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// Copyright 2011 The Go Authors. All rights reserved.
// Use of this source code is governed by a BSD-style
// license that can be found in the LICENSE file.
package template
import (
"bytes"
"errors"
"flag"
"fmt"
"io"
"reflect"
"strings"
"sync"
"testing"
)
var debug = flag.Bool("debug", false, "show the errors produced by the tests")
// T has lots of interesting pieces to use to test execution.
type T struct {
// Basics
True bool
I int
U16 uint16
X, S string
FloatZero float64
ComplexZero complex128
// Nested structs.
U *U
// Struct with String method.
V0 V
V1, V2 *V
// Struct with Error method.
W0 W
W1, W2 *W
// Slices
SI []int
SICap []int
SIEmpty []int
SB []bool
// Arrays
AI [3]int
// Maps
MSI map[string]int
MSIone map[string]int // one element, for deterministic output
MSIEmpty map[string]int
MXI map[any]int
MII map[int]int
MI32S map[int32]string
MI64S map[int64]string
MUI32S map[uint32]string
MUI64S map[uint64]string
MI8S map[int8]string
MUI8S map[uint8]string
SMSI []map[string]int
// Empty interfaces; used to see if we can dig inside one.
Empty0 any // nil
Empty1 any
Empty2 any
Empty3 any
Empty4 any
// Non-empty interfaces.
NonEmptyInterface I
NonEmptyInterfacePtS *I
NonEmptyInterfaceNil I
NonEmptyInterfaceTypedNil I
// Stringer.
Str fmt.Stringer
Err error
// Pointers
PI *int
PS *string
PSI *[]int
NIL *int
// Function (not method)
BinaryFunc func(string, string) string
VariadicFunc func(...string) string
VariadicFuncInt func(int, ...string) string
NilOKFunc func(*int) bool
ErrFunc func() (string, error)
PanicFunc func() string
// Template to test evaluation of templates.
Tmpl *Template
// Unexported field; cannot be accessed by template.
unexported int
}
type S []string
func (S) Method0() string {
return "M0"
}
type U struct {
V string
}
type V struct {
j int
}
func (v *V) String() string {
if v == nil {
return "nilV"
}
return fmt.Sprintf("<%d>", v.j)
}
type W struct {
k int
}
func (w *W) Error() string {
if w == nil {
return "nilW"
}
return fmt.Sprintf("[%d]", w.k)
}
var siVal = I(S{"a", "b"})
var tVal = &T{
True: true,
I: 17,
U16: 16,
X: "x",
S: "xyz",
U: &U{"v"},
V0: V{6666},
V1: &V{7777}, // leave V2 as nil
W0: W{888},
W1: &W{999}, // leave W2 as nil
SI: []int{3, 4, 5},
SICap: make([]int, 5, 10),
AI: [3]int{3, 4, 5},
SB: []bool{true, false},
MSI: map[string]int{"one": 1, "two": 2, "three": 3},
MSIone: map[string]int{"one": 1},
MXI: map[any]int{"one": 1},
MII: map[int]int{1: 1},
MI32S: map[int32]string{1: "one", 2: "two"},
MI64S: map[int64]string{2: "i642", 3: "i643"},
MUI32S: map[uint32]string{2: "u322", 3: "u323"},
MUI64S: map[uint64]string{2: "ui642", 3: "ui643"},
MI8S: map[int8]string{2: "i82", 3: "i83"},
MUI8S: map[uint8]string{2: "u82", 3: "u83"},
SMSI: []map[string]int{
{"one": 1, "two": 2},
{"eleven": 11, "twelve": 12},
},
Empty1: 3,
Empty2: "empty2",
Empty3: []int{7, 8},
Empty4: &U{"UinEmpty"},
NonEmptyInterface: &T{X: "x"},
NonEmptyInterfacePtS: &siVal,
NonEmptyInterfaceTypedNil: (*T)(nil),
Str: bytes.NewBuffer([]byte("foozle")),
Err: errors.New("erroozle"),
PI: newInt(23),
PS: newString("a string"),
PSI: newIntSlice(21, 22, 23),
BinaryFunc: func(a, b string) string { return fmt.Sprintf("[%s=%s]", a, b) },
VariadicFunc: func(s ...string) string { return fmt.Sprint("<", strings.Join(s, "+"), ">") },
VariadicFuncInt: func(a int, s ...string) string { return fmt.Sprint(a, "=<", strings.Join(s, "+"), ">") },
NilOKFunc: func(s *int) bool { return s == nil },
ErrFunc: func() (string, error) { return "bla", nil },
PanicFunc: func() string { panic("test panic") },
Tmpl: Must(New("x").Parse("test template")), // "x" is the value of .X
}
var tSliceOfNil = []*T{nil}
// A non-empty interface.
type I interface {
Method0() string
}
var iVal I = tVal
// Helpers for creation.
func newInt(n int) *int {
return &n
}
func newString(s string) *string {
return &s
}
func newIntSlice(n ...int) *[]int {
p := new([]int)
*p = make([]int, len(n))
copy(*p, n)
return p
}
// Simple methods with and without arguments.
func (t *T) Method0() string {
return "M0"
}
func (t *T) Method1(a int) int {
return a
}
func (t *T) Method2(a uint16, b string) string {
return fmt.Sprintf("Method2: %d %s", a, b)
}
func (t *T) Method3(v any) string {
return fmt.Sprintf("Method3: %v", v)
}
func (t *T) Copy() *T {
n := new(T)
*n = *t
return n
}
func (t *T) MAdd(a int, b []int) []int {
v := make([]int, len(b))
for i, x := range b {
v[i] = x + a
}
return v
}
var myError = errors.New("my error")
// MyError returns a value and an error according to its argument.
func (t *T) MyError(error bool) (bool, error) {
if error {
return true, myError
}
return false, nil
}
// A few methods to test chaining.
func (t *T) GetU() *U {
return t.U
}
func (u *U) TrueFalse(b bool) string {
if b {
return "true"
}
return ""
}
func typeOf(arg any) string {
return fmt.Sprintf("%T", arg)
}
type execTest struct {
name string
input string
output string
data any
ok bool
}
// bigInt and bigUint are hex string representing numbers either side
// of the max int boundary.
// We do it this way so the test doesn't depend on ints being 32 bits.
var (
bigInt = fmt.Sprintf("0x%x", int(1<<uint(reflect.TypeOf(0).Bits()-1)-1))
bigUint = fmt.Sprintf("0x%x", uint(1<<uint(reflect.TypeOf(0).Bits()-1)))
)
var execTests = []execTest{
// Trivial cases.
{"empty", "", "", nil, true},
{"text", "some text", "some text", nil, true},
{"nil action", "{{nil}}", "", nil, false},
// Ideal constants.
{"ideal int", "{{typeOf 3}}", "int", 0, true},
{"ideal float", "{{typeOf 1.0}}", "float64", 0, true},
{"ideal exp float", "{{typeOf 1e1}}", "float64", 0, true},
{"ideal complex", "{{typeOf 1i}}", "complex128", 0, true},
{"ideal int", "{{typeOf " + bigInt + "}}", "int", 0, true},
{"ideal too big", "{{typeOf " + bigUint + "}}", "", 0, false},
{"ideal nil without type", "{{nil}}", "", 0, false},
// Fields of structs.
{".X", "-{{.X}}-", "-x-", tVal, true},
{".U.V", "-{{.U.V}}-", "-v-", tVal, true},
{".unexported", "{{.unexported}}", "", tVal, false},
// Fields on maps.
{"map .one", "{{.MSI.one}}", "1", tVal, true},
{"map .two", "{{.MSI.two}}", "2", tVal, true},
{"map .NO", "{{.MSI.NO}}", "<no value>", tVal, true},
{"map .one interface", "{{.MXI.one}}", "1", tVal, true},
{"map .WRONG args", "{{.MSI.one 1}}", "", tVal, false},
{"map .WRONG type", "{{.MII.one}}", "", tVal, false},
// Dots of all kinds to test basic evaluation.
{"dot int", "<{{.}}>", "<13>", 13, true},
{"dot uint", "<{{.}}>", "<14>", uint(14), true},
{"dot float", "<{{.}}>", "<15.1>", 15.1, true},
{"dot bool", "<{{.}}>", "<true>", true, true},
{"dot complex", "<{{.}}>", "<(16.2-17i)>", 16.2 - 17i, true},
{"dot string", "<{{.}}>", "<hello>", "hello", true},
{"dot slice", "<{{.}}>", "<[-1 -2 -3]>", []int{-1, -2, -3}, true},
{"dot map", "<{{.}}>", "<map[two:22]>", map[string]int{"two": 22}, true},
{"dot struct", "<{{.}}>", "<{7 seven}>", struct {
a int
b string
}{7, "seven"}, true},
// Variables.
{"$ int", "{{$}}", "123", 123, true},
{"$.I", "{{$.I}}", "17", tVal, true},
{"$.U.V", "{{$.U.V}}", "v", tVal, true},
{"declare in action", "{{$x := $.U.V}}{{$x}}", "v", tVal, true},
{"simple assignment", "{{$x := 2}}{{$x = 3}}{{$x}}", "3", tVal, true},
{"nested assignment",
"{{$x := 2}}{{if true}}{{$x = 3}}{{end}}{{$x}}",
"3", tVal, true},
{"nested assignment changes the last declaration",
"{{$x := 1}}{{if true}}{{$x := 2}}{{if true}}{{$x = 3}}{{end}}{{end}}{{$x}}",
"1", tVal, true},
// Type with String method.
