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         "io/ioutil"
  13         "reflect"
  14         "strings"
  15         "testing"
  16 )
  17
  18 var debug = flag.Bool("debug", false, "show the errors produced by the tests")
  19
  20 // T has lots of interesting pieces to use to test execution.
  21 type T struct {
  22         // Basics
  23         True        bool
  24         I           int
  25         U16         uint16
  26         X           string
  27         FloatZero   float64
  28         ComplexZero complex128
  29         // Nested structs.
  30         U *U
  31         // Struct with String method.
  32         V0     V
  33         V1, V2 *V
  34         // Struct with Error method.
  35         W0     W
  36         W1, W2 *W
  37         // Slices
  38         SI      []int
  39         SIEmpty []int
  40         SB      []bool
  41         // Maps
  42         MSI      map[string]int
  43         MSIone   map[string]int // one element, for deterministic output
  44         MSIEmpty map[string]int
  45         MXI      map[interface{}]int
  46         MII      map[int]int
  47         MI32S    map[int32]string
  48         MI64S    map[int64]string
  49         MUI32S   map[uint32]string
  50         MUI64S   map[uint64]string
  51         MI8S     map[int8]string
  52         MUI8S    map[uint8]string
  53         SMSI     []map[string]int
  54         // Empty interfaces; used to see if we can dig inside one.
  55         Empty0 interface{} // nil
  56         Empty1 interface{}
  57         Empty2 interface{}
  58         Empty3 interface{}
  59         Empty4 interface{}
  60         // Non-empty interfaces.
  61         NonEmptyInterface    I
  62         NonEmptyInterfacePtS *I
  63         // Stringer.
  64         Str fmt.Stringer
  65         Err error
  66         // Pointers
  67         PI  *int
  68         PS  *string
  69         PSI *[]int
  70         NIL *int
  71         // Function (not method)
  72         BinaryFunc      func(string, string) string
  73         VariadicFunc    func(...string) string
  74         VariadicFuncInt func(int, ...string) string
  75         NilOKFunc       func(*int) bool
  76         ErrFunc         func() (string, error)
  77         // Template to test evaluation of templates.
  78         Tmpl *Template
  79         // Unexported field; cannot be accessed by template.
  80         unexported int
  81 }
  82
  83 type S []string
  84
  85 func (S) Method0() string {
  86         return "M0"
  87 }
  88
  89 type U struct {
  90         V string
  91 }
  92
  93 type V struct {
  94         j int
  95 }
  96
  97 func (v *V) String() string {
  98         if v == nil {
  99                 return "nilV"
 100         }
 101         return fmt.Sprintf("<%d>", v.j)
 102 }
 103
 104 type W struct {
 105         k int
 106 }
 107
 108 func (w *W) Error() string {
 109         if w == nil {
 110                 return "nilW"
 111         }
 112         return fmt.Sprintf("[%d]", w.k)
 113 }
 114
 115 var siVal = I(S{"a", "b"})
 116
 117 var tVal = &T{
 118         True:   true,
 119         I:      17,
 120         U16:    16,
 121         X:      "x",
 122         U:      &U{"v"},
 123         V0:     V{6666},
 124         V1:     &V{7777}, // leave V2 as nil
 125         W0:     W{888},
 126         W1:     &W{999}, // leave W2 as nil
 127         SI:     []int{3, 4, 5},
 128         SB:     []bool{true, false},
 129         MSI:    map[string]int{"one": 1, "two": 2, "three": 3},
 130         MSIone: map[string]int{"one": 1},
 131         MXI:    map[interface{}]int{"one": 1},
 132         MII:    map[int]int{1: 1},
 133         MI32S:  map[int32]string{1: "one", 2: "two"},
 134         MI64S:  map[int64]string{2: "i642", 3: "i643"},
 135         MUI32S: map[uint32]string{2: "u322", 3: "u323"},
 136         MUI64S: map[uint64]string{2: "ui642", 3: "ui643"},
 137         MI8S:   map[int8]string{2: "i82", 3: "i83"},
 138         MUI8S:  map[uint8]string{2: "u82", 3: "u83"},
 139         SMSI: []map[string]int{
 140                 {"one": 1, "two": 2},
 141                 {"eleven": 11, "twelve": 12},
 142         },
 143         Empty1:               3,
 144         Empty2:               "empty2",
 145         Empty3:               []int{7, 8},
 146         Empty4:               &U{"UinEmpty"},
 147         NonEmptyInterface:    &T{X: "x"},
 148         NonEmptyInterfacePtS: &siVal,
 149         Str:                  bytes.NewBuffer([]byte("foozle")),
 150         Err:                  errors.New("erroozle"),
 151         PI:                   newInt(23),
 152         PS:                   newString("a string"),
 153         PSI:                  newIntSlice(21, 22, 23),
 154         BinaryFunc:           func(a, b string) string { return fmt.Sprintf("[%s=%s]", a, b) },
 155         VariadicFunc:         func(s ...string) string { return fmt.Sprint("<", strings.Join(s, "+"), ">") },
 156         VariadicFuncInt:      func(a int, s ...string) string { return fmt.Sprint(a, "=<", strings.Join(s, "+"), ">") },
 157         NilOKFunc:            func(s *int) bool { return s == nil },
 158         ErrFunc:              func() (string, error) { return "bla", nil },
 159         Tmpl:                 Must(New("x").Parse("test template")), // "x" is the value of .X
 160 }
 161
 162 var tSliceOfNil = []*T{nil}
 163
 164 // A non-empty interface.
 165 type I interface {
 166         Method0() string
 167 }
 168
 169 var iVal I = tVal
 170
 171 // Helpers for creation.
 172 func newInt(n int) *int {
 173         return &n
 174 }
 175
 176 func newString(s string) *string {
 177         return &s
 178 }
 179
 180 func newIntSlice(n ...int) *[]int {
 181         p := new([]int)
 182         *p = make([]int, len(n))
 183         copy(*p, n)
 184         return p
 185 }
 186
 187 // Simple methods with and without arguments.
 188 func (t *T) Method0() string {
 189         return "M0"
 190 }
 191
 192 func (t *T) Method1(a int) int {
 193         return a
 194 }
 195
 196 func (t *T) Method2(a uint16, b string) string {
 197         return fmt.Sprintf("Method2: %d %s", a, b)
 198 }
 199
 200 func (t *T) Method3(v interface{}) string {
 201         return fmt.Sprintf("Method3: %v", v)
 202 }
 203
 204 func (t *T) Copy() *T {
 205         n := new(T)
 206         *n = *t
 207         return n
 208 }
 209
 210 func (t *T) MAdd(a int, b []int) []int {
 211         v := make([]int, len(b))
 212         for i, x := range b {
 213                 v[i] = x + a
 214         }
 215         return v
 216 }
 217
 218 var myError = errors.New("my error")
 219
 220 // MyError returns a value and an error according to its argument.
 221 func (t *T) MyError(error bool) (bool, error) {
 222         if error {
 223                 return true, myError
 224         }
 225         return false, nil
 226 }
 227
 228 // A few methods to test chaining.
 229 func (t *T) GetU() *U {
 230         return t.U
 231 }
 232
 233 func (u *U) TrueFalse(b bool) string {
 234         if b {
 235                 return "true"
 236         }
 237         return ""
 238 }
 239
 240 func typeOf(arg interface{}) string {
 241         return fmt.Sprintf("%T", arg)
 242 }
 243
 244 type execTest struct {
 245         name   string
 246         input  string
 247         output string
 248         data   interface{}
 249         ok     bool
 250 }
 251
 252 // bigInt and bigUint are hex string representing numbers either side
 253 // of the max int boundary.
 254 // We do it this way so the test doesn't depend on ints being 32 bits.
 255 var (
 256         bigInt  = fmt.Sprintf("0x%x", int(1<<uint(reflect.TypeOf(0).Bits()-1)-1))
 257         bigUint = fmt.Sprintf("0x%x", uint(1<<uint(reflect.TypeOf(0).Bits()-1)))
 258 )
 259
 260 var execTests = []execTest{
 261         // Trivial cases.
 262         {"empty", "", "", nil, true},
 263         {"text", "some text", "some text", nil, true},
 264         {"nil action", "{{nil}}", "", nil, false},
 265
 266         // Ideal constants.
 267         {"ideal int", "{{typeOf 3}}", "int", 0, true},
 268         {"ideal float", "{{typeOf 1.0}}", "float64", 0, true},
 269         {"ideal exp float", "{{typeOf 1e1}}", "float64", 0, true},
 270         {"ideal complex", "{{typeOf 1i}}", "complex128", 0, true},
 271         {"ideal int", "{{typeOf " + bigInt + "}}", "int", 0, true},
 272         {"ideal too big", "{{typeOf " + bigUint + "}}", "", 0, false},
 273         {"ideal nil without type", "{{nil}}", "", 0, false},
 274
 275         // Fields of structs.
