internal/frontend/readme_test.go - pkgsite - Git at Google

 // Copyright 2020 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 frontend

 import (
 	"context"
 	"strings"
 	"testing"
 	"unicode"

 	"github.com/google/go-cmp/cmp"
 	"github.com/google/go-cmp/cmp/cmpopts"
 	"golang.org/x/pkgsite/internal"
 	"golang.org/x/pkgsite/internal/experiment"
 	"golang.org/x/pkgsite/internal/source"
 	"golang.org/x/pkgsite/internal/testing/sample"
 )

 func TestReadme(t *testing.T) {
 	ctx := experiment.NewContext(context.Background())
 	unit := sample.UnitEmpty(sample.PackagePath, sample.ModulePath, sample.VersionString)
 	for _, test := range []struct {
 		name        string
 		unit        *internal.Unit
 		readme      *internal.Readme
 		wantHTML    string
 		wantOutline []*Heading
 	}{
 		{
 			name: "Top level heading of h4 becomes h3, and following header levels become hN-1",
 			unit: unit,
 			readme: &internal.Readme{
 				Filepath: sample.ReadmeFilePath,
 				Contents: "#### Four\n\n##### Five\n\n##### Five\n\n#### Four",
 			},
 			wantHTML: "<h3 class=\"h4\" id=\"readme-four\">Four</h3>\n" +
 				"<h4 class=\"h5\" id=\"readme-five\">Five</h4>\n" +
 				"<h4 class=\"h5\" id=\"readme-five-1\">Five</h4>\n" +
 				"<h3 class=\"h4\" id=\"readme-four-1\">Four</h3>",
 			wantOutline: []*Heading{
 				{
 					Level: 4,
 					Text:  "Four",
 					ID:    "readme-four",
 					Children: []*Heading{
 						{Level: 5, Text: "Five", ID: "readme-five"},
 						{Level: 5, Text: "Five", ID: "readme-five-1"},
 					},
 				},
 				{
 					Level: 4,
 					Text:  "Four",
 					ID:    "readme-four-1",
 				},
 			},
 		},
 		{
 			name: "The highest level heading is dropped when no other headings exist at same level",
 			unit: unit,
 			readme: &internal.Readme{
 				Filepath: sample.ReadmeFilePath,
 				Contents: "#### Four\n\n##### Five\n\n###### Six\n\n##### Five",
 			},
 			wantHTML: "<h3 class=\"h4\" id=\"readme-four\">Four</h3>\n" +
 				"<h4 class=\"h5\" id=\"readme-five\">Five</h4>\n" +
 				"<h5 class=\"h6\" id=\"readme-six\">Six</h5>\n" +
 				"<h4 class=\"h5\" id=\"readme-five-1\">Five</h4>",
 			wantOutline: []*Heading{
 				{Level: 5, Text: "Five", ID: "readme-five", Children: []*Heading{
 					{Level: 6, Text: "Six", ID: "readme-six"},
 				}},
 				{Level: 5, Text: "Five", ID: "readme-five-1"},
 			},
 		},
 		{
 			name: "Heading levels out of order",
 			unit: unit,
 			readme: &internal.Readme{
 				Filepath: sample.ReadmeFilePath,
 				Contents: "## Two\n\n# One\n\n### Three",
 			},
 			wantHTML: "<h3 class=\"h2\" id=\"readme-two\">Two</h3>\n" +
 				"<h2 class=\"h1\" id=\"readme-one\">One</h2>\n" +
 				"<h4 class=\"h3\" id=\"readme-three\">Three</h4>",
 			wantOutline: []*Heading{
 				{Level: 2, Text: "Two", ID: "readme-two"},
 				{Level: 1, Text: "One", ID: "readme-one", Children: []*Heading{
 					{Level: 3, Text: "Three", ID: "readme-three"},
 				}},
 			},
 		},
 		{
 			name: "Heading levels not consecutive",
 			unit: unit,
 			readme: &internal.Readme{
 				Filepath: sample.ReadmeFilePath,
 				Contents: "# One\n\n#### Four\n\n#### Four\n\n# One",
 			},
 			wantHTML: "<h3 class=\"h1\" id=\"readme-one\">One</h3>\n" +
 				"<h6 class=\"h4\" id=\"readme-four\">Four</h6>\n" +
 				"<h6 class=\"h4\" id=\"readme-four-1\">Four</h6>\n" +
 				"<h3 class=\"h1\" id=\"readme-one-1\">One</h3>",
 			wantOutline: []*Heading{
 				{Level: 1, Text: "One", ID: "readme-one", Children: []*Heading{
 					{Level: 4, Text: "Four", ID: "readme-four"},
 					{Level: 4, Text: "Four", ID: "readme-four-1"},
 				}},
 				{Level: 1, Text: "One", ID: "readme-one-1"},
 			},
 		},
 		{
 			name: "Heading levels in reverse",
 			unit: unit,
 			readme: &internal.Readme{
 				Filepath: sample.ReadmeFilePath,
 				Contents: "### Three\n\n## Two\n\n# One",
 			},
 			wantHTML: "<h3 class=\"h3\" id=\"readme-three\">Three</h3>\n" +
 				"<h2 class=\"h2\" id=\"readme-two\">Two</h2>\n" +
 				"<h1 class=\"h1\" id=\"readme-one\">One</h1>",
 			wantOutline: []*Heading{
 				{Level: 3, Text: "Three", ID: "readme-three"},
 				{Level: 2, Text: "Two", ID: "readme-two"},
 				{Level: 1, Text: "One", ID: "readme-one"},
 			},
 		},
 		{
 			name: "Heading level six",
 			unit: unit,
 			readme: &internal.Readme{
 				Filepath: sample.ReadmeFilePath,
 				Contents: "# One\n\n###### Six\n\n# One",
 			},
 			wantHTML: "<h3 class=\"h1\" id=\"readme-one\">One</h3>\n" +
 				"<div role=\"heading\" aria-level=\"6\" id=\"readme-six\">Six</div>\n" +
 				"<h3 class=\"h1\" id=\"readme-one-1\">One</h3>",

