Source file src/html/template/clone_test.go

Documentation: html/template

		 1  // Copyright 2011 The Go Authors. All rights reserved.
		 2  // Use of this source code is governed by a BSD-style
		 3  // license that can be found in the LICENSE file.
		 4  
		 5  package template
		 6  
		 7  import (
		 8  	"bytes"
		 9  	"errors"
		10  	"fmt"
		11  	"io"
		12  	"strings"
		13  	"sync"
		14  	"testing"
		15  	"text/template/parse"
		16  )
		17  
		18  func TestAddParseTreeHTML(t *testing.T) {
		19  	root := Must(New("root").Parse(`{{define "a"}} {{.}} {{template "b"}} {{.}} "></a>{{end}}`))
		20  	tree, err := parse.Parse("t", `{{define "b"}}<a href="{{end}}`, "", "", nil, nil)
		21  	if err != nil {
		22  		t.Fatal(err)
		23  	}
		24  	added := Must(root.AddParseTree("b", tree["b"]))
		25  	b := new(bytes.Buffer)
		26  	err = added.ExecuteTemplate(b, "a", "1>0")
		27  	if err != nil {
		28  		t.Fatal(err)
		29  	}
		30  	if got, want := b.String(), ` 1&gt;0 <a href=" 1%3e0 "></a>`; got != want {
		31  		t.Errorf("got %q want %q", got, want)
		32  	}
		33  }
		34  
		35  func TestClone(t *testing.T) {
		36  	// The {{.}} will be executed with data "<i>*/" in different contexts.
		37  	// In the t0 template, it will be in a text context.
		38  	// In the t1 template, it will be in a URL context.
		39  	// In the t2 template, it will be in a JavaScript context.
		40  	// In the t3 template, it will be in a CSS context.
		41  	const tmpl = `{{define "a"}}{{template "lhs"}}{{.}}{{template "rhs"}}{{end}}`
		42  	b := new(bytes.Buffer)
		43  
		44  	// Create an incomplete template t0.
		45  	t0 := Must(New("t0").Parse(tmpl))
		46  
		47  	// Clone t0 as t1.
		48  	t1 := Must(t0.Clone())
		49  	Must(t1.Parse(`{{define "lhs"}} <a href=" {{end}}`))
		50  	Must(t1.Parse(`{{define "rhs"}} "></a> {{end}}`))
		51  
		52  	// Execute t1.
		53  	b.Reset()
		54  	if err := t1.ExecuteTemplate(b, "a", "<i>*/"); err != nil {
		55  		t.Fatal(err)
		56  	}
		57  	if got, want := b.String(), ` <a href=" %3ci%3e*/ "></a> `; got != want {
		58  		t.Errorf("t1: got %q want %q", got, want)
		59  	}
		60  
		61  	// Clone t0 as t2.
		62  	t2 := Must(t0.Clone())
		63  	Must(t2.Parse(`{{define "lhs"}} <p onclick="javascript: {{end}}`))
		64  	Must(t2.Parse(`{{define "rhs"}} "></p> {{end}}`))
		65  
		66  	// Execute t2.
		67  	b.Reset()
		68  	if err := t2.ExecuteTemplate(b, "a", "<i>*/"); err != nil {
		69  		t.Fatal(err)
		70  	}
		71  	if got, want := b.String(), ` <p onclick="javascript: &#34;\u003ci\u003e*/&#34; "></p> `; got != want {
		72  		t.Errorf("t2: got %q want %q", got, want)
		73  	}
		74  
		75  	// Clone t0 as t3, but do not execute t3 yet.
		76  	t3 := Must(t0.Clone())
		77  	Must(t3.Parse(`{{define "lhs"}} <style> {{end}}`))
		78  	Must(t3.Parse(`{{define "rhs"}} </style> {{end}}`))
		79  
		80  	// Complete t0.
		81  	Must(t0.Parse(`{{define "lhs"}} ( {{end}}`))
		82  	Must(t0.Parse(`{{define "rhs"}} ) {{end}}`))
		83  
		84  	// Clone t0 as t4. Redefining the "lhs" template should not fail.
		85  	t4 := Must(t0.Clone())
		86  	if _, err := t4.Parse(`{{define "lhs"}} OK {{end}}`); err != nil {
		87  		t.Errorf(`redefine "lhs": got err %v want nil`, err)
		88  	}
		89  	// Cloning t1 should fail as it has been executed.