 276         {".X", "-{{.X}}-", "-x-", tVal, true},
 277         {".U.V", "-{{.U.V}}-", "-v-", tVal, true},
 278         {".unexported", "{{.unexported}}", "", tVal, false},
 279
 280         // Fields on maps.
 281         {"map .one", "{{.MSI.one}}", "1", tVal, true},
 282         {"map .two", "{{.MSI.two}}", "2", tVal, true},
 283         {"map .NO", "{{.MSI.NO}}", "<no value>", tVal, true},
 284         {"map .one interface", "{{.MXI.one}}", "1", tVal, true},
 285         {"map .WRONG args", "{{.MSI.one 1}}", "", tVal, false},
 286         {"map .WRONG type", "{{.MII.one}}", "", tVal, false},
 287
 288         // Dots of all kinds to test basic evaluation.
 289         {"dot int", "<{{.}}>", "<13>", 13, true},
 290         {"dot uint", "<{{.}}>", "<14>", uint(14), true},
 291         {"dot float", "<{{.}}>", "<15.1>", 15.1, true},
 292         {"dot bool", "<{{.}}>", "<true>", true, true},
 293         {"dot complex", "<{{.}}>", "<(16.2-17i)>", 16.2 - 17i, true},
 294         {"dot string", "<{{.}}>", "<hello>", "hello", true},
 295         {"dot slice", "<{{.}}>", "<[-1 -2 -3]>", []int{-1, -2, -3}, true},
 296         {"dot map", "<{{.}}>", "<map[two:22]>", map[string]int{"two": 22}, true},
 297         {"dot struct", "<{{.}}>", "<{7 seven}>", struct {
 298                 a int
 299                 b string
 300         }{7, "seven"}, true},
 301
 302         // Variables.
 303         {"$ int", "{{$}}", "123", 123, true},
 304         {"$.I", "{{$.I}}", "17", tVal, true},
 305         {"$.U.V", "{{$.U.V}}", "v", tVal, true},
 306         {"declare in action", "{{$x := $.U.V}}{{$x}}", "v", tVal, true},
 307
 308         // Type with String method.
 309         {"V{6666}.String()", "-{{.V0}}-", "-<6666>-", tVal, true},
 310         {"&V{7777}.String()", "-{{.V1}}-", "-<7777>-", tVal, true},
 311         {"(*V)(nil).String()", "-{{.V2}}-", "-nilV-", tVal, true},
 312
 313         // Type with Error method.
 314         {"W{888}.Error()", "-{{.W0}}-", "-[888]-", tVal, true},
 315         {"&W{999}.Error()", "-{{.W1}}-", "-[999]-", tVal, true},
 316         {"(*W)(nil).Error()", "-{{.W2}}-", "-nilW-", tVal, true},
 317
 318         // Pointers.
 319         {"*int", "{{.PI}}", "23", tVal, true},
 320         {"*string", "{{.PS}}", "a string", tVal, true},
 321         {"*[]int", "{{.PSI}}", "[21 22 23]", tVal, true},
 322         {"*[]int[1]", "{{index .PSI 1}}", "22", tVal, true},
 323         {"NIL", "{{.NIL}}", "<nil>", tVal, true},
 324
 325         // Empty interfaces holding values.
 326         {"empty nil", "{{.Empty0}}", "<no value>", tVal, true},
 327         {"empty with int", "{{.Empty1}}", "3", tVal, true},
 328         {"empty with string", "{{.Empty2}}", "empty2", tVal, true},
 329         {"empty with slice", "{{.Empty3}}", "[7 8]", tVal, true},
 330         {"empty with struct", "{{.Empty4}}", "{UinEmpty}", tVal, true},
 331         {"empty with struct, field", "{{.Empty4.V}}", "UinEmpty", tVal, true},
 332
 333         // Method calls.
 334         {".Method0", "-{{.Method0}}-", "-M0-", tVal, true},
 335         {".Method1(1234)", "-{{.Method1 1234}}-", "-1234-", tVal, true},
 336         {".Method1(.I)", "-{{.Method1 .I}}-", "-17-", tVal, true},
 337         {".Method2(3, .X)", "-{{.Method2 3 .X}}-", "-Method2: 3 x-", tVal, true},
 338         {".Method2(.U16, `str`)", "-{{.Method2 .U16 `str`}}-", "-Method2: 16 str-", tVal, true},
 339         {".Method2(.U16, $x)", "{{if $x := .X}}-{{.Method2 .U16 $x}}{{end}}-", "-Method2: 16 x-", tVal, true},
 340         {".Method3(nil constant)", "-{{.Method3 nil}}-", "-Method3: <nil>-", tVal, true},
 341         {".Method3(nil value)", "-{{.Method3 .MXI.unset}}-", "-Method3: <nil>-", tVal, true},
 342         {"method on var", "{{if $x := .}}-{{$x.Method2 .U16 $x.X}}{{end}}-", "-Method2: 16 x-", tVal, true},
 343         {"method on chained var",
 344                 "{{range .MSIone}}{{if $.U.TrueFalse $.True}}{{$.U.TrueFalse $.True}}{{else}}WRONG{{end}}{{end}}",
 345                 "true", tVal, true},
 346         {"chained method",
 347                 "{{range .MSIone}}{{if $.GetU.TrueFalse $.True}}{{$.U.TrueFalse $.True}}{{else}}WRONG{{end}}{{end}}",
 348                 "true", tVal, true},
 349         {"chained method on variable",
 350                 "{{with $x := .}}{{with .SI}}{{$.GetU.TrueFalse $.True}}{{end}}{{end}}",
 351                 "true", tVal, true},
 352         {".NilOKFunc not nil", "{{call .NilOKFunc .PI}}", "false", tVal, true},
 353         {".NilOKFunc nil", "{{call .NilOKFunc nil}}", "true", tVal, true},
 354         {"method on nil value from slice", "-{{range .}}{{.Method1 1234}}{{end}}-", "-1234-", tSliceOfNil, true},
 355
 356         // Function call builtin.
 357         {".BinaryFunc", "{{call .BinaryFunc `1` `2`}}", "[1=2]", tVal, true},
 358         {".VariadicFunc0", "{{call .VariadicFunc}}", "<>", tVal, true},
 359         {".VariadicFunc2", "{{call .VariadicFunc `he` `llo`}}", "<he+llo>", tVal, true},
 360         {".VariadicFuncInt", "{{call .VariadicFuncInt 33 `he` `llo`}}", "33=<he+llo>", tVal, true},
 361         {"if .BinaryFunc call", "{{ if .BinaryFunc}}{{call .BinaryFunc `1` `2`}}{{end}}", "[1=2]", tVal, true},
 362         {"if not .BinaryFunc call", "{{ if not .BinaryFunc}}{{call .BinaryFunc `1` `2`}}{{else}}No{{end}}", "No", tVal, true},
 363         {"Interface Call", `{{stringer .S}}`, "foozle", map[string]interface{}{"S": bytes.NewBufferString("foozle")}, true},
 364         {".ErrFunc", "{{call .ErrFunc}}", "bla", tVal, true},
 365         {"call nil", "{{call nil}}", "", tVal, false},
 366
 367         // Erroneous function calls (check args).
 368         {".BinaryFuncTooFew", "{{call .BinaryFunc `1`}}", "", tVal, false},
 369         {".BinaryFuncTooMany", "{{call .BinaryFunc `1` `2` `3`}}", "", tVal, false},
 370         {".BinaryFuncBad0", "{{call .BinaryFunc 1 3}}", "", tVal, false},
 371         {".BinaryFuncBad1", "{{call .BinaryFunc `1` 3}}", "", tVal, false},
 372         {".VariadicFuncBad0", "{{call .VariadicFunc 3}}", "", tVal, false},
 373         {".VariadicFuncIntBad0", "{{call .VariadicFuncInt}}", "", tVal, false},
 374         {".VariadicFuncIntBad`", "{{call .VariadicFuncInt `x`}}", "", tVal, false},
 375         {".VariadicFuncNilBad", "{{call .VariadicFunc nil}}", "", tVal, false},
 376
 377         // Pipelines.