 			wantOutline: []*Heading{
 				{Level: 1, Text: "One", ID: "readme-one", Children: []*Heading{
 					{Level: 6, Text: "Six", ID: "readme-six"},
 				}},
 				{Level: 1, Text: "One", ID: "readme-one-1"},
 			},
 		},
 		{
 			name: "Non-ASCII Heading",
 			unit: unit,
 			readme: &internal.Readme{
 				Filepath: sample.ReadmeFilePath,
 				Contents: "# 中文¹",
 			},
 			wantHTML:    "<h3 class=\"h1\" id=\"readme-heading\">中文¹</h3>",
 			wantOutline: []*Heading{{Level: 1, Text: "中文¹", ID: "readme-heading"}},
 		},
 		{
 			name: "Github markdown emoji markup is properly rendered",
 			unit: unit,
 			readme: &internal.Readme{
 				Filepath: sample.ReadmeFilePath,
 				Contents: "# :zap: Zap \n\n :joy:",
 			},
 			wantHTML: "<h3 class=\"h1\" id=\"readme-zap\">⚡ Zap</h3>\n<p>😂</p>",
 			wantOutline: []*Heading{
 				{Level: 1, Text: "⚡ Zap", ID: "readme-zap"},
 			},
 		},
 		{
 			name: "valid markdown readme",
 			unit: &internal.Unit{},
 			readme: &internal.Readme{
 				Filepath: "README.md",
 				Contents: "This package collects pithy sayings.\n\n" +
 					"It's part of a demonstration of\n" +
 					"[package versioning in Go](https://research.swtch.com/vgo1).",
 			},
 			wantHTML: "<p>This package collects pithy sayings.</p>\n" +
 				"<p>It&#39;s part of a demonstration of\n" +
 				`<a href="https://research.swtch.com/vgo1" rel="nofollow">package versioning in Go</a>.</p>`,
 			wantOutline: nil,
 		},
 		{
 			name: "valid markdown readme with alternative case and extension",
 			unit: &internal.Unit{},
 			readme: &internal.Readme{
 				Filepath: "README.MARKDOWN",
 				Contents: "This package collects pithy sayings.\n\n" +
 					"It's part of a demonstration of\n" +
 					"[package versioning in Go](https://research.swtch.com/vgo1).",
 			},
 			wantHTML: "<p>This package collects pithy sayings.</p>\n" +
 				"<p>It&#39;s part of a demonstration of\n" +
 				`<a href="https://research.swtch.com/vgo1" rel="nofollow">package versioning in Go</a>.</p>`,
 			wantOutline: nil,
 		},
 		{
 			name: "valid markdown readme with CRLF",
 			unit: &internal.Unit{},
 			readme: &internal.Readme{
 				Filepath: "README.md",
 				Contents: "This package collects pithy sayings.\r\n\r\n" +
 					"- It's part of a demonstration of\r\n" +
 					"- [package versioning in Go](https://research.swtch.com/vgo1).",
 			},
 			wantHTML: "<p>This package collects pithy sayings.</p>\n" +
 				"<ul>\n" +
 				"<li>It&#39;s part of a demonstration of</li>\n" +
 				`<li><a href="https://research.swtch.com/vgo1" rel="nofollow">package versioning in Go</a>.</li>` + "\n" +
 				"</ul>",
 			wantOutline: nil,
 		},
 		{
 			name: "not markdown readme",
 			unit: &internal.Unit{},
 			readme: &internal.Readme{
 				Filepath: "README.rst",
 				Contents: "This package collects pithy sayings.\n\n" +
 					"It's part of a demonstration of\n" +
 					"[package versioning in Go](https://research.swtch.com/vgo1).",
 			},
 			wantHTML: "<pre class=\"readme\">This package collects pithy sayings.\n\n" +
 				"It&#39;s part of a demonstration of\n[package versioning in Go](https://research.swtch.com/vgo1).</pre>",
 			wantOutline: nil,
 		},
 		{
 			name:        "empty readme",
 			unit:        &internal.Unit{},
 			wantHTML:    "",
 			wantOutline: nil,
 		},
 		{
 			name: "sanitized readme",
 			unit: &internal.Unit{},
 			readme: &internal.Readme{
 				Filepath: "README",
 				Contents: `<a onblur="alert(secret)" href="http://www.google.com">Google</a>`,
 			},
 			wantHTML:    `<pre class="readme">&lt;a onblur=&#34;alert(secret)&#34; href=&#34;http://www.google.com&#34;&gt;Google&lt;/a&gt;</pre>`,
 			wantOutline: nil,
 		},
 		{
 			name: "relative image markdown is made absolute for GitHub",
 			unit: &internal.Unit{
 				UnitMeta: internal.UnitMeta{
 					ModuleInfo: internal.ModuleInfo{
 						SourceInfo: source.NewGitHubInfo("http://github.com/golang/go", "", "master"),
 					},
 				},
 			},
 			readme: &internal.Readme{
 				Filepath: "README.md",
 				Contents: "![Go logo](doc/logo.png)",
 			},
 			wantHTML:    `<p><img src="http://github.com/golang/go/raw/master/doc/logo.png" alt="Go logo"/></p>`,
 			wantOutline: nil,
 		},
 		{
 			name: "relative image markdown is made absolute for GitHub, .git removed from repo URL",
 			unit: &internal.Unit{
 				UnitMeta: internal.UnitMeta{
 					ModuleInfo: internal.ModuleInfo{
 						SourceInfo: source.NewGitHubInfo("https://github.com/robpike/ivy.git", "", "v0.1.0"),
 					},
 				},
 			},
 			readme: &internal.Readme{
 				Filepath: "README.md",
 				Contents: "![ivy](ivy.jpg)",
 			},
 			wantHTML:    `<p><img src="https://github.com/robpike/ivy/raw/v0.1.0/ivy.jpg" alt="ivy"/></p>`,
 			wantOutline: nil,
 		},
 		{
 			name: "relative image markdown is left alone for unknown origins",
 			unit: &internal.Unit{},
 			readme: &internal.Readme{
 				Filepath: "README.md",
 				Contents: "![Go logo](doc/logo.png)",
 			},
 			wantHTML:    `<p><img src="doc/logo.png" alt="Go logo"/></p>`,
 			wantOutline: nil,
 		},
 		{
 			name: "module versions are referenced in relative images",
 			unit: unit,
 			readme: &internal.Readme{
 				Filepath: "README.md",
 				Contents: "![Hugo logo](doc/logo.png)",
 			},
 			wantHTML:    `<p><img src="https://github.com/valid/module_name/raw/v1.0.0/doc/logo.png" alt="Hugo logo"/></p>`,
 			wantOutline: nil,
 		},
 		{
 			name: "image URLs relative to README directory",
 			unit: unit,
 			readme: &internal.Readme{
 				Filepath: "dir/sub/README.md",
 				Contents: "![alt](img/thing.png)",
 			},
 			wantHTML:    `<p><img src="https://github.com/valid/module_name/raw/v1.0.0/dir/sub/img/thing.png" alt="alt"/></p>`,
 			wantOutline: nil,
 		},
 		{
 			name: "non-image links relative to README directory",
 			unit: unit,
 			readme: &internal.Readme{
 				Filepath: "dir/sub/README.md",
 				Contents: "[something](doc/thing.md)",
 			},
 			wantHTML:    `<p><a href="https://github.com/valid/module_name/blob/v1.0.0/dir/sub/doc/thing.md" rel="nofollow">something</a></p>`,
 			wantOutline: nil,
 		},
 		{
 			name: "image link in embedded HTML",
 			unit: unit,
 			readme: &internal.Readme{
 				Filepath: "README.md",
 				Contents: "<img src=\"resources/logoSmall.png\" />\n\n# Heading\n",
 			},
 			wantHTML: `<img src="https://github.com/valid/module_name/raw/v1.0.0/resources/logoSmall.png"/>` + "\n" +
 				`<h3 class="h1" id="readme-heading">Heading</h3>`,
 			wantOutline: []*Heading{
 				{Level: 1, Text: "Heading", ID: "readme-heading"},
 			},
 		},
 		{