{"V{6666}.String()", "-{{.V0}}-", "-<6666>-", tVal, true},
{"&V{7777}.String()", "-{{.V1}}-", "-<7777>-", tVal, true},
{"(*V)(nil).String()", "-{{.V2}}-", "-nilV-", tVal, true},
// Type with Error method.
{"W{888}.Error()", "-{{.W0}}-", "-[888]-", tVal, true},
{"&W{999}.Error()", "-{{.W1}}-", "-[999]-", tVal, true},
{"(*W)(nil).Error()", "-{{.W2}}-", "-nilW-", tVal, true},
// Pointers.
{"*int", "{{.PI}}", "23", tVal, true},
{"*string", "{{.PS}}", "a string", tVal, true},
{"*[]int", "{{.PSI}}", "[21 22 23]", tVal, true},
{"*[]int[1]", "{{index .PSI 1}}", "22", tVal, true},
{"NIL", "{{.NIL}}", "<nil>", tVal, true},
// Empty interfaces holding values.
{"empty nil", "{{.Empty0}}", "<no value>", tVal, true},
{"empty with int", "{{.Empty1}}", "3", tVal, true},
{"empty with string", "{{.Empty2}}", "empty2", tVal, true},
{"empty with slice", "{{.Empty3}}", "[7 8]", tVal, true},
{"empty with struct", "{{.Empty4}}", "{UinEmpty}", tVal, true},
{"empty with struct, field", "{{.Empty4.V}}", "UinEmpty", tVal, true},
// Edge cases with <no value> with an interface value
{"field on interface", "{{.foo}}", "<no value>", nil, true},
{"field on parenthesized interface", "{{(.).foo}}", "<no value>", nil, true},
// Issue 31810: Parenthesized first element of pipeline with arguments.
// See also TestIssue31810.
{"unparenthesized non-function", "{{1 2}}", "", nil, false},
{"parenthesized non-function", "{{(1) 2}}", "", nil, false},
{"parenthesized non-function with no args", "{{(1)}}", "1", nil, true}, // This is fine.
// Method calls.
{".Method0", "-{{.Method0}}-", "-M0-", tVal, true},
{".Method1(1234)", "-{{.Method1 1234}}-", "-1234-", tVal, true},
{".Method1(.I)", "-{{.Method1 .I}}-", "-17-", tVal, true},
{".Method2(3, .X)", "-{{.Method2 3 .X}}-", "-Method2: 3 x-", tVal, true},
{".Method2(.U16, `str`)", "-{{.Method2 .U16 `str`}}-", "-Method2: 16 str-", tVal, true},
{".Method2(.U16, $x)", "{{if $x := .X}}-{{.Method2 .U16 $x}}{{end}}-", "-Method2: 16 x-", tVal, true},
{".Method3(nil constant)", "-{{.Method3 nil}}-", "-Method3: <nil>-", tVal, true},
{".Method3(nil value)", "-{{.Method3 .MXI.unset}}-", "-Method3: <nil>-", tVal, true},
{"method on var", "{{if $x := .}}-{{$x.Method2 .U16 $x.X}}{{end}}-", "-Method2: 16 x-", tVal, true},
{"method on chained var",
"{{range .MSIone}}{{if $.U.TrueFalse $.True}}{{$.U.TrueFalse $.True}}{{else}}WRONG{{end}}{{end}}",
"true", tVal, true},
{"chained method",
"{{range .MSIone}}{{if $.GetU.TrueFalse $.True}}{{$.U.TrueFalse $.True}}{{else}}WRONG{{end}}{{end}}",
"true", tVal, true},
{"chained method on variable",
"{{with $x := .}}{{with .SI}}{{$.GetU.TrueFalse $.True}}{{end}}{{end}}",
"true", tVal, true},
{".NilOKFunc not nil", "{{call .NilOKFunc .PI}}", "false", tVal, true},
{".NilOKFunc nil", "{{call .NilOKFunc nil}}", "true", tVal, true},
{"method on nil value from slice", "-{{range .}}{{.Method1 1234}}{{end}}-", "-1234-", tSliceOfNil, true},
{"method on typed nil interface value", "{{.NonEmptyInterfaceTypedNil.Method0}}", "M0", tVal, true},
// Function call builtin.
{".BinaryFunc", "{{call .BinaryFunc `1` `2`}}", "[1=2]", tVal, true},
{".VariadicFunc0", "{{call .VariadicFunc}}", "<>", tVal, true},
{".VariadicFunc2", "{{call .VariadicFunc `he` `llo`}}", "<he+llo>", tVal, true},
{".VariadicFuncInt", "{{call .VariadicFuncInt 33 `he` `llo`}}", "33=<he+llo>", tVal, true},
{"if .BinaryFunc call", "{{ if .BinaryFunc}}{{call .BinaryFunc `1` `2`}}{{end}}", "[1=2]", tVal, true},
{"if not .BinaryFunc call", "{{ if not .BinaryFunc}}{{call .BinaryFunc `1` `2`}}{{else}}No{{end}}", "No", tVal, true},
{"Interface Call", `{{stringer .S}}`, "foozle", map[string]any{"S": bytes.NewBufferString("foozle")}, true},
{".ErrFunc", "{{call .ErrFunc}}", "bla", tVal, true},
{"call nil", "{{call nil}}", "", tVal, false},
// Erroneous function calls (check args).
{".BinaryFuncTooFew", "{{call .BinaryFunc `1`}}", "", tVal, false},
{".BinaryFuncTooMany", "{{call .BinaryFunc `1` `2` `3`}}", "", tVal, false},
{".BinaryFuncBad0", "{{call .BinaryFunc 1 3}}", "", tVal, false},
{".BinaryFuncBad1", "{{call .BinaryFunc `1` 3}}", "", tVal, false},
{".VariadicFuncBad0", "{{call .VariadicFunc 3}}", "", tVal, false},
{".VariadicFuncIntBad0", "{{call .VariadicFuncInt}}", "", tVal, false},
{".VariadicFuncIntBad`", "{{call .VariadicFuncInt `x`}}", "", tVal, false},
{".VariadicFuncNilBad", "{{call .VariadicFunc nil}}", "", tVal, false},
// Pipelines.
{"pipeline", "-{{.Method0 | .Method2 .U16}}-", "-Method2: 16 M0-", tVal, true},
{"pipeline func", "-{{call .VariadicFunc `llo` | call .VariadicFunc `he` }}-", "-<he+<llo>>-", tVal, true},
// Nil values aren't missing arguments.
{"nil pipeline", "{{ .Empty0 | call .NilOKFunc }}", "true", tVal, true},
{"nil call arg", "{{ call .NilOKFunc .Empty0 }}", "true", tVal, true},
{"bad nil pipeline", "{{ .Empty0 | .VariadicFunc }}", "", tVal, false},
// Parenthesized expressions
{"parens in pipeline", "{{printf `%d %d %d` (1) (2 | add 3) (add 4 (add 5 6))}}", "1 5 15", tVal, true},
// Parenthesized expressions with field accesses
{"parens: $ in paren", "{{($).X}}", "x", tVal, true},
{"parens: $.GetU in paren", "{{($.GetU).V}}", "v", tVal, true},
{"parens: $ in paren in pipe", "{{($ | echo).X}}", "x", tVal, true},
{"parens: spaces and args", `{{(makemap "up" "down" "left" "right").left}}`, "right", tVal, true},
// If.