 378         {"pipeline", "-{{.Method0 | .Method2 .U16}}-", "-Method2: 16 M0-", tVal, true},
 379         {"pipeline func", "-{{call .VariadicFunc `llo` | call .VariadicFunc `he` }}-", "-<he+<llo>>-", tVal, true},
 380
 381         // Parenthesized expressions
 382         {"parens in pipeline", "{{printf `%d %d %d` (1) (2 | add 3) (add 4 (add 5 6))}}", "1 5 15", tVal, true},
 383
 384         // Parenthesized expressions with field accesses
 385         {"parens: $ in paren", "{{($).X}}", "x", tVal, true},
 386         {"parens: $.GetU in paren", "{{($.GetU).V}}", "v", tVal, true},
 387         {"parens: $ in paren in pipe", "{{($ | echo).X}}", "x", tVal, true},
 388         {"parens: spaces and args", `{{(makemap "up" "down" "left" "right").left}}`, "right", tVal, true},
 389
 390         // If.
 391         {"if true", "{{if true}}TRUE{{end}}", "TRUE", tVal, true},
 392         {"if false", "{{if false}}TRUE{{else}}FALSE{{end}}", "FALSE", tVal, true},
 393         {"if nil", "{{if nil}}TRUE{{end}}", "", tVal, false},
 394         {"if 1", "{{if 1}}NON-ZERO{{else}}ZERO{{end}}", "NON-ZERO", tVal, true},
 395         {"if 0", "{{if 0}}NON-ZERO{{else}}ZERO{{end}}", "ZERO", tVal, true},
 396         {"if 1.5", "{{if 1.5}}NON-ZERO{{else}}ZERO{{end}}", "NON-ZERO", tVal, true},
 397         {"if 0.0", "{{if .FloatZero}}NON-ZERO{{else}}ZERO{{end}}", "ZERO", tVal, true},
 398         {"if 1.5i", "{{if 1.5i}}NON-ZERO{{else}}ZERO{{end}}", "NON-ZERO", tVal, true},
 399         {"if 0.0i", "{{if .ComplexZero}}NON-ZERO{{else}}ZERO{{end}}", "ZERO", tVal, true},
 400         {"if emptystring", "{{if ``}}NON-EMPTY{{else}}EMPTY{{end}}", "EMPTY", tVal, true},
 401         {"if string", "{{if `notempty`}}NON-EMPTY{{else}}EMPTY{{end}}", "NON-EMPTY", tVal, true},
 402         {"if emptyslice", "{{if .SIEmpty}}NON-EMPTY{{else}}EMPTY{{end}}", "EMPTY", tVal, true},
 403         {"if slice", "{{if .SI}}NON-EMPTY{{else}}EMPTY{{end}}", "NON-EMPTY", tVal, true},
 404         {"if emptymap", "{{if .MSIEmpty}}NON-EMPTY{{else}}EMPTY{{end}}", "EMPTY", tVal, true},
 405         {"if map", "{{if .MSI}}NON-EMPTY{{else}}EMPTY{{end}}", "NON-EMPTY", tVal, true},
 406         {"if map unset", "{{if .MXI.none}}NON-ZERO{{else}}ZERO{{end}}", "ZERO", tVal, true},
 407         {"if map not unset", "{{if not .MXI.none}}ZERO{{else}}NON-ZERO{{end}}", "ZERO", tVal, true},
 408         {"if $x with $y int", "{{if $x := true}}{{with $y := .I}}{{$x}},{{$y}}{{end}}{{end}}", "true,17", tVal, true},
 409         {"if $x with $x int", "{{if $x := true}}{{with $x := .I}}{{$x}},{{end}}{{$x}}{{end}}", "17,true", tVal, true},
 410         {"if else if", "{{if false}}FALSE{{else if true}}TRUE{{end}}", "TRUE", tVal, true},
 411         {"if else chain", "{{if eq 1 3}}1{{else if eq 2 3}}2{{else if eq 3 3}}3{{end}}", "3", tVal, true},
 412
 413         // Print etc.
 414         {"print", `{{print "hello, print"}}`, "hello, print", tVal, true},
 415         {"print 123", `{{print 1 2 3}}`, "1 2 3", tVal, true},
 416         {"print nil", `{{print nil}}`, "<nil>", tVal, true},
 417         {"println", `{{println 1 2 3}}`, "1 2 3\n", tVal, true},
 418         {"printf int", `{{printf "%04x" 127}}`, "007f", tVal, true},
 419         {"printf float", `{{printf "%g" 3.5}}`, "3.5", tVal, true},
 420         {"printf complex", `{{printf "%g" 1+7i}}`, "(1+7i)", tVal, true},
 421         {"printf string", `{{printf "%s" "hello"}}`, "hello", tVal, true},
 422         {"printf function", `{{printf "%#q" zeroArgs}}`, "`zeroArgs`", tVal, true},
 423         {"printf field", `{{printf "%s" .U.V}}`, "v", tVal, true},
 424         {"printf method", `{{printf "%s" .Method0}}`, "M0", tVal, true},
 425         {"printf dot", `{{with .I}}{{printf "%d" .}}{{end}}`, "17", tVal, true},
 426         {"printf var", `{{with $x := .I}}{{printf "%d" $x}}{{end}}`, "17", tVal, true},
 427         {"printf lots", `{{printf "%d %s %g %s" 127 "hello" 7-3i .Method0}}`, "127 hello (7-3i) M0", tVal, true},
 428
 429         // HTML.
 430         {"html", `{{html "<script>alert(\"XSS\");</script>"}}`,
 431                 "&lt;script&gt;alert(&#34;XSS&#34;);&lt;/script&gt;", nil, true},
 432         {"html pipeline", `{{printf "<script>alert(\"XSS\");</script>" | html}}`,
 433                 "&lt;script&gt;alert(&#34;XSS&#34;);&lt;/script&gt;", nil, true},
 434         {"html", `{{html .PS}}`, "a string", tVal, true},
 435
 436         // JavaScript.
 437         {"js", `{{js .}}`, `It\'d be nice.`, `It'd be nice.`, true},
 438
 439         // URL query.
 440         {"urlquery", `{{"http://www.example.org/"|urlquery}}`, "http%3A%2F%2Fwww.example.org%2F", nil, true},
 441
 442         // Booleans
 443         {"not", "{{not true}} {{not false}}", "false true", nil, true},
 444         {"and", "{{and false 0}} {{and 1 0}} {{and 0 true}} {{and 1 1}}", "false 0 0 1", nil, true},
 445         {"or", "{{or 0 0}} {{or 1 0}} {{or 0 true}} {{or 1 1}}", "0 1 true 1", nil, true},
 446         {"boolean if", "{{if and true 1 `hi`}}TRUE{{else}}FALSE{{end}}", "TRUE", tVal, true},
 447         {"boolean if not", "{{if and true 1 `hi` | not}}TRUE{{else}}FALSE{{end}}", "FALSE", nil, true},
 448
 449         // Indexing.
 450         {"slice[0]", "{{index .SI 0}}", "3", tVal, true},
 451         {"slice[1]", "{{index .SI 1}}", "4", tVal, true},
 452         {"slice[HUGE]", "{{index .SI 10}}", "", tVal, false},
 453         {"slice[WRONG]", "{{index .SI `hello`}}", "", tVal, false},
 454         {"slice[nil]", "{{index .SI nil}}", "", tVal, false},
 455         {"map[one]", "{{index .MSI `one`}}", "1", tVal, true},
 456         {"map[two]", "{{index .MSI `two`}}", "2", tVal, true},
 457         {"map[NO]", "{{index .MSI `XXX`}}", "0", tVal, true},
 458         {"map[nil]", "{{index .MSI nil}}", "", tVal, false},
 459         {"map[``]", "{{index .MSI ``}}", "0", tVal, true},
 460         {"map[WRONG]", "{{index .MSI 10}}", "", tVal, false},
 461         {"double index", "{{index .SMSI 1 `eleven`}}", "11", tVal, true},
 462         {"nil[1]", "{{index nil 1}}", "", tVal, false},
 463         {"map MI64S", "{{index .MI64S 2}}", "i642", tVal, true},
 464         {"map MI32S", "{{index .MI32S 2}}", "two", tVal, true},
 465         {"map MUI64S", "{{index .MUI64S 3}}", "ui643", tVal, true},
 466         {"map MI8S", "{{index .MI8S 3}}", "i83", tVal, true},
 467         {"map MUI8S", "{{index .MUI8S 2}}", "u82", tVal, true},
 468
 469         // Len.
 470         {"slice", "{{len .SI}}", "3", tVal, true},
 471         {"map", "{{len .MSI }}", "3", tVal, true},
 472         {"len of int", "{{len 3}}", "", tVal, false},
 473         {"len of nothing", "{{len .Empty0}}", "", tVal, false},
 474
 475         // With.