 			name: "image link in embedded HTML with surrounding p tag",
 			unit: unit,
 			readme: &internal.Readme{
 				Filepath: "README.md",
 				Contents: "<p align=\"center\"><img src=\"foo.png\" /></p>\n\n# Heading",
 			},
 			wantHTML: `<p align="center"><img src="https://github.com/valid/module_name/raw/v1.0.0/foo.png"/></p>` + "\n" +
 				`<h3 class="h1" id="readme-heading">Heading</h3>`,
 			wantOutline: []*Heading{
 				{Level: 1, Text: "Heading", ID: "readme-heading"},
 			},
 		},
 		{
 			name: "image link in embedded HTML with surrounding div",
 			unit: unit,
 			readme: &internal.Readme{
 				Filepath: "README.md",
 				Contents: "<div align=\"center\"><img src=\"foo.png\" /></div>\n\n# Heading",
 			},
 			wantHTML: `<div align="center"><img src="https://github.com/valid/module_name/raw/v1.0.0/foo.png"/></div>` + "\n" +
 				`<h3 class="h1" id="readme-heading">Heading</h3>`,
 			wantOutline: []*Heading{
 				{Level: 1, Text: "Heading", ID: "readme-heading"},
 			},
 		},
 		{
 			name: "image link with bad URL",
 			unit: &internal.Unit{
 				UnitMeta: internal.UnitMeta{
 					ModuleInfo: internal.ModuleInfo{
 						Version:    "v1.2.3",
 						SourceInfo: source.NewGitHubInfo("https://github.com/some/<script>", "", "v1.2.3"),
 					},
 				},
 			},
 			readme: &internal.Readme{
 				Filepath: "README.md",
 				Contents: "<div align=\"center\"><img src=\"foo.png\" /></div>\n\n# Heading",
 			},
 			wantHTML: `<div align="center"><img src="https://github.com/some/%3Cscript%3E/raw/v1.2.3/foo.png"/></div>` + "\n" +
 				`<h3 class="h1" id="readme-heading">Heading</h3>`,
 			wantOutline: []*Heading{
 				{Level: 1, Text: "Heading", ID: "readme-heading"},
 			},
 		},
 		{
 			name: "body has more than one child",
 			unit: unit,
 			readme: &internal.Readme{
 				Filepath: "dir/sub/README.md",
 				// The final newline here is important for creating the right markdown tree; do not remove it.
 				Contents: `<p><img src="./foo.png"></p><p><img src="../bar.png"</p>` + "\n",
 			},
 			wantHTML: `<p><img src="https://github.com/valid/module_name/raw/v1.0.0/dir/sub/foo.png"/></p>` +
 				`<p><img src="https://github.com/valid/module_name/raw/v1.0.0/dir/bar.png"/></p>`,
 			wantOutline: nil,
 		},
 		{
 			name: "escaped image source",
 			unit: unit,
 			readme: &internal.Readme{
 				Filepath: "README.md",
 				Contents: `<img src="./images/Jupyter%20Notebook_sparkline.svg">`,
 			},
 			wantHTML:    `<img src="https://github.com/valid/module_name/raw/v1.0.0/images/Jupyter%20Notebook_sparkline.svg"/>`,
 			wantOutline: nil,
 		},
 		{
 			name: "relative link to local heading is prefixed with readme-",
 			unit: unit,
 			readme: &internal.Readme{
 				Filepath: "README.md",
 				Contents: `[Local Heading](#local-heading)` + "\n" +
 					`# Local Heading`,
 			},
 			wantHTML: `<p><a href="#readme-local-heading" rel="nofollow">Local Heading</a></p>` + "\n" +
 				`<h3 class="h1" id="readme-local-heading">Local Heading</h3>`,
 			wantOutline: []*Heading{
 				{Level: 1, Text: "Local Heading", ID: "readme-local-heading"},
 			},
 		},
 		{
 			name: "text is extracted from headings that contain only non-text nodes",
 			unit: unit,
 			readme: &internal.Readme{
 				Filepath: "README.md",
 				Contents: `# [![Image Text](file.svg)](link.html)
 				`,
 			},
 			wantHTML: `<h3 class="h1" id="readme-image-text"><a href="https://github.com/valid/module_name/blob/v1.0.0/link.html" rel="nofollow"><img src="https://github.com/valid/module_name/raw/v1.0.0/file.svg" alt="Image Text"/></a></h3>`,
 			wantOutline: []*Heading{
 				{Level: 1, Text: "Image Text", ID: "readme-image-text"},
 			},
 		},
 		{
 			name: "duplicated headings ids have incremental suffix",
 			unit: unit,
 			readme: &internal.Readme{
 				Filepath: "README.md",
 				Contents: "# Heading\n## Heading\n## Heading\n# Heading",
 			},
 			wantHTML: `<h3 class="h1" id="readme-heading">Heading</h3>` + "\n" +
 				`<h4 class="h2" id="readme-heading-1">Heading</h4>` + "\n" +
 				`<h4 class="h2" id="readme-heading-2">Heading</h4>` + "\n" +
 				`<h3 class="h1" id="readme-heading-3">Heading</h3>`,
 			wantOutline: []*Heading{
 				{Level: 1, Text: "Heading", ID: "readme-heading", Children: []*Heading{
 					{Level: 2, Text: "Heading", ID: "readme-heading-1"},
 					{Level: 2, Text: "Heading", ID: "readme-heading-2"},
 				}},
 				{Level: 1, Text: "Heading", ID: "readme-heading-3"},
 			},
 		},
 		{
 			name: "only letters and numbers are preserved in ids",
 			unit: unit,
 			readme: &internal.Readme{
 				Filepath: "README.md",
 				Contents: "# Heading 😎\n## 👾\n## Heading 🚀\n# Heading",
 			},
 			wantHTML: `<h3 class="h1" id="readme-heading">Heading 😎</h3>` + "\n" +
 				`<h4 class="h2" id="readme-heading-1">👾</h4>` + "\n" +
 				`<h4 class="h2" id="readme-heading-2">Heading 🚀</h4>` + "\n" +
 				`<h3 class="h1" id="readme-heading-3">Heading</h3>`,
 			wantOutline: []*Heading{
 				{Level: 1, Text: "Heading 😎", ID: "readme-heading", Children: []*Heading{
 					{Level: 2, Text: "👾", ID: "readme-heading-1"},
 					{Level: 2, Text: "Heading 🚀", ID: "readme-heading-2"},
 				}},
 				{Level: 1, Text: "Heading", ID: "readme-heading-3"},
 			},
 		},
 		{
 			name: "tag in heading",
 			unit: unit,
 			readme: &internal.Readme{
 				Filepath: "README.md",
 				Contents: `# A link <a href="link">link</a>`,
 			},
 			wantHTML: `<h3 class="h1" id="readme-a-link-link">A link <a href="link" rel="nofollow">link</a></h3>`,
 			wantOutline: []*Heading{
 				{Level: 1, Text: "A link link", ID: "readme-a-link-link"},
 			},
 		},
 		{
 			name: "rewritten link in emph",
 			unit: unit,
 			readme: &internal.Readme{
 				Filepath: "README.md",
 				Contents: `**![alt](https://github.com/gobuffalo/buffalo/blob/master/logo.svg)**`,
 			},
 			wantHTML:    `<p><strong><img src="https://github.com/gobuffalo/buffalo/raw/master/logo.svg" alt="alt"/></strong></p>`,
 			wantOutline: nil,
 		},
 	} {
 		t.Run(test.name, func(t *testing.T) {
 			test.unit.Readme = test.readme
 			readme, err := ProcessReadme(ctx, test.unit)
 			if err != nil {
 				t.Fatal(err)
 			}
 			gotHTML := strings.TrimSpace(readme.HTML.String())
 			if diff := cmp.Diff(test.wantHTML, gotHTML); diff != "" {
 				t.Errorf("Readme(%v) html mismatch (-want +got):\n%s", test.unit.UnitMeta, diff)
 			}
 			if diff := cmp.Diff(test.wantOutline, readme.Outline, cmp.Options{
 				cmpopts.IgnoreUnexported(Heading{}),
 			}); diff != "" {
 				t.Errorf("Readme(%v) outline mismatch (-want +got):\n%s", test.unit.UnitMeta, diff)
 			}
 		})
 	}
 }

