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         {"simple assignment", "{{$x := 2}}{{$x = 3}}{{$x}}", "3", tVal, true},
 308         {"nested assignment",
 309                 "{{$x := 2}}{{if true}}{{$x = 3}}{{end}}{{$x}}",
 310                 "3", tVal, true},
 311         {"nested assignment changes the last declaration",
 312                 "{{$x := 1}}{{if true}}{{$x := 2}}{{if true}}{{$x = 3}}{{end}}{{end}}{{$x}}",
 313                 "1", tVal, true},
 314
 315         // Type with String method.
 316         {"V{6666}.String()", "-{{.V0}}-", "-<6666>-", tVal, true},
 317         {"&V{7777}.String()", "-{{.V1}}-", "-<7777>-", tVal, true},
 318         {"(*V)(nil).String()", "-{{.V2}}-", "-nilV-", tVal, true},
 319
 320         // Type with Error method.
 321         {"W{888}.Error()", "-{{.W0}}-", "-[888]-", tVal, true},
 322         {"&W{999}.Error()", "-{{.W1}}-", "-[999]-", tVal, true},
 323         {"(*W)(nil).Error()", "-{{.W2}}-", "-nilW-", tVal, true},
 324
 325         // Pointers.
 326         {"*int", "{{.PI}}", "23", tVal, true},
 327         {"*string", "{{.PS}}", "a string", tVal, true},
 328         {"*[]int", "{{.PSI}}", "[21 22 23]", tVal, true},
 329         {"*[]int[1]", "{{index .PSI 1}}", "22", tVal, true},
 330         {"NIL", "{{.NIL}}", "<nil>", tVal, true},
 331
 332         // Empty interfaces holding values.
 333         {"empty nil", "{{.Empty0}}", "<no value>", tVal, true},
 334         {"empty with int", "{{.Empty1}}", "3", tVal, true},
 335         {"empty with string", "{{.Empty2}}", "empty2", tVal, true},
 336         {"empty with slice", "{{.Empty3}}", "[7 8]", tVal, true},
 337         {"empty with struct", "{{.Empty4}}", "{UinEmpty}", tVal, true},
 338         {"empty with struct, field", "{{.Empty4.V}}", "UinEmpty", tVal, true},
 339
 340         // Edge cases with <no value> with an interface value
 341         {"field on interface", "{{.foo}}", "<no value>", nil, true},
 342         {"field on parenthesized interface", "{{(.).foo}}", "<no value>", nil, true},
 343
 344         // Method calls.
 345         {".Method0", "-{{.Method0}}-", "-M0-", tVal, true},
 346         {".Method1(1234)", "-{{.Method1 1234}}-", "-1234-", tVal, true},
 347         {".Method1(.I)", "-{{.Method1 .I}}-", "-17-", tVal, true},
 348         {".Method2(3, .X)", "-{{.Method2 3 .X}}-", "-Method2: 3 x-", tVal, true},
 349         {".Method2(.U16, `str`)", "-{{.Method2 .U16 `str`}}-", "-Method2: 16 str-", tVal, true},
 350         {".Method2(.U16, $x)", "{{if $x := .X}}-{{.Method2 .U16 $x}}{{end}}-", "-Method2: 16 x-", tVal, true},
 351         {".Method3(nil constant)", "-{{.Method3 nil}}-", "-Method3: <nil>-", tVal, true},
 352         {".Method3(nil value)", "-{{.Method3 .MXI.unset}}-", "-Method3: <nil>-", tVal, true},
 353         {"method on var", "{{if $x := .}}-{{$x.Method2 .U16 $x.X}}{{end}}-", "-Method2: 16 x-", tVal, true},
 354         {"method on chained var",
 355                 "{{range .MSIone}}{{if $.U.TrueFalse $.True}}{{$.U.TrueFalse $.True}}{{else}}WRONG{{end}}{{end}}",
 356                 "true", tVal, true},
 357         {"chained method",
 358                 "{{range .MSIone}}{{if $.GetU.TrueFalse $.True}}{{$.U.TrueFalse $.True}}{{else}}WRONG{{end}}{{end}}",
 359                 "true", tVal, true},
 360         {"chained method on variable",
 361                 "{{with $x := .}}{{with .SI}}{{$.GetU.TrueFalse $.True}}{{end}}{{end}}",
 362                 "true", tVal, true},
 363         {".NilOKFunc not nil", "{{call .NilOKFunc .PI}}", "false", tVal, true},
 364         {".NilOKFunc nil", "{{call .NilOKFunc nil}}", "true", tVal, true},
 365         {"method on nil value from slice", "-{{range .}}{{.Method1 1234}}{{end}}-", "-1234-", tSliceOfNil, true},
 366
 367         // Function call builtin.
 368         {".BinaryFunc", "{{call .BinaryFunc `1` `2`}}", "[1=2]", tVal, true},
 369         {".VariadicFunc0", "{{call .VariadicFunc}}", "<>", tVal, true},
 370         {".VariadicFunc2", "{{call .VariadicFunc `he` `llo`}}", "<he+llo>", tVal, true},
 371         {".VariadicFuncInt", "{{call .VariadicFuncInt 33 `he` `llo`}}", "33=<he+llo>", tVal, true},
 372         {"if .BinaryFunc call", "{{ if .BinaryFunc}}{{call .BinaryFunc `1` `2`}}{{end}}", "[1=2]", tVal, true},
 373         {"if not .BinaryFunc call", "{{ if not .BinaryFunc}}{{call .BinaryFunc `1` `2`}}{{else}}No{{end}}", "No", tVal, true},
 374         {"Interface Call", `{{stringer .S}}`, "foozle", map[string]interface{}{"S": bytes.NewBufferString("foozle")}, true},
 375         {".ErrFunc", "{{call .ErrFunc}}", "bla", tVal, true},
 376         {"call nil", "{{call nil}}", "", tVal, false},
 377
 378         // Erroneous function calls (check args).
 379         {".BinaryFuncTooFew", "{{call .BinaryFunc `1`}}", "", tVal, false},
 380         {".BinaryFuncTooMany", "{{call .BinaryFunc `1` `2` `3`}}", "", tVal, false},
 381         {".BinaryFuncBad0", "{{call .BinaryFunc 1 3}}", "", tVal, false},
 382         {".BinaryFuncBad1", "{{call .BinaryFunc `1` 3}}", "", tVal, false},
 383         {".VariadicFuncBad0", "{{call .VariadicFunc 3}}", "", tVal, false},
 384         {".VariadicFuncIntBad0", "{{call .VariadicFuncInt}}", "", tVal, false},
 385         {".VariadicFuncIntBad`", "{{call .VariadicFuncInt `x`}}", "", tVal, false},
 386         {".VariadicFuncNilBad", "{{call .VariadicFunc nil}}", "", tVal, false},
 387
 388         // Pipelines.
 389         {"pipeline", "-{{.Method0 | .Method2 .U16}}-", "-Method2: 16 M0-", tVal, true},
 390         {"pipeline func", "-{{call .VariadicFunc `llo` | call .VariadicFunc `he` }}-", "-<he+<llo>>-", tVal, true},
 391
 392         // Nil values aren't missing arguments.