{"if true", "{{if true}}TRUE{{end}}", "TRUE", tVal, true},
{"if false", "{{if false}}TRUE{{else}}FALSE{{end}}", "FALSE", tVal, true},
{"if nil", "{{if nil}}TRUE{{end}}", "", tVal, false},
{"if on typed nil interface value", "{{if .NonEmptyInterfaceTypedNil}}TRUE{{ end }}", "", tVal, true},
{"if 1", "{{if 1}}NON-ZERO{{else}}ZERO{{end}}", "NON-ZERO", tVal, true},
{"if 0", "{{if 0}}NON-ZERO{{else}}ZERO{{end}}", "ZERO", tVal, true},
{"if 1.5", "{{if 1.5}}NON-ZERO{{else}}ZERO{{end}}", "NON-ZERO", tVal, true},
{"if 0.0", "{{if .FloatZero}}NON-ZERO{{else}}ZERO{{end}}", "ZERO", tVal, true},
{"if 1.5i", "{{if 1.5i}}NON-ZERO{{else}}ZERO{{end}}", "NON-ZERO", tVal, true},
{"if 0.0i", "{{if .ComplexZero}}NON-ZERO{{else}}ZERO{{end}}", "ZERO", tVal, true},
{"if emptystring", "{{if ``}}NON-EMPTY{{else}}EMPTY{{end}}", "EMPTY", tVal, true},
{"if string", "{{if `notempty`}}NON-EMPTY{{else}}EMPTY{{end}}", "NON-EMPTY", tVal, true},
{"if emptyslice", "{{if .SIEmpty}}NON-EMPTY{{else}}EMPTY{{end}}", "EMPTY", tVal, true},
{"if slice", "{{if .SI}}NON-EMPTY{{else}}EMPTY{{end}}", "NON-EMPTY", tVal, true},
{"if emptymap", "{{if .MSIEmpty}}NON-EMPTY{{else}}EMPTY{{end}}", "EMPTY", tVal, true},
{"if map", "{{if .MSI}}NON-EMPTY{{else}}EMPTY{{end}}", "NON-EMPTY", tVal, true},
{"if map unset", "{{if .MXI.none}}NON-ZERO{{else}}ZERO{{end}}", "ZERO", tVal, true},
{"if map not unset", "{{if not .MXI.none}}ZERO{{else}}NON-ZERO{{end}}", "ZERO", tVal, true},
{"if $x with $y int", "{{if $x := true}}{{with $y := .I}}{{$x}},{{$y}}{{end}}{{end}}", "true,17", tVal, true},
{"if $x with $x int", "{{if $x := true}}{{with $x := .I}}{{$x}},{{end}}{{$x}}{{end}}", "17,true", tVal, true},
{"if else if", "{{if false}}FALSE{{else if true}}TRUE{{end}}", "TRUE", tVal, true},
{"if else chain", "{{if eq 1 3}}1{{else if eq 2 3}}2{{else if eq 3 3}}3{{end}}", "3", tVal, true},
// Print etc.
{"print", `{{print "hello, print"}}`, "hello, print", tVal, true},
{"print 123", `{{print 1 2 3}}`, "1 2 3", tVal, true},
{"print nil", `{{print nil}}`, "<nil>", tVal, true},
{"println", `{{println 1 2 3}}`, "1 2 3\n", tVal, true},
{"printf int", `{{printf "%04x" 127}}`, "007f", tVal, true},
{"printf float", `{{printf "%g" 3.5}}`, "3.5", tVal, true},
{"printf complex", `{{printf "%g" 1+7i}}`, "(1+7i)", tVal, true},
{"printf string", `{{printf "%s" "hello"}}`, "hello", tVal, true},
{"printf function", `{{printf "%#q" zeroArgs}}`, "`zeroArgs`", tVal, true},
{"printf field", `{{printf "%s" .U.V}}`, "v", tVal, true},
{"printf method", `{{printf "%s" .Method0}}`, "M0", tVal, true},
{"printf dot", `{{with .I}}{{printf "%d" .}}{{end}}`, "17", tVal, true},
{"printf var", `{{with $x := .I}}{{printf "%d" $x}}{{end}}`, "17", tVal, true},
{"printf lots", `{{printf "%d %s %g %s" 127 "hello" 7-3i .Method0}}`, "127 hello (7-3i) M0", tVal, true},
// HTML.
{"html", `{{html "<script>alert(\"XSS\");</script>"}}`,
"&lt;script&gt;alert(&#34;XSS&#34;);&lt;/script&gt;", nil, true},
{"html pipeline", `{{printf "<script>alert(\"XSS\");</script>" | html}}`,
"&lt;script&gt;alert(&#34;XSS&#34;);&lt;/script&gt;", nil, true},
{"html", `{{html .PS}}`, "a string", tVal, true},
{"html typed nil", `{{html .NIL}}`, "&lt;nil&gt;", tVal, true},
{"html untyped nil", `{{html .Empty0}}`, "&lt;no value&gt;", tVal, true},
// JavaScript.
{"js", `{{js .}}`, `It\'d be nice.`, `It'd be nice.`, true},
// URL query.
{"urlquery", `{{"http://www.example.org/"|urlquery}}`, "http%3A%2F%2Fwww.example.org%2F", nil, true},
// Booleans
{"not", "{{not true}} {{not false}}", "false true", nil, true},
{"and", "{{and false 0}} {{and 1 0}} {{and 0 true}} {{and 1 1}}", "false 0 0 1", nil, true},
{"or", "{{or 0 0}} {{or 1 0}} {{or 0 true}} {{or 1 1}}", "0 1 true 1", nil, true},
{"or short-circuit", "{{or 0 1 (die)}}", "1", nil, true},
{"and short-circuit", "{{and 1 0 (die)}}", "0", nil, true},
{"or short-circuit2", "{{or 0 0 (die)}}", "", nil, false},
{"and short-circuit2", "{{and 1 1 (die)}}", "", nil, false},
{"and pipe-true", "{{1 | and 1}}", "1", nil, true},
{"and pipe-false", "{{0 | and 1}}", "0", nil, true},
{"or pipe-true", "{{1 | or 0}}", "1", nil, true},
{"or pipe-false", "{{0 | or 0}}", "0", nil, true},
{"and undef", "{{and 1 .Unknown}}", "<no value>", nil, true},
{"or undef", "{{or 0 .Unknown}}", "<no value>", nil, true},
{"boolean if", "{{if and true 1 `hi`}}TRUE{{else}}FALSE{{end}}", "TRUE", tVal, true},
{"boolean if not", "{{if and true 1 `hi` | not}}TRUE{{else}}FALSE{{end}}", "FALSE", nil, true},
{"boolean if pipe", "{{if true | not | and 1}}TRUE{{else}}FALSE{{end}}", "FALSE", nil, true},
// Indexing.
{"slice[0]", "{{index .SI 0}}", "3", tVal, true},
{"slice[1]", "{{index .SI 1}}", "4", tVal, true},
{"slice[HUGE]", "{{index .SI 10}}", "", tVal, false},
{"slice[WRONG]", "{{index .SI `hello`}}", "", tVal, false},
{"slice[nil]", "{{index .SI nil}}", "", tVal, false},
{"map[one]", "{{index .MSI `one`}}", "1", tVal, true},
{"map[two]", "{{index .MSI `two`}}", "2", tVal, true},
{"map[NO]", "{{index .MSI `XXX`}}", "0", tVal, true},
{"map[nil]", "{{index .MSI nil}}", "", tVal, false},
{"map[``]", "{{index .MSI ``}}", "0", tVal, true},
{"map[WRONG]", "{{index .MSI 10}}", "", tVal, false},
{"double index", "{{index .SMSI 1 `eleven`}}", "11", tVal, true},
{"nil[1]", "{{index nil 1}}", "", tVal, false},
{"map MI64S", "{{index .MI64S 2}}", "i642", tVal, true},
{"map MI32S", "{{index .MI32S 2}}", "two", tVal, true},
{"map MUI64S", "{{index .MUI64S 3}}", "ui643", tVal, true},
{"map MI8S", "{{index .MI8S 3}}", "i83", tVal, true},
{"map MUI8S", "{{index .MUI8S 2}}", "u82", tVal, true},
{"index of an interface field", "{{index .Empty3 0}}", "7", tVal, true},
// Slicing.
{"slice[:]", "{{slice .SI}}", "[3 4 5]", tVal, true},
{"slice[1:]", "{{slice .SI 1}}", "[4 5]", tVal, true},
{"slice[1:2]", "{{slice .SI 1 2}}", "[4]", tVal, true},
{"slice[-1:]", "{{slice .SI -1}}", "", tVal, false},
{"slice[1:-2]", "{{slice .SI 1 -2}}", "", tVal, false},
{"slice[1:2:-1]", "{{slice .SI 1 2 -1}}", "", tVal, false},
{"slice[2:1]", "{{slice .SI 2 1}}", "", tVal, false},
{"slice[2:2:1]", "{{slice .SI 2 2 1}}", "", tVal, false},
{"out of range", "{{slice .SI 4 5}}", "", tVal, false},
{"out of range", "{{slice .SI 2 2 5}}", "", tVal, false},
{"len(s) < indexes < cap(s)", "{{slice .SICap 6 10}}", "[0 0 0 0]", tVal, true},
{"len(s) < indexes < cap(s)", "{{slice .SICap 6 10 10}}", "[0 0 0 0]", tVal, true},
{"indexes > cap(s)", "{{slice .SICap 10 11}}", "", tVal, false},
{"indexes > cap(s)", "{{slice .SICap 6 10 11}}", "", tVal, false},
{"array[:]", "{{slice .AI}}", "[3 4 5]", tVal, true},
{"array[1:]", "{{slice .AI 1}}", "[4 5]", tVal, true},
{"array[1:2]", "{{slice .AI 1 2}}", "[4]", tVal, true},
{"string[:]", "{{slice .S}}", "xyz", tVal, true},
{"string[0:1]", "{{slice .S 0 1}}", "x", tVal, true},
{"string[1:]", "{{slice .S 1}}", "yz", tVal, true},
{"string[1:2]", "{{slice .S 1 2}}", "y", tVal, true},
{"out of range", "{{slice .S 1 5}}", "", tVal, false},
{"3-index slice of string", "{{slice .S 1 2 2}}", "", tVal, false},
{"slice of an interface field", "{{slice .Empty3 0 1}}", "[7]", tVal, true},
// Len.
