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
5package template
6
7import (
8	"bytes"
9	"errors"
10	"flag"
11	"fmt"
12	"io/ioutil"
13	"reflect"
14	"strings"
15	"testing"
16)
17
18var 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.
21type 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
83type S []string
84
85func (S) Method0() string {
86	return "M0"
87}
88
89type U struct {
90	V string
91}
92
93type V struct {
94	j int
95}
96
97func (v *V) String() string {
98	if v == nil {
99		return "nilV"
100	}
101	return fmt.Sprintf("<%d>", v.j)
102}
103
104type W struct {
105	k int
106}
107
108func (w *W) Error() string {
109	if w == nil {
110		return "nilW"
111	}
112	return fmt.Sprintf("[%d]", w.k)
113}
114
115var siVal = I(S{"a", "b"})
116
117var 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
162var tSliceOfNil = []*T{nil}
163
164// A non-empty interface.
165type I interface {
166	Method0() string
167}
168
169var iVal I = tVal
170
171// Helpers for creation.
172func newInt(n int) *int {
173	return &n
174}
175
176func newString(s string) *string {
177	return &s
178}
179
180func 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.
188func (t *T) Method0() string {
189	return "M0"
190}
191
192func (t *T) Method1(a int) int {
193	return a
194}
195
196func (t *T) Method2(a uint16, b string) string {
197	return fmt.Sprintf("Method2: %d %s", a, b)
198}
199
200func (t *T) Method3(v interface{}) string {
201	return fmt.Sprintf("Method3: %v", v)
202}
203
204func (t *T) Copy() *T {
205	n := new(T)
206	*n = *t
207	return n
208}
209
210func (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
218var myError = errors.New("my error")
219
220// MyError returns a value and an error according to its argument.
221func (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.
229func (t *T) GetU() *U {
230	return t.U
231}
232
233func (u *U) TrueFalse(b bool) string {
234	if b {
235		return "true"
236	}
237	return ""
238}
239
240func typeOf(arg interface{}) string {
241	return fmt.Sprintf("%T", arg)
242}
243
244type 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.
255var (
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
260var 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
590func zeroArgs() string {
591	return "zeroArgs"
592}
593
594func oneArg(a string) string {
595	return "oneArg=" + a
596}
597
598func twoArgs(a, b string) string {
599	return "twoArgs=" + a + b
600}
601
602func 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"
607func 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
622func vfunc(V, *V) string {
623	return "vfunc"
624}
625
626// valueString takes a string, not a pointer.
627func valueString(v string) string {
628	return "value is ignored"
629}
630
631// returnInt returns an int
632func returnInt() int {
633	return 7
634}
635
636func add(args ...int) int {
637	sum := 0
638	for _, x := range args {
639		sum += x
640	}
641	return sum
642}
643
644func echo(arg interface{}) interface{} {
645	return arg
646}
647
648func 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
659func stringer(s fmt.Stringer) string {
660	return s.String()
661}
662
663func mapOfThree() interface{} {
664	return map[string]int{"three": 3}
665}
666
667func 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
719func TestExecute(t *testing.T) {
720	testExecute(execTests, nil, t)
721}
722
723var delimPairs = []string{
724	"", "", // default
725	"{{", "}}", // same as default
726	"<<", ">>", // distinct
727	"|", "|", // same
728	"(日)", "(本)", // peculiar
729}
730
731func 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.
768func 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
786const execErrorText = `line 1
787line 2
788line 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.
795func 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
812func 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
833type 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.
840const 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
854func 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
918func 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
929const testTemplates = `{{define "one"}}one{{end}}{{define "two"}}two{{end}}`
930
931func 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
966func 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
978type cmpTest struct {
979	expr  string
980	truth string
981	ok    bool
982}
983
984var 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
1088func 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
1116func 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.
1175func 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
1186const alwaysErrorText = "always be failing"
1187
1188var alwaysError = errors.New(alwaysErrorText)
1189
1190type ErrorWriter int
1191
1192func (e ErrorWriter) Write(p []byte) (int, error) {
1193	return 0, alwaysError
1194}
1195
1196func 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
1228func funcNameTestFunc() int {
1229	return 0
1230}
1231
1232func 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
1252func 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
1263func 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
1277func 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
1313func 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
1327func 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
1340func 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
1363func 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}
1435