q got %q", hello+trueLeft, b.String())
 681                 }
 682         }
 683 }
 684
 685 // Check that an error from a method flows back to the top.
 686 func TestExecuteError(t *testing.T) {
 687         b := new(bytes.Buffer)
 688         tmpl := New("error")
 689         _, err := tmpl.Parse("{{.MyError true}}")
 690         if err != nil {
 691                 t.Fatalf("parse error: %s", err)
 692         }
 693         err = tmpl.Execute(b, tVal)
 694         if err == nil {
 695                 t.Errorf("expected error; got none")
 696         } else if !strings.Contains(err.Error(), myError.Error()) {
 697                 if *debug {
 698                         fmt.Printf("test execute error: %s\n", err)
 699                 }
 700                 t.Errorf("expected myError; got %s", err)
 701         }
 702 }
 703
 704 const execErrorText = `line 1
 705 line 2
 706 line 3
 707 {{template "one" .}}
 708 {{define "one"}}{{template "two" .}}{{end}}
 709 {{define "two"}}{{template "three" .}}{{end}}
 710 {{define "three"}}{{index "hi" $}}{{end}}`
 711
 712 // Check that an error from a nested template contains all the relevant information.
 713 func TestExecError(t *testing.T) {
 714         tmpl, err := New("top").Parse(execErrorText)
 715         if err != nil {
 716                 t.Fatal("parse error:", err)
 717         }
 718         var b bytes.Buffer
 719         err = tmpl.Execute(&b, 5) // 5 is out of range indexing "hi"
 720         if err == nil {
 721                 t.Fatal("expected error")
 722         }
 723         const want = `template: top:7:20: executing "three" at <index "hi" $>: error calling index: index out of range: 5`
 724         got := err.Error()
 725         if got != want {
 726                 t.Errorf("expected\n%q\ngot\n%q", want, got)
 727         }
 728 }
 729
 730 func TestJSEscaping(t *testing.T) {
 731         testCases := []struct {
 732                 in, exp string
 733         }{
 734                 {`a`, `a`},
 735                 {`'foo`, `\'foo`},
 736                 {`Go "jump" \`, `Go \"jump\" \\`},
 737                 {`Yukihiro says "今日は世界"`, `Yukihiro says \"今日は世界\"`},
 738                 {"unprintable \uFDFF", `unprintable \uFDFF`},
 739                 {`<html>`, `\x3Chtml\x3E`},
 740         }
 741         for _, tc := range testCases {
 742                 s := JSEscapeString(tc.in)
 743                 if s != tc.exp {
 744                         t.Errorf("JS escaping [%s] got [%s] want [%s]", tc.in, s, tc.exp)
 745                 }
 746         }
 747 }
 748
 749 // A nice example: walk a binary tree.
 750
 751 type Tree struct {
 752         Val         int
 753         Left, Right *Tree
 754 }
 755
 756 // Use different delimiters to test Set.Delims.
 757 const treeTemplate = `
 758         (define "tree")
 759         [
 760                 (.Val)
 761                 (with .Left)
 762                         (template "tree" .)
 763                 (end)
 764                 (with .Right)
 765                         (template "tree" .)
 766                 (end)
 767         ]
 768         (end)
 769 `
 770
 771 func TestTree(t *testing.T) {
 772         var tree = &Tree{
 773                 1,
 774                 &Tree{
 775                         2, &Tree{
 776                                 3,
 777                                 &Tree{
 778                                         4, nil, nil,
 779                                 },
 780                                 nil,
 781                         },
 782                         &Tree{
 783                                 5,
 784                                 &Tree{
 785                                         6, nil, nil,
 786                                 },
 787                                 nil,
 788                         },
 789                 },
 790                 &Tree{
 791                         7,
 792                         &Tree{
 793                                 8,
 794                                 &Tree{
 795                                         9, nil, nil,
 796                                 },
 797                                 nil,
 798                         },
 799                         &Tree{
 800                                 10,
 801                                 &Tree{
 802                                         11, nil, nil,
 803                                 },
 804                                 nil,
 805                         },
 806                 },
 807         }
 808         tmpl, err := New("root").Delims("(", ")").Parse(treeTemplate)
 809         if err != nil {
 810                 t.Fatal("parse error:", err)
 811         }
 812         var b bytes.Buffer
 813         stripSpace := func(r rune) rune {
 814                 if r == '\t' || r == '\n' {
 815                         return -1
 816                 }
 817                 return r
 818         }
 819         const expect = "[1[2[3[4]][5[6]]][7[8[9]][10[11]]]]"
 820         // First by looking up the template.