{"slice", "{{len .SI}}", "3", tVal, true},
{"map", "{{len .MSI }}", "3", tVal, true},
{"len of int", "{{len 3}}", "", tVal, false},
{"len of nothing", "{{len .Empty0}}", "", tVal, false},
{"len of an interface field", "{{len .Empty3}}", "2", tVal, true},
// With.
{"with true", "{{with true}}{{.}}{{end}}", "true", tVal, true},
{"with false", "{{with false}}{{.}}{{else}}FALSE{{end}}", "FALSE", tVal, true},
{"with 1", "{{with 1}}{{.}}{{else}}ZERO{{end}}", "1", tVal, true},
{"with 0", "{{with 0}}{{.}}{{else}}ZERO{{end}}", "ZERO", tVal, true},
{"with 1.5", "{{with 1.5}}{{.}}{{else}}ZERO{{end}}", "1.5", tVal, true},
{"with 0.0", "{{with .FloatZero}}{{.}}{{else}}ZERO{{end}}", "ZERO", tVal, true},
{"with 1.5i", "{{with 1.5i}}{{.}}{{else}}ZERO{{end}}", "(0+1.5i)", tVal, true},
{"with 0.0i", "{{with .ComplexZero}}{{.}}{{else}}ZERO{{end}}", "ZERO", tVal, true},
{"with emptystring", "{{with ``}}{{.}}{{else}}EMPTY{{end}}", "EMPTY", tVal, true},
{"with string", "{{with `notempty`}}{{.}}{{else}}EMPTY{{end}}", "notempty", tVal, true},
{"with emptyslice", "{{with .SIEmpty}}{{.}}{{else}}EMPTY{{end}}", "EMPTY", tVal, true},
{"with slice", "{{with .SI}}{{.}}{{else}}EMPTY{{end}}", "[3 4 5]", tVal, true},
{"with emptymap", "{{with .MSIEmpty}}{{.}}{{else}}EMPTY{{end}}", "EMPTY", tVal, true},
{"with map", "{{with .MSIone}}{{.}}{{else}}EMPTY{{end}}", "map[one:1]", tVal, true},
{"with empty interface, struct field", "{{with .Empty4}}{{.V}}{{end}}", "UinEmpty", tVal, true},
{"with $x int", "{{with $x := .I}}{{$x}}{{end}}", "17", tVal, true},
{"with $x struct.U.V", "{{with $x := $}}{{$x.U.V}}{{end}}", "v", tVal, true},
{"with variable and action", "{{with $x := $}}{{$y := $.U.V}}{{$y}}{{end}}", "v", tVal, true},
{"with on typed nil interface value", "{{with .NonEmptyInterfaceTypedNil}}TRUE{{ end }}", "", tVal, true},
// Range.
{"range []int", "{{range .SI}}-{{.}}-{{end}}", "-3--4--5-", tVal, true},
{"range empty no else", "{{range .SIEmpty}}-{{.}}-{{end}}", "", tVal, true},
{"range []int else", "{{range .SI}}-{{.}}-{{else}}EMPTY{{end}}", "-3--4--5-", tVal, true},
{"range empty else", "{{range .SIEmpty}}-{{.}}-{{else}}EMPTY{{end}}", "EMPTY", tVal, true},
{"range []int break else", "{{range .SI}}-{{.}}-{{break}}NOTREACHED{{else}}EMPTY{{end}}", "-3-", tVal, true},
{"range []int continue else", "{{range .SI}}-{{.}}-{{continue}}NOTREACHED{{else}}EMPTY{{end}}", "-3--4--5-", tVal, true},
{"range []bool", "{{range .SB}}-{{.}}-{{end}}", "-true--false-", tVal, true},
{"range []int method", "{{range .SI | .MAdd .I}}-{{.}}-{{end}}", "-20--21--22-", tVal, true},
{"range map", "{{range .MSI}}-{{.}}-{{end}}", "-1--3--2-", tVal, true},
{"range empty map no else", "{{range .MSIEmpty}}-{{.}}-{{end}}", "", tVal, true},
{"range map else", "{{range .MSI}}-{{.}}-{{else}}EMPTY{{end}}", "-1--3--2-", tVal, true},
{"range empty map else", "{{range .MSIEmpty}}-{{.}}-{{else}}EMPTY{{end}}", "EMPTY", tVal, true},
{"range empty interface", "{{range .Empty3}}-{{.}}-{{else}}EMPTY{{end}}", "-7--8-", tVal, true},
{"range empty nil", "{{range .Empty0}}-{{.}}-{{end}}", "", tVal, true},
{"range $x SI", "{{range $x := .SI}}<{{$x}}>{{end}}", "<3><4><5>", tVal, true},
{"range $x $y SI", "{{range $x, $y := .SI}}<{{$x}}={{$y}}>{{end}}", "<0=3><1=4><2=5>", tVal, true},
{"range $x MSIone", "{{range $x := .MSIone}}<{{$x}}>{{end}}", "<1>", tVal, true},
{"range $x $y MSIone", "{{range $x, $y := .MSIone}}<{{$x}}={{$y}}>{{end}}", "<one=1>", tVal, true},
{"range $x PSI", "{{range $x := .PSI}}<{{$x}}>{{end}}", "<21><22><23>", tVal, true},
{"declare in range", "{{range $x := .PSI}}<{{$foo:=$x}}{{$x}}>{{end}}", "<21><22><23>", tVal, true},
{"range count", `{{range $i, $x := count 5}}[{{$i}}]{{$x}}{{end}}`, "[0]a[1]b[2]c[3]d[4]e", tVal, true},
{"range nil count", `{{range $i, $x := count 0}}{{else}}empty{{end}}`, "empty", tVal, true},
// Cute examples.
{"or as if true", `{{or .SI "slice is empty"}}`, "[3 4 5]", tVal, true},
{"or as if false", `{{or .SIEmpty "slice is empty"}}`, "slice is empty", tVal, true},
// Error handling.
{"error method, error", "{{.MyError true}}", "", tVal, false},
{"error method, no error", "{{.MyError false}}", "false", tVal, true},
// Numbers
{"decimal", "{{print 1234}}", "1234", tVal, true},
{"decimal _", "{{print 12_34}}", "1234", tVal, true},
{"binary", "{{print 0b101}}", "5", tVal, true},
{"binary _", "{{print 0b_1_0_1}}", "5", tVal, true},
{"BINARY", "{{print 0B101}}", "5", tVal, true},
{"octal0", "{{print 0377}}", "255", tVal, true},
{"octal", "{{print 0o377}}", "255", tVal, true},
{"octal _", "{{print 0o_3_7_7}}", "255", tVal, true},
{"OCTAL", "{{print 0O377}}", "255", tVal, true},
{"hex", "{{print 0x123}}", "291", tVal, true},
{"hex _", "{{print 0x1_23}}", "291", tVal, true},
{"HEX", "{{print 0X123ABC}}", "1194684", tVal, true},
{"float", "{{print 123.4}}", "123.4", tVal, true},
{"float _", "{{print 0_0_1_2_3.4}}", "123.4", tVal, true},
{"hex float", "{{print +0x1.ep+2}}", "7.5", tVal, true},
{"hex float _", "{{print +0x_1.e_0p+0_2}}", "7.5", tVal, true},
{"HEX float", "{{print +0X1.EP+2}}", "7.5", tVal, true},
{"print multi", "{{print 1_2_3_4 7.5_00_00_00}}", "1234 7.5", tVal, true},
{"print multi2", "{{print 1234 0x0_1.e_0p+02}}", "1234 7.5", tVal, true},
// Fixed bugs.
// Must separate dot and receiver; otherwise args are evaluated with dot set to variable.
{"bug0", "{{range .MSIone}}{{if $.Method1 .}}X{{end}}{{end}}", "X", tVal, true},
// Do not loop endlessly in indirect for non-empty interfaces.
// The bug appears with *interface only; looped forever.
{"bug1", "{{.Method0}}", "M0", &iVal, true},
// Was taking address of interface field, so method set was empty.
{"bug2", "{{$.NonEmptyInterface.Method0}}", "M0", tVal, true},
// Struct values were not legal in with - mere oversight.
{"bug3", "{{with $}}{{.Method0}}{{end}}", "M0", tVal, true},
// Nil interface values in if.
{"bug4", "{{if .Empty0}}non-nil{{else}}nil{{end}}", "nil", tVal, true},
// Stringer.
{"bug5", "{{.Str}}", "foozle", tVal, true},
{"bug5a", "{{.Err}}", "erroozle", tVal, true},
// Args need to be indirected and dereferenced sometimes.
{"bug6a", "{{vfunc .V0 .V1}}", "vfunc", tVal, true},
{"bug6b", "{{vfunc .V0 .V0}}", "vfunc", tVal, true},
{"bug6c", "{{vfunc .V1 .V0}}", "vfunc", tVal, true},
{"bug6d", "{{vfunc .V1 .V1}}", "vfunc", tVal, true},
// Legal parse but illegal execution: non-function should have no arguments.
{"bug7a", "{{3 2}}", "", tVal, false},
{"bug7b", "{{$x := 1}}{{$x 2}}", "", tVal, false},
{"bug7c", "{{$x := 1}}{{3 | $x}}", "", tVal, false},
// Pipelined arg was not being type-checked.