 393         {"nil pipeline", "{{ .Empty0 | call .NilOKFunc }}", "true", tVal, true},
 394         {"nil call arg", "{{ call .NilOKFunc .Empty0 }}", "true", tVal, true},
 395         {"bad nil pipeline", "{{ .Empty0 | .VariadicFunc }}", "", tVal, false},
 396
 397         // Parenthesized expressions
 398         {"parens in pipeline", "{{printf `%d %d %d` (1) (2 | add 3) (add 4 (add 5 6))}}", "1 5 15", tVal, true},
 399
 400         // Parenthesized expressions with field accesses
 401         {"parens: $ in paren", "{{($).X}}", "x", tVal, true},
 402         {"parens: $.GetU in paren", "{{($.GetU).V}}", "v", tVal, true},
 403         {"parens: $ in paren in pipe", "{{($ | echo).X}}", "x", tVal, true},
 404         {"parens: spaces and args", `{{(makemap "up" "down" "left" "right").left}}`, "right", tVal, true},
 405
 406         // If.
 407         {"if true", "{{if true}}TRUE{{end}}", "TRUE", tVal, true},
 408         {"if false", "{{if false}}TRUE{{else}}FALSE{{end}}", "FALSE", tVal, true},
 409         {"if nil", "{{if nil}}TRUE{{end}}", "", tVal, false},
 410         {"if 1", "{{if 1}}NON-ZERO{{else}}ZERO{{end}}", "NON-ZERO", tVal, true},
 411         {"if 0", "{{if 0}}NON-ZERO{{else}}ZERO{{end}}", "ZERO", tVal, true},
 412         {"if 1.5", "{{if 1.5}}NON-ZERO{{else}}ZERO{{end}}", "NON-ZERO", tVal, true},
 413         {"if 0.0", "{{if .FloatZero}}NON-ZERO{{else}}ZERO{{end}}", "ZERO", tVal, true},
 414         {"if 1.5i", "{{if 1.5i}}NON-ZERO{{else}}ZERO{{end}}", "NON-ZERO", tVal, true},
 415         {"if 0.0i", "{{if .ComplexZero}}NON-ZERO{{else}}ZERO{{end}}", "ZERO", tVal, true},
 416         {"if emptystring", "{{if ``}}NON-EMPTY{{else}}EMPTY{{end}}", "EMPTY", tVal, true},
 417         {"if string", "{{if `notempty`}}NON-EMPTY{{else}}EMPTY{{end}}", "NON-EMPTY", tVal, true},
 418         {"if emptyslice", "{{if .SIEmpty}}NON-EMPTY{{else}}EMPTY{{end}}", "EMPTY", tVal, true},
 419         {"if slice", "{{if .SI}}NON-EMPTY{{else}}EMPTY{{end}}", "NON-EMPTY", tVal, true},
 420         {"if emptymap", "{{if .MSIEmpty}}NON-EMPTY{{else}}EMPTY{{end}}", "EMPTY", tVal, true},
 421         {"if map", "{{if .MSI}}NON-EMPTY{{else}}EMPTY{{end}}", "NON-EMPTY", tVal, true},
 422         {"if map unset", "{{if .MXI.none}}NON-ZERO{{else}}ZERO{{end}}", "ZERO", tVal, true},
 423         {"if map not unset", "{{if not .MXI.none}}ZERO{{else}}NON-ZERO{{end}}", "ZERO", tVal, true},
 424         {"if $x with $y int", "{{if $x := true}}{{with $y := .I}}{{$x}},{{$y}}{{end}}{{end}}", "true,17", tVal, true},
 425         {"if $x with $x int", "{{if $x := true}}{{with $x := .I}}{{$x}},{{end}}{{$x}}{{end}}", "17,true", tVal, true},
 426         {"if else if", "{{if false}}FALSE{{else if true}}TRUE{{end}}", "TRUE", tVal, true},
 427         {"if else chain", "{{if eq 1 3}}1{{else if eq 2 3}}2{{else if eq 3 3}}3{{end}}", "3", tVal, true},
 428
 429         // Print etc.
 430         {"print", `{{print "hello, print"}}`, "hello, print", tVal, true},
 431         {"print 123", `{{print 1 2 3}}`, "1 2 3", tVal, true},
 432         {"print nil", `{{print nil}}`, "<nil>", tVal, true},
 433         {"println", `{{println 1 2 3}}`, "1 2 3\n", tVal, true},
 434         {"printf int", `{{printf "%04x" 127}}`, "007f", tVal, true},
 435         {"printf float", `{{printf "%g" 3.5}}`, "3.5", tVal, true},
 436         {"printf complex", `{{printf "%g" 1+7i}}`, "(1+7i)", tVal, true},
 437         {"printf string", `{{printf "%s" "hello"}}`, "hello", tVal, true},
 438         {"printf function", `{{printf "%#q" zeroArgs}}`, "`zeroArgs`", tVal, true},
 439         {"printf field", `{{printf "%s" .U.V}}`, "v", tVal, true},
 440         {"printf method", `{{printf "%s" .Method0}}`, "M0", tVal, true},
 441         {"printf dot", `{{with .I}}{{printf "%d" .}}{{end}}`, "17", tVal, true},
 442         {"printf var", `{{with $x := .I}}{{printf "%d" $x}}{{end}}`, "17", tVal, true},
 443         {"printf lots", `{{printf "%d %s %g %s" 127 "hello" 7-3i .Method0}}`, "127 hello (7-3i) M0", tVal, true},
 444
 445         // HTML.
 446         {"html", `{{html "<script>alert(\"XSS\");</script>"}}`,
 447                 "&lt;script&gt;alert(&#34;XSS&#34;);&lt;/script&gt;", nil, true},
 448         {"html pipeline", `{{printf "<script>alert(\"XSS\");</script>" | html}}`,
 449                 "&lt;script&gt;alert(&#34;XSS&#34;);&lt;/script&gt;", nil, true},
 450         {"html", `{{html .PS}}`, "a string", tVal, true},
 451         {"html typed nil", `{{html .NIL}}`, "&lt;nil&gt;", tVal, true},
 452         {"html untyped nil", `{{html .Empty0}}`, "&lt;no value&gt;", tVal, true},
 453
 454         // JavaScript.
 455         {"js", `{{js .}}`, `It\'d be nice.`, `It'd be nice.`, true},
 456
 457         // URL query.
 458         {"urlquery", `{{"http://www.example.org/"|urlquery}}`, "http%3A%2F%2Fwww.example.org%2F", nil, true},
 459
 460         // Booleans
 461         {"not", "{{not true}} {{not false}}", "false true", nil, true},
 462         {"and", "{{and false 0}} {{and 1 0}} {{and 0 true}} {{and 1 1}}", "false 0 0 1", nil, true},
 463         {"or", "{{or 0 0}} {{or 1 0}} {{or 0 true}} {{or 1 1}}", "0 1 true 1", nil, true},
 464         {"boolean if", "{{if and true 1 `hi`}}TRUE{{else}}FALSE{{end}}", "TRUE", tVal, true},
 465         {"boolean if not", "{{if and true 1 `hi` | not}}TRUE{{else}}FALSE{{end}}", "FALSE", nil, true},
 466
 467         // Indexing.
