internal/godoc/dochtml/dochtml_test.go - pkgsite - Git at Google

 // Copyright 2019 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 dochtml

 import (
 	"bytes"
 	"context"
 	"go/ast"
 	"go/parser"
 	"go/token"
 	"io/ioutil"
 	"path/filepath"
 	"strings"
 	"testing"

 	"github.com/google/go-cmp/cmp"
 	"github.com/google/go-cmp/cmp/cmpopts"
 	"github.com/google/safehtml/template"
 	"golang.org/x/net/html"
 	"golang.org/x/pkgsite/internal/godoc/dochtml/internal/render"
 	"golang.org/x/pkgsite/internal/godoc/internal/doc"
 	"golang.org/x/pkgsite/internal/testing/htmlcheck"
 )

 var templateSource = template.TrustedSourceFromConstant("../../../content/static/html/doc")

 var (
 	in           = htmlcheck.In
 	hasAttr      = htmlcheck.HasAttr
 	hasHref      = htmlcheck.HasHref
 	hasExactText = htmlcheck.HasExactText
 )

 func TestRender(t *testing.T) {
 	LoadTemplates(templateSource)
 	fset, d := mustLoadPackage("everydecl")

 	rawDoc, err := Render(context.Background(), fset, d, RenderOptions{
 		FileLinkFunc:   func(string) string { return "file" },
 		SourceLinkFunc: func(ast.Node) string { return "src" },
 	})
 	if err != nil {
 		t.Fatal(err)
 	}

 	htmlDoc, err := html.Parse(strings.NewReader(rawDoc.String()))
 	if err != nil {
 		t.Fatal(err)
 	}
 	// Check that there are no duplicate id attributes.
 	t.Run("duplicate ids", func(t *testing.T) {
 		testDuplicateIDs(t, htmlDoc)
 	})
 	t.Run("ids-and-kinds", func(t *testing.T) {
 		// Check that the id and data-kind labels are right.
 		testIDsAndKinds(t, htmlDoc)
 	})

 	checker := in(".Documentation-note",
 		in("h3", hasAttr("id", "pkg-note-BUG"), hasExactText("Bugs ¶")),
 		in("a", hasHref("#pkg-note-BUG")))
 	if err := checker(htmlDoc); err != nil {
 		t.Errorf("note check: %v", err)
 	}

 	checker = in(".Documentation-index",
 		in(".Documentation-indexNote", in("a", hasHref("#pkg-note-BUG"), hasExactText("Bugs"))))
 	if err := checker(htmlDoc); err != nil {
 		t.Errorf("note check: %v", err)
 	}

 	checker = in(".DocNav-notes",
 		in("#nav-group-notes", in("li", in("a", hasHref("#pkg-note-BUG"), hasExactText("Bugs")))))
 	if err := checker(htmlDoc); err != nil {
 		t.Errorf("note check: %v", err)
 	}

 	checker = in("#DocNavMobile-select",
 		in("optgroup[label=Notes]", in("option", hasAttr("value", "pkg-note-BUG"), hasExactText("Bugs"))))
 	if err := checker(htmlDoc); err != nil {
 		t.Errorf("note check: %v", err)
 	}
 }

 func TestRenderParts(t *testing.T) {
 	LoadTemplates(templateSource)
 	fset, d := mustLoadPackage("everydecl")

 	ctx := context.Background()
 	parts, err := RenderParts(ctx, fset, d, RenderOptions{
 		FileLinkFunc:   func(string) string { return "file" },
 		SourceLinkFunc: func(ast.Node) string { return "src" },
 	})
 	if err != nil {
 		t.Fatal(err)
 	}
 	bodyDoc, err := html.Parse(strings.NewReader(parts.Body.String()))
 	if err != nil {
 		t.Fatal(err)
 	}
 	sidenavDoc, err := html.Parse(strings.NewReader(parts.Outline.String()))
 	if err != nil {
 		t.Fatal(err)
 	}
 	mobileDoc, err := html.Parse(strings.NewReader(parts.MobileOutline.String()))
 	if err != nil {
 		t.Fatal(err)
 	}
 	// Check that there are no duplicate id attributes.
 	t.Run("duplicate ids", func(t *testing.T) {
 		testDuplicateIDs(t, bodyDoc)
 	})
 	t.Run("ids-and-kinds", func(t *testing.T) {
 		// Check that the id and data-kind labels are right.
 		testIDsAndKinds(t, bodyDoc)
 	})

 	checker := in(".Documentation-note",
 		in("h3", hasAttr("id", "pkg-note-BUG"), hasExactText("Bugs ¶")),
 		in("a", hasHref("#pkg-note-BUG")))
 	if err := checker(bodyDoc); err != nil {
 		t.Errorf("note check: %v", err)
 	}