{"bug8a", "{{3|oneArg}}", "", tVal, false},
{"bug8b", "{{4|dddArg 3}}", "", tVal, false},
// A bug was introduced that broke map lookups for lower-case names.
{"bug9", "{{.cause}}", "neglect", map[string]string{"cause": "neglect"}, true},
// Field chain starting with function did not work.
{"bug10", "{{mapOfThree.three}}-{{(mapOfThree).three}}", "3-3", 0, true},
// Dereferencing nil pointer while evaluating function arguments should not panic. Issue 7333.
{"bug11", "{{valueString .PS}}", "", T{}, false},
// 0xef gave constant type float64. Issue 8622.
{"bug12xe", "{{printf `%T` 0xef}}", "int", T{}, true},
{"bug12xE", "{{printf `%T` 0xEE}}", "int", T{}, true},
{"bug12Xe", "{{printf `%T` 0Xef}}", "int", T{}, true},
{"bug12XE", "{{printf `%T` 0XEE}}", "int", T{}, true},
// Chained nodes did not work as arguments. Issue 8473.
{"bug13", "{{print (.Copy).I}}", "17", tVal, true},
// Didn't protect against nil or literal values in field chains.
{"bug14a", "{{(nil).True}}", "", tVal, false},
{"bug14b", "{{$x := nil}}{{$x.anything}}", "", tVal, false},
{"bug14c", `{{$x := (1.0)}}{{$y := ("hello")}}{{$x.anything}}{{$y.true}}`, "", tVal, false},
// Didn't call validateType on function results. Issue 10800.
{"bug15", "{{valueString returnInt}}", "", tVal, false},
// Variadic function corner cases. Issue 10946.
{"bug16a", "{{true|printf}}", "", tVal, false},
{"bug16b", "{{1|printf}}", "", tVal, false},
{"bug16c", "{{1.1|printf}}", "", tVal, false},
{"bug16d", "{{'x'|printf}}", "", tVal, false},
{"bug16e", "{{0i|printf}}", "", tVal, false},
{"bug16f", "{{true|twoArgs \"xxx\"}}", "", tVal, false},
{"bug16g", "{{\"aaa\" |twoArgs \"bbb\"}}", "twoArgs=bbbaaa", tVal, true},
{"bug16h", "{{1|oneArg}}", "", tVal, false},
{"bug16i", "{{\"aaa\"|oneArg}}", "oneArg=aaa", tVal, true},
{"bug16j", "{{1+2i|printf \"%v\"}}", "(1+2i)", tVal, true},
{"bug16k", "{{\"aaa\"|printf }}", "aaa", tVal, true},
{"bug17a", "{{.NonEmptyInterface.X}}", "x", tVal, true},
{"bug17b", "-{{.NonEmptyInterface.Method1 1234}}-", "-1234-", tVal, true},
{"bug17c", "{{len .NonEmptyInterfacePtS}}", "2", tVal, true},
{"bug17d", "{{index .NonEmptyInterfacePtS 0}}", "a", tVal, true},
{"bug17e", "{{range .NonEmptyInterfacePtS}}-{{.}}-{{end}}", "-a--b-", tVal, true},
// More variadic function corner cases. Some runes would get evaluated
// as constant floats instead of ints. Issue 34483.
{"bug18a", "{{eq . '.'}}", "true", '.', true},
{"bug18b", "{{eq . 'e'}}", "true", 'e', true},
{"bug18c", "{{eq . 'P'}}", "true", 'P', true},
{"issue56490", "{{$i := 0}}{{$x := 0}}{{range $i = .AI}}{{end}}{{$i}}", "5", tVal, true},
}
func zeroArgs() string {
return "zeroArgs"
}
func oneArg(a string) string {
return "oneArg=" + a
}
func twoArgs(a, b string) string {
return "twoArgs=" + a + b
}
func dddArg(a int, b ...string) string {
return fmt.Sprintln(a, b)
}
// count returns a channel that will deliver n sequential 1-letter strings starting at "a"
func count(n int) chan string {
if n == 0 {
return nil
}
c := make(chan string)
go func() {
for i := 0; i < n; i++ {
c <- "abcdefghijklmnop"[i : i+1]
}
close(c)
}()
return c
}
// vfunc takes a *V and a V
func vfunc(V, *V) string {
return "vfunc"
}
// valueString takes a string, not a pointer.
func valueString(v string) string {
return "value is ignored"
}
// returnInt returns an int
func returnInt() int {
return 7
}
func add(args ...int) int {
sum := 0
for _, x := range args {
sum += x
}
return sum
}
func echo(arg any) any {
return arg
}
func makemap(arg ...string) map[string]string {
if len(arg)%2 != 0 {
panic("bad makemap")
}
m := make(map[string]string)
for i := 0; i < len(arg); i += 2 {
m[arg[i]] = arg[i+1]
}
return m
}
func stringer(s fmt.Stringer) string {
return s.String()
}
func mapOfThree() any {
return map[string]int{"three": 3}
}
func testExecute(execTests []execTest, template *Template, t *testing.T) {
b := new(strings.Builder)
funcs := FuncMap{
"add": add,
"count": count,
"dddArg": dddArg,
"die": func() bool { panic("die") },
"echo": echo,
"makemap": makemap,
"mapOfThree": mapOfThree,
"oneArg": oneArg,
"returnInt": returnInt,
"stringer": stringer,
"twoArgs": twoArgs,
"typeOf": typeOf,
"valueString": valueString,
"vfunc": vfunc,
"zeroArgs": zeroArgs,
}
for _, test := range execTests {
var tmpl *Template
var err error
if template == nil {
tmpl, err = New(test.name).Funcs(funcs).Parse(test.input)
} else {
tmpl, err = template.New(test.name).Funcs(funcs).Parse(test.input)
}
if err != nil {
t.Errorf("%s: parse error: %s", test.name, err)
continue
}
b.Reset()
err = tmpl.Execute(b, test.data)
switch {
case !test.ok && err == nil:
t.Errorf("%s: expected error; got none", test.name)
continue
case test.ok && err != nil:
t.Errorf("%s: unexpected execute error: %s", test.name, err)
continue
case !test.ok && err != nil:
// expected error, got one
if *debug {
fmt.Printf("%s: %s\n\t%s\n", test.name, test.input, err)
}
}
result := b.String()
if result != test.output {
t.Errorf("%s: expected\n\t%q\ngot\n\t%q", test.name, test.output, result)
}
}
}
func TestExecute(t *testing.T) {
testExecute(execTests, nil, t)
}
var delimPairs = []string{
"", "", // default
"{{", "}}", // same as default
"<<", ">>", // distinct
"|", "|", // same
"(日)", "(本)", // peculiar
}
func TestDelims(t *testing.T) {
const hello = "Hello, world"
var value = struct{ Str string }{hello}
for i := 0; i < len(delimPairs); i += 2 {
text := ".Str"
left := delimPairs[i+0]
trueLeft := left
right := delimPairs[i+1]
trueRight := right
if left == "" { // default case
trueLeft = "{{"
}
if right == "" { // default case
trueRight = "}}"
}
text = trueLeft + text + trueRight
// Now add a comment
text += trueLeft + "/*comment*/" + trueRight
// Now add an action containing a string.
text += trueLeft + `"` + trueLeft + `"` + trueRight
// At this point text looks like `{{.Str}}{{/*comment*/}}{{"{{"}}`.
tmpl, err := New("delims").Delims(left, right).Parse(text)
if err != nil {
t.Fatalf("delim %q text %q parse err %s", left, text, err)
}
var b = new(strings.Builder)
err = tmpl.Execute(b, value)
if err != nil {
t.Fatalf("delim %q exec err %s", left, err)
}
if b.String() != hello+trueLeft {
t.Errorf("expected %q got %q", hello+trueLeft, b.String())
}
}
}
// Check that an error from a method flows back to the top.
func TestExecuteError(t *testing.T) {
b := new(bytes.Buffer)
tmpl := New("error")
_, err := tmpl.Parse("{{.MyError true}}")
if err != nil {
t.Fatalf("parse error: %s", err)
}
err = tmpl.Execute(b, tVal)
if err == nil {
t.Errorf("expected error; got none")
} else if !strings.Contains(err.Error(), myError.Error()) {
if *debug {
fmt.Printf("test execute error: %s\n", err)
}
t.Errorf("expected myError; got %s", err)
}
}
const execErrorText = `line 1
line 2
line 3
{{template "one" .}}
{{define "one"}}{{template "two" .}}{{end}}
{{define "two"}}{{template "three" .}}{{end}}
{{define "three"}}{{index "hi" $}}{{end}}`
// Check that an error from a nested template contains all the relevant information.
func TestExecError(t *testing.T) {
tmpl, err := New("top").Parse(execErrorText)
if err != nil {
t.Fatal("parse error:", err)
}
var b bytes.Buffer
err = tmpl.Execute(&b, 5) // 5 is out of range indexing "hi"
if err == nil {
t.Fatal("expected error")
}
const want = `template: top:7:20: executing "three" at <index "hi" $>: error calling index: index out of range: 5`
got := err.Error()
if got != want {
t.Errorf("expected\n%q\ngot\n%q", want, got)
}
}
type CustomError struct{}
func (*CustomError) Error() string { return "heyo !" }
// Check that a custom error can be returned.