 468         {"slice[0]", "{{index .SI 0}}", "3", tVal, true},
 469         {"slice[1]", "{{index .SI 1}}", "4", tVal, true},
 470         {"slice[HUGE]", "{{index .SI 10}}", "", tVal, false},
 471         {"slice[WRONG]", "{{index .SI `hello`}}", "", tVal, false},
 472         {"slice[nil]", "{{index .SI nil}}", "", tVal, false},
 473         {"map[one]", "{{index .MSI `one`}}", "1", tVal, true},
 474         {"map[two]", "{{index .MSI `two`}}", "2", tVal, true},
 475         {"map[NO]", "{{index .MSI `XXX`}}", "0", tVal, true},
 476         {"map[nil]", "{{index .MSI nil}}", "", tVal, false},
 477         {"map[``]", "{{index .MSI ``}}", "0", tVal, true},
 478         {"map[WRONG]", "{{index .MSI 10}}", "", tVal, false},
 479         {"double index", "{{index .SMSI 1 `eleven`}}", "11", tVal, true},
 480         {"nil[1]", "{{index nil 1}}", "", tVal, false},
 481         {"map MI64S", "{{index .MI64S 2}}", "i642", tVal, true},
 482         {"map MI32S", "{{index .MI32S 2}}", "two", tVal, true},
 483         {"map MUI64S", "{{index .MUI64S 3}}", "ui643", tVal, true},
 484         {"map MI8S", "{{index .MI8S 3}}", "i83", tVal, true},
 485         {"map MUI8S", "{{index .MUI8S 2}}", "u82", tVal, true},
 486
 487         // Len.
 488         {"slice", "{{len .SI}}", "3", tVal, true},
 489         {"map", "{{len .MSI }}", "3", tVal, true},
 490         {"len of int", "{{len 3}}", "", tVal, false},
 491         {"len of nothing", "{{len .Empty0}}", "", tVal, false},
 492
 493         // With.
 494         {"with true", "{{with true}}{{.}}{{end}}", "true", tVal, true},
 495         {"with false", "{{with false}}{{.}}{{else}}FALSE{{end}}", "FALSE", tVal, true},
 496         {"with 1", "{{with 1}}{{.}}{{else}}ZERO{{end}}", "1", tVal, true},
 497         {"with 0", "{{with 0}}{{.}}{{else}}ZERO{{end}}", "ZERO", tVal, true},
 498         {"with 1.5", "{{with 1.5}}{{.}}{{else}}ZERO{{end}}", "1.5", tVal, true},
 499         {"with 0.0", "{{with .FloatZero}}{{.}}{{else}}ZERO{{end}}", "ZERO", tVal, true},
 500         {"with 1.5i", "{{with 1.5i}}{{.}}{{else}}ZERO{{end}}", "(0+1.5i)", tVal, true},
 501         {"with 0.0i", "{{with .ComplexZero}}{{.}}{{else}}ZERO{{end}}", "ZERO", tVal, true},
 502         {"with emptystring", "{{with ``}}{{.}}{{else}}EMPTY{{end}}", "EMPTY", tVal, true},
 503         {"with string", "{{with `notempty`}}{{.}}{{else}}EMPTY{{end}}", "notempty", tVal, true},
 504         {"with emptyslice", "{{with .SIEmpty}}{{.}}{{else}}EMPTY{{end}}", "EMPTY", tVal, true},
 505         {"with slice", "{{with .SI}}{{.}}{{else}}EMPTY{{end}}", "[3 4 5]", tVal, true},
 506         {"with emptymap", "{{with .MSIEmpty}}{{.}}{{else}}EMPTY{{end}}", "EMPTY", tVal, true},
 507         {"with map", "{{with .MSIone}}{{.}}{{else}}EMPTY{{end}}", "map[one:1]", tVal, true},
 508         {"with empty interface, struct field", "{{with .Empty4}}{{.V}}{{end}}", "UinEmpty", tVal, true},
 509         {"with $x int", "{{with $x := .I}}{{$x}}{{end}}", "17", tVal, true},
 510         {"with $x struct.U.V", "{{with $x := $}}{{$x.U.V}}{{end}}", "v", tVal, true},
 511         {"with variable and action", "{{with $x := $}}{{$y := $.U.V}}{{$y}}{{end}}", "v", tVal, true},
 512
 513         // Range.
 514         {"range []int", "{{range .SI}}-{{.}}-{{end}}", "-3--4--5-", tVal, true},
 515         {"range empty no else", "{{range .SIEmpty}}-{{.}}-{{end}}", "", tVal, true},
 516         {"range []int else", "{{range .SI}}-{{.}}-{{else}}EMPTY{{end}}", "-3--4--5-", tVal, true},
 517         {"range empty else", "{{range .SIEmpty}}-{{.}}-{{else}}EMPTY{{end}}", "EMPTY", tVal, true},
 518         {"range []bool", "{{range .SB}}-{{.}}-{{end}}", "-true--false-", tVal, true},
 519         {"range []int method", "{{range .SI | .MAdd .I}}-{{.}}-{{end}}", "-20--21--22-", tVal, true},
 520         {"range map", "{{range .MSI}}-{{.}}-{{end}}", "-1--3--2-", tVal, true},
 521         {"range empty map no else", "{{range .MSIEmpty}}-{{.}}-{{end}}", "", tVal, true},
 522         {"range map else", "{{range .MSI}}-{{.}}-{{else}}EMPTY{{end}}", "-1--3--2-", tVal, true},
 523         {"range empty map else", "{{range .MSIEmpty}}-{{.}}-{{else}}EMPTY{{end}}", "EMPTY", tVal, true},
 524         {"range empty interface", "{{range .Empty3}}-{{.}}-{{else}}EMPTY{{end}}", "-7--8-", tVal, true},
 525         {"range empty nil", "{{range .Empty0}}-{{.}}-{{end}}", "", tVal, true},
 526         {"range $x SI", "{{range $x := .SI}}<{{$x}}>{{end}}", "<3><4><5>", tVal, true},
 527         {"range $x $y SI", "{{range $x, $y := .SI}}<{{$x}}={{$y}}>{{end}}", "<0=3><1=4><2=5>", tVal, true},
 528         {"range $x MSIone", "{{range $x := .MSIone}}<{{$x}}>{{end}}", "<1>", tVal, true},
 529         {"range $x $y MSIone", "{{range $x, $y := .MSIone}}<{{$x}}={{$y}}>{{end}}", "<one=1>", tVal, true},
 530         {"range $x PSI", "{{range $x := .PSI}}<{{$x}}>{{end}}", "<21><22><23>", tVal, true},
 531         {"declare in range", "{{range $x := .PSI}}<{{$foo:=$x}}{{$x}}>{{end}}", "<21><22><23>", tVal, true},
 532         {"range count", `{{range $i, $x := count 5}}[{{$i}}]{{$x}}{{end}}`, "[0]a[1]b[2]c[3]d[4]e", tVal, true},
 533         {"range nil count", `{{range $i, $x := count 0}}{{else}}empty{{end}}`, "empty", tVal, true},
 534
 535         // Cute examples.
 536         {"or as if true", `{{or .SI "slice is empty"}}`, "[3 4 5]", tVal, true},
 537         {"or as if false", `{{or .SIEmpty "slice is empty"}}`, "slice is empty", tVal, true},
 538
 539         // Error handling.
 540         {"error method, error", "{{.MyError true}}", "", tVal, false},
 541         {"error method, no error", "{{.MyError false}}", "false", tVal, true},
 542
 543         // Fixed bugs.
 544         // Must separate dot and receiver; otherwise args are evaluated with dot set to variable.
 545         {"bug0", "{{range .MSIone}}{{if $.Method1 .}}X{{end}}{{end}}", "X", tVal, true},
 546         // Do not loop endlessly in indirect for non-empty interfaces.
 547         // The bug appears with *interface only; looped forever.
 548         {"bug1", "{{.Method0}}", "M0", &iVal, true},
 549         // Was taking address of interface field, so method set was empty.