 	checker = in(".Documentation-index",
 		in(".Documentation-indexNote", in("a", hasHref("#pkg-note-BUG"), hasExactText("Bugs"))))
 	if err := checker(bodyDoc); err != nil {
 		t.Errorf("note check: %v", err)
 	}

 	checker = in(".DocNav-notes",
 		in("#nav-group-notes", in("li", in("a", hasHref("#pkg-note-BUG"), hasExactText("Bugs")))))
 	if err := checker(sidenavDoc); err != nil {
 		t.Errorf("note check: %v", err)
 	}

 	checker = in("#DocNavMobile-select",
 		in("optgroup[label=Notes]", in("option", hasAttr("value", "pkg-note-BUG"), hasExactText("Bugs"))))
 	if err := checker(mobileDoc); err != nil {
 		t.Errorf("note check: %v", err)
 	}

 	wantLinks := []render.Link{
 		{Href: "https://go.googlesource.com/pkgsite", Text: "pkgsite repo"},
 		{Href: "https://play-with-go.dev", Text: "Play with Go"},
 	}
 	if diff := cmp.Diff(wantLinks, parts.Links); diff != "" {
 		t.Errorf("links mismatch (-want, +got):\n%s", diff)
 	}
 }

 func TestExampleRender(t *testing.T) {
 	LoadTemplates(templateSource)
 	ctx := context.Background()
 	fset, d := mustLoadPackage("example_test")

 	rawDoc, err := Render(ctx, fset, d, RenderOptions{
 		FileLinkFunc:   func(string) string { return "file" },
 		SourceLinkFunc: func(ast.Node) string { return "src" },
 	})
 	if err != nil {
 		t.Fatal(err)
 	}

 	htmlDoc, err := html.Parse(strings.NewReader(rawDoc.String()))
 	if err != nil {
 		t.Fatal(err)
 	}

 	got := make(map[string]string)
 	walk(htmlDoc, func(n *html.Node) {
 		if attr(n, "class") == "Documentation-exampleDetails js-exampleContainer" {
 			var b bytes.Buffer
 			err := html.Render(&b, n)
 			if err != nil {
 				t.Fatal(err)
 			}
 			got[attr(n, "id")] = b.String()
 		}
 	})

 	for _, test := range []struct {
 		name   string
 		htmlID string
 		want   string
 	}{
 		{
 			name:   "Non executable example (no play buttons)",
 			htmlID: "example-package-AppRunNoAction",
 			want: `<details tabindex="-1" id="example-package-AppRunNoAction" class="Documentation-exampleDetails js-exampleContainer">
 <summary class="Documentation-exampleDetailsHeader">Example (AppRunNoAction) <a href="#example-package-AppRunNoAction">¶</a></summary>
 <div class="Documentation-exampleDetailsBody">
 <p>non-executable example taken from <a href="https://github.com/urfave/cli/blob/master/app_test.go#L184">https://github.com/urfave/cli/blob/master/app_test.go#L184</a>
 </p>
 <p>Code:</p>

 <pre class="Documentation-exampleCode"><span class="comment">// example comment</span>
 app := App{}
 app.Name = &#34;greet&#34;
 _ = app.Run([]string{&#34;greet&#34;})
 </pre>

 <pre class="Documentation-exampleOutput">NAME:
    greet - A new cli application

 USAGE:
    greet [global options] command [command options] [arguments...]

 COMMANDS:
    help, h  Shows a list of commands or help for one command

 GLOBAL OPTIONS:
    --help, -h  show help (default: false)
 </pre>
 </div>
 </details>`,
 		},
 		{
 			name:   "Executable examples (with play buttons)",
 			htmlID: "example-package-StringsCompare",
 			want: `<details tabindex="-1" id="example-package-StringsCompare" class="Documentation-exampleDetails js-exampleContainer">
 <summary class="Documentation-exampleDetailsHeader">Example (StringsCompare) <a href="#example-package-StringsCompare">¶</a></summary>
 <div class="Documentation-exampleDetailsBody">
 <p>executable example
 </p>
 <p>Code:</p>

 <pre class="Documentation-exampleCode">package main

 import (
 	&#34;fmt&#34;
 	&#34;strings&#34;
 )

 func main() {
 	<span class="comment">// example comment</span>
 	fmt.Println(strings.Compare(&#34;a&#34;, &#34;b&#34;))
 	fmt.Println(strings.Compare(&#34;a&#34;, &#34;a&#34;))
 	fmt.Println(strings.Compare(&#34;b&#34;, &#34;a&#34;))