		90  	if _, err := t1.Clone(); err == nil {
		91  		t.Error("cloning t1: got nil err want non-nil")
		92  	}
		93  	// Redefining the "lhs" template in t1 should fail as it has been executed.
		94  	if _, err := t1.Parse(`{{define "lhs"}} OK {{end}}`); err == nil {
		95  		t.Error(`redefine "lhs": got nil err want non-nil`)
		96  	}
		97  
		98  	// Execute t0.
		99  	b.Reset()
	 100  	if err := t0.ExecuteTemplate(b, "a", "<i>*/"); err != nil {
	 101  		t.Fatal(err)
	 102  	}
	 103  	if got, want := b.String(), ` ( &lt;i&gt;*/ ) `; got != want {
	 104  		t.Errorf("t0: got %q want %q", got, want)
	 105  	}
	 106  
	 107  	// Clone t0. This should fail, as t0 has already executed.
	 108  	if _, err := t0.Clone(); err == nil {
	 109  		t.Error(`t0.Clone(): got nil err want non-nil`)
	 110  	}
	 111  
	 112  	// Similarly, cloning sub-templates should fail.
	 113  	if _, err := t0.Lookup("a").Clone(); err == nil {
	 114  		t.Error(`t0.Lookup("a").Clone(): got nil err want non-nil`)
	 115  	}
	 116  	if _, err := t0.Lookup("lhs").Clone(); err == nil {
	 117  		t.Error(`t0.Lookup("lhs").Clone(): got nil err want non-nil`)
	 118  	}
	 119  
	 120  	// Execute t3.
	 121  	b.Reset()
	 122  	if err := t3.ExecuteTemplate(b, "a", "<i>*/"); err != nil {
	 123  		t.Fatal(err)
	 124  	}
	 125  	if got, want := b.String(), ` <style> ZgotmplZ </style> `; got != want {
	 126  		t.Errorf("t3: got %q want %q", got, want)
	 127  	}
	 128  }
	 129  
	 130  func TestTemplates(t *testing.T) {
	 131  	names := []string{"t0", "a", "lhs", "rhs"}
	 132  	// Some template definitions borrowed from TestClone.
	 133  	const tmpl = `
	 134  		{{define "a"}}{{template "lhs"}}{{.}}{{template "rhs"}}{{end}}
	 135  		{{define "lhs"}} <a href=" {{end}}
	 136  		{{define "rhs"}} "></a> {{end}}`
	 137  	t0 := Must(New("t0").Parse(tmpl))
	 138  	templates := t0.Templates()
	 139  	if len(templates) != len(names) {
	 140  		t.Errorf("expected %d templates; got %d", len(names), len(templates))
	 141  	}
	 142  	for _, name := range names {
	 143  		found := false
	 144  		for _, tmpl := range templates {
	 145  			if name == tmpl.text.Name() {
	 146  				found = true
	 147  				break
	 148  			}
	 149  		}
	 150  		if !found {
	 151  			t.Error("could not find template", name)
	 152  		}
	 153  	}
	 154  }
	 155  
	 156  // This used to crash; https://golang.org/issue/3281
	 157  func TestCloneCrash(t *testing.T) {
	 158  	t1 := New("all")
	 159  	Must(t1.New("t1").Parse(`{{define "foo"}}foo{{end}}`))
	 160  	t1.Clone()
	 161  }
	 162  
	 163  // Ensure that this guarantee from the docs is upheld:
	 164  // "Further calls to Parse in the copy will add templates
	 165  // to the copy but not to the original."
	 166  func TestCloneThenParse(t *testing.T) {
	 167  	t0 := Must(New("t0").Parse(`{{define "a"}}{{template "embedded"}}{{end}}`))
	 168  	t1 := Must(t0.Clone())
	 169  	Must(t1.Parse(`{{define "embedded"}}t1{{end}}`))
	 170  	if len(t0.Templates())+1 != len(t1.Templates()) {
	 171  		t.Error("adding a template to a clone added it to the original")
	 172  	}
	 173  	// double check that the embedded template isn't available in the original
	 174  	err := t0.ExecuteTemplate(io.Discard, "a", nil)
	 175  	if err == nil {
	 176  		t.Error("expected 'no such template' error")
	 177  	}
	 178  }
	 179  
	 180  // https://golang.org/issue/5980
	 181  func TestFuncMapWorksAfterClone(t *testing.T) {
	 182  	funcs := FuncMap{"customFunc": func() (string, error) {
	 183  		return "", errors.New("issue5980")
	 184  	}}
	 185  
	 186  	// get the expected error output (no clone)
	 187  	uncloned := Must(New("").Funcs(funcs).Parse("{{customFunc}}"))
	 188  	wantErr := uncloned.Execute(io.Discard, nil)
	 189  
	 190  	// toClone must be the same as uncloned. It has to be recreated from scratch,
	 191  	// since cloning cannot occur after execution.