 550         {"bug2", "{{$.NonEmptyInterface.Method0}}", "M0", tVal, true},
 551         // Struct values were not legal in with - mere oversight.
 552         {"bug3", "{{with $}}{{.Method0}}{{end}}", "M0", tVal, true},
 553         // Nil interface values in if.
 554         {"bug4", "{{if .Empty0}}non-nil{{else}}nil{{end}}", "nil", tVal, true},
 555         // Stringer.
 556         {"bug5", "{{.Str}}", "foozle", tVal, true},
 557         {"bug5a", "{{.Err}}", "erroozle", tVal, true},
 558         // Args need to be indirected and dereferenced sometimes.
 559         {"bug6a", "{{vfunc .V0 .V1}}", "vfunc", tVal, true},
 560         {"bug6b", "{{vfunc .V0 .V0}}", "vfunc", tVal, true},
 561         {"bug6c", "{{vfunc .V1 .V0}}", "vfunc", tVal, true},
 562         {"bug6d", "{{vfunc .V1 .V1}}", "vfunc", tVal, true},
 563         // Legal parse but illegal execution: non-function should have no arguments.
 564         {"bug7a", "{{3 2}}", "", tVal, false},
 565         {"bug7b", "{{$x := 1}}{{$x 2}}", "", tVal, false},
 566         {"bug7c", "{{$x := 1}}{{3 | $x}}", "", tVal, false},
 567         // Pipelined arg was not being type-checked.
 568         {"bug8a", "{{3|oneArg}}", "", tVal, false},
 569         {"bug8b", "{{4|dddArg 3}}", "", tVal, false},
 570         // A bug was introduced that broke map lookups for lower-case names.
 571         {"bug9", "{{.cause}}", "neglect", map[string]string{"cause": "neglect"}, true},
 572         // Field chain starting with function did not work.
 573         {"bug10", "{{mapOfThree.three}}-{{(mapOfThree).three}}", "3-3", 0, true},
 574         // Dereferencing nil pointer while evaluating function arguments should not panic. Issue 7333.
 575         {"bug11", "{{valueString .PS}}", "", T{}, false},
 576         // 0xef gave constant type float64. Issue 8622.
 577         {"bug12xe", "{{printf `%T` 0xef}}", "int", T{}, true},
 578         {"bug12xE", "{{printf `%T` 0xEE}}", "int", T{}, true},
 579         {"bug12Xe", "{{printf `%T` 0Xef}}", "int", T{}, true},
 580         {"bug12XE", "{{printf `%T` 0XEE}}", "int", T{}, true},
 581         // Chained nodes did not work as arguments. Issue 8473.
 582         {"bug13", "{{print (.Copy).I}}", "17", tVal, true},
 583         // Didn't protect against nil or literal values in field chains.
 584         {"bug14a", "{{(nil).True}}", "", tVal, false},
 585         {"bug14b", "{{$x := nil}}{{$x.anything}}", "", tVal, false},
 586         {"bug14c", `{{$x := (1.0)}}{{$y := ("hello")}}{{$x.anything}}{{$y.true}}`, "", tVal, false},
 587         // Didn't call validateType on function results. Issue 10800.
 588         {"bug15", "{{valueString returnInt}}", "", tVal, false},
 589         // Variadic function corner cases. Issue 10946.
 590         {"bug16a", "{{true|printf}}", "", tVal, false},
 591         {"bug16b", "{{1|printf}}", "", tVal, false},
 592         {"bug16c", "{{1.1|printf}}", "", tVal, false},
 593         {"bug16d", "{{'x'|printf}}", "", tVal, false},
 594         {"bug16e", "{{0i|printf}}", "", tVal, false},
 595         {"bug16f", "{{true|twoArgs \"xxx\"}}", "", tVal, false},
 596         {"bug16g", "{{\"aaa\" |twoArgs \"bbb\"}}", "twoArgs=bbbaaa", tVal, true},
 597         {"bug16h", "{{1|oneArg}}", "", tVal, false},
 598         {"bug16i", "{{\"aaa\"|oneArg}}", "oneArg=aaa", tVal, true},
 599         {"bug16j", "{{1+2i|printf \"%v\"}}", "(1+2i)", tVal, true},
 600         {"bug16k", "{{\"aaa\"|printf }}", "aaa", tVal, true},
 601         {"bug17a", "{{.NonEmptyInterface.X}}", "x", tVal, true},
 602         {"bug17b", "-{{.NonEmptyInterface.Method1 1234}}-", "-1234-", tVal, true},
 603         {"bug17c", "{{len .NonEmptyInterfacePtS}}", "2", tVal, true},
 604         {"bug17d", "{{index .NonEmptyInterfacePtS 0}}", "a", tVal, true},
 605         {"bug17e", "{{range .NonEmptyInterfacePtS}}-{{.}}-{{end}}", "-a--b-", tVal, true},
 606 }
 607
 608 func zeroArgs() string {
 609         return "zeroArgs"
 610 }
 611
 612 func oneArg(a string) string {
 613         return "oneArg=" + a
 614 }
 615
 616 func twoArgs(a, b string) string {
 617         return "twoArgs=" + a + b
 618 }
 619
 620 func dddArg(a int, b ...string) string {
 621         return fmt.Sprintln(a, b)
 622 }
 623
 624 // count returns a channel that will deliver n sequential 1-letter strings starting at "a"
 625 func count(n int) chan string {
 626         if n == 0 {
 627                 return nil
 628         }
 629         c := make(chan string)
 630         go func() {
 631                 for i := 0; i < n; i++ {
 632                         c <- "abcdefghijklmnop"[i : i+1]
 633                 }
 634                 close(c)
 635         }()
 636         return c
 637 }
 638
 639 // vfunc takes a *V and a V
 640 func vfunc(V, *V) string {
 641         return "vfunc"
 642 }
 643
 644 // valueString takes a string, not a pointer.