func TestExecError_CustomError(t *testing.T) {
failingFunc := func() (string, error) {
return "", &CustomError{}
}
tmpl := Must(New("top").Funcs(FuncMap{
"err": failingFunc,
}).Parse("{{ err }}"))
var b bytes.Buffer
err := tmpl.Execute(&b, nil)
var e *CustomError
if !errors.As(err, &e) {
t.Fatalf("expected custom error; got %s", err)
}
}
func TestJSEscaping(t *testing.T) {
testCases := []struct {
in, exp string
}{
{`a`, `a`},
{`'foo`, `\'foo`},
{`Go "jump" \`, `Go \"jump\" \\`},
{`Yukihiro says "今日は世界"`, `Yukihiro says \"今日は世界\"`},
{"unprintable \uFDFF", `unprintable \uFDFF`},
{`<html>`, `\u003Chtml\u003E`},
{`no = in attributes`, `no \u003D in attributes`},
{`&#x27; does not become HTML entity`, `\u0026#x27; does not become HTML entity`},
}
for _, tc := range testCases {
s := JSEscapeString(tc.in)
if s != tc.exp {
t.Errorf("JS escaping [%s] got [%s] want [%s]", tc.in, s, tc.exp)
}
}
}
// A nice example: walk a binary tree.
type Tree struct {
Val int
Left, Right *Tree
}
// Use different delimiters to test Set.Delims.
// Also test the trimming of leading and trailing spaces.
const treeTemplate = `
(- define "tree" -)
[
(- .Val -)
(- with .Left -)
(template "tree" . -)
(- end -)
(- with .Right -)
(- template "tree" . -)
(- end -)
]
(- end -)
`
func TestTree(t *testing.T) {
var tree = &Tree{
1,
&Tree{
2, &Tree{
3,
&Tree{
4, nil, nil,
},
nil,
},
&Tree{
5,
&Tree{
6, nil, nil,
},
nil,
},
},
&Tree{
7,
&Tree{
8,
&Tree{
9, nil, nil,
},
nil,
},
&Tree{
10,
&Tree{
11, nil, nil,
},
nil,
},
},
}
tmpl, err := New("root").Delims("(", ")").Parse(treeTemplate)
if err != nil {
t.Fatal("parse error:", err)
}
var b strings.Builder
const expect = "[1[2[3[4]][5[6]]][7[8[9]][10[11]]]]"
// First by looking up the template.
err = tmpl.Lookup("tree").Execute(&b, tree)
if err != nil {
t.Fatal("exec error:", err)
}
result := b.String()
if result != expect {
t.Errorf("expected %q got %q", expect, result)
}
// Then direct to execution.
b.Reset()
err = tmpl.ExecuteTemplate(&b, "tree", tree)
if err != nil {
t.Fatal("exec error:", err)
}
result = b.String()
if result != expect {
t.Errorf("expected %q got %q", expect, result)
}
}
func TestExecuteOnNewTemplate(t *testing.T) {
// This is issue 3872.
New("Name").Templates()
// This is issue 11379.
new(Template).Templates()
new(Template).Parse("")
new(Template).New("abc").Parse("")
new(Template).Execute(nil, nil) // returns an error (but does not crash)
new(Template).ExecuteTemplate(nil, "XXX", nil) // returns an error (but does not crash)
}
const testTemplates = `{{define "one"}}one{{end}}{{define "two"}}two{{end}}`
func TestMessageForExecuteEmpty(t *testing.T) {
// Test a truly empty template.
tmpl := New("empty")
var b bytes.Buffer
err := tmpl.Execute(&b, 0)
if err == nil {
t.Fatal("expected initial error")
}
got := err.Error()
want := `template: empty: "empty" is an incomplete or empty template`
if got != want {
t.Errorf("expected error %s got %s", want, got)
}
// Add a non-empty template to check that the error is helpful.
tests, err := New("").Parse(testTemplates)
if err != nil {
t.Fatal(err)
}
tmpl.AddParseTree("secondary", tests.Tree)
err = tmpl.Execute(&b, 0)
if err == nil {
t.Fatal("expected second error")
}
got = err.Error()
want = `template: empty: "empty" is an incomplete or empty template`
if got != want {
t.Errorf("expected error %s got %s", want, got)
}
// Make sure we can execute the secondary.
err = tmpl.ExecuteTemplate(&b, "secondary", 0)
if err != nil {
t.Fatal(err)
}
}
func TestFinalForPrintf(t *testing.T) {
tmpl, err := New("").Parse(`{{"x" | printf}}`)
if err != nil {
t.Fatal(err)
}
var b bytes.Buffer
err = tmpl.Execute(&b, 0)
if err != nil {
t.Fatal(err)
}
}
type cmpTest struct {
expr string
truth string
ok bool
}
var cmpTests = []cmpTest{
{"eq true true", "true", true},
{"eq true false", "false", true},
{"eq 1+2i 1+2i", "true", true},
{"eq 1+2i 1+3i", "false", true},
{"eq 1.5 1.5", "true", true},
{"eq 1.5 2.5", "false", true},
{"eq 1 1", "true", true},
{"eq 1 2", "false", true},
{"eq `xy` `xy`", "true", true},
{"eq `xy` `xyz`", "false", true},
{"eq .Uthree .Uthree", "true", true},
{"eq .Uthree .Ufour", "false", true},
{"eq 3 4 5 6 3", "true", true},
{"eq 3 4 5 6 7", "false", true},
{"ne true true", "false", true},
{"ne true false", "true", true},
{"ne 1+2i 1+2i", "false", true},
{"ne 1+2i 1+3i", "true", true},
{"ne 1.5 1.5", "false", true},
{"ne 1.5 2.5", "true", true},
{"ne 1 1", "false", true},
{"ne 1 2", "true", true},
{"ne `xy` `xy`", "false", true},
{"ne `xy` `xyz`", "true", true},
{"ne .Uthree .Uthree", "false", true},
{"ne .Uthree .Ufour", "true", true},
{"lt 1.5 1.5", "false", true},
{"lt 1.5 2.5", "true", true},
{"lt 1 1", "false", true},
{"lt 1 2", "true", true},
{"lt `xy` `xy`", "false", true},
{"lt `xy` `xyz`", "true", true},
{"lt .Uthree .Uthree", "false", true},
{"lt .Uthree .Ufour", "true", true},
{"le 1.5 1.5", "true", true},
{"le 1.5 2.5", "true", true},
{"le 2.5 1.5", "false", true},
{"le 1 1", "true", true},
{"le 1 2", "true", true},
{"le 2 1", "false", true},
{"le `xy` `xy`", "true", true},
{"le `xy` `xyz`", "true", true},
{"le `xyz` `xy`", "false", true},
{"le .Uthree .Uthree", "true", true},
{"le .Uthree .Ufour", "true", true},
{"le .Ufour .Uthree", "false", true},
{"gt 1.5 1.5", "false", true},
{"gt 1.5 2.5", "false", true},
{"gt 1 1", "false", true},
{"gt 2 1", "true", true},
{"gt 1 2", "false", true},
{"gt `xy` `xy`", "false", true},
{"gt `xy` `xyz`", "false", true},
{"gt .Uthree .Uthree", "false", true},
{"gt .Uthree .Ufour", "false", true},
{"gt .Ufour .Uthree", "true", true},
{"ge 1.5 1.5", "true", true},
{"ge 1.5 2.5", "false", true},
{"ge 2.5 1.5", "true", true},
{"ge 1 1", "true", true},
{"ge 1 2", "false", true},
{"ge 2 1", "true", true},
{"ge `xy` `xy`", "true", true},
{"ge `xy` `xyz`", "false", true},
{"ge `xyz` `xy`", "true", true},
{"ge .Uthree .Uthree", "true", true},
{"ge .Uthree .Ufour", "false", true},
{"ge .Ufour .Uthree", "true", true},
// Mixing signed and unsigned integers.
{"eq .Uthree .Three", "true", true},
{"eq .Three .Uthree", "true", true},
{"le .Uthree .Three", "true", true},
{"le .Three .Uthree", "true", true},
{"ge .Uthree .Three", "true", true},
{"ge .Three .Uthree", "true", true},
{"lt .Uthree .Three", "false", true},
{"lt .Three .Uthree", "false", true},
{"gt .Uthree .Three", "false", true},
{"gt .Three .Uthree", "false", true},
{"eq .Ufour .Three", "false", true},
{"lt .Ufour .Three", "false", true},
{"gt .Ufour .Three", "true", true},
{"eq .NegOne .Uthree", "false", true},
{"eq .Uthree .NegOne", "false", true},
{"ne .NegOne .Uthree", "true", true},
{"ne .Uthree .NegOne", "true", true},
{"lt .NegOne .Uthree", "true", true},
{"lt .Uthree .NegOne", "false", true},
{"le .NegOne .Uthree", "true", true},
{"le .Uthree .NegOne", "false", true},
{"gt .NegOne .Uthree", "false", true},
{"gt .Uthree .NegOne", "true", true},
{"ge .NegOne .Uthree", "false", true},
{"ge .Uthree .NegOne", "true", true},
{"eq (index `x` 0) 'x'", "true", true}, // The example that triggered this rule.