 func TestReadmeLinks(t *testing.T) {
 	ctx := experiment.NewContext(context.Background())
 	unit := sample.UnitEmpty(sample.PackagePath, sample.ModulePath, sample.VersionString)
 	for _, test := range []struct {
 		name     string
 		contents string
 		want     []link
 	}{
 		{
 			name: "no links",
 			contents: `
 				# Heading
 				Some stuff.
 			`,
 			want: nil,
 		},
 		{
 			name: "simple links",
 			contents: `
 				# Heading
 				Some stuff.

 				## Links
 				Here are some links:

 				- [a](http://a)
 				- [b](http://b)

 				Whatever.

 				1. [c](http://c)
 			`,
 			want: []link{
 				{"http://a", "a"},
 				{"http://b", "b"},
 				{"http://c", "c"},
 			},
 		},
 		{
 			name: "ignore links not in a list",
 			contents: `
 				# Links
 				Try [a](http://a).
 				- [b](http://b)
 			`,
 			want: []link{
 				{"http://b", "b"},
 			},
 		},
 		{
 			name: "ignore extra text",
 			contents: `
 				# Links
 				- Try [a](http://a).
 				- [b](http://b)
 			`,
 			want: []link{
 				{"http://b", "b"},
 			},
 		},
 		{
 			name: "ignore sub-headings",
 			contents: `
 				# Links
 				- [a](http://a)
 				## Sub
 				- [b](http://b)
 				## Links
 				- [c](http://c)
 			`,
 			want: []link{{"http://a", "a"}},
 		},
 		{
 			name: "ignore nested links",
 			contents: `
 				# Links
 				- [a](http://a)
 				   - [b](http://b)
 				- [c](http://c)
 			`,
 			want: []link{
 				{"http://a", "a"},
 				{"http://c", "c"},
 			},
 		},
 		{
 			name: "two links sections",
 			contents: `
 				# Links
 				- [a](http://a)
 				# Links
 				- [b](http://b)
 			`,
 			want: []link{{"http://a", "a"}},
 		},
 	} {
 		t.Run(test.name, func(t *testing.T) {

 			unit.Readme = &internal.Readme{
 				Filepath: "README.md",
 				Contents: unindent(test.contents),
 			}
 			got, err := ProcessReadme(ctx, unit)
 			if err != nil {
 				t.Fatal(err)
 			}
 			if diff := cmp.Diff(test.want, got.Links); diff != "" {
 				t.Errorf("mismatch (-want +got):\n%s", diff)
 			}
 		})
 	}
 }