 }
 </pre>

 <pre class="Documentation-exampleOutput">-1
 0
 1
 </pre>
 </div>
 <div class="Documentation-exampleButtonsContainer">
         <p class="Documentation-exampleError" role="alert" aria-atomic="true"></p>
         <button class="Documentation-examplePlayButton" aria-label="Play Code">Play</button>
       </div></details>`,
 		},
 	} {
 		t.Run(test.name, func(t *testing.T) {
 			diff := cmp.Diff(test.want, got[test.htmlID])
 			if diff != "" {
 				t.Errorf("mismatch (-want, +got):\n%s", diff)
 			}
 		})
 	}
 }

 func TestLinkHTML(t *testing.T) {
 	for _, test := range []struct {
 		name string
 		in   string
 		link string
 		want string
 	}{
 		{
 			name: "regular string and link are rendered",
 			in:   `escape.go`,
 			link: `https://golang.org/src/html/escape.go`,
 			want: `<a class="class" href="https://golang.org/src/html/escape.go">escape.go</a>`,
 		},
 		{
 			name: "name is escaped",
 			in:   `"File & name" <'file@name.com>`,
 			link: "",
 			want: `&#34;File &amp; name&#34; &lt;&#39;file@name.com&gt;`,
 		},
 		{
 			name: "link is escaped",
 			in:   "file.go",
 			link: `"abc@go's.com"`,
 			want: `<a class="class" href="%22abc@go%27s.com%22">file.go</a>`,
 		},
 		{
 			name: "file name and link are escaped",
 			in:   `"a's.com@/`,
 			link: `"x@go's.com"`,
 			want: `<a class="class" href="%22x@go%27s.com%22">&#34;a&#39;s.com@/</a>`,
 		},
 		{
 			name: "HTML injection escaped",
 			in:   `<a href="gfr.con"></a>`,
 			link: `"><script>bad</script>`,
 			want: `<a class="class" href="%22%3e%3cscript%3ebad%3c/script%3e">&lt;a href=&#34;gfr.con&#34;&gt;&lt;/a&gt;</a>`,
 		},
 	} {
 		t.Run(test.name, func(t *testing.T) {
 			got := linkHTML(test.in, test.link, "class")
 			diff := cmp.Diff(test.want, got.String())
 			if diff != "" {
 				t.Errorf("mismatch (-want, +got):\n%s", diff)
 			}
 		})
 	}
 }