 645 func valueString(v string) string {
 646         return "value is ignored"
 647 }
 648
 649 // returnInt returns an int
 650 func returnInt() int {
 651         return 7
 652 }
 653
 654 func add(args ...int) int {
 655         sum := 0
 656         for _, x := range args {
 657                 sum += x
 658         }
 659         return sum
 660 }
 661
 662 func echo(arg interface{}) interface{} {
 663         return arg
 664 }
 665
 666 func makemap(arg ...string) map[string]string {
 667         if len(arg)%2 != 0 {
 668                 panic("bad makemap")
 669         }
 670         m := make(map[string]string)
 671         for i := 0; i < len(arg); i += 2 {
 672                 m[arg[i]] = arg[i+1]
 673         }
 674         return m
 675 }
 676
 677 func stringer(s fmt.Stringer) string {
 678         return s.String()
 679 }
 680
 681 func mapOfThree() interface{} {
 682         return map[string]int{"three": 3}
 683 }
 684
 685 func testExecute(execTests []execTest, template *Template, t *testing.T) {
 686         b := new(bytes.Buffer)
 687         funcs := FuncMap{
 688                 "add":         add,
 689                 "count":       count,
 690                 "dddArg":      dddArg,
 691                 "echo":        echo,
 692                 "makemap":     makemap,
 693                 "mapOfThree":  mapOfThree,
 694                 "oneArg":      oneArg,
 695                 "returnInt":   returnInt,
 696                 "stringer":    stringer,
 697                 "twoArgs":     twoArgs,
 698                 "typeOf":      typeOf,
 699                 "valueString": valueString,
 700                 "vfunc":       vfunc,
 701                 "zeroArgs":    zeroArgs,
 702         }
 703         for _, test := range execTests {
 704                 var tmpl *Template
 705                 var err error
 706                 if template == nil {
 707                         tmpl, err = New(test.name).Funcs(funcs).Parse(test.input)
 708                 } else {
 709                         tmpl, err = template.New(test.name).Funcs(funcs).Parse(test.input)
 710                 }
 711                 if err != nil {
 712                         t.Errorf("%s: parse error: %s", test.name, err)
 713                         continue
 714                 }
 715                 b.Reset()
 716                 err = tmpl.Execute(b, test.data)
 717                 switch {
 718                 case !test.ok && err == nil:
 719                         t.Errorf("%s: expected error; got none", test.name)
 720                         continue
 721                 case test.ok && err != nil:
 722                         t.Errorf("%s: unexpected execute error: %s", test.name, err)
 723                         continue
 724                 case !test.ok && err != nil:
 725                         // expected error, got one
 726                         if *debug {
 727                                 fmt.Printf("%s: %s\n\t%s\n", test.name, test.input, err)
 728                         }
 729                 }
 730                 result := b.String()
 731                 if result != test.output {
 732                         t.Errorf("%s: expected\n\t%q\ngot\n\t%q", test.name, test.output, result)
 733                 }
 734         }
 735 }
 736
 737 func TestExecute(t *testing.T) {
 738         testExecute(execTests, nil, t)
 739 }
 740
 741 var delimPairs = []string{
 742         "", "", // default
 743         "{{", "}}", // same as default
 744         "<<", ">>", // distinct
 745         "|", "|", // same
 746         "(日)", "(本)", // peculiar
 747 }
 748
 749 func TestDelims(t *testing.T) {
 750         const hello = "Hello, world"
 751         var value = struct{ Str string }{hello}
 752         for i := 0; i < len(delimPairs); i += 2 {
 753                 text := ".Str"
 754                 left := delimPairs[i+0]
 755                 trueLeft := left
 756                 right := delimPairs[i+1]
 757                 trueRight := right
 758                 if left == "" { // default case
 759                         trueLeft = "{{"
 760                 }
 761                 if right == "" { // default case
 762                         trueRight = "}}"
 763                 }
 764                 text = trueLeft + text + trueRight
 765                 // Now add a comment
 766                 text += trueLeft + "/*comment*/" + trueRight
 767                 // Now add  an action containing a string.
 768                 text += trueLeft + `"` + trueLeft + `"` + trueRight
 769                 // At this point text looks like `{{.Str}}{{/*comment*/}}{{"{{"}}`.
 770                 tmpl, err := New("delims").Delims(left, right).Parse(text)
 771                 if err != nil {
 772                         t.Fatalf("delim %q text %q parse err %s", left, text, err)
 773                 }
 774                 var b = new(bytes.Buffer)
 775                 err = tmpl.Execute(b, value)
 776                 if err != nil {
 777                         t.Fatalf("delim %q exec err %s", left, err)
 778                 }
 779                 if b.String() != hello+trueLeft {
 780                         t.Errorf("expected %q got %q", hello+trueLeft, b.String())
 781                 }
 782         }
 783 }
 784
 785 // Check that an error from a method flows back to the top.
 786 func TestExecuteError(t *testing.T) {
 787         b := new(bytes.Buffer)
 788         tmpl := New("error")
 789         _, err := tmpl.Parse("{{.MyError true}}")
 790         if err != nil {
 791                 t.Fatalf("parse error: %s", err)
 792         }
 793         err = tmpl.Execute(b, tVal)
 794         if err == nil {
 795                 t.Errorf("expected error; got none")
 796         } else if !strings.Contains(err.Error(), myError.Error()) {
 797                 if *debug {
 798                         fmt.Printf("test execute error: %s\n", err)
 799                 }
 800                 t.Errorf("expected myError; got %s", err)
 801         }
 802 }
 803
 804 const execErrorText = `line 1
 805 line 2
 806 line 3
 807 {{template "one" .}}
 808 {{define "one"}}{{template "two" .}}{{end}}
 809 {{define "two"}}{{template "three" .}}{{end}}
 810 {{define "three"}}{{index "hi" $}}{{end}}`
 811
 812 // Check that an error from a nested template contains all the relevant information.
 813 func TestExecError(t *testing.T) {
 814         tmpl, err := New("top").Parse(execErrorText)
 815         if err != nil {
 816                 t.Fatal("parse error:", err)
 817         }
 818         var b bytes.Buffer
 819         err = tmpl.Execute(&b, 5) // 5 is out of range indexing "hi"
 820         if err == nil {
 821                 t.Fatal("expected error")
 822         }
 823         const want = `template: top:7:20: executing "three" at <index "hi" $>: error calling index: index out of range: 5`
 824         got := err.Error()
 825         if got != want {
 826                 t.Errorf("expected\n%q\ngot\n%q", want, got)
 827         }
 828 }
 829
 830 func TestJSEscaping(t *testing.T) {
 831         testCases := []struct {
 832                 in, exp string
 833         }{
 834                 {`a`, `a`},
 835                 {`'foo`, `\'foo`},
 836                 {`Go "jump" \`, `Go \"jump\" \\`},
 837                 {`Yukihiro says "今日は世界"`, `Yukihiro says \"今日は世界\"`},
 838                 {"unprintable \uFDFF", `unprintable \uFDFF`},
 839                 {`<html>`, `\x3Chtml\x3E`},
 840         }
 841         for _, tc := range testCases {
 842                 s := JSEscapeString(tc.in)
 843                 if s != tc.exp {
 844                         t.Errorf("JS escaping [%s] got [%s] want [%s]", tc.in, s, tc.exp)
 845                 }
 846         }
 847 }
 848
 849 // A nice example: walk a binary tree.
 850
 851 type Tree struct {
 852         Val         int
 853         Left, Right *Tree
 854 }
 855
 856 // Use different delimiters to test Set.Delims.
 857 // Also test the trimming of leading and trailing spaces.
 858 const treeTemplate = `
 859         (- define "tree" -)
 860         [
 861                 (- .Val -)
 862                 (- with .Left -)
 863                         (template "tree" . -)
 864                 (- end -)
 865                 (- with .Right -)
 866                         (- template "tree" . -)
 867                 (- end -)
 868         ]
 869         (- end -)
 870 `
 871
 872 func TestTree(t *testing.T) {
 873         var tree = &Tree{
 874                 1,
 875                 &Tree{
 876                         2, &Tree{
 877                                 3,
 878                                 &Tree{
 879                                         4, nil, nil,
 880                                 },
 881                                 nil,
 882                         },
 883                         &Tree{
 884                                 5,
 885                                 &Tree{
 886                                         6, nil, nil,
 887                                 },
 888                                 nil,
 889                         },
 890                 },
 891                 &Tree{
 892                         7,
 893                         &Tree{
 894                                 8,
 895                                 &Tree{
 896                                         9, nil, nil,
 897                                 },
 898                                 nil,
 899                         },
 900                         &Tree{
 901                                 10,
 902                                 &Tree{
 903                                         11, nil, nil,
 904                                 },
 905                                 nil,
 906                         },
 907                 },
 908         }
 909         tmpl, err := New("root").Delims("(", ")").Parse(treeTemplate)
 910         if err != nil {
 911                 t.Fatal("parse error:", err)
 912         }
 913         var b bytes.Buffer
 914         const expect = "[1[2[3[4]][5[6]]][7[8[9]][10[11]]]]"
 915         // First by looking up the template.