 476         {"with true", "{{with true}}{{.}}{{end}}", "true", tVal, true},
 477         {"with false", "{{with false}}{{.}}{{else}}FALSE{{end}}", "FALSE", tVal, true},
 478         {"with 1", "{{with 1}}{{.}}{{else}}ZERO{{end}}", "1", tVal, true},
 479         {"with 0", "{{with 0}}{{.}}{{else}}ZERO{{end}}", "ZERO", tVal, true},
 480         {"with 1.5", "{{with 1.5}}{{.}}{{else}}ZERO{{end}}", "1.5", tVal, true},
 481         {"with 0.0", "{{with .FloatZero}}{{.}}{{else}}ZERO{{end}}", "ZERO", tVal, true},
 482         {"with 1.5i", "{{with 1.5i}}{{.}}{{else}}ZERO{{end}}", "(0+1.5i)", tVal, true},
 483         {"with 0.0i", "{{with .ComplexZero}}{{.}}{{else}}ZERO{{end}}", "ZERO", tVal, true},
 484         {"with emptystring", "{{with ``}}{{.}}{{else}}EMPTY{{end}}", "EMPTY", tVal, true},
 485         {"with string", "{{with `notempty`}}{{.}}{{else}}EMPTY{{end}}", "notempty", tVal, true},
 486         {"with emptyslice", "{{with .SIEmpty}}{{.}}{{else}}EMPTY{{end}}", "EMPTY", tVal, true},
 487         {"with slice", "{{with .SI}}{{.}}{{else}}EMPTY{{end}}", "[3 4 5]", tVal, true},
 488         {"with emptymap", "{{with .MSIEmpty}}{{.}}{{else}}EMPTY{{end}}", "EMPTY", tVal, true},
 489         {"with map", "{{with .MSIone}}{{.}}{{else}}EMPTY{{end}}", "map[one:1]", tVal, true},
 490         {"with empty interface, struct field", "{{with .Empty4}}{{.V}}{{end}}", "UinEmpty", tVal, true},
 491         {"with $x int", "{{with $x := .I}}{{$x}}{{end}}", "17", tVal, true},
 492         {"with $x struct.U.V", "{{with $x := $}}{{$x.U.V}}{{end}}", "v", tVal, true},
 493         {"with variable and action", "{{with $x := $}}{{$y := $.U.V}}{{$y}}{{end}}", "v", tVal, true},
 494
 495         // Range.
 496         {"range []int", "{{range .SI}}-{{.}}-{{end}}", "-3--4--5-", tVal, true},
 497         {"range empty no else", "{{range .SIEmpty}}-{{.}}-{{end}}", "", tVal, true},
 498         {"range []int else", "{{range .SI}}-{{.}}-{{else}}EMPTY{{end}}", "-3--4--5-", tVal, true},
 499         {"range empty else", "{{range .SIEmpty}}-{{.}}-{{else}}EMPTY{{end}}", "EMPTY", tVal, true},
 500         {"range []bool", "{{range .SB}}-{{.}}-{{end}}", "-true--false-", tVal, true},
 501         {"range []int method", "{{range .SI | .MAdd .I}}-{{.}}-{{end}}", "-20--21--22-", tVal, true},
 502         {"range map", "{{range .MSI}}-{{.}}-{{end}}", "-1--3--2-", tVal, true},
 503         {"range empty map no else", "{{range .MSIEmpty}}-{{.}}-{{end}}", "", tVal, true},
 504         {"range map else", "{{range .MSI}}-{{.}}-{{else}}EMPTY{{end}}", "-1--3--2-", tVal, true},
 505         {"range empty map else", "{{range .MSIEmpty}}-{{.}}-{{else}}EMPTY{{end}}", "EMPTY", tVal, true},
 506         {"range empty interface", "{{range .Empty3}}-{{.}}-{{else}}EMPTY{{end}}", "-7--8-", tVal, true},
 507         {"range empty nil", "{{range .Empty0}}-{{.}}-{{end}}", "", tVal, true},
 508         {"range $x SI", "{{range $x := .SI}}<{{$x}}>{{end}}", "<3><4><5>", tVal, true},
 509         {"range $x $y SI", "{{range $x, $y := .SI}}<{{$x}}={{$y}}>{{end}}", "<0=3><1=4><2=5>", tVal, true},
 510         {"range $x MSIone", "{{range $x := .MSIone}}<{{$x}}>{{end}}", "<1>", tVal, true},
 511         {"range $x $y MSIone", "{{range $x, $y := .MSIone}}<{{$x}}={{$y}}>{{end}}", "<one=1>", tVal, true},
 512         {"range $x PSI", "{{range $x := .PSI}}<{{$x}}>{{end}}", "<21><22><23>", tVal, true},
 513         {"declare in range", "{{range $x := .PSI}}<{{$foo:=$x}}{{$x}}>{{end}}", "<21><22><23>", tVal, true},
 514         {"range count", `{{range $i, $x := count 5}}[{{$i}}]{{$x}}{{end}}`, "[0]a[1]b[2]c[3]d[4]e", tVal, true},
 515         {"range nil count", `{{range $i, $x := count 0}}{{else}}empty{{end}}`, "empty", tVal, true},
 516
 517         // Cute examples.
 518         {"or as if true", `{{or .SI "slice is empty"}}`, "[3 4 5]", tVal, true},
 519         {"or as if false", `{{or .SIEmpty "slice is empty"}}`, "slice is empty", tVal, true},
 520
 521         // Error handling.
 522         {"error method, error", "{{.MyError true}}", "", tVal, false},
 523         {"error method, no error", "{{.MyError false}}", "false", tVal, true},
 524
 525         // Fixed bugs.
 526         // Must separate dot and receiver; otherwise args are evaluated with dot set to variable.
 527         {"bug0", "{{range .MSIone}}{{if $.Method1 .}}X{{end}}{{end}}", "X", tVal, true},
 528         // Do not loop endlessly in indirect for non-empty interfaces.
 529         // The bug appears with *interface only; looped forever.
 530         {"bug1", "{{.Method0}}", "M0", &iVal, true},
 531         // Was taking address of interface field, so method set was empty.
 532         {"bug2", "{{$.NonEmptyInterface.Method0}}", "M0", tVal, true},
 533         // Struct values were not legal in with - mere oversight.
 534         {"bug3", "{{with $}}{{.Method0}}{{end}}", "M0", tVal, true},
 535         // Nil interface values in if.
 536         {"bug4", "{{if .Empty0}}non-nil{{else}}nil{{end}}", "nil", tVal, true},
 537         // Stringer.
 538         {"bug5", "{{.Str}}", "foozle", tVal, true},
 539         {"bug5a", "{{.Err}}", "erroozle", tVal, true},
 540         // Args need to be indirected and dereferenced sometimes.
 541         {"bug6a", "{{vfunc .V0 .V1}}", "vfunc", tVal, true},
 542         {"bug6b", "{{vfunc .V0 .V0}}", "vfunc", tVal, true},
 543         {"bug6c", "{{vfunc .V1 .V0}}", "vfunc", tVal, true},
 544         {"bug6d", "{{vfunc .V1 .V1}}", "vfunc", tVal, true},
 545         // Legal parse but illegal execution: non-function should have no arguments.
 546         {"bug7a", "{{3 2}}", "", tVal, false},
 547         {"bug7b", "{{$x := 1}}{{$x 2}}", "", tVal, false},
 548         {"bug7c", "{{$x := 1}}{{3 | $x}}", "", tVal, false},
 549         // Pipelined arg was not being type-checked.
 550         {"bug8a", "{{3|oneArg}}", "", tVal, false},
 551         {"bug8b", "{{4|dddArg 3}}", "", tVal, false},
 552         // A bug was introduced that broke map lookups for lower-case names.
 553         {"bug9", "{{.cause}}", "neglect", map[string]string{"cause": "neglect"}, true},
 554         // Field chain starting with function did not work.
 555         {"bug10", "{{mapOfThree.three}}-{{(mapOfThree).three}}", "3-3", 0, true},
 556         // Dereferencing nil pointer while evaluating function arguments should not panic. Issue 7333.
 557         {"bug11", "{{valueString .PS}}", "", T{}, false},
 558         // 0xef gave constant type float64. Issue 8622.
 559         {"bug12xe", "{{printf `%T` 0xef}}", "int", T{}, true},
 560         {"bug12xE", "{{printf `%T` 0xEE}}", "int", T{}, true},
 561         {"bug12Xe", "{{printf `%T` 0Xef}}", "int", T{}, true},
 562         {"bug12XE", "{{printf `%T` 0XEE}}", "int", T{}, true},
 563         // Chained nodes did not work as arguments. Issue 8473.