 func TestVersionedPkgPath(t *testing.T) {
 	for _, test := range []struct {
 		name    string
 		pkgPath string
 		modInfo *ModuleInfo
 		want    string
 	}{
 		{
 			name:    "builtin package is not versioned",
 			pkgPath: "builtin",
 			modInfo: &ModuleInfo{
 				ModulePath:      "std",
 				ResolvedVersion: "v1.14.4",
 				ModulePackages:  map[string]bool{"std/builtin": true, "std/net/http": true},
 			},
 			want: "builtin",
 		},
 		{
 			name:    "std packages are not versioned",
 			pkgPath: "net/http",
 			modInfo: &ModuleInfo{
 				ModulePath:      "std",
 				ResolvedVersion: "v1.14.4",
 				ModulePackages:  map[string]bool{"std/builtin": true, "std/net/http": true},
 			},
 			want: "net/http",
 		},
 		{
 			name:    "imports from other modules are not versioned",
 			pkgPath: "golang.org/x/pkgsite",
 			modInfo: &ModuleInfo{
 				ModulePath:      "cloud.google.com/go",
 				ResolvedVersion: "v0.60.0",
 				ModulePackages:  map[string]bool{"cloud.google.com/go/civil": true},
 			},
 			want: "golang.org/x/pkgsite",
 		},
 		{
 			name:    "imports from other modules with shared prefixes are not versioned",
 			pkgPath: "golang.org/x/pkgsite",
 			modInfo: &ModuleInfo{
 				ModulePath:      "golang.org/x/time",
 				ResolvedVersion: "v1.2.3",
 				ModulePackages:  map[string]bool{"golang.org/x/time/rate": true},
 			},
 			want: "golang.org/x/pkgsite",
 		},
 		{
 			name:    "imports from same module are versioned",
 			pkgPath: "golang.org/x/pkgsite/internal/log",
 			modInfo: &ModuleInfo{
 				ModulePath:      "golang.org/x/pkgsite",
 				ResolvedVersion: "v1.1.2",
 				ModulePackages:  map[string]bool{"golang.org/x/pkgsite/internal/log": true},
 			},
 			want: "golang.org/x/pkgsite@v1.1.2/internal/log",
 		},
 		{
 			name:    "imports from same module with pseudo version are versioned",
 			pkgPath: "golang.org/x/pkgsite/internal/log",
 			modInfo: &ModuleInfo{
 				ModulePath:      "golang.org/x/pkgsite",
 				ResolvedVersion: "v0.0.0-20200709011933-a59b4ce778c4",
 				ModulePackages:  map[string]bool{"golang.org/x/pkgsite/internal/log": true},
 			},
 			want: "golang.org/x/pkgsite@v0.0.0-20200709011933-a59b4ce778c4/internal/log",
 		},
 		{
 			name:    "imports from same v2 module are versioned",
 			pkgPath: "k8s.io/klog/v2/klogr",
 			modInfo: &ModuleInfo{
 				ModulePath:      "k8s.io/klog/v2",
 				ResolvedVersion: "v2.3.0",
 				ModulePackages:  map[string]bool{"k8s.io/klog/v2": true, "k8s.io/klog/v2/klogr": true},
 			},
 			want: "k8s.io/klog/v2@v2.3.0/klogr",
 		},
 		{
 			name:    "imports from older major module version are not versioned",
 			pkgPath: "rsc.io/quote",
 			modInfo: &ModuleInfo{
 				ModulePath:      "rsc.io/quote/v3",
 				ResolvedVersion: "v3.1.0",
 				ModulePackages:  map[string]bool{"rsc.io/quote/v3": true},
 			},
 			want: "rsc.io/quote",
 		},
 		{
 			name:    "imports from newer major module version are not versioned",
 			pkgPath: "rsc.io/quote/v3",
 			modInfo: &ModuleInfo{
 				ModulePath:      "rsc.io/quote",
 				ResolvedVersion: "v1.5.3",
 				ModulePackages:  map[string]bool{"rsc.io/quote": true},
 			},
 			want: "rsc.io/quote/v3",
 		},
 		{
 			name:    "imports from nested module are not versioned",
 			pkgPath: "A/B/C/D",
 			modInfo: &ModuleInfo{
 				ModulePath:      "A",
 				ResolvedVersion: "v1.0.0",
 				ModulePackages:  map[string]bool{"A/B": true, "A/B/C": true},
 			},
 			want: "A/B/C/D",
 		},
 	} {
 		t.Run(test.name, func(t *testing.T) {
 			got := versionedPkgPath(test.pkgPath, test.modInfo)
 			if got != test.want {
 				t.Errorf("versionedPkgPath(%q) = %q, want %q", test.pkgPath, got, test.want)
 			}
 		})
 	}
 }

 func testDuplicateIDs(t *testing.T, htmlDoc *html.Node) {
 	idCounts := map[string]int{}
 	walk(htmlDoc, func(n *html.Node) {
 		id := attr(n, "id")
 		if id != "" {
 			idCounts[id]++
 		}
 	})
 	var dups []string
 	for id, n := range idCounts {
 		if n > 1 {
 			dups = append(dups, id)
 		}
 	}
 	if len(dups) > 0 {
 		t.Errorf("duplicate ids: %v", dups)
 	}
 }

 func testIDsAndKinds(t *testing.T, htmlDoc *html.Node) {
 	type attrs struct {
 		ID, Kind string // export fields for cmp
 	}

 	// want is a complete list of id, kind pairs we expect to see the HTML.
 	want := []attrs{
 		{"C", "constant"},
 		{"CT", "constant"},
 		{"F", "function"},
 		{"TF", "function"},
 		{"T.M", "method"},
 		{"V", "variable"},
 		{"VT", "variable"},
 		{"T", "type"},
 		{"S1", "type"},
 		{"S1.F", "field"},
 		{"S2", "type"},
 		{"S2.S1", "field"},
 		{"S2.G", "field"},
 		{"I1", "type"},
 		{"I1.M1", "method"},
 		{"I2", "type"},
 		{"I2.M2", "method"},
 	}

 	var got []attrs
 	walk(htmlDoc, func(n *html.Node) {
 		if kind := attr(n, "data-kind"); kind != "" {
 			got = append(got, attrs{attr(n, "id"), kind})
 		}
 	})

 	diff := cmp.Diff(want, got, cmpopts.SortSlices(func(a1, a2 attrs) bool {
 		return a1.ID < a2.ID
 	}))
 	if diff != "" {
 		t.Errorf("mismatch (-want, +got):\n%s", diff)
 	}
 }

 func walk(n *html.Node, f func(*html.Node)) {
 	f(n)
 	for c := n.FirstChild; c != nil; c = c.NextSibling {
 		walk(c, f)
 	}
 }

 func attr(n *html.Node, key string) string {
 	for _, a := range n.Attr {
 		if a.Key == key {
 			return a.Val
 		}
 	}
 	return ""
 }