 916         err = tmpl.Lookup("tree").Execute(&b, tree)
 917         if err != nil {
 918                 t.Fatal("exec error:", err)
 919         }
 920         result := b.String()
 921         if result != expect {
 922                 t.Errorf("expected %q got %q", expect, result)
 923         }
 924         // Then direct to execution.
 925         b.Reset()
 926         err = tmpl.ExecuteTemplate(&b, "tree", tree)
 927         if err != nil {
 928                 t.Fatal("exec error:", err)
 929         }
 930         result = b.String()
 931         if result != expect {
 932                 t.Errorf("expected %q got %q", expect, result)
 933         }
 934 }
 935
 936 func TestExecuteOnNewTemplate(t *testing.T) {
 937         // This is issue 3872.
 938         New("Name").Templates()
 939         // This is issue 11379.
 940         new(Template).Templates()
 941         new(Template).Parse("")
 942         new(Template).New("abc").Parse("")
 943         new(Template).Execute(nil, nil)                // returns an error (but does not crash)
 944         new(Template).ExecuteTemplate(nil, "XXX", nil) // returns an error (but does not crash)
 945 }
 946
 947 const testTemplates = `{{define "one"}}one{{end}}{{define "two"}}two{{end}}`
 948
 949 func TestMessageForExecuteEmpty(t *testing.T) {
 950         // Test a truly empty template.
 951         tmpl := New("empty")
 952         var b bytes.Buffer
 953         err := tmpl.Execute(&b, 0)
 954         if err == nil {
 955                 t.Fatal("expected initial error")
 956         }
 957         got := err.Error()
 958         want := `template: empty: "empty" is an incomplete or empty template`
 959         if got != want {
 960                 t.Errorf("expected error %s got %s", want, got)
 961         }
 962         // Add a non-empty template to check that the error is helpful.
 963         tests, err := New("").Parse(testTemplates)
 964         if err != nil {
 965                 t.Fatal(err)
 966         }
 967         tmpl.AddParseTree("secondary", tests.Tree)
 968         err = tmpl.Execute(&b, 0)
 969         if err == nil {
 970                 t.Fatal("expected second error")
 971         }
 972         got = err.Error()
 973         want = `template: empty: "empty" is an incomplete or empty template`
 974         if got != want {
 975                 t.Errorf("expected error %s got %s", want, got)
 976         }
 977         // Make sure we can execute the secondary.
 978         err = tmpl.ExecuteTemplate(&b, "secondary", 0)
 979         if err != nil {
 980                 t.Fatal(err)
 981         }
 982 }
 983
 984 func TestFinalForPrintf(t *testing.T) {
 985         tmpl, err := New("").Parse(`{{"x" | printf}}`)
 986         if err != nil {
 987                 t.Fatal(err)
 988         }
 989         var b bytes.Buffer
 990         err = tmpl.Execute(&b, 0)
 991         if err != nil {
 992                 t.Fatal(err)
 993         }
 994 }
 995
 996 type cmpTest struct {
 997         expr  string
 998         truth string
 999         ok    bool
1000 }
1001
1002 var cmpTests = []cmpTest{
1003         {"eq true true", "true", true},
1004         {"eq true false", "false", true},
1005         {"eq 1+2i 1+2i", "true", true},
1006         {"eq 1+2i 1+3i", "false", true},
1007         {"eq 1.5 1.5", "true", true},
1008         {"eq 1.5 2.5", "false", true},
1009         {"eq 1 1", "true", true},
1010         {"eq 1 2", "false", true},
1011         {"eq `xy` `xy`", "true", true},
1012         {"eq `xy` `xyz`", "false", true},
1013         {"eq .Uthree .Uthree", "true", true},
1014         {"eq .Uthree .Ufour", "false", true},
1015         {"eq 3 4 5 6 3", "true", true},
1016         {"eq 3 4 5 6 7", "false", true},
1017         {"ne true true", "false", true},
1018         {"ne true false", "true", true},
1019         {"ne 1+2i 1+2i", "false", true},
1020         {"ne 1+2i 1+3i", "true", true},
1021         {"ne 1.5 1.5", "false", true},
1022         {"ne 1.5 2.5", "true", true},
1023         {"ne 1 1", "false", true},
1024         {"ne 1 2", "true", true},
1025         {"ne `xy` `xy`", "false", true},
1026         {"ne `xy` `xyz`", "true", true},
1027         {"ne .Uthree .Uthree", "false", true},
1028         {"ne .Uthree .Ufour", "true", true},
1029         {"lt 1.5 1.5", "false", true},
1030         {"lt 1.5 2.5", "true", true},
1031         {"lt 1 1", "false", true},
1032         {"lt 1 2", "true", true},
1033         {"lt `xy` `xy`", "false", true},
1034         {"lt `xy` `xyz`", "true", true},
1035         {"lt .Uthree .Uthree", "false", true},
1036         {"lt .Uthree .Ufour", "true", true},
1037         {"le 1.5 1.5", "true", true},
1038         {"le 1.5 2.5", "true", true},
1039         {"le 2.5 1.5", "false", true},
1040         {"le 1 1", "true", true},
1041         {"le 1 2", "true", true},
1042         {"le 2 1", "false", true},
1043         {"le `xy` `xy`", "true", true},
1044         {"le `xy` `xyz`", "true", true},
1045         {"le `xyz` `xy`", "false", true},
1046         {"le .Uthree .Uthree", "true", true},
1047         {"le .Uthree .Ufour", "true", true},
1048         {"le .Ufour .Uthree", "false", true},
1049         {"gt 1.5 1.5", "false", true},
1050         {"gt 1.5 2.5", "false", true},
1051         {"gt 1 1", "false", true},
1052         {"gt 2 1", "true", true},
1053         {"gt 1 2", "false", true},
1054         {"gt `xy` `xy`", "false", true},
1055         {"gt `xy` `xyz`", "false", true},
1056         {"gt .Uthree .Uthree", "false", true},
1057         {"gt .Uthree .Ufour", "false", true},
1058         {"gt .Ufour .Uthree", "true", true},
1059         {"ge 1.5 1.5", "true", true},
1060         {"ge 1.5 2.5", "false", true},
1061         {"ge 2.5 1.5", "true", true},
1062         {"ge 1 1", "true", true},
1063         {"ge 1 2", "false", true},
1064         {"ge 2 1", "true", true},
1065         {"ge `xy` `xy`", "true", true},
1066         {"ge `xy` `xyz`", "false", true},
1067         {"ge `xyz` `xy`", "true", true},
1068         {"ge .Uthree .Uthree", "true", true},
1069         {"ge .Uthree .Ufour", "false", true},
1070         {"ge .Ufour .Uthree", "true", true},
1071         // Mixing signed and unsigned integers.