 // unindent removes indentation from s. It assumes that s starts with an initial
 // newline followed by one or more indented lines.
 func unindent(s string) string {
 	i := strings.IndexFunc(s, func(r rune) bool { return !unicode.IsSpace(r) })
 	if i < 0 {
 		return s
 	}
 	indent := s[:i]
 	return strings.ReplaceAll(s, indent, "\n")[1:]
 }

 func TestUnindent(t *testing.T) {
 	s := `
 		a
 		 - b
 		c
 	`
 	got := unindent(s)
 	want := "a\n - b\nc\n\t"
 	if got != want {
 		t.Errorf("got %q, want %q", got, want)
 	}
 }
	// Copyright 2020 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 frontend

	import (
	"context"
	"strings"
	"testing"
	"unicode"

	"github.com/google/go-cmp/cmp"
	"github.com/google/go-cmp/cmp/cmpopts"
	"golang.org/x/pkgsite/internal"
	"golang.org/x/pkgsite/internal/experiment"
	"golang.org/x/pkgsite/internal/source"
	"golang.org/x/pkgsite/internal/testing/sample"
	)

	func TestReadme(t *testing.T) {
	ctx := experiment.NewContext(context.Background())
	unit := sample.UnitEmpty(sample.PackagePath, sample.ModulePath, sample.VersionString)
	for _, test := range []struct {
	name string
	unit *internal.Unit
	readme *internal.Readme
	wantHTML string
	wantOutline []*Heading
	}{
	{
	name: "Top level heading of h4 becomes h3, and following header levels become hN-1",
	unit: unit,
	readme: &internal.Readme{
	Filepath: sample.ReadmeFilePath,
	Contents: "#### Four\n\n##### Five\n\n##### Five\n\n#### Four",
	},
	wantHTML: "<h3 class=\"h4\" id=\"readme-four\">Four</h3>\n" +
	"<h4 class=\"h5\" id=\"readme-five\">Five</h4>\n" +
	"<h4 class=\"h5\" id=\"readme-five-1\">Five</h4>\n" +
	"<h3 class=\"h4\" id=\"readme-four-1\">Four</h3>",
	wantOutline: []*Heading{
	{
	Level: 4,
	Text: "Four",
	ID: "readme-four",
	Children: []*Heading{
	{Level: 5, Text: "Five", ID: "readme-five"},
	{Level: 5, Text: "Five", ID: "readme-five-1"},
	},
	},
	{
	Level: 4,
	Text: "Four",
	ID: "readme-four-1",
	},
	},
	},
	{
	name: "The highest level heading is dropped when no other headings exist at same level",
	unit: unit,
	readme: &internal.Readme{
	Filepath: sample.ReadmeFilePath,
	Contents: "#### Four\n\n##### Five\n\n###### Six\n\n##### Five",
	},
	wantHTML: "<h3 class=\"h4\" id=\"readme-four\">Four</h3>\n" +
	"<h4 class=\"h5\" id=\"readme-five\">Five</h4>\n" +
	"<h5 class=\"h6\" id=\"readme-six\">Six</h5>\n" +
	"<h4 class=\"h5\" id=\"readme-five-1\">Five</h4>",
	wantOutline: []*Heading{
	{Level: 5, Text: "Five", ID: "readme-five", Children: []*Heading{
	{Level: 6, Text: "Six", ID: "readme-six"},
	}},
	{Level: 5, Text: "Five", ID: "readme-five-1"},
	},
	},
	{
	name: "Heading levels out of order",
	unit: unit,
	readme: &internal.Readme{
	Filepath: sample.ReadmeFilePath,
	Contents: "## Two\n\n# One\n\n### Three",
	},
	wantHTML: "<h3 class=\"h2\" id=\"readme-two\">Two</h3>\n" +
	"<h2 class=\"h1\" id=\"readme-one\">One</h2>\n" +
	"<h4 class=\"h3\" id=\"readme-three\">Three</h4>",
	wantOutline: []*Heading{
	{Level: 2, Text: "Two", ID: "readme-two"},
	{Level: 1, Text: "One", ID: "readme-one", Children: []*Heading{
	{Level: 3, Text: "Three", ID: "readme-three"},
	}},
	},
	},
	{
	name: "Heading levels not consecutive",
	unit: unit,
	readme: &internal.Readme{
	Filepath: sample.ReadmeFilePath,
	Contents: "# One\n\n#### Four\n\n#### Four\n\n# One",
	},
	wantHTML: "<h3 class=\"h1\" id=\"readme-one\">One</h3>\n" +
	"<h6 class=\"h4\" id=\"readme-four\">Four</h6>\n" +
	"<h6 class=\"h4\" id=\"readme-four-1\">Four</h6>\n" +
	"<h3 class=\"h1\" id=\"readme-one-1\">One</h3>",
	wantOutline: []*Heading{
	{Level: 1, Text: "One", ID: "readme-one", Children: []*Heading{
	{Level: 4, Text: "Four", ID: "readme-four"},
	{Level: 4, Text: "Four", ID: "readme-four-1"},
	}},
	{Level: 1, Text: "One", ID: "readme-one-1"},
	},
	},
	{
	name: "Heading levels in reverse",
	unit: unit,
	readme: &internal.Readme{
	Filepath: sample.ReadmeFilePath,
	Contents: "### Three\n\n## Two\n\n# One",
	},
	wantHTML: "<h3 class=\"h3\" id=\"readme-three\">Three</h3>\n" +
	"<h2 class=\"h2\" id=\"readme-two\">Two</h2>\n" +
	"<h1 class=\"h1\" id=\"readme-one\">One</h1>",
	wantOutline: []*Heading{
	{Level: 3, Text: "Three", ID: "readme-three"},
	{Level: 2, Text: "Two", ID: "readme-two"},
	{Level: 1, Text: "One", ID: "readme-one"},
	},
	},
	{
	name: "Heading level six",
	unit: unit,
	readme: &internal.Readme{
	Filepath: sample.ReadmeFilePath,
	Contents: "# One\n\n###### Six\n\n# One",
	},
	wantHTML: "<h3 class=\"h1\" id=\"readme-one\">One</h3>\n" +
	"<div role=\"heading\" aria-level=\"6\" id=\"readme-six\">Six</div>\n" +
	"<h3 class=\"h1\" id=\"readme-one-1\">One</h3>",