 // Copied from internal/render/render_test.go, with the slight modification of returning the fset.
 func mustLoadPackage(path string) (*token.FileSet, *doc.Package) {
 	srcName := filepath.Base(path) + ".go"
 	code, err := ioutil.ReadFile(filepath.Join("testdata", srcName))
 	if err != nil {
 		panic(err)
 	}

 	fset := token.NewFileSet()
 	astFile, _ := parser.ParseFile(fset, srcName, code, parser.ParseComments)
 	files := []*ast.File{astFile}

 	astPackage, err := doc.NewFromFiles(fset, files, path, doc.AllDecls)
 	if err != nil {
 		panic(err)
 	}

 	return fset, astPackage
 }
	// Copyright 2019 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 dochtml

	import (
	"bytes"
	"context"
	"go/ast"
	"go/parser"
	"go/token"
	"io/ioutil"
	"path/filepath"
	"strings"
	"testing"

	"github.com/google/go-cmp/cmp"
	"github.com/google/go-cmp/cmp/cmpopts"
	"github.com/google/safehtml/template"
	"golang.org/x/net/html"
	"golang.org/x/pkgsite/internal/godoc/dochtml/internal/render"
	"golang.org/x/pkgsite/internal/godoc/internal/doc"
	"golang.org/x/pkgsite/internal/testing/htmlcheck"
	)

	var templateSource = template.TrustedSourceFromConstant("../../../content/static/html/doc")

	var (
	in = htmlcheck.In
	hasAttr = htmlcheck.HasAttr
	hasHref = htmlcheck.HasHref
	hasExactText = htmlcheck.HasExactText
	)

	func TestRender(t *testing.T) {
	LoadTemplates(templateSource)
	fset, d := mustLoadPackage("everydecl")

	rawDoc, err := Render(context.Background(), fset, d, RenderOptions{
	FileLinkFunc: func(string) string { return "file" },
	SourceLinkFunc: func(ast.Node) string { return "src" },
	})
	if err != nil {
	t.Fatal(err)
	}

	htmlDoc, err := html.Parse(strings.NewReader(rawDoc.String()))
	if err != nil {
	t.Fatal(err)
	}
	// Check that there are no duplicate id attributes.
	t.Run("duplicate ids", func(t *testing.T) {
	testDuplicateIDs(t, htmlDoc)
	})
	t.Run("ids-and-kinds", func(t *testing.T) {
	// Check that the id and data-kind labels are right.
	testIDsAndKinds(t, htmlDoc)
	})

	checker := in(".Documentation-note",
	in("h3", hasAttr("id", "pkg-note-BUG"), hasExactText("Bugs ¶")),
	in("a", hasHref("#pkg-note-BUG")))
	if err := checker(htmlDoc); err != nil {
	t.Errorf("note check: %v", err)
	}

	checker = in(".Documentation-index",
	in(".Documentation-indexNote", in("a", hasHref("#pkg-note-BUG"), hasExactText("Bugs"))))
	if err := checker(htmlDoc); err != nil {
	t.Errorf("note check: %v", err)
	}

	checker = in(".DocNav-notes",
	in("#nav-group-notes", in("li", in("a", hasHref("#pkg-note-BUG"), hasExactText("Bugs")))))
	if err := checker(htmlDoc); err != nil {
	t.Errorf("note check: %v", err)
	}

	checker = in("#DocNavMobile-select",
	in("optgroup[label=Notes]", in("option", hasAttr("value", "pkg-note-BUG"), hasExactText("Bugs"))))
	if err := checker(htmlDoc); err != nil {
	t.Errorf("note check: %v", err)
	}
	}

	func TestRenderParts(t *testing.T) {
	LoadTemplates(templateSource)
	fset, d := mustLoadPackage("everydecl")

	ctx := context.Background()
	parts, err := RenderParts(ctx, fset, d, RenderOptions{
	FileLinkFunc: func(string) string { return "file" },
	SourceLinkFunc: func(ast.Node) string { return "src" },
	})
	if err != nil {
	t.Fatal(err)
	}
	bodyDoc, err := html.Parse(strings.NewReader(parts.Body.String()))
	if err != nil {
	t.Fatal(err)
	}
	sidenavDoc, err := html.Parse(strings.NewReader(parts.Outline.String()))
	if err != nil {
	t.Fatal(err)
	}
	mobileDoc, err := html.Parse(strings.NewReader(parts.MobileOutline.String()))
	if err != nil {
	t.Fatal(err)
	}
	// Check that there are no duplicate id attributes.
	t.Run("duplicate ids", func(t *testing.T) {
	testDuplicateIDs(t, bodyDoc)
	})
	t.Run("ids-and-kinds", func(t *testing.T) {
	// Check that the id and data-kind labels are right.
	testIDsAndKinds(t, bodyDoc)
	})