 821         err = tmpl.Lookup("tree").Execute(&b, tree)
 822         if err != nil {
 823                 t.Fatal("exec error:", err)
 824         }
 825         result := strings.Map(stripSpace, b.String())
 826         if result != expect {
 827                 t.Errorf("expected %q got %q", expect, result)
 828         }
 829         // Then direct to execution.
 830         b.Reset()
 831         err = tmpl.ExecuteTemplate(&b, "tree", tree)
 832         if err != nil {
 833                 t.Fatal("exec error:", err)
 834         }
 835         result = strings.Map(stripSpace, b.String())
 836         if result != expect {
 837                 t.Errorf("expected %q got %q", expect, result)
 838         }
 839 }
 840
 841 func TestExecuteOnNewTemplate(t *testing.T) {
 842         // This is issue 3872.
 843         _ = New("Name").Templates()
 844 }
 845
 846 const testTemplates = `{{define "one"}}one{{end}}{{define "two"}}two{{end}}`
 847
 848 func TestMessageForExecuteEmpty(t *testing.T) {
 849         // Test a truly empty template.
 850         tmpl := New("empty")
 851         var b bytes.Buffer
 852         err := tmpl.Execute(&b, 0)
 853         if err == nil {
 854                 t.Fatal("expected initial error")
 855         }
 856         got := err.Error()
 857         want := `template: empty: "empty" is an incomplete or empty template`
 858         if got != want {
 859                 t.Errorf("expected error %s got %s", want, got)
 860         }
 861         // Add a non-empty template to check that the error is helpful.
 862         tests, err := New("").Parse(testTemplates)
 863         if err != nil {
 864                 t.Fatal(err)
 865         }
 866         tmpl.AddParseTree("secondary", tests.Tree)
 867         err = tmpl.Execute(&b, 0)
 868         if err == nil {
 869                 t.Fatal("expected second error")
 870         }
 871         got = err.Error()
 872         want = `template: empty: "empty" is an incomplete or empty template; defined templates are: "secondary"`
 873         if got != want {
 874                 t.Errorf("expected error %s got %s", want, got)
 875         }
 876         // Make sure we can execute the secondary.
 877         err = tmpl.ExecuteTemplate(&b, "secondary", 0)
 878         if err != nil {
 879                 t.Fatal(err)
 880         }
 881 }
 882
 883 type cmpTest struct {
 884         expr  string
 885         truth string
 886         ok    bool
 887 }
 888
 889 var cmpTests = []cmpTest{
 890         {"eq true true", "true", true},
 891         {"eq true false", "false", true},
 892         {"eq 1+2i 1+2i", "true", true},
 893         {"eq 1+2i 1+3i", "false", true},
 894         {"eq 1.5 1.5", "true", true},
 895         {"eq 1.5 2.5", "false", true},
 896         {"eq 1 1", "true", true},
 897         {"eq 1 2", "false", true},
 898         {"eq `xy` `xy`", "true", true},
 899         {"eq `xy` `xyz`", "false", true},
 900         {"eq .Xuint .Xuint", "true", true},
 901         {"eq .Xuint .Yuint", "false", true},
 902         {"eq 3 4 5 6 3", "true", true},
 903         {"eq 3 4 5 6 7", "false", true},
 904         {"ne true true", "false", true},
 905         {"ne true false", "true", true},
 906         {"ne 1+2i 1+2i", "false", true},
 907         {"ne 1+2i 1+3i", "true", true},
 908         {"ne 1.5 1.5", "false", true},
 909         {"ne 1.5 2.5", "true", true},
 910         {"ne 1 1", "false", true},