	wantOutline: []*Heading{
	{Level: 1, Text: "One", ID: "readme-one", Children: []*Heading{
	{Level: 6, Text: "Six", ID: "readme-six"},
	}},
	{Level: 1, Text: "One", ID: "readme-one-1"},
	},
	},
	{
	name: "Non-ASCII Heading",
	unit: unit,
	readme: &internal.Readme{
	Filepath: sample.ReadmeFilePath,
	Contents: "# 中文¹",
	},
	wantHTML: "<h3 class=\"h1\" id=\"readme-heading\">中文¹</h3>",
	wantOutline: []*Heading{{Level: 1, Text: "中文¹", ID: "readme-heading"}},
	},
	{
	name: "Github markdown emoji markup is properly rendered",
	unit: unit,
	readme: &internal.Readme{
	Filepath: sample.ReadmeFilePath,
	Contents: "# :zap: Zap \n\n :joy:",
	},
	wantHTML: "<h3 class=\"h1\" id=\"readme-zap\">⚡ Zap</h3>\n<p>😂</p>",
	wantOutline: []*Heading{
	{Level: 1, Text: "⚡ Zap", ID: "readme-zap"},
	},
	},
	{
	name: "valid markdown readme",
	unit: &internal.Unit{},
	readme: &internal.Readme{
	Filepath: "README.md",
	Contents: "This package collects pithy sayings.\n\n" +
	"It's part of a demonstration of\n" +
	"[package versioning in Go](https://research.swtch.com/vgo1).",
	},
	wantHTML: "<p>This package collects pithy sayings.</p>\n" +
	"<p>It's part of a demonstration of\n" +
	`<a href="https://research.swtch.com/vgo1" rel="nofollow">package versioning in Go</a>.</p>`,
	wantOutline: nil,
	},
	{
	name: "valid markdown readme with alternative case and extension",
	unit: &internal.Unit{},
	readme: &internal.Readme{
	Filepath: "README.MARKDOWN",
	Contents: "This package collects pithy sayings.\n\n" +
	"It's part of a demonstration of\n" +
	"[package versioning in Go](https://research.swtch.com/vgo1).",
	},
	wantHTML: "<p>This package collects pithy sayings.</p>\n" +
	"<p>It's part of a demonstration of\n" +
	`<a href="https://research.swtch.com/vgo1" rel="nofollow">package versioning in Go</a>.</p>`,
	wantOutline: nil,
	},
	{
	name: "valid markdown readme with CRLF",
	unit: &internal.Unit{},
	readme: &internal.Readme{
	Filepath: "README.md",
	Contents: "This package collects pithy sayings.\r\n\r\n" +
	"- It's part of a demonstration of\r\n" +
	"- [package versioning in Go](https://research.swtch.com/vgo1).",
	},
	wantHTML: "<p>This package collects pithy sayings.</p>\n" +
	"<ul>\n" +
	"<li>It's part of a demonstration of</li>\n" +
	`<li><a href="https://research.swtch.com/vgo1" rel="nofollow">package versioning in Go</a>.</li>` + "\n" +
	"</ul>",
	wantOutline: nil,
	},
	{
	name: "not markdown readme",
	unit: &internal.Unit{},
	readme: &internal.Readme{
	Filepath: "README.rst",
	Contents: "This package collects pithy sayings.\n\n" +
	"It's part of a demonstration of\n" +
	"[package versioning in Go](https://research.swtch.com/vgo1).",
	},
	wantHTML: "<pre class=\"readme\">This package collects pithy sayings.\n\n" +
	"It's part of a demonstration of\n[package versioning in Go](https://research.swtch.com/vgo1).</pre>",
	wantOutline: nil,
	},
	{
	name: "empty readme",
	unit: &internal.Unit{},
	wantHTML: "",
	wantOutline: nil,
	},
	{
	name: "sanitized readme",
	unit: &internal.Unit{},
	readme: &internal.Readme{
	Filepath: "README",
	Contents: `<a onblur="alert(secret)" href="http://www.google.com">Google</a>`,
	},
	wantHTML: `<pre class="readme"><a onblur="alert(secret)" href="http://www.google.com">Google</a></pre>`,
	wantOutline: nil,
	},
	{
	name: "relative image markdown is made absolute for GitHub",
	unit: &internal.Unit{
	UnitMeta: internal.UnitMeta{
	ModuleInfo: internal.ModuleInfo{
	SourceInfo: source.NewGitHubInfo("http://github.com/golang/go", "", "master"),
	},
	},
	},
	readme: &internal.Readme{
	Filepath: "README.md",
	Contents: "![Go logo](doc/logo.png)",
	},
	wantHTML: `<p><img src="http://github.com/golang/go/raw/master/doc/logo.png" alt="Go logo"/></p>`,
	wantOutline: nil,
	},
	{
	name: "relative image markdown is made absolute for GitHub, .git removed from repo URL",
	unit: &internal.Unit{
	UnitMeta: internal.UnitMeta{
	ModuleInfo: internal.ModuleInfo{
	SourceInfo: source.NewGitHubInfo("https://github.com/robpike/ivy.git", "", "v0.1.0"),
	},
	},
	},
	readme: &internal.Readme{
	Filepath: "README.md",
	Contents: "![ivy](ivy.jpg)",
	},
	wantHTML: `<p><img src="https://github.com/robpike/ivy/raw/v0.1.0/ivy.jpg" alt="ivy"/></p>`,
	wantOutline: nil,
	},
	{
	name: "relative image markdown is left alone for unknown origins",
	unit: &internal.Unit{},
	readme: &internal.Readme{
	Filepath: "README.md",
	Contents: "![Go logo](doc/logo.png)",
	},
	wantHTML: `<p><img src="doc/logo.png" alt="Go logo"/></p>`,
	wantOutline: nil,
	},
	{
	name: "module versions are referenced in relative images",
	unit: unit,
	readme: &internal.Readme{
	Filepath: "README.md",
	Contents: "![Hugo logo](doc/logo.png)",
	},
	wantHTML: `<p><img src="https://github.com/valid/module_name/raw/v1.0.0/doc/logo.png" alt="Hugo logo"/></p>`,
	wantOutline: nil,
	},
	{
	name: "image URLs relative to README directory",
	unit: unit,
	readme: &internal.Readme{
	Filepath: "dir/sub/README.md",
	Contents: "![alt](img/thing.png)",
	},
	wantHTML: `<p><img src="https://github.com/valid/module_name/raw/v1.0.0/dir/sub/img/thing.png" alt="alt"/></p>`,
	wantOutline: nil,
	},
	{
	name: "non-image links relative to README directory",
	unit: unit,
	readme: &internal.Readme{
	Filepath: "dir/sub/README.md",
	Contents: "[something](doc/thing.md)",
	},
	wantHTML: `<p><a href="https://github.com/valid/module_name/blob/v1.0.0/dir/sub/doc/thing.md" rel="nofollow">something</a></p>`,
	wantOutline: nil,
	},
	{
	name: "image link in embedded HTML",
	unit: unit,
	readme: &internal.Readme{
	Filepath: "README.md",
	Contents: "<img src=\"resources/logoSmall.png\" />\n\n# Heading\n",
	},
	wantHTML: `<img src="https://github.com/valid/module_name/raw/v1.0.0/resources/logoSmall.png"/>` + "\n" +
	`<h3 class="h1" id="readme-heading">Heading</h3>`,
	wantOutline: []*Heading{
	{Level: 1, Text: "Heading", ID: "readme-heading"},
	},
	},
	{
	name: "image link in embedded HTML with surrounding p tag",
	unit: unit,