{"eq (index `x` 0) 'y'", "false", true},
{"eq .V1 .V2", "true", true},
{"eq .Ptr .Ptr", "true", true},
{"eq .Ptr .NilPtr", "false", true},
{"eq .NilPtr .NilPtr", "true", true},
{"eq .Iface1 .Iface1", "true", true},
{"eq .Iface1 .NilIface", "false", true},
{"eq .NilIface .NilIface", "true", true},
{"eq .NilIface .Iface1", "false", true},
{"eq .NilIface 0", "false", true},
{"eq 0 .NilIface", "false", true},
{"eq .Map .Map", "true", true}, // Uncomparable types but nil is OK.
{"eq .Map nil", "true", true}, // Uncomparable types but nil is OK.
{"eq nil .Map", "true", true}, // Uncomparable types but nil is OK.
{"eq .Map .NonNilMap", "false", true}, // Uncomparable types but nil is OK.
// Errors
{"eq `xy` 1", "", false}, // Different types.
{"eq 2 2.0", "", false}, // Different types.
{"lt true true", "", false}, // Unordered types.
{"lt 1+0i 1+0i", "", false}, // Unordered types.
{"eq .Ptr 1", "", false}, // Incompatible types.
{"eq .Ptr .NegOne", "", false}, // Incompatible types.
{"eq .Map .V1", "", false}, // Uncomparable types.
{"eq .NonNilMap .NonNilMap", "", false}, // Uncomparable types.
}
func TestComparison(t *testing.T) {
b := new(strings.Builder)
var cmpStruct = struct {
Uthree, Ufour uint
NegOne, Three int
Ptr, NilPtr *int
NonNilMap map[int]int
Map map[int]int
V1, V2 V
Iface1, NilIface fmt.Stringer
}{
Uthree: 3,
Ufour: 4,
NegOne: -1,
Three: 3,
Ptr: new(int),
NonNilMap: make(map[int]int),
Iface1: b,
}
for _, test := range cmpTests {
text := fmt.Sprintf("{{if %s}}true{{else}}false{{end}}", test.expr)
tmpl, err := New("empty").Parse(text)
if err != nil {
t.Fatalf("%q: %s", test.expr, err)
}
b.Reset()
err = tmpl.Execute(b, &cmpStruct)
if test.ok && err != nil {
t.Errorf("%s errored incorrectly: %s", test.expr, err)
continue
}
if !test.ok && err == nil {
t.Errorf("%s did not error", test.expr)
continue
}
if b.String() != test.truth {
t.Errorf("%s: want %s; got %s", test.expr, test.truth, b.String())
}
}
}
func TestMissingMapKey(t *testing.T) {
data := map[string]int{
"x": 99,
}
tmpl, err := New("t1").Parse("{{.x}} {{.y}}")
if err != nil {
t.Fatal(err)
}
var b strings.Builder
// By default, just get "<no value>"
err = tmpl.Execute(&b, data)
if err != nil {
t.Fatal(err)
}
want := "99 <no value>"
got := b.String()
if got != want {
t.Errorf("got %q; expected %q", got, want)
}
// Same if we set the option explicitly to the default.
tmpl.Option("missingkey=default")
b.Reset()
err = tmpl.Execute(&b, data)
if err != nil {
t.Fatal("default:", err)
}
want = "99 <no value>"
got = b.String()
if got != want {
t.Errorf("got %q; expected %q", got, want)
}
// Next we ask for a zero value
tmpl.Option("missingkey=zero")
b.Reset()
err = tmpl.Execute(&b, data)
if err != nil {
t.Fatal("zero:", err)
}
want = "99 0"
got = b.String()
if got != want {
t.Errorf("got %q; expected %q", got, want)
}
// Now we ask for an error.
tmpl.Option("missingkey=error")
err = tmpl.Execute(&b, data)
if err == nil {
t.Errorf("expected error; got none")
}
// same Option, but now a nil interface: ask for an error
err = tmpl.Execute(&b, nil)
t.Log(err)
if err == nil {
t.Errorf("expected error for nil-interface; got none")
}
}
// Test that the error message for multiline unterminated string
// refers to the line number of the opening quote.
func TestUnterminatedStringError(t *testing.T) {
_, err := New("X").Parse("hello\n\n{{`unterminated\n\n\n\n}}\n some more\n\n")
if err == nil {
t.Fatal("expected error")
}
str := err.Error()
if !strings.Contains(str, "X:3: unterminated raw quoted string") {
t.Fatalf("unexpected error: %s", str)
}
}
const alwaysErrorText = "always be failing"
var alwaysError = errors.New(alwaysErrorText)
type ErrorWriter int
func (e ErrorWriter) Write(p []byte) (int, error) {
return 0, alwaysError
}
func TestExecuteGivesExecError(t *testing.T) {
// First, a non-execution error shouldn't be an ExecError.
tmpl, err := New("X").Parse("hello")
if err != nil {
t.Fatal(err)
}
err = tmpl.Execute(ErrorWriter(0), 0)
if err == nil {
t.Fatal("expected error; got none")
}
if err.Error() != alwaysErrorText {
t.Errorf("expected %q error; got %q", alwaysErrorText, err)
}
// This one should be an ExecError.
tmpl, err = New("X").Parse("hello, {{.X.Y}}")
if err != nil {
t.Fatal(err)
}
err = tmpl.Execute(io.Discard, 0)
if err == nil {
t.Fatal("expected error; got none")
}
eerr, ok := err.(ExecError)
if !ok {
t.Fatalf("did not expect ExecError %s", eerr)
}
expect := "field X in type int"
if !strings.Contains(err.Error(), expect) {
t.Errorf("expected %q; got %q", expect, err)
}
}
func funcNameTestFunc() int {
return 0
}
func TestGoodFuncNames(t *testing.T) {
names := []string{
"_",
"a",
"a1",
"a1",
"Ӵ",
}
for _, name := range names {
tmpl := New("X").Funcs(
FuncMap{
name: funcNameTestFunc,
},
)
if tmpl == nil {
t.Fatalf("nil result for %q", name)
}
}
}
func TestBadFuncNames(t *testing.T) {
names := []string{
"",
"2",
"a-b",
}
for _, name := range names {
testBadFuncName(name, t)
}
}
func testBadFuncName(name string, t *testing.T) {
t.Helper()
defer func() {
recover()
}()
New("X").Funcs(
FuncMap{
name: funcNameTestFunc,
},
)
// If we get here, the name did not cause a panic, which is how Funcs
// reports an error.
t.Errorf("%q succeeded incorrectly as function name", name)
}
func TestBlock(t *testing.T) {
const (
input = `a({{block "inner" .}}bar({{.}})baz{{end}})b`
want = `a(bar(hello)baz)b`
overlay = `{{define "inner"}}foo({{.}})bar{{end}}`
want2 = `a(foo(goodbye)bar)b`
)
tmpl, err := New("outer").Parse(input)
if err != nil {
t.Fatal(err)
}
tmpl2, err := Must(tmpl.Clone()).Parse(overlay)
if err != nil {
t.Fatal(err)
}
var buf strings.Builder
if err := tmpl.Execute(&buf, "hello"); err != nil {
t.Fatal(err)
}
if got := buf.String(); got != want {
t.Errorf("got %q, want %q", got, want)
}
buf.Reset()
if err := tmpl2.Execute(&buf, "goodbye"); err != nil {
t.Fatal(err)
}
if got := buf.String(); got != want2 {
t.Errorf("got %q, want %q", got, want2)
}
}
func TestEvalFieldErrors(t *testing.T) {
tests := []struct {
name, src string
value any
want string
}{
{
// Check that calling an invalid field on nil pointer
// prints a field error instead of a distracting nil
// pointer error. https://golang.org/issue/15125
"MissingFieldOnNil",
"{{.MissingField}}",
(*T)(nil),
"can't evaluate field MissingField in type *template.T",
},
{
"MissingFieldOnNonNil",
"{{.MissingField}}",
&T{},
"can't evaluate field MissingField in type *template.T",
},
{
"ExistingFieldOnNil",
"{{.X}}",
(*T)(nil),
"nil pointer evaluating *template.T.X",
},
{
"MissingKeyOnNilMap",
"{{.MissingKey}}",
(*map[string]string)(nil),
"nil pointer evaluating *map[string]string.MissingKey",
},
{
"MissingKeyOnNilMapPtr",
"{{.MissingKey}}",
(*map[string]string)(nil),
"nil pointer evaluating *map[string]string.MissingKey",
},
{
"MissingKeyOnMapPtrToNil",
"{{.MissingKey}}",
&map[string]string{},
"<nil>",
},
}
for _, tc := range tests {
t.Run(tc.name, func(t *testing.T) {
tmpl := Must(New("tmpl").Parse(tc.src))
err := tmpl.Execute(io.Discard, tc.value)
got := "<nil>"
if err != nil {
got = err.Error()
}
if !strings.HasSuffix(got, tc.want) {
t.Fatalf("got error %q, want %q", got, tc.want)
}
})
}
}
func TestMaxExecDepth(t *testing.T) {
if testing.Short() {
t.Skip("skipping in -short mode")
}
tmpl := Must(New("tmpl").Parse(`{{template "tmpl" .}}`))
err := tmpl.Execute(io.Discard, nil)
got := "<nil>"
if err != nil {
got = err.Error()
}
const want = "exceeded maximum template depth"
if !strings.Contains(got, want) {
t.Errorf("got error %q; want %q", got, want)
}
}
func TestAddrOfIndex(t *testing.T) {
// golang.org/issue/14916.