	checker := in(".Documentation-note",
	in("h3", hasAttr("id", "pkg-note-BUG"), hasExactText("Bugs ¶")),
	in("a", hasHref("#pkg-note-BUG")))
	if err := checker(bodyDoc); err != nil {
	t.Errorf("note check: %v", err)
	}

	checker = in(".Documentation-index",
	in(".Documentation-indexNote", in("a", hasHref("#pkg-note-BUG"), hasExactText("Bugs"))))
	if err := checker(bodyDoc); err != nil {
	t.Errorf("note check: %v", err)
	}

	checker = in(".DocNav-notes",
	in("#nav-group-notes", in("li", in("a", hasHref("#pkg-note-BUG"), hasExactText("Bugs")))))
	if err := checker(sidenavDoc); err != nil {
	t.Errorf("note check: %v", err)
	}

	checker = in("#DocNavMobile-select",
	in("optgroup[label=Notes]", in("option", hasAttr("value", "pkg-note-BUG"), hasExactText("Bugs"))))
	if err := checker(mobileDoc); err != nil {
	t.Errorf("note check: %v", err)
	}

	wantLinks := []render.Link{
	{Href: "https://go.googlesource.com/pkgsite", Text: "pkgsite repo"},
	{Href: "https://play-with-go.dev", Text: "Play with Go"},
	}
	if diff := cmp.Diff(wantLinks, parts.Links); diff != "" {
	t.Errorf("links mismatch (-want, +got):\n%s", diff)
	}
	}

	func TestExampleRender(t *testing.T) {
	LoadTemplates(templateSource)
	ctx := context.Background()
	fset, d := mustLoadPackage("example_test")

	rawDoc, err := Render(ctx, fset, d, RenderOptions{
	FileLinkFunc: func(string) string { return "file" },
	SourceLinkFunc: func(ast.Node) string { return "src" },
	})
	if err != nil {
	t.Fatal(err)
	}

	htmlDoc, err := html.Parse(strings.NewReader(rawDoc.String()))
	if err != nil {
	t.Fatal(err)
	}

	got := make(map[string]string)
	walk(htmlDoc, func(n *html.Node) {
	if attr(n, "class") == "Documentation-exampleDetails js-exampleContainer" {
	var b bytes.Buffer
	err := html.Render(&b, n)
	if err != nil {
	t.Fatal(err)
	}
	got[attr(n, "id")] = b.String()
	}
	})

	for _, test := range []struct {
	name string
	htmlID string
	want string
	}{
	{
	name: "Non executable example (no play buttons)",
	htmlID: "example-package-AppRunNoAction",
	want: `<details tabindex="-1" id="example-package-AppRunNoAction" class="Documentation-exampleDetails js-exampleContainer">
	<summary class="Documentation-exampleDetailsHeader">Example (AppRunNoAction) <a href="#example-package-AppRunNoAction">¶</a></summary>
	<div class="Documentation-exampleDetailsBody">
	<p>non-executable example taken from <a href="https://github.com/urfave/cli/blob/master/app_test.go#L184">https://github.com/urfave/cli/blob/master/app_test.go#L184</a>
	</p>
	<p>Code:</p>

	<pre class="Documentation-exampleCode"><span class="comment">// example comment</span>
	app := App{}
	app.Name = "greet"
	_ = app.Run([]string{"greet"})
	</pre>

	<pre class="Documentation-exampleOutput">NAME:
	greet - A new cli application

	USAGE:
	greet [global options] command [command options] [arguments...]

	COMMANDS:
	help, h Shows a list of commands or help for one command

	GLOBAL OPTIONS:
	--help, -h show help (default: false)
	</pre>
	</div>
	</details>`,
	},
	{
	name: "Executable examples (with play buttons)",
	htmlID: "example-package-StringsCompare",
	want: `<details tabindex="-1" id="example-package-StringsCompare" class="Documentation-exampleDetails js-exampleContainer">
	<summary class="Documentation-exampleDetailsHeader">Example (StringsCompare) <a href="#example-package-StringsCompare">¶</a></summary>
	<div class="Documentation-exampleDetailsBody">
	<p>executable example
	</p>
	<p>Code:</p>

	<pre class="Documentation-exampleCode">package main

	import (
	"fmt"
	"strings"
	)

	func main() {
	<span class="comment">// example comment</span>
	fmt.Println(strings.Compare("a", "b"))
	fmt.Println(strings.Compare("a", "a"))
	fmt.Println(strings.Compare("b", "a"))