 911         {"ne 1 2", "true", true},
 912         {"ne `xy` `xy`", "false", true},
 913         {"ne `xy` `xyz`", "true", true},
 914         {"ne .Xuint .Xuint", "false", true},
 915         {"ne .Xuint .Yuint", "true", true},
 916         {"lt 1.5 1.5", "false", true},
 917         {"lt 1.5 2.5", "true", true},
 918         {"lt 1 1", "false", true},
 919         {"lt 1 2", "true", true},
 920         {"lt `xy` `xy`", "false", true},
 921         {"lt `xy` `xyz`", "true", true},
 922         {"lt .Xuint .Xuint", "false", true},
 923         {"lt .Xuint .Yuint", "true", true},
 924         {"le 1.5 1.5", "true", true},
 925         {"le 1.5 2.5", "true", true},
 926         {"le 2.5 1.5", "false", true},
 927         {"le 1 1", "true", true},
 928         {"le 1 2", "true", true},
 929         {"le 2 1", "false", true},
 930         {"le `xy` `xy`", "true", true},
 931         {"le `xy` `xyz`", "true", true},
 932         {"le `xyz` `xy`", "false", true},
 933         {"le .Xuint .Xuint", "true", true},
 934         {"le .Xuint .Yuint", "true", true},
 935         {"le .Yuint .Xuint", "false", true},
 936         {"gt 1.5 1.5", "false", true},
 937         {"gt 1.5 2.5", "false", true},
 938         {"gt 1 1", "false", true},
 939         {"gt 2 1", "true", true},
 940         {"gt 1 2", "false", true},
 941         {"gt `xy` `xy`", "false", true},
 942         {"gt `xy` `xyz`", "false", true},
 943         {"gt .Xuint .Xuint", "false", true},
 944         {"gt .Xuint .Yuint", "false", true},
 945         {"gt .Yuint .Xuint", "true", true},
 946         {"ge 1.5 1.5", "true", true},
 947         {"ge 1.5 2.5", "false", true},
 948         {"ge 2.5 1.5", "true", true},
 949         {"ge 1 1", "true", true},
 950         {"ge 1 2", "false", true},
 951         {"ge 2 1", "true", true},
 952         {"ge `xy` `xy`", "true", true},
 953         {"ge `xy` `xyz`", "false", true},
 954         {"ge `xyz` `xy`", "true", true},
 955         {"ge .Xuint .Xuint", "true", true},
 956         {"ge .Xuint .Yuint", "false", true},
 957         {"ge .Yuint .Xuint", "true", true},
 958         // Errors
 959         {"eq `xy` 1", "", false},    // Different types.
 960         {"lt true true", "", false}, // Unordered types.
 961         {"lt 1+0i 1+0i", "", false}, // Unordered types.
 962 }
 963
 964 func TestComparison(t *testing.T) {
 965         b := new(bytes.Buffer)
 966         var cmpStruct = struct {
 967                 Xuint, Yuint uint
 968         }{3, 4}
 969         for _, test := range cmpTests {
 970                 text := fmt.Sprintf("{{if %s}}true{{else}}false{{end}}", test.expr)
 971                 tmpl, err := New("empty").Parse(text)
 972                 if err != nil {
 973                         t.Fatal(err)
 974                 }
 975                 b.Reset()
 976                 err = tmpl.Execute(b, &cmpStruct)
 977                 if test.ok && err != nil {
 978                         t.Errorf("%s errored incorrectly: %s", test.expr, err)
 979                         continue
 980                 }
 981                 if !test.ok && err == nil {
 982                         t.Errorf("%s did not error", test.expr)
 983                         continue
 984                 }
 985                 if b.String() != test.truth {
 986                         t.Errorf("%s: want %s; got %s", test.expr, test.truth, b.String())
 987                 }
 988         }
 989 }