// Before index worked on reflect.Values, the .String could not be
// found on the (incorrectly unaddressable) V value,
// in contrast to range, which worked fine.
// Also testing that passing a reflect.Value to tmpl.Execute works.
texts := []string{
`{{range .}}{{.String}}{{end}}`,
`{{with index . 0}}{{.String}}{{end}}`,
}
for _, text := range texts {
tmpl := Must(New("tmpl").Parse(text))
var buf strings.Builder
err := tmpl.Execute(&buf, reflect.ValueOf([]V{{1}}))
if err != nil {
t.Fatalf("%s: Execute: %v", text, err)
}
if buf.String() != "<1>" {
t.Fatalf("%s: template output = %q, want %q", text, &buf, "<1>")
}
}
}
func TestInterfaceValues(t *testing.T) {
// golang.org/issue/17714.
// Before index worked on reflect.Values, interface values
// were always implicitly promoted to the underlying value,
// except that nil interfaces were promoted to the zero reflect.Value.
// Eliminating a round trip to interface{} and back to reflect.Value
// eliminated this promotion, breaking these cases.
tests := []struct {
text string
out string
}{
{`{{index .Nil 1}}`, "ERROR: index of untyped nil"},
{`{{index .Slice 2}}`, "2"},
{`{{index .Slice .Two}}`, "2"},
{`{{call .Nil 1}}`, "ERROR: call of nil"},
{`{{call .PlusOne 1}}`, "2"},
{`{{call .PlusOne .One}}`, "2"},
{`{{and (index .Slice 0) true}}`, "0"},
{`{{and .Zero true}}`, "0"},
{`{{and (index .Slice 1) false}}`, "false"},
{`{{and .One false}}`, "false"},
{`{{or (index .Slice 0) false}}`, "false"},
{`{{or .Zero false}}`, "false"},
{`{{or (index .Slice 1) true}}`, "1"},
{`{{or .One true}}`, "1"},
{`{{not (index .Slice 0)}}`, "true"},
{`{{not .Zero}}`, "true"},
{`{{not (index .Slice 1)}}`, "false"},
{`{{not .One}}`, "false"},
{`{{eq (index .Slice 0) .Zero}}`, "true"},
{`{{eq (index .Slice 1) .One}}`, "true"},
{`{{ne (index .Slice 0) .Zero}}`, "false"},
{`{{ne (index .Slice 1) .One}}`, "false"},
{`{{ge (index .Slice 0) .One}}`, "false"},
{`{{ge (index .Slice 1) .Zero}}`, "true"},
{`{{gt (index .Slice 0) .One}}`, "false"},
{`{{gt (index .Slice 1) .Zero}}`, "true"},
{`{{le (index .Slice 0) .One}}`, "true"},
{`{{le (index .Slice 1) .Zero}}`, "false"},
{`{{lt (index .Slice 0) .One}}`, "true"},
{`{{lt (index .Slice 1) .Zero}}`, "false"},
}
for _, tt := range tests {
tmpl := Must(New("tmpl").Parse(tt.text))
var buf strings.Builder
err := tmpl.Execute(&buf, map[string]any{
"PlusOne": func(n int) int {
return n + 1
},
"Slice": []int{0, 1, 2, 3},
"One": 1,
"Two": 2,
"Nil": nil,
"Zero": 0,
})
if strings.HasPrefix(tt.out, "ERROR:") {
e := strings.TrimSpace(strings.TrimPrefix(tt.out, "ERROR:"))
if err == nil || !strings.Contains(err.Error(), e) {
t.Errorf("%s: Execute: %v, want error %q", tt.text, err, e)
}
continue
}
if err != nil {
t.Errorf("%s: Execute: %v", tt.text, err)
continue
}
if buf.String() != tt.out {
t.Errorf("%s: template output = %q, want %q", tt.text, &buf, tt.out)
}
}
}
// Check that panics during calls are recovered and returned as errors.
func TestExecutePanicDuringCall(t *testing.T) {
funcs := map[string]any{
"doPanic": func() string {
panic("custom panic string")
},
}
tests := []struct {
name string
input string
data any
wantErr string
}{
{
"direct func call panics",
"{{doPanic}}", (*T)(nil),
`template: t:1:2: executing "t" at <doPanic>: error calling doPanic: custom panic string`,
},
{
"indirect func call panics",
"{{call doPanic}}", (*T)(nil),
`template: t:1:7: executing "t" at <doPanic>: error calling doPanic: custom panic string`,
},
{
"direct method call panics",
"{{.GetU}}", (*T)(nil),
`template: t:1:2: executing "t" at <.GetU>: error calling GetU: runtime error: invalid memory address or nil pointer dereference`,
},
{
"indirect method call panics",
"{{call .GetU}}", (*T)(nil),
`template: t:1:7: executing "t" at <.GetU>: error calling GetU: runtime error: invalid memory address or nil pointer dereference`,
},
{
"func field call panics",
"{{call .PanicFunc}}", tVal,
`template: t:1:2: executing "t" at <call .PanicFunc>: error calling call: test panic`,
},
{
"method call on nil interface",
"{{.NonEmptyInterfaceNil.Method0}}", tVal,
`template: t:1:23: executing "t" at <.NonEmptyInterfaceNil.Method0>: nil pointer evaluating template.I.Method0`,
},
}
for _, tc := range tests {
b := new(bytes.Buffer)
tmpl, err := New("t").Funcs(funcs).Parse(tc.input)
if err != nil {
t.Fatalf("parse error: %s", err)
}
err = tmpl.Execute(b, tc.data)
if err == nil {
t.Errorf("%s: expected error; got none", tc.name)
} else if !strings.Contains(err.Error(), tc.wantErr) {
if *debug {
fmt.Printf("%s: test execute error: %s\n", tc.name, err)
}
t.Errorf("%s: expected error:\n%s\ngot:\n%s", tc.name, tc.wantErr, err)
}
}
}
// Issue 31810. Check that a parenthesized first argument behaves properly.
func TestIssue31810(t *testing.T) {
// A simple value with no arguments is fine.
var b strings.Builder
const text = "{{ (.) }}"
tmpl, err := New("").Parse(text)
if err != nil {
t.Error(err)
}
err = tmpl.Execute(&b, "result")
if err != nil {
t.Error(err)
}
if b.String() != "result" {
t.Errorf("%s got %q, expected %q", text, b.String(), "result")
}
// Even a plain function fails - need to use call.
f := func() string { return "result" }
b.Reset()
err = tmpl.Execute(&b, f)
if err == nil {
t.Error("expected error with no call, got none")
}
// Works if the function is explicitly called.
const textCall = "{{ (call .) }}"
tmpl, err = New("").Parse(textCall)
b.Reset()
err = tmpl.Execute(&b, f)
if err != nil {
t.Error(err)
}
if b.String() != "result" {
t.Errorf("%s got %q, expected %q", textCall, b.String(), "result")
}
}
// Issue 43065, range over send only channel
func TestIssue43065(t *testing.T) {
var b bytes.Buffer
tmp := Must(New("").Parse(`{{range .}}{{end}}`))
ch := make(chan<- int)
err := tmp.Execute(&b, ch)
if err == nil {
t.Error("expected err got nil")
} else if !strings.Contains(err.Error(), "range over send-only channel") {
t.Errorf("%s", err)
}
}
// Issue 39807: data race in html/template & text/template
func TestIssue39807(t *testing.T) {
var wg sync.WaitGroup
tplFoo, err := New("foo").Parse(`{{ template "bar" . }}`)
if err != nil {
t.Error(err)
}
tplBar, err := New("bar").Parse("bar")
if err != nil {
t.Error(err)
}
gofuncs := 10
numTemplates := 10
for i := 1; i <= gofuncs; i++ {
wg.Add(1)
go func() {
defer wg.Done()
for j := 0; j < numTemplates; j++ {
_, err := tplFoo.AddParseTree(tplBar.Name(), tplBar.Tree)
if err != nil {
t.Error(err)
}
err = tplFoo.Execute(io.Discard, nil)
if err != nil {
t.Error(err)
}
}
}()
}
wg.Wait()
}
// Issue 48215: embedded nil pointer causes panic.
// Fixed by adding FieldByIndexErr to the reflect package.
func TestIssue48215(t *testing.T) {
type A struct {
S string
}
type B struct {
*A
}
tmpl, err := New("").Parse(`{{ .S }}`)
if err != nil {
t.Fatal(err)
}
err = tmpl.Execute(io.Discard, B{})
// We expect an error, not a panic.
if err == nil {
t.Fatal("did not get error for nil embedded struct")
}
if !strings.Contains(err.Error(), "reflect: indirection through nil pointer to embedded struct field A") {
t.Fatal(err)
}
}