 564         {"bug13", "{{print (.Copy).I}}", "17", tVal, true},
 565         // Didn't protect against nil or literal values in field chains.
 566         {"bug14a", "{{(nil).True}}", "", tVal, false},
 567         {"bug14b", "{{$x := nil}}{{$x.anything}}", "", tVal, false},
 568         {"bug14c", `{{$x := (1.0)}}{{$y := ("hello")}}{{$x.anything}}{{$y.true}}`, "", tVal, false},
 569         // Didn't call validateType on function results. Issue 10800.
 570         {"bug15", "{{valueString returnInt}}", "", tVal, false},
 571         // Variadic function corner cases. Issue 10946.
 572         {"bug16a", "{{true|printf}}", "", tVal, false},
 573         {"bug16b", "{{1|printf}}", "", tVal, false},
 574         {"bug16c", "{{1.1|printf}}", "", tVal, false},
 575         {"bug16d", "{{'x'|printf}}", "", tVal, false},
 576         {"bug16e", "{{0i|printf}}", "", tVal, false},
 577         {"bug16f", "{{true|twoArgs \"xxx\"}}", "", tVal, false},
 578         {"bug16g", "{{\"aaa\" |twoArgs \"bbb\"}}", "twoArgs=bbbaaa", tVal, true},
 579         {"bug16h", "{{1|oneArg}}", "", tVal, false},
 580         {"bug16i", "{{\"aaa\"|oneArg}}", "oneArg=aaa", tVal, true},
 581         {"bug16j", "{{1+2i|printf \"%v\"}}", "(1+2i)", tVal, true},
 582         {"bug16k", "{{\"aaa\"|printf }}", "aaa", tVal, true},
 583         {"bug17a", "{{.NonEmptyInterface.X}}", "x", tVal, true},
 584         {"bug17b", "-{{.NonEmptyInterface.Method1 1234}}-", "-1234-", tVal, true},
 585         {"bug17c", "{{len .NonEmptyInterfacePtS}}", "2", tVal, true},
 586         {"bug17d", "{{index .NonEmptyInterfacePtS 0}}", "a", tVal, true},
 587         {"bug17e", "{{range .NonEmptyInterfacePtS}}-{{.}}-{{end}}", "-a--b-", tVal, true},
 588 }
 589
 590 func zeroArgs() string {
 591         return "zeroArgs"
 592 }
 593
 594 func oneArg(a string) string {
 595         return "oneArg=" + a
 596 }
 597
 598 func twoArgs(a, b string) string {
 599         return "twoArgs=" + a + b
 600 }
 601
 602 func dddArg(a int, b ...string) string {
 603         return fmt.Sprintln(a, b)
 604 }
 605
 606 // count returns a channel that will deliver n sequential 1-letter strings starting at "a"
 607 func count(n int) chan string {
 608         if n == 0 {
 609                 return nil
 610         }
 611         c := make(chan string)
 612         go func() {
 613                 for i := 0; i < n; i++ {
 614                         c <- "abcdefghijklmnop"[i : i+1]
 615                 }
 616                 close(c)
 617         }()
 618         return c
 619 }
 620
 621 // vfunc takes a *V and a V
 622 func vfunc(V, *V) string {
 623         return "vfunc"
 624 }
 625
 626 // valueString takes a string, not a pointer.
 627 func valueString(v string) string {
 628         return "value is ignored"
 629 }
 630
 631 // returnInt returns an int
 632 func returnInt() int {
 633         return 7
 634 }
 635
 636 func add(args ...int) int {
 637         sum := 0
 638         for _, x := range args {
 639                 sum += x
 640         }
 641         return sum
 642 }
 643
 644 func echo(arg interface{}) interface{} {
 645         return arg
 646 }
 647
 648 func makemap(arg ...string) map[string]string {
 649         if len(arg)%2 != 0 {
 650                 panic("bad makemap")
 651         }
 652         m := make(map[string]string)
 653         for i := 0; i < len(arg); i += 2 {
 654                 m[arg[i]] = arg[i+1]
 655         }
 656         return m
 657 }
 658
 659 func stringer(s fmt.Stringer) string {
 660         return s.String()
 661 }
 662
 663 func mapOfThree() interface{} {
 664         return map[string]int{"three": 3}
 665 }
 666
 667 func testExecute(execTests []execTest, template *Template, t *testing.T) {
 668         b := new(bytes.Buffer)
 669         funcs := FuncMap{
 670                 "add":         add,
 671                 "count":       count,
 672                 "dddArg":      dddArg,
 673                 "echo":        echo,
 674                 "makemap":     makemap,
 675                 "mapOfThree":  mapOfThree,
 676                 "oneArg":      oneArg,
 677                 "returnInt":   returnInt,
 678                 "stringer":    stringer,
 679                 "twoArgs":     twoArgs,
 680                 "typeOf":      typeOf,
 681                 "valueString": valueString,
 682                 "vfunc":       vfunc,
 683                 "zeroArgs":    zeroArgs,
 684         }
 685         for _, test := range execTests {
 686                 var tmpl *Template
 687                 var err error
 688                 if template == nil {
 689                         tmpl, err = New(test.name).Funcs(funcs).Parse(test.input)
 690                 } else {
 691                         tmpl, err = template.New(test.name).Funcs(funcs).Parse(test.input)
 692                 }
 693                 if err != nil {
 694                         t.Errorf("%s: parse error: %s", test.name, err)
 695                         continue
 696                 }
 697                 b.Reset()
 698                 err = tmpl.Execute(b, test.data)
 699                 switch {
 700                 case !test.ok && err == nil:
 701                         t.Errorf("%s: expected error; got none", test.name)
 702                         continue
 703                 case test.ok && err != nil:
 704                         t.Errorf("%s: unexpected execute error: %s", test.name, err)
 705                         continue
 706                 case !test.ok && err != nil:
 707                         // expected error, got one
 708                         if *debug {
 709                                 fmt.Printf("%s: %s\n\t%s\n", test.name, test.input, err)
 710                         }
 711                 }
 712                 result := b.String()
 713                 if result != test.output {
 714                         t.Errorf("%s: expected\n\t%q\ngot\n\t%q", test.name, test.output, result)
 715                 }
 716         }
 717 }
 718
 719 func TestExecute(t *testing.T) {
 720         testExecute(execTests, nil, t)
 721 }
 722
 723 var delimPairs = []string{
 724         "", "", // default
 725         "{{", "}}", // same as default
 726         "<<", ">>", // distinct
 727         "|", "|", // same
 728         "(日)", "(本)", // peculiar
 729 }
 730
 731 func TestDelims(t *testing.T) {
 732         const hello = "Hello, world"
 733         var value = struct{ Str string }{hello}
 734         for i := 0; i < len(delimPairs); i += 2 {
 735                 text := ".Str"
 736                 left := delimPairs[i+0]
 737                 trueLeft := left
 738                 right := delimPairs[i+1]
 739                 trueRight := right
 740                 if left == "" { // default case
 741                         trueLeft = "{{"
 742                 }
 743                 if right == "" { // default case
 744                         trueRight = "}}"
 745                 }
 746                 text = trueLeft + text + trueRight
 747                 // Now add a comment
 748                 text += trueLeft + "/*comment*/" + trueRight
 749                 // Now add  an action containing a string.
 750                 text += trueLeft + `"` + trueLeft + `"` + trueRight
 751                 // At this point text looks like `{{.Str}}{{/*comment*/}}{{"{{"}}`.
 752                 tmpl, err := New("delims").Delims(left, right).Parse(text)
 753                 if err != nil {
 754                         t.Fatalf("delim %q text %q parse err %s", left, text, err)
 755                 }
 756                 var b = new(bytes.Buffer)
 757                 err = tmpl.Execute(b, value)
 758                 if err != nil {
 759                         t.Fatalf("delim %q exec err %s", left, err)
 760                 }
 761                 if b.String() != hello+trueLeft {
 762                         t.Errorf("expected %q got %q", hello+trueLeft, b.String())
 763                 }
 764         }
 765 }
 766
 767 // Check that an error from a method flows back to the top.
 768 func TestExecuteError(t *testing.T) {
 769         b := new(bytes.Buffer)
 770         tmpl := New("error")
 771         _, err := tmpl.Parse("{{.MyError true}}")
 772         if err != nil {
 773                 t.Fatalf("parse error: %s", err)
 774         }
 775         err = tmpl.Execute(b, tVal)
 776         if err == nil {
 777                 t.Errorf("expected error; got none")
 778         } else if !strings.Contains(err.Error(), myError.Error()) {
 779                 if *debug {
 780                         fmt.Printf("test execute error: %s\n", err)
 781                 }
 782                 t.Errorf("expected myError; got %s", err)
 783         }
 784 }
 785
 786 const execErrorText = `line 1
 787 line 2
 788 line 3
 789 {{template "one" .}}
 790 {{define "one"}}{{template "two" .}}{{end}}
 791 {{define "two"}}{{template "three" .}}{{end}}
 792 {{define "three"}}{{index "hi" $}}{{end}}`
 793
 794 // Check that an error from a nested template contains all the relevant information.