	readme: &internal.Readme{
	Filepath: "README.md",
	Contents: "<p align=\"center\"><img src=\"foo.png\" /></p>\n\n# Heading",
	},
	wantHTML: `<p align="center"><img src="https://github.com/valid/module_name/raw/v1.0.0/foo.png"/></p>` + "\n" +
	`<h3 class="h1" id="readme-heading">Heading</h3>`,
	wantOutline: []*Heading{
	{Level: 1, Text: "Heading", ID: "readme-heading"},
	},
	},
	{
	name: "image link in embedded HTML with surrounding div",
	unit: unit,
	readme: &internal.Readme{
	Filepath: "README.md",
	Contents: "<div align=\"center\"><img src=\"foo.png\" /></div>\n\n# Heading",
	},
	wantHTML: `<div align="center"><img src="https://github.com/valid/module_name/raw/v1.0.0/foo.png"/></div>` + "\n" +
	`<h3 class="h1" id="readme-heading">Heading</h3>`,
	wantOutline: []*Heading{
	{Level: 1, Text: "Heading", ID: "readme-heading"},
	},
	},
	{
	name: "image link with bad URL",
	unit: &internal.Unit{
	UnitMeta: internal.UnitMeta{
	ModuleInfo: internal.ModuleInfo{
	Version: "v1.2.3",
	SourceInfo: source.NewGitHubInfo("https://github.com/some/<script>", "", "v1.2.3"),
	},
	},
	},
	readme: &internal.Readme{
	Filepath: "README.md",
	Contents: "<div align=\"center\"><img src=\"foo.png\" /></div>\n\n# Heading",
	},
	wantHTML: `<div align="center"><img src="https://github.com/some/%3Cscript%3E/raw/v1.2.3/foo.png"/></div>` + "\n" +
	`<h3 class="h1" id="readme-heading">Heading</h3>`,
	wantOutline: []*Heading{
	{Level: 1, Text: "Heading", ID: "readme-heading"},
	},
	},
	{
	name: "body has more than one child",
	unit: unit,
	readme: &internal.Readme{
	Filepath: "dir/sub/README.md",
	// The final newline here is important for creating the right markdown tree; do not remove it.
	Contents: `<p><img src="./foo.png"></p><p><img src="../bar.png"</p>` + "\n",
	},
	wantHTML: `<p><img src="https://github.com/valid/module_name/raw/v1.0.0/dir/sub/foo.png"/></p>` +
	`<p><img src="https://github.com/valid/module_name/raw/v1.0.0/dir/bar.png"/></p>`,
	wantOutline: nil,
	},
	{
	name: "escaped image source",
	unit: unit,
	readme: &internal.Readme{
	Filepath: "README.md",
	Contents: `<img src="./images/Jupyter%20Notebook_sparkline.svg">`,
	},
	wantHTML: `<img src="https://github.com/valid/module_name/raw/v1.0.0/images/Jupyter%20Notebook_sparkline.svg"/>`,
	wantOutline: nil,
	},
	{
	name: "relative link to local heading is prefixed with readme-",
	unit: unit,
	readme: &internal.Readme{
	Filepath: "README.md",
	Contents: `[Local Heading](#local-heading)` + "\n" +
	`# Local Heading`,
	},
	wantHTML: `<p><a href="#readme-local-heading" rel="nofollow">Local Heading</a></p>` + "\n" +
	`<h3 class="h1" id="readme-local-heading">Local Heading</h3>`,
	wantOutline: []*Heading{
	{Level: 1, Text: "Local Heading", ID: "readme-local-heading"},
	},
	},
	{
	name: "text is extracted from headings that contain only non-text nodes",
	unit: unit,
	readme: &internal.Readme{
	Filepath: "README.md",
	Contents: `# [![Image Text](file.svg)](link.html)
	`,
	},
	wantHTML: `<h3 class="h1" id="readme-image-text"><a href="https://github.com/valid/module_name/blob/v1.0.0/link.html" rel="nofollow"><img src="https://github.com/valid/module_name/raw/v1.0.0/file.svg" alt="Image Text"/></a></h3>`,
	wantOutline: []*Heading{
	{Level: 1, Text: "Image Text", ID: "readme-image-text"},
	},
	},
	{
	name: "duplicated headings ids have incremental suffix",
	unit: unit,
	readme: &internal.Readme{
	Filepath: "README.md",
	Contents: "# Heading\n## Heading\n## Heading\n# Heading",
	},
	wantHTML: `<h3 class="h1" id="readme-heading">Heading</h3>` + "\n" +
	`<h4 class="h2" id="readme-heading-1">Heading</h4>` + "\n" +
	`<h4 class="h2" id="readme-heading-2">Heading</h4>` + "\n" +
	`<h3 class="h1" id="readme-heading-3">Heading</h3>`,
	wantOutline: []*Heading{
	{Level: 1, Text: "Heading", ID: "readme-heading", Children: []*Heading{
	{Level: 2, Text: "Heading", ID: "readme-heading-1"},
	{Level: 2, Text: "Heading", ID: "readme-heading-2"},
	}},
	{Level: 1, Text: "Heading", ID: "readme-heading-3"},
	},
	},
	{
	name: "only letters and numbers are preserved in ids",
	unit: unit,
	readme: &internal.Readme{
	Filepath: "README.md",
	Contents: "# Heading 😎\n## 👾\n## Heading 🚀\n# Heading",
	},
	wantHTML: `<h3 class="h1" id="readme-heading">Heading 😎</h3>` + "\n" +
	`<h4 class="h2" id="readme-heading-1">👾</h4>` + "\n" +
	`<h4 class="h2" id="readme-heading-2">Heading 🚀</h4>` + "\n" +
	`<h3 class="h1" id="readme-heading-3">Heading</h3>`,
	wantOutline: []*Heading{
	{Level: 1, Text: "Heading 😎", ID: "readme-heading", Children: []*Heading{
	{Level: 2, Text: "👾", ID: "readme-heading-1"},
	{Level: 2, Text: "Heading 🚀", ID: "readme-heading-2"},
	}},
	{Level: 1, Text: "Heading", ID: "readme-heading-3"},
	},
	},
	{
	name: "tag in heading",
	unit: unit,
	readme: &internal.Readme{
	Filepath: "README.md",
	Contents: `# A link <a href="link">link</a>`,
	},
	wantHTML: `<h3 class="h1" id="readme-a-link-link">A link <a href="link" rel="nofollow">link</a></h3>`,
	wantOutline: []*Heading{
	{Level: 1, Text: "A link link", ID: "readme-a-link-link"},
	},
	},
	{
	name: "rewritten link in emph",
	unit: unit,
	readme: &internal.Readme{
	Filepath: "README.md",
	Contents: `![alt](https://github.com/gobuffalo/buffalo/blob/master/logo.svg)`,
	},
	wantHTML: `<p><strong><img src="https://github.com/gobuffalo/buffalo/raw/master/logo.svg" alt="alt"/></strong></p>`,
	wantOutline: nil,
	},
	} {
	t.Run(test.name, func(t *testing.T) {
	test.unit.Readme = test.readme
	readme, err := ProcessReadme(ctx, test.unit)
	if err != nil {
	t.Fatal(err)
	}
	gotHTML := strings.TrimSpace(readme.HTML.String())
	if diff := cmp.Diff(test.wantHTML, gotHTML); diff != "" {
	t.Errorf("Readme(%v) html mismatch (-want +got):\n%s", test.unit.UnitMeta, diff)
	}
	if diff := cmp.Diff(test.wantOutline, readme.Outline, cmp.Options{
	cmpopts.IgnoreUnexported(Heading{}),
	}); diff != "" {
	t.Errorf("Readme(%v) outline mismatch (-want +got):\n%s", test.unit.UnitMeta, diff)
	}
	})
	}
	}