	}
	</pre>

	<pre class="Documentation-exampleOutput">-1
	0
	1
	</pre>
	</div>
	<div class="Documentation-exampleButtonsContainer">
	<p class="Documentation-exampleError" role="alert" aria-atomic="true"></p>
	<button class="Documentation-examplePlayButton" aria-label="Play Code">Play</button>
	</div></details>`,
	},
	} {
	t.Run(test.name, func(t *testing.T) {
	diff := cmp.Diff(test.want, got[test.htmlID])
	if diff != "" {
	t.Errorf("mismatch (-want, +got):\n%s", diff)
	}
	})
	}
	}

	func TestLinkHTML(t *testing.T) {
	for _, test := range []struct {
	name string
	in string
	link string
	want string
	}{
	{
	name: "regular string and link are rendered",
	in: `escape.go`,
	link: `https://golang.org/src/html/escape.go`,
	want: `<a class="class" href="https://golang.org/src/html/escape.go">escape.go</a>`,
	},
	{
	name: "name is escaped",
	in: `"File & name" <'file@name.com>`,
	link: "",
	want: `"File & name" <'file@name.com>`,
	},
	{
	name: "link is escaped",
	in: "file.go",
	link: `"abc@go's.com"`,
	want: `<a class="class" href="%22abc@go%27s.com%22">file.go</a>`,
	},
	{
	name: "file name and link are escaped",
	in: `"a's.com@/`,
	link: `"x@go's.com"`,
	want: `<a class="class" href="%22x@go%27s.com%22">"a's.com@/</a>`,
	},
	{
	name: "HTML injection escaped",
	in: `<a href="gfr.con"></a>`,
	link: `"><script>bad</script>`,
	want: `<a class="class" href="%22%3e%3cscript%3ebad%3c/script%3e"><a href="gfr.con"></a></a>`,
	},
	} {
	t.Run(test.name, func(t *testing.T) {
	got := linkHTML(test.in, test.link, "class")
	diff := cmp.Diff(test.want, got.String())
	if diff != "" {
	t.Errorf("mismatch (-want, +got):\n%s", diff)
	}
	})
	}
	}

	func TestVersionedPkgPath(t *testing.T) {
	for _, test := range []struct {
	name string
	pkgPath string
	modInfo *ModuleInfo
	want string
	}{
	{
	name: "builtin package is not versioned",
	pkgPath: "builtin",
	modInfo: &ModuleInfo{
	ModulePath: "std",
	ResolvedVersion: "v1.14.4",
	ModulePackages: map[string]bool{"std/builtin": true, "std/net/http": true},
	},
	want: "builtin",
	},
	{
	name: "std packages are not versioned",
	pkgPath: "net/http",
	modInfo: &ModuleInfo{
	ModulePath: "std",
	ResolvedVersion: "v1.14.4",
	ModulePackages: map[string]bool{"std/builtin": true, "std/net/http": true},
	},
	want: "net/http",
	},
	{
	name: "imports from other modules are not versioned",
	pkgPath: "golang.org/x/pkgsite",
	modInfo: &ModuleInfo{
	ModulePath: "cloud.google.com/go",
	ResolvedVersion: "v0.60.0",
	ModulePackages: map[string]bool{"cloud.google.com/go/civil": true},
	},
	want: "golang.org/x/pkgsite",
	},
	{
	name: "imports from other modules with shared prefixes are not versioned",
	pkgPath: "golang.org/x/pkgsite",
	modInfo: &ModuleInfo{
	ModulePath: "golang.org/x/time",
	ResolvedVersion: "v1.2.3",
	ModulePackages: map[string]bool{"golang.org/x/time/rate": true},
	},
	want: "golang.org/x/pkgsite",
	},
	{
	name: "imports from same module are versioned",
	pkgPath: "golang.org/x/pkgsite/internal/log",
	modInfo: &ModuleInfo{
	ModulePath: "golang.org/x/pkgsite",
	ResolvedVersion: "v1.1.2",
	ModulePackages: map[string]bool{"golang.org/x/pkgsite/internal/log": true},
	},
	want: "golang.org/x/pkgsite@v1.1.2/internal/log",
	},
	{
	name: "imports from same module with pseudo version are versioned",
	pkgPath: "golang.org/x/pkgsite/internal/log",
	modInfo: &ModuleInfo{
	ModulePath: "golang.org/x/pkgsite",
	ResolvedVersion: "v0.0.0-20200709011933-a59b4ce778c4",
	ModulePackages: map[string]bool{"golang.org/x/pkgsite/internal/log": true},
	},
	want: "golang.org/x/pkgsite@v0.0.0-20200709011933-a59b4ce778c4/internal/log",
	},
	{
	name: "imports from same v2 module are versioned",
	pkgPath: "k8s.io/klog/v2/klogr",
	modInfo: &ModuleInfo{
	ModulePath: "k8s.io/klog/v2",
	ResolvedVersion: "v2.3.0",
	ModulePackages: map[string]bool{"k8s.io/klog/v2": true, "k8s.io/klog/v2/klogr": true},
	},
	want: "k8s.io/klog/v2@v2.3.0/klogr",
	},
	{
	name: "imports from older major module version are not versioned",
	pkgPath: "rsc.io/quote",
	modInfo: &ModuleInfo{
	ModulePath: "rsc.io/quote/v3",
	ResolvedVersion: "v3.1.0",
	ModulePackages: map[string]bool{"rsc.io/quote/v3": true},
	},
	want: "rsc.io/quote",
	},
	{
	name: "imports from newer major module version are not versioned",
	pkgPath: "rsc.io/quote/v3",
	modInfo: &ModuleInfo{
	ModulePath: "rsc.io/quote",
	ResolvedVersion: "v1.5.3",
	ModulePackages: map[string]bool{"rsc.io/quote": true},
	},
	want: "rsc.io/quote/v3",
	},
	{
	name: "imports from nested module are not versioned",
	pkgPath: "A/B/C/D",
	modInfo: &ModuleInfo{
	ModulePath: "A",
	ResolvedVersion: "v1.0.0",
	ModulePackages: map[string]bool{"A/B": true, "A/B/C": true},
	},
	want: "A/B/C/D",
	},
	} {
	t.Run(test.name, func(t *testing.T) {
	got := versionedPkgPath(test.pkgPath, test.modInfo)
	if got != test.want {
	t.Errorf("versionedPkgPath(%q) = %q, want %q", test.pkgPath, got, test.want)
	}
	})
	}
	}