1072         {"eq .Uthree .Three", "true", true},
1073         {"eq .Three .Uthree", "true", true},
1074         {"le .Uthree .Three", "true", true},
1075         {"le .Three .Uthree", "true", true},
1076         {"ge .Uthree .Three", "true", true},
1077         {"ge .Three .Uthree", "true", true},
1078         {"lt .Uthree .Three", "false", true},
1079         {"lt .Three .Uthree", "false", true},
1080         {"gt .Uthree .Three", "false", true},
1081         {"gt .Three .Uthree", "false", true},
1082         {"eq .Ufour .Three", "false", true},
1083         {"lt .Ufour .Three", "false", true},
1084         {"gt .Ufour .Three", "true", true},
1085         {"eq .NegOne .Uthree", "false", true},
1086         {"eq .Uthree .NegOne", "false", true},
1087         {"ne .NegOne .Uthree", "true", true},
1088         {"ne .Uthree .NegOne", "true", true},
1089         {"lt .NegOne .Uthree", "true", true},
1090         {"lt .Uthree .NegOne", "false", true},
1091         {"le .NegOne .Uthree", "true", true},
1092         {"le .Uthree .NegOne", "false", true},
1093         {"gt .NegOne .Uthree", "false", true},
1094         {"gt .Uthree .NegOne", "true", true},
1095         {"ge .NegOne .Uthree", "false", true},
1096         {"ge .Uthree .NegOne", "true", true},
1097         {"eq (index `x` 0) 'x'", "true", true}, // The example that triggered this rule.
1098         {"eq (index `x` 0) 'y'", "false", true},
1099         // Errors
1100         {"eq `xy` 1", "", false},    // Different types.
1101         {"eq 2 2.0", "", false},     // Different types.
1102         {"lt true true", "", false}, // Unordered types.
1103         {"lt 1+0i 1+0i", "", false}, // Unordered types.
1104 }
1105
1106 func TestComparison(t *testing.T) {
1107         b := new(bytes.Buffer)
1108         var cmpStruct = struct {
1109                 Uthree, Ufour uint
1110                 NegOne, Three int
1111         }{3, 4, -1, 3}
1112         for _, test := range cmpTests {
1113                 text := fmt.Sprintf("{{if %s}}true{{else}}false{{end}}", test.expr)
1114                 tmpl, err := New("empty").Parse(text)
1115                 if err != nil {
1116                         t.Fatalf("%q: %s", test.expr, err)
1117                 }
1118                 b.Reset()
1119                 err = tmpl.Execute(b, &cmpStruct)
1120                 if test.ok && err != nil {
1121                         t.Errorf("%s errored incorrectly: %s", test.expr, err)
1122                         continue
1123                 }
1124                 if !test.ok && err == nil {
1125                         t.Errorf("%s did not error", test.expr)
1126                         continue
1127                 }
1128                 if b.String() != test.truth {
1129                         t.Errorf("%s: want %s; got %s", test.expr, test.truth, b.String())
1130                 }
1131         }
1132 }
1133
1134 func TestMissingMapKey(t *testing.T) {
1135         data := map[string]int{
1136                 "x": 99,
1137         }
1138         tmpl, err := New("t1").Parse("{{.x}} {{.y}}")
1139         if err != nil {
1140                 t.Fatal(err)
1141         }
1142         var b bytes.Buffer
1143         // By default, just get "<no value>"
1144         err = tmpl.Execute(&b, data)
1145         if err != nil {
1146                 t.Fatal(err)
1147         }
1148         want := "99 <no value>"
1149         got := b.String()
1150         if got != want {
1151                 t.Errorf("got %q; expected %q", got, want)
1152         }
1153         // Same if we set the option explicitly to the default.
1154         tmpl.Option("missingkey=default")
1155         b.Reset()
1156         err = tmpl.Execute(&b, data)
1157         if err != nil {
1158                 t.Fatal("default:", err)
1159         }
1160         want = "99 <no value>"
1161         got = b.String()
1162         if got != want {
1163                 t.Errorf("got %q; expected %q", got, want)
1164         }
1165         // Next we ask for a zero value
1166         tmpl.Option("missingkey=zero")
1167         b.Reset()
1168         err = tmpl.Execute(&b, data)
1169         if err != nil {
1170                 t.Fatal("zero:", err)
1171         }
1172         want = "99 0"
1173         got = b.String()
1174         if got != want {
1175                 t.Errorf("got %q; expected %q", got, want)
1176         }
1177         // Now we ask for an error.
1178         tmpl.Option("missingkey=error")
1179         err = tmpl.Execute(&b, data)
1180         if err == nil {
1181                 t.Errorf("expected error; got none")
1182         }
1183         // same Option, but now a nil interface: ask for an error
1184         err = tmpl.Execute(&b, nil)
1185         t.Log(err)
1186         if err == nil {
1187                 t.Errorf("expected error for nil-interface; got none")
1188         }
1189 }
1190
1191 // Test that the error message for multiline unterminated string
1192 // refers to the line number of the opening quote.
1193 func TestUnterminatedStringError(t *testing.T) {
1194         _, err := New("X").Parse("hello\n\n{{`unterminated\n\n\n\n}}\n some more\n\n")
1195         if err == nil {
1196                 t.Fatal("expected error")
1197         }
1198         str := err.Error()
1199         if !strings.Contains(str, "X:3: unexpected unterminated raw quoted string") {
1200                 t.Fatalf("unexpected error: %s", str)
1201         }
1202 }
1203
1204 const alwaysErrorText = "always be failing"
1205
1206 var alwaysError = errors.New(alwaysErrorText)
1207
1208 type ErrorWriter int
1209
1210 func (e ErrorWriter) Write(p []byte) (int, error) {
1211         return 0, alwaysError
1212 }
1213
1214 func TestExecuteGivesExecError(t *testing.T) {
1215         // First, a non-execution error shouldn't be an ExecError.
1216         tmpl, err := New("X").Parse("hello")
1217         if err != nil {
1218                 t.Fatal(err)
1219         }
1220         err = tmpl.Execute(ErrorWriter(0), 0)
1221         if err == nil {
1222                 t.Fatal("expected error; got none")
1223         }
1224         if err.Error() != alwaysErrorText {
1225                 t.Errorf("expected %q error; got %q", alwaysErrorText, err)
1226         }
1227         // This one should be an ExecError.
1228         tmpl, err = New("X").Parse("hello, {{.X.Y}}")
1229         if err != nil {
1230                 t.Fatal(err)
1231         }
1232         err = tmpl.Execute(ioutil.Discard, 0)
1233         if err == nil {
1234                 t.Fatal("expected error; got none")
1235         }
1236         eerr, ok := err.(ExecError)
1237         if !ok {
1238                 t.Fatalf("did not expect ExecError %s", eerr)
1239         }
1240         expect := "field X in type int"
1241         if !strings.Contains(err.Error(), expect) {
1242                 t.Errorf("expected %q; got %q", expect, err)
1243         }
1244 }
1245
1246 func funcNameTestFunc() int {
1247         return 0
1248 }
1249
1250 func TestGoodFuncNames(t *testing.T) {
1251         names := []string{
1252                 "_",
1253                 "a",
1254                 "a1",
1255                 "a1",
1256                 "Ӵ",
1257         }
1258         for _, name := range names {
1259                 tmpl := New("X").Funcs(
1260                         FuncMap{
1261                                 name: funcNameTestFunc,
1262                         },
1263                 )
1264                 if tmpl == nil {
1265                         t.Fatalf("nil result for %q", name)
1266                 }
1267         }
1268 }
1269
1270 func TestBadFuncNames(t *testing.T) {
1271         names := []string{
1272                 "",
1273                 "2",
1274                 "a-b",
1275         }
1276         for _, name := range names {
1277                 testBadFuncName(name, t)
1278         }
1279 }
1280
1281 func testBadFuncName(name string, t *testing.T) {
1282         defer func() {
1283                 recover()
1284         }()
1285         New("X").Funcs(
1286                 FuncMap{
1287                         name: funcNameTestFunc,
1288                 },
1289         )
1290         // If we get here, the name did not cause a panic, which is how Funcs
1291         // reports an error.