 795 func TestExecError(t *testing.T) {
 796         tmpl, err := New("top").Parse(execErrorText)
 797         if err != nil {
 798                 t.Fatal("parse error:", err)
 799         }
 800         var b bytes.Buffer
 801         err = tmpl.Execute(&b, 5) // 5 is out of range indexing "hi"
 802         if err == nil {
 803                 t.Fatal("expected error")
 804         }
 805         const want = `template: top:7:20: executing "three" at <index "hi" $>: error calling index: index out of range: 5`
 806         got := err.Error()
 807         if got != want {
 808                 t.Errorf("expected\n%q\ngot\n%q", want, got)
 809         }
 810 }
 811
 812 func TestJSEscaping(t *testing.T) {
 813         testCases := []struct {
 814                 in, exp string
 815         }{
 816                 {`a`, `a`},
 817                 {`'foo`, `\'foo`},
 818                 {`Go "jump" \`, `Go \"jump\" \\`},
 819                 {`Yukihiro says "今日は世界"`, `Yukihiro says \"今日は世界\"`},
 820                 {"unprintable \uFDFF", `unprintable \uFDFF`},
 821                 {`<html>`, `\x3Chtml\x3E`},
 822         }
 823         for _, tc := range testCases {
 824                 s := JSEscapeString(tc.in)
 825                 if s != tc.exp {
 826                         t.Errorf("JS escaping [%s] got [%s] want [%s]", tc.in, s, tc.exp)
 827                 }
 828         }
 829 }
 830
 831 // A nice example: walk a binary tree.
 832
 833 type Tree struct {
 834         Val         int
 835         Left, Right *Tree
 836 }
 837
 838 // Use different delimiters to test Set.Delims.
 839 // Also test the trimming of leading and trailing spaces.
 840 const treeTemplate = `
 841         (- define "tree" -)
 842         [
 843                 (- .Val -)
 844                 (- with .Left -)
 845                         (template "tree" . -)
 846                 (- end -)
 847                 (- with .Right -)
 848                         (- template "tree" . -)
 849                 (- end -)
 850         ]
 851         (- end -)
 852 `
 853
 854 func TestTree(t *testing.T) {
 855         var tree = &Tree{
 856                 1,
 857                 &Tree{
 858                         2, &Tree{
 859                                 3,
 860                                 &Tree{
 861                                         4, nil, nil,
 862                                 },
 863                                 nil,
 864                         },
 865                         &Tree{
 866                                 5,
 867                                 &Tree{
 868                                         6, nil, nil,
 869                                 },
 870                                 nil,
 871                         },
 872                 },
 873                 &Tree{
 874                         7,
 875                         &Tree{
 876                                 8,
 877                                 &Tree{
 878                                         9, nil, nil,
 879                                 },
 880                                 nil,
 881                         },
 882                         &Tree{
 883                                 10,
 884                                 &Tree{
 885                                         11, nil, nil,
 886                                 },
 887                                 nil,
 888                         },
 889                 },
 890         }
 891         tmpl, err := New("root").Delims("(", ")").Parse(treeTemplate)
 892         if err != nil {
 893                 t.Fatal("parse error:", err)
 894         }
 895         var b bytes.Buffer
 896         const expect = "[1[2[3[4]][5[6]]][7[8[9]][10[11]]]]"
 897         // First by looking up the template.
 898         err = tmpl.Lookup("tree").Execute(&b, tree)
 899         if err != nil {
 900                 t.Fatal("exec error:", err)
 901         }
 902         result := b.String()
 903         if result != expect {
 904                 t.Errorf("expected %q got %q", expect, result)
 905         }
 906         // Then direct to execution.
 907         b.Reset()
 908         err = tmpl.ExecuteTemplate(&b, "tree", tree)
 909         if err != nil {
 910                 t.Fatal("exec error:", err)
 911         }
 912         result = b.String()
 913         if result != expect {
 914                 t.Errorf("expected %q got %q", expect, result)
 915         }
 916 }
 917
 918 func TestExecuteOnNewTemplate(t *testing.T) {
 919         // This is issue 3872.
 920         New("Name").Templates()
 921         // This is issue 11379.
 922         new(Template).Templates()
 923         new(Template).Parse("")
 924         new(Template).New("abc").Parse("")
 925         new(Template).Execute(nil, nil)                // returns an error (but does not crash)
 926         new(Template).ExecuteTemplate(nil, "XXX", nil) // returns an error (but does not crash)
 927 }
 928
 929 const testTemplates = `{{define "one"}}one{{end}}{{define "two"}}two{{end}}`
 930
 931 func TestMessageForExecuteEmpty(t *testing.T) {
 932         // Test a truly empty template.
 933         tmpl := New("empty")
 934         var b bytes.Buffer
 935         err := tmpl.Execute(&b, 0)
 936         if err == nil {
 937                 t.Fatal("expected initial error")
 938         }
 939         got := err.Error()
 940         want := `template: empty: "empty" is an incomplete or empty template`
 941         if got != want {
 942                 t.Errorf("expected error %s got %s", want, got)
 943         }
 944         // Add a non-empty template to check that the error is helpful.
 945         tests, err := New("").Parse(testTemplates)
 946         if err != nil {
 947                 t.Fatal(err)
 948         }
 949         tmpl.AddParseTree("secondary", tests.Tree)
 950         err = tmpl.Execute(&b, 0)
 951         if err == nil {
 952                 t.Fatal("expected second error")
 953         }
 954         got = err.Error()
 955         want = `template: empty: "empty" is an incomplete or empty template`
 956         if got != want {
 957                 t.Errorf("expected error %s got %s", want, got)
 958         }
 959         // Make sure we can execute the secondary.
 960         err = tmpl.ExecuteTemplate(&b, "secondary", 0)
 961         if err != nil {
 962                 t.Fatal(err)
 963         }
 964 }
 965
 966 func TestFinalForPrintf(t *testing.T) {
 967         tmpl, err := New("").Parse(`{{"x" | printf}}`)
 968         if err != nil {
 969                 t.Fatal(err)
 970         }
 971         var b bytes.Buffer
 972         err = tmpl.Execute(&b, 0)
 973         if err != nil {
 974                 t.Fatal(err)
 975         }
 976 }
 977
 978 type cmpTest struct {
 979         expr  string
 980         truth string
 981         ok    bool
 982 }
 983
 984 var cmpTests = []cmpTest{
 985         {"eq true true", "true", true},
 986         {"eq true false", "false", true},
 987         {"eq 1+2i 1+2i", "true", true},
 988         {"eq 1+2i 1+3i", "false", true},
 989         {"eq 1.5 1.5", "true", true},
 990         {"eq 1.5 2.5", "false", true},
 991         {"eq 1 1", "true", true},
 992         {"eq 1 2", "false", true},
 993         {"eq `xy` `xy`", "true", true},
 994         {"eq `xy` `xyz`", "false", true},
 995         {"eq .Uthree .Uthree", "true", true},
 996         {"eq .Uthree .Ufour", "false", true},
 997         {"eq 3 4 5 6 3", "true", true},
 998         {"eq 3 4 5 6 7", "false", true},
 999         {"ne true true", "false", true},
1000         {"ne true false", "true", true},
1001         {"ne 1+2i 1+2i", "false", true},
1002         {"ne 1+2i 1+3i", "true", true},
1003         {"ne 1.5 1.5", "false", true},
1004         {"ne 1.5 2.5", "true", true},
1005         {"ne 1 1", "false", true},
1006         {"ne 1 2", "true", true},
1007         {"ne `xy` `xy`", "false", true},
1008         {"ne `xy` `xyz`", "true", true},
1009         {"ne .Uthree .Uthree", "false", true},
1010         {"ne .Uthree .Ufour", "true", true},
1011         {"lt 1.5 1.5", "false", true},
1012         {"lt 1.5 2.5", "true", true},
1013         {"lt 1 1", "false", true},
1014         {"lt 1 2", "true", true},
1015         {"lt `xy` `xy`", "false", true},
1016         {"lt `xy` `xyz`", "true", true},
1017         {"lt .Uthree .Uthree", "false", true},
1018         {"lt .Uthree .Ufour", "true", true},
1019         {"le 1.5 1.5", "true", true},
1020         {"le 1.5 2.5", "true", true},
1021         {"le 2.5 1.5", "false", true},
1022         {"le 1 1", "true", true},
1023         {"le 1 2", "true", true},
1024         {"le 2 1", "false", true},
1025         {"le `xy` `xy`", "true", true},
1026         {"le `xy` `xyz`", "true", true},
1027         {"le `xyz` `xy`", "false", true},
1028         {"le .Uthree .Uthree", "true", true},
1029         {"le .Uthree .Ufour", "true", true},
1030         {"le .Ufour .Uthree", "false", true},
1031         {"gt 1.5 1.5", "false", true},
1032         {"gt 1.5 2.5", "false", true},
1033         {"gt 1 1", "false", true},
1034         {"gt 2 1", "true", true},
1035         {"gt 1 2", "false", true},
1036         {"gt `xy` `xy`", "false", true},
1037         {"gt `xy` `xyz`", "false", true},
1038         {"gt .Uthree .Uthree", "false", true},
1039         {"gt .Uthree .Ufour", "false", true},
1040         {"gt .Ufour .Uthree", "true", true},
1041         {"ge 1.5 1.5", "true", true},
1042         {"ge 1.5 2.5", "false", true},
1043         {"ge 2.5 1.5", "true", true},
1044         {"ge 1 1", "true", true},
1045         {"ge 1 2", "false", true},
1046         {"ge 2 1", "true", true},
1047         {"ge `xy` `xy`", "true", true},
1048         {"ge `xy` `xyz`", "false", true},
1049         {"ge `xyz` `xy`", "true", true},
1050         {"ge .Uthree .Uthree", "true", true},
1051         {"ge .Uthree .Ufour", "false", true},
1052         {"ge .Ufour .Uthree", "true", true},
1053         // Mixing signed and unsigned integers.