	func testDuplicateIDs(t testing.T, htmlDoc html.Node) {
	idCounts := map[string]int{}
	walk(htmlDoc, func(n *html.Node) {
	id := attr(n, "id")
	if id != "" {
	idCounts[id]++
	}
	})
	var dups []string
	for id, n := range idCounts {
	if n > 1 {
	dups = append(dups, id)
	}
	}
	if len(dups) > 0 {
	t.Errorf("duplicate ids: %v", dups)
	}
	}

	func testIDsAndKinds(t testing.T, htmlDoc html.Node) {
	type attrs struct {
	ID, Kind string // export fields for cmp
	}

	// want is a complete list of id, kind pairs we expect to see the HTML.
	want := []attrs{
	{"C", "constant"},
	{"CT", "constant"},
	{"F", "function"},
	{"TF", "function"},
	{"T.M", "method"},
	{"V", "variable"},
	{"VT", "variable"},
	{"T", "type"},
	{"S1", "type"},
	{"S1.F", "field"},
	{"S2", "type"},
	{"S2.S1", "field"},
	{"S2.G", "field"},
	{"I1", "type"},
	{"I1.M1", "method"},
	{"I2", "type"},
	{"I2.M2", "method"},
	}

	var got []attrs
	walk(htmlDoc, func(n *html.Node) {
	if kind := attr(n, "data-kind"); kind != "" {
	got = append(got, attrs{attr(n, "id"), kind})
	}
	})

	diff := cmp.Diff(want, got, cmpopts.SortSlices(func(a1, a2 attrs) bool {
	return a1.ID < a2.ID
	}))
	if diff != "" {
	t.Errorf("mismatch (-want, +got):\n%s", diff)
	}
	}

	func walk(n html.Node, f func(html.Node)) {
	f(n)
	for c := n.FirstChild; c != nil; c = c.NextSibling {
	walk(c, f)
	}
	}

	func attr(n *html.Node, key string) string {
	for _, a := range n.Attr {
	if a.Key == key {
	return a.Val
	}
	}
	return ""
	}

	// Copied from internal/render/render_test.go, with the slight modification of returning the fset.
	func mustLoadPackage(path string) (token.FileSet, doc.Package) {
	srcName := filepath.Base(path) + ".go"
	code, err := ioutil.ReadFile(filepath.Join("testdata", srcName))
	if err != nil {
	panic(err)
	}

	fset := token.NewFileSet()
	astFile, _ := parser.ParseFile(fset, srcName, code, parser.ParseComments)
	files := []*ast.File{astFile}

	astPackage, err := doc.NewFromFiles(fset, files, path, doc.AllDecls)
	if err != nil {
	panic(err)
	}

	return fset, astPackage
	}