1292         t.Errorf("%q succeeded incorrectly as function name", name)
1293 }
1294
1295 func TestBlock(t *testing.T) {
1296         const (
1297                 input   = `a({{block "inner" .}}bar({{.}})baz{{end}})b`
1298                 want    = `a(bar(hello)baz)b`
1299                 overlay = `{{define "inner"}}foo({{.}})bar{{end}}`
1300                 want2   = `a(foo(goodbye)bar)b`
1301         )
1302         tmpl, err := New("outer").Parse(input)
1303         if err != nil {
1304                 t.Fatal(err)
1305         }
1306         tmpl2, err := Must(tmpl.Clone()).Parse(overlay)
1307         if err != nil {
1308                 t.Fatal(err)
1309         }
1310
1311         var buf bytes.Buffer
1312         if err := tmpl.Execute(&buf, "hello"); err != nil {
1313                 t.Fatal(err)
1314         }
1315         if got := buf.String(); got != want {
1316                 t.Errorf("got %q, want %q", got, want)
1317         }
1318
1319         buf.Reset()
1320         if err := tmpl2.Execute(&buf, "goodbye"); err != nil {
1321                 t.Fatal(err)
1322         }
1323         if got := buf.String(); got != want2 {
1324                 t.Errorf("got %q, want %q", got, want2)
1325         }
1326 }
1327
1328 // Check that calling an invalid field on nil pointer prints
1329 // a field error instead of a distracting nil pointer error.
1330 // https://golang.org/issue/15125
1331 func TestMissingFieldOnNil(t *testing.T) {
1332         tmpl := Must(New("tmpl").Parse("{{.MissingField}}"))
1333         var d *T
1334         err := tmpl.Execute(ioutil.Discard, d)
1335         got := "<nil>"
1336         if err != nil {
1337                 got = err.Error()
1338         }
1339         want := "can't evaluate field MissingField in type *template.T"
1340         if !strings.HasSuffix(got, want) {
1341                 t.Errorf("got error %q, want %q", got, want)
1342         }
1343 }
1344
1345 func TestMaxExecDepth(t *testing.T) {
1346         tmpl := Must(New("tmpl").Parse(`{{template "tmpl" .}}`))
1347         err := tmpl.Execute(ioutil.Discard, nil)
1348         got := "<nil>"
1349         if err != nil {
1350                 got = err.Error()
1351         }
1352         const want = "exceeded maximum template depth"
1353         if !strings.Contains(got, want) {
1354                 t.Errorf("got error %q; want %q", got, want)
1355         }
1356 }
1357
1358 func TestAddrOfIndex(t *testing.T) {
1359         // golang.org/issue/14916.
1360         // Before index worked on reflect.Values, the .String could not be
1361         // found on the (incorrectly unaddressable) V value,
1362         // in contrast to range, which worked fine.
1363         // Also testing that passing a reflect.Value to tmpl.Execute works.
1364         texts := []string{
1365                 `{{range .}}{{.String}}{{end}}`,
1366                 `{{with index . 0}}{{.String}}{{end}}`,
1367         }
1368         for _, text := range texts {
1369                 tmpl := Must(New("tmpl").Parse(text))
1370                 var buf bytes.Buffer
1371                 err := tmpl.Execute(&buf, reflect.ValueOf([]V{{1}}))
1372                 if err != nil {
1373                         t.Fatalf("%s: Execute: %v", text, err)
1374                 }
1375                 if buf.String() != "<1>" {
1376                         t.Fatalf("%s: template output = %q, want %q", text, &buf, "<1>")
1377                 }
1378         }
1379 }
1380
1381 func TestInterfaceValues(t *testing.T) {
1382         // golang.org/issue/17714.
1383         // Before index worked on reflect.Values, interface values
1384         // were always implicitly promoted to the underlying value,
1385         // except that nil interfaces were promoted to the zero reflect.Value.
1386         // Eliminating a round trip to interface{} and back to reflect.Value
1387         // eliminated this promotion, breaking these cases.
1388         tests := []struct {
1389                 text string
1390                 out  string
1391         }{
1392                 {`{{index .Nil 1}}`, "ERROR: index of untyped nil"},
1393                 {`{{index .Slice 2}}`, "2"},
1394                 {`{{index .Slice .Two}}`, "2"},
1395                 {`{{call .Nil 1}}`, "ERROR: call of nil"},
1396                 {`{{call .PlusOne 1}}`, "2"},
1397                 {`{{call .PlusOne .One}}`, "2"},
1398                 {`{{and (index .Slice 0) true}}`, "0"},
1399                 {`{{and .Zero true}}`, "0"},
1400                 {`{{and (index .Slice 1) false}}`, "false"},
1401                 {`{{and .One false}}`, "false"},
1402                 {`{{or (index .Slice 0) false}}`, "false"},
1403                 {`{{or .Zero false}}`, "false"},
1404                 {`{{or (index .Slice 1) true}}`, "1"},
1405                 {`{{or .One true}}`, "1"},
1406                 {`{{not (index .Slice 0)}}`, "true"},
1407                 {`{{not .Zero}}`, "true"},
1408                 {`{{not (index .Slice 1)}}`, "false"},
1409                 {`{{not .One}}`, "false"},
1410                 {`{{eq (index .Slice 0) .Zero}}`, "true"},
1411                 {`{{eq (index .Slice 1) .One}}`, "true"},
1412                 {`{{ne (index .Slice 0) .Zero}}`, "false"},
1413                 {`{{ne (index .Slice 1) .One}}`, "false"},
1414                 {`{{ge (index .Slice 0) .One}}`, "false"},
1415                 {`{{ge (index .Slice 1) .Zero}}`, "true"},
1416                 {`{{gt (index .Slice 0) .One}}`, "false"},
1417                 {`{{gt (index .Slice 1) .Zero}}`, "true"},
1418                 {`{{le (index .Slice 0) .One}}`, "true"},
1419                 {`{{le (index .Slice 1) .Zero}}`, "false"},
1420                 {`{{lt (index .Slice 0) .One}}`, "true"},
1421                 {`{{lt (index .Slice 1) .Zero}}`, "false"},
1422         }
1423
1424         for _, tt := range tests {
1425                 tmpl := Must(New("tmpl").Parse(tt.text))
1426                 var buf bytes.Buffer
1427                 err := tmpl.Execute(&buf, map[string]interface{}{
1428                         "PlusOne": func(n int) int {
1429                                 return n + 1
1430                         },
1431                         "Slice": []int{0, 1, 2, 3},
1432                         "One":   1,
1433                         "Two":   2,
1434                         "Nil":   nil,
1435                         "Zero":  0,
1436                 })
1437                 if strings.HasPrefix(tt.out, "ERROR:") {
1438                         e := strings.TrimSpace(strings.TrimPrefix(tt.out, "ERROR:"))
1439                         if err == nil || !strings.Contains(err.Error(), e) {
1440                                 t.Errorf("%s: Execute: %v, want error %q", tt.text, err, e)
1441                         }
1442                         continue
1443                 }
1444                 if err != nil {
1445                         t.Errorf("%s: Execute: %v", tt.text, err)
1446                         continue
1447                 }
1448                 if buf.String() != tt.out {
1449                         t.Errorf("%s: template output = %q, want %q", tt.text, &buf, tt.out)
1450                 }
1451         }
1452 }