1054         {"eq .Uthree .Three", "true", true},
1055         {"eq .Three .Uthree", "true", true},
1056         {"le .Uthree .Three", "true", true},
1057         {"le .Three .Uthree", "true", true},
1058         {"ge .Uthree .Three", "true", true},
1059         {"ge .Three .Uthree", "true", true},
1060         {"lt .Uthree .Three", "false", true},
1061         {"lt .Three .Uthree", "false", true},
1062         {"gt .Uthree .Three", "false", true},
1063         {"gt .Three .Uthree", "false", true},
1064         {"eq .Ufour .Three", "false", true},
1065         {"lt .Ufour .Three", "false", true},
1066         {"gt .Ufour .Three", "true", true},
1067         {"eq .NegOne .Uthree", "false", true},
1068         {"eq .Uthree .NegOne", "false", true},
1069         {"ne .NegOne .Uthree", "true", true},
1070         {"ne .Uthree .NegOne", "true", true},
1071         {"lt .NegOne .Uthree", "true", true},
1072         {"lt .Uthree .NegOne", "false", true},
1073         {"le .NegOne .Uthree", "true", true},
1074         {"le .Uthree .NegOne", "false", true},
1075         {"gt .NegOne .Uthree", "false", true},
1076         {"gt .Uthree .NegOne", "true", true},
1077         {"ge .NegOne .Uthree", "false", true},
1078         {"ge .Uthree .NegOne", "true", true},
1079         {"eq (index `x` 0) 'x'", "true", true}, // The example that triggered this rule.
1080         {"eq (index `x` 0) 'y'", "false", true},
1081         // Errors
1082         {"eq `xy` 1", "", false},    // Different types.
1083         {"eq 2 2.0", "", false},     // Different types.
1084         {"lt true true", "", false}, // Unordered types.
1085         {"lt 1+0i 1+0i", "", false}, // Unordered types.
1086 }
1087
1088 func TestComparison(t *testing.T) {
1089         b := new(bytes.Buffer)
1090         var cmpStruct = struct {
1091                 Uthree, Ufour uint
1092                 NegOne, Three int
1093         }{3, 4, -1, 3}
1094         for _, test := range cmpTests {
1095                 text := fmt.Sprintf("{{if %s}}true{{else}}false{{end}}", test.expr)
1096                 tmpl, err := New("empty").Parse(text)
1097                 if err != nil {
1098                         t.Fatalf("%q: %s", test.expr, err)
1099                 }
1100                 b.Reset()
1101                 err = tmpl.Execute(b, &cmpStruct)
1102                 if test.ok && err != nil {
1103                         t.Errorf("%s errored incorrectly: %s", test.expr, err)
1104                         continue
1105                 }
1106                 if !test.ok && err == nil {
1107                         t.Errorf("%s did not error", test.expr)
1108                         continue
1109                 }
1110                 if b.String() != test.truth {
1111                         t.Errorf("%s: want %s; got %s", test.expr, test.truth, b.String())
1112                 }
1113         }
1114 }
1115
1116 func TestMissingMapKey(t *testing.T) {
1117         data := map[string]int{
1118                 "x": 99,
1119         }
1120         tmpl, err := New("t1").Parse("{{.x}} {{.y}}")
1121         if err != nil {
1122                 t.Fatal(err)
1123         }
1124         var b bytes.Buffer
1125         // By default, just get "<no value>"
1126         err = tmpl.Execute(&b, data)
1127         if err != nil {
1128                 t.Fatal(err)
1129         }
1130         want := "99 <no value>"
1131         got := b.String()
1132         if got != want {
1133                 t.Errorf("got %q; expected %q", got, want)
1134         }
1135         // Same if we set the option explicitly to the default.
1136         tmpl.Option("missingkey=default")
1137         b.Reset()
1138         err = tmpl.Execute(&b, data)
1139         if err != nil {
1140                 t.Fatal("default:", err)
1141         }
1142         want = "99 <no value>"
1143         got = b.String()
1144         if got != want {
1145                 t.Errorf("got %q; expected %q", got, want)
1146         }
1147         // Next we ask for a zero value
1148         tmpl.Option("missingkey=zero")
1149         b.Reset()
1150         err = tmpl.Execute(&b, data)
1151         if err != nil {
1152                 t.Fatal("zero:", err)
1153         }
1154         want = "99 0"
1155         got = b.String()
1156         if got != want {
1157                 t.Errorf("got %q; expected %q", got, want)
1158         }
1159         // Now we ask for an error.
1160         tmpl.Option("missingkey=error")
1161         err = tmpl.Execute(&b, data)
1162         if err == nil {
1163                 t.Errorf("expected error; got none")
1164         }
1165         // same Option, but now a nil interface: ask for an error
1166         err = tmpl.Execute(&b, nil)
1167         t.Log(err)
1168         if err == nil {
1169                 t.Errorf("expected error for nil-interface; got none")
1170         }
1171 }
1172
1173 // Test that the error message for multiline unterminated string
1174 // refers to the line number of the opening quote.
1175 func TestUnterminatedStringError(t *testing.T) {
1176         _, err := New("X").Parse("hello\n\n{{`unterminated\n\n\n\n}}\n some more\n\n")
1177         if err == nil {
1178                 t.Fatal("expected error")
1179         }
1180         str := err.Error()
1181         if !strings.Contains(str, "X:3: unexpected unterminated raw quoted string") {
1182                 t.Fatalf("unexpected error: %s", str)
1183         }
1184 }
1185
1186 const alwaysErrorText = "always be failing"
1187
1188 var alwaysError = errors.New(alwaysErrorText)
1189
1190 type ErrorWriter int
1191
1192 func (e ErrorWriter) Write(p []byte) (int, error) {
1193         return 0, alwaysError
1194 }
1195
1196 func TestExecuteGivesExecError(t *testing.T) {
1197         // First, a non-execution error shouldn't be an ExecError.
1198         tmpl, err := New("X").Parse("hello")
1199         if err != nil {
1200                 t.Fatal(err)
1201         }
1202         err = tmpl.Execute(ErrorWriter(0), 0)
1203         if err == nil {
1204                 t.Fatal("expected error; got none")
1205         }
1206         if err.Error() != alwaysErrorText {
1207                 t.Errorf("expected %q error; got %q", alwaysErrorText, err)
1208         }
1209         // This one should be an ExecError.