	func TestReadmeLinks(t *testing.T) {
	ctx := experiment.NewContext(context.Background())
	unit := sample.UnitEmpty(sample.PackagePath, sample.ModulePath, sample.VersionString)
	for _, test := range []struct {
	name string
	contents string
	want []link
	}{
	{
	name: "no links",
	contents: `
	# Heading
	Some stuff.
	`,
	want: nil,
	},
	{
	name: "simple links",
	contents: `
	# Heading
	Some stuff.

	## Links
	Here are some links:

	- [a](http://a)
	- [b](http://b)

	Whatever.

	1. [c](http://c)
	`,
	want: []link{
	{"http://a", "a"},
	{"http://b", "b"},
	{"http://c", "c"},
	},
	},
	{
	name: "ignore links not in a list",
	contents: `
	# Links
	Try [a](http://a).
	- [b](http://b)
	`,
	want: []link{
	{"http://b", "b"},
	},
	},
	{
	name: "ignore extra text",
	contents: `
	# Links
	- Try [a](http://a).
	- [b](http://b)
	`,
	want: []link{
	{"http://b", "b"},
	},
	},
	{
	name: "ignore sub-headings",
	contents: `
	# Links
	- [a](http://a)
	## Sub
	- [b](http://b)
	## Links
	- [c](http://c)
	`,
	want: []link{{"http://a", "a"}},
	},
	{
	name: "ignore nested links",
	contents: `
	# Links
	- [a](http://a)
	- [b](http://b)
	- [c](http://c)
	`,
	want: []link{
	{"http://a", "a"},
	{"http://c", "c"},
	},
	},
	{
	name: "two links sections",
	contents: `
	# Links
	- [a](http://a)
	# Links
	- [b](http://b)
	`,
	want: []link{{"http://a", "a"}},
	},
	} {
	t.Run(test.name, func(t *testing.T) {

	unit.Readme = &internal.Readme{
	Filepath: "README.md",
	Contents: unindent(test.contents),
	}
	got, err := ProcessReadme(ctx, unit)
	if err != nil {
	t.Fatal(err)
	}
	if diff := cmp.Diff(test.want, got.Links); diff != "" {
	t.Errorf("mismatch (-want +got):\n%s", diff)
	}
	})
	}
	}

	// unindent removes indentation from s. It assumes that s starts with an initial
	// newline followed by one or more indented lines.
	func unindent(s string) string {
	i := strings.IndexFunc(s, func(r rune) bool { return !unicode.IsSpace(r) })
	if i < 0 {
	return s
	}
	indent := s[:i]
	return strings.ReplaceAll(s, indent, "\n")[1:]
	}

	func TestUnindent(t *testing.T) {
	s := `
	a
	- b
	c
	`
	got := unindent(s)
	want := "a\n - b\nc\n\t"
	if got != want {
	t.Errorf("got %q, want %q", got, want)
	}
	}