src/html/template/clone_test.go

// 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"
	"io/ioutil"
	"testing"
	"text/template/parse"
)

func TestAddParseTree(t *testing.T) {
	root := Must(New("root").Parse(`{{define "a"}} {{.}} {{template "b"}} {{.}} "></a>{{end}}`))
	tree, err := parse.Parse("t", `{{define "b"}}<a href="{{end}}`, "", "", nil, nil)
	if err != nil {
		t.Fatal(err)
	}
	added := Must(root.AddParseTree("b", tree["b"]))
	b := new(bytes.Buffer)
	err = added.ExecuteTemplate(b, "a", "1>0")
	if err != nil {
		t.Fatal(err)
	}
	if got, want := b.String(), ` 1&gt;0 <a href=" 1%3e0 "></a>`; got != want {
		t.Errorf("got %q want %q", got, want)
	}
}

func TestClone(t *testing.T) {
	// The {{.}} will be executed with data "<i>*/" in different contexts.
	// In the t0 template, it will be in a text context.
	// In the t1 template, it will be in a URL context.
	// In the t2 template, it will be in a JavaScript context.
	// In the t3 template, it will be in a CSS context.
	const tmpl = `{{define "a"}}{{template "lhs"}}{{.}}{{template "rhs"}}{{end}}`
	b := new(bytes.Buffer)

	// Create an incomplete template t0.
	t0 := Must(New("t0").Parse(tmpl))

	// Clone t0 as t1.
	t1 := Must(t0.Clone())
	Must(t1.Parse(`{{define "lhs"}} <a href=" {{end}}`))
	Must(t1.Parse(`{{define "rhs"}} "></a> {{end}}`))

	// Execute t1.
	b.Reset()
	if err := t1.ExecuteTemplate(b, "a", "<i>*/"); err != nil {
		t.Fatal(err)
	}
	if got, want := b.String(), ` <a href=" %3ci%3e*/ "></a> `; got != want {
		t.Errorf("t1: got %q want %q", got, want)
	}

	// Clone t0 as t2.
	t2 := Must(t0.Clone())
	Must(t2.Parse(`{{define "lhs"}} <p onclick="javascript: {{end}}`))
	Must(t2.Parse(`{{define "rhs"}} "></p> {{end}}`))

	// Execute t2.
	b.Reset()
	if err := t2.ExecuteTemplate(b, "a", "<i>*/"); err != nil {
		t.Fatal(err)
	}
	if got, want := b.String(), ` <p onclick="javascript: &#34;\u003ci\u003e*/&#34; "></p> `; got != want {
		t.Errorf("t2: got %q want %q", got, want)
	}

	// Clone t0 as t3, but do not execute t3 yet.
	t3 := Must(t0.Clone())
	Must(t3.Parse(`{{define "lhs"}} <style> {{end}}`))
	Must(t3.Parse(`{{define "rhs"}} </style> {{end}}`))

	// Complete t0.
	Must(t0.Parse(`{{define "lhs"}} ( {{end}}`))
	Must(t0.Parse(`{{define "rhs"}} ) {{end}}`))

	// Clone t0 as t4. Redefining the "lhs" template should fail.
	t4 := Must(t0.Clone())
	if _, err := t4.Parse(`{{define "lhs"}} FAIL {{end}}`); err == nil {
		t.Error(`redefine "lhs": got nil err want non-nil`)
	}

	// Execute t0.
	b.Reset()
	if err := t0.ExecuteTemplate(b, "a", "<i>*/"); err != nil {
		t.Fatal(err)
	}
	if got, want := b.String(), ` ( &lt;i&gt;*/ ) `; got != want {
		t.Errorf("t0: got %q want %q", got, want)
	}

	// Clone t0. This should fail, as t0 has already executed.
	if _, err := t0.Clone(); err == nil {
		t.Error(`t0.Clone(): got nil err want non-nil`)
	}

	// Similarly, cloning sub-templates should fail.
	if _, err := t0.Lookup("a").Clone(); err == nil {
		t.Error(`t0.Lookup("a").Clone(): got nil err want non-nil`)
	}
	if _, err := t0.Lookup("lhs").Clone(); err == nil {
		t.Error(`t0.Lookup("lhs").Clone(): got nil err want non-nil`)
	}

	// Execute t3.
	b.Reset()
	if err := t3.ExecuteTemplate(b, "a", "<i>*/"); err != nil {
		t.Fatal(err)
	}
	if got, want := b.String(), ` <style> ZgotmplZ </style> `; got != want {
		t.Errorf("t3: got %q want %q", got, want)
	}
}

func TestTemplates(t *testing.T) {
	names := []string{"t0", "a", "lhs", "rhs"}
	// Some template definitions borrowed from TestClone.
	const tmpl = `
		{{define "a"}}{{template "lhs"}}{{.}}{{template "rhs"}}{{end}}
		{{define "lhs"}} <a href=" {{end}}
		{{define "rhs"}} "></a> {{end}}`
	t0 := Must(New("t0").Parse(tmpl))
	templates := t0.Templates()
	if len(templates) != len(names) {
		t.Errorf("expected %d templates; got %d", len(names), len(templates))
	}
	for _, name := range names {
		found := false
		for _, tmpl := range templates {
			if name == tmpl.text.Name() {
				found = true
				break
			}
		}
		if !found {
			t.Error("could not find template", name)
		}
	}
}

// This used to crash; http://golang.org/issue/3281
func TestCloneCrash(t *testing.T) {
	t1 := New("all")
	Must(t1.New("t1").Parse(`{{define "foo"}}foo{{end}}`))
	t1.Clone()
}

// Ensure that this guarantee from the docs is upheld:
// "Further calls to Parse in the copy will add templates
// to the copy but not to the original."
func TestCloneThenParse(t *testing.T) {
	t0 := Must(New("t0").Parse(`{{define "a"}}{{template "embedded"}}{{end}}`))
	t1 := Must(t0.Clone())
	Must(t1.Parse(`{{define "embedded"}}t1{{end}}`))
	if len(t0.Templates())+1 != len(t1.Templates()) {
		t.Error("adding a template to a clone added it to the original")
	}
	// double check that the embedded template isn't available in the original
	err := t0.ExecuteTemplate(ioutil.Discard, "a", nil)
	if err == nil {
		t.Error("expected 'no such template' error")
	}
}

// https://code.google.com/p/go/issues/detail?id=5980
func TestFuncMapWorksAfterClone(t *testing.T) {
	funcs := FuncMap{"customFunc": func() (string, error) {
		return "", errors.New("issue5980")
	}}

	// get the expected error output (no clone)
	uncloned := Must(New("").Funcs(funcs).Parse("{{customFunc}}"))
	wantErr := uncloned.Execute(ioutil.Discard, nil)

	// toClone must be the same as uncloned. It has to be recreated from scratch,
	// since cloning cannot occur after execution.
	toClone := Must(New("").Funcs(funcs).Parse("{{customFunc}}"))
	cloned := Must(toClone.Clone())
	gotErr := cloned.Execute(ioutil.Discard, nil)

	if wantErr.Error() != gotErr.Error() {
		t.Errorf("clone error message mismatch want %q got %q", wantErr, gotErr)
	}
}