1210         tmpl, err = New("X").Parse("hello, {{.X.Y}}")
1211         if err != nil {
1212                 t.Fatal(err)
1213         }
1214         err = tmpl.Execute(ioutil.Discard, 0)
1215         if err == nil {
1216                 t.Fatal("expected error; got none")
1217         }
1218         eerr, ok := err.(ExecError)
1219         if !ok {
1220                 t.Fatalf("did not expect ExecError %s", eerr)
1221         }
1222         expect := "field X in type int"
1223         if !strings.Contains(err.Error(), expect) {
1224                 t.Errorf("expected %q; got %q", expect, err)
1225         }
1226 }
1227
1228 func funcNameTestFunc() int {
1229         return 0
1230 }
1231
1232 func TestGoodFuncNames(t *testing.T) {
1233         names := []string{
1234                 "_",
1235                 "a",
1236                 "a1",
1237                 "a1",
1238                 "Ӵ",
1239         }
1240         for _, name := range names {
1241                 tmpl := New("X").Funcs(
1242                         FuncMap{
1243                                 name: funcNameTestFunc,
1244                         },
1245                 )
1246                 if tmpl == nil {
1247                         t.Fatalf("nil result for %q", name)
1248                 }
1249         }
1250 }
1251
1252 func TestBadFuncNames(t *testing.T) {
1253         names := []string{
1254                 "",
1255                 "2",
1256                 "a-b",
1257         }
1258         for _, name := range names {
1259                 testBadFuncName(name, t)
1260         }
1261 }
1262
1263 func testBadFuncName(name string, t *testing.T) {
1264         defer func() {
1265                 recover()
1266         }()
1267         New("X").Funcs(
1268                 FuncMap{
1269                         name: funcNameTestFunc,
1270                 },
1271         )
1272         // If we get here, the name did not cause a panic, which is how Funcs
1273         // reports an error.
1274         t.Errorf("%q succeeded incorrectly as function name", name)
1275 }
1276
1277 func TestBlock(t *testing.T) {
1278         const (
1279                 input   = `a({{block "inner" .}}bar({{.}})baz{{end}})b`
1280                 want    = `a(bar(hello)baz)b`
1281                 overlay = `{{define "inner"}}foo({{.}})bar{{end}}`
1282                 want2   = `a(foo(goodbye)bar)b`
1283         )
1284         tmpl, err := New("outer").Parse(input)
1285         if err != nil {
1286                 t.Fatal(err)
1287         }
1288         tmpl2, err := Must(tmpl.Clone()).Parse(overlay)
1289         if err != nil {
1290                 t.Fatal(err)
1291         }
1292
1293         var buf bytes.Buffer
1294         if err := tmpl.Execute(&buf, "hello"); err != nil {
1295                 t.Fatal(err)
1296         }
1297         if got := buf.String(); got != want {
1298                 t.Errorf("got %q, want %q", got, want)
1299         }
1300
1301         buf.Reset()
1302         if err := tmpl2.Execute(&buf, "goodbye"); err != nil {
1303                 t.Fatal(err)
1304         }
1305         if got := buf.String(); got != want2 {
1306                 t.Errorf("got %q, want %q", got, want2)
1307         }
1308 }
1309
1310 // Check that calling an invalid field on nil pointer prints
1311 // a field error instead of a distracting nil pointer error.
1312 // https://golang.org/issue/15125
1313 func TestMissingFieldOnNil(t *testing.T) {
1314         tmpl := Must(New("tmpl").Parse("{{.MissingField}}"))
1315         var d *T
1316         err := tmpl.Execute(ioutil.Discard, d)
1317         got := "<nil>"
1318         if err != nil {
1319                 got = err.Error()
1320         }
1321         want := "can't evaluate field MissingField in type *template.T"
1322         if !strings.HasSuffix(got, want) {
1323                 t.Errorf("got error %q, want %q", got, want)
1324         }
1325 }
1326
1327 func TestMaxExecDepth(t *testing.T) {
1328         tmpl := Must(New("tmpl").Parse(`{{template "tmpl" .}}`))
1329         err := tmpl.Execute(ioutil.Discard, nil)
1330         got := "<nil>"
1331         if err != nil {
1332                 got = err.Error()
1333         }
1334         const want = "exceeded maximum template depth"
1335         if !strings.Contains(got, want) {
1336                 t.Errorf("got error %q; want %q", got, want)
1337         }
1338 }
1339
1340 func TestAddrOfIndex(t *testing.T) {
1341         // golang.org/issue/14916.
1342         // Before index worked on reflect.Values, the .String could not be
1343         // found on the (incorrectly unaddressable) V value,
1344         // in contrast to range, which worked fine.
1345         // Also testing that passing a reflect.Value to tmpl.Execute works.
1346         texts := []string{
1347                 `{{range .}}{{.String}}{{end}}`,
1348                 `{{with index . 0}}{{.String}}{{end}}`,
1349         }
1350         for _, text := range texts {
1351                 tmpl := Must(New("tmpl").Parse(text))
1352                 var buf bytes.Buffer
1353                 err := tmpl.Execute(&buf, reflect.ValueOf([]V{{1}}))
1354                 if err != nil {
1355                         t.Fatalf("%s: Execute: %v", text, err)
1356                 }
1357                 if buf.String() != "<1>" {
1358                         t.Fatalf("%s: template output = %q, want %q", text, &buf, "<1>")
1359                 }
1360         }
1361 }
1362
1363 func TestInterfaceValues(t *testing.T) {
1364         // golang.org/issue/17714.
1365         // Before index worked on reflect.Values, interface values
1366         // were always implicitly promoted to the underlying value,
1367         // except that nil interfaces were promoted to the zero reflect.Value.
1368         // Eliminating a round trip to interface{} and back to reflect.Value
1369         // eliminated this promotion, breaking these cases.
1370         tests := []struct {
1371                 text string
1372                 out  string
1373         }{
1374                 {`{{index .Nil 1}}`, "ERROR: index of untyped nil"},
1375                 {`{{index .Slice 2}}`, "2"},
1376                 {`{{index .Slice .Two}}`, "2"},
1377                 {`{{call .Nil 1}}`, "ERROR: call of nil"},
1378                 {`{{call .PlusOne 1}}`, "2"},
1379                 {`{{call .PlusOne .One}}`, "2"},
1380                 {`{{and (index .Slice 0) true}}`, "0"},
1381                 {`{{and .Zero true}}`, "0"},
1382                 {`{{and (index .Slice 1) false}}`, "false"},
1383                 {`{{and .One false}}`, "false"},
1384                 {`{{or (index .Slice 0) false}}`, "false"},
1385                 {`{{or .Zero false}}`, "false"},
1386                 {`{{or (index .Slice 1) true}}`, "1"},
1387                 {`{{or .One true}}`, "1"},
1388                 {`{{not (index .Slice 0)}}`, "true"},
1389                 {`{{not .Zero}}`, "true"},
1390                 {`{{not (index .Slice 1)}}`, "false"},
1391                 {`{{not .One}}`, "false"},
1392                 {`{{eq (index .Slice 0) .Zero}}`, "true"},
1393                 {`{{eq (index .Slice 1) .One}}`, "true"},
1394                 {`{{ne (index .Slice 0) .Zero}}`, "false"},
1395                 {`{{ne (index .Slice 1) .One}}`, "false"},
1396                 {`{{ge (index .Slice 0) .One}}`, "false"},
1397                 {`{{ge (index .Slice 1) .Zero}}`, "true"},
1398                 {`{{gt (index .Slice 0) .One}}`, "false"},
1399                 {`{{gt (index .Slice 1) .Zero}}`, "true"},
1400                 {`{{le (index .Slice 0) .One}}`, "true"},
1401                 {`{{le (index .Slice 1) .Zero}}`, "false"},
1402                 {`{{lt (index .Slice 0) .One}}`, "true"},
1403                 {`{{lt (index .Slice 1) .Zero}}`, "false"},
1404         }
1405
1406         for _, tt := range tests {
1407                 tmpl := Must(New("tmpl").Parse(tt.text))
1408                 var buf bytes.Buffer
1409                 err := tmpl.Execute(&buf, map[string]interface{}{
1410                         "PlusOne": func(n int) int {
1411                                 return n + 1
1412                         },
1413                         "Slice": []int{0, 1, 2, 3},
1414                         "One":   1,
1415                         "Two":   2,
1416                         "Nil":   nil,
1417                         "Zero":  0,
1418                 })
1419                 if strings.HasPrefix(tt.out, "ERROR:") {
1420                         e := strings.TrimSpace(strings.TrimPrefix(tt.out, "ERROR:"))
1421                         if err == nil || !strings.Contains(err.Error(), e) {
1422                                 t.Errorf("%s: Execute: %v, want error %q", tt.text, err, e)
1423                         }
1424                         continue
1425                 }
1426                 if err != nil {
1427                         t.Errorf("%s: Execute: %v", tt.text, err)
1428                         continue
1429                 }
1430                 if buf.String() != tt.out {
1431                         t.Errorf("%s: template output = %q, want %q", tt.text, &buf, tt.out)
1432                 }
1433         }
1434 }