	 192  	toClone := Must(New("").Funcs(funcs).Parse("{{customFunc}}"))
	 193  	cloned := Must(toClone.Clone())
	 194  	gotErr := cloned.Execute(io.Discard, nil)
	 195  
	 196  	if wantErr.Error() != gotErr.Error() {
	 197  		t.Errorf("clone error message mismatch want %q got %q", wantErr, gotErr)
	 198  	}
	 199  }
	 200  
	 201  // https://golang.org/issue/16101
	 202  func TestTemplateCloneExecuteRace(t *testing.T) {
	 203  	const (
	 204  		input	 = `<title>{{block "a" .}}a{{end}}</title><body>{{block "b" .}}b{{end}}<body>`
	 205  		overlay = `{{define "b"}}A{{end}}`
	 206  	)
	 207  	outer := Must(New("outer").Parse(input))
	 208  	tmpl := Must(Must(outer.Clone()).Parse(overlay))
	 209  
	 210  	var wg sync.WaitGroup
	 211  	for i := 0; i < 10; i++ {
	 212  		wg.Add(1)
	 213  		go func() {
	 214  			defer wg.Done()
	 215  			for i := 0; i < 100; i++ {
	 216  				if err := tmpl.Execute(io.Discard, "data"); err != nil {
	 217  					panic(err)
	 218  				}
	 219  			}
	 220  		}()
	 221  	}
	 222  	wg.Wait()
	 223  }
	 224  
	 225  func TestTemplateCloneLookup(t *testing.T) {
	 226  	// Template.escape makes an assumption that the template associated
	 227  	// with t.Name() is t. Check that this holds.
	 228  	tmpl := Must(New("x").Parse("a"))
	 229  	tmpl = Must(tmpl.Clone())
	 230  	if tmpl.Lookup(tmpl.Name()) != tmpl {
	 231  		t.Error("after Clone, tmpl.Lookup(tmpl.Name()) != tmpl")
	 232  	}
	 233  }
	 234  
	 235  func TestCloneGrowth(t *testing.T) {
	 236  	tmpl := Must(New("root").Parse(`<title>{{block "B". }}Arg{{end}}</title>`))
	 237  	tmpl = Must(tmpl.Clone())
	 238  	Must(tmpl.Parse(`{{define "B"}}Text{{end}}`))
	 239  	for i := 0; i < 10; i++ {
	 240  		tmpl.Execute(io.Discard, nil)
	 241  	}
	 242  	if len(tmpl.DefinedTemplates()) > 200 {
	 243  		t.Fatalf("too many templates: %v", len(tmpl.DefinedTemplates()))
	 244  	}
	 245  }
	 246  
	 247  // https://golang.org/issue/17735
	 248  func TestCloneRedefinedName(t *testing.T) {
	 249  	const base = `
	 250  {{ define "a" -}}<title>{{ template "b" . -}}</title>{{ end -}}
	 251  {{ define "b" }}{{ end -}}
	 252  `
	 253  	const page = `{{ template "a" . }}`
	 254  
	 255  	t1 := Must(New("a").Parse(base))
	 256  
	 257  	for i := 0; i < 2; i++ {
	 258  		t2 := Must(t1.Clone())
	 259  		t2 = Must(t2.New(fmt.Sprintf("%d", i)).Parse(page))
	 260  		err := t2.Execute(io.Discard, nil)
	 261  		if err != nil {
	 262  			t.Fatal(err)
	 263  		}
	 264  	}
	 265  }
	 266  
	 267  // Issue 24791.
	 268  func TestClonePipe(t *testing.T) {
	 269  	a := Must(New("a").Parse(`{{define "a"}}{{range $v := .A}}{{$v}}{{end}}{{end}}`))
	 270  	data := struct{ A []string }{A: []string{"hi"}}
	 271  	b := Must(a.Clone())
	 272  	var buf strings.Builder
	 273  	if err := b.Execute(&buf, &data); err != nil {
	 274  		t.Fatal(err)
	 275  	}
	 276  	if got, want := buf.String(), "hi"; got != want {
	 277  		t.Errorf("got %q want %q", got, want)
	 278  	}
	 279  }
	 280  

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