cmd/gerritbot/internal/rules/rules_test.go - build - Git at Google

 // Copyright 2023 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 rules

 import (
 	"strings"
 	"testing"

 	"github.com/google/go-cmp/cmp"
 )

 func TestFormatRuleResults(t *testing.T) {
 	tests := []struct {
 		title        string
 		repo         string // if empty string, treated as "go" repo
 		body         string
 		wantFindings string
 		wantNotes    string
 	}{
 		{
 			title:        `fmt: improve some things`, // We consider this a good commit message title.
 			body:         goodCommitBody,
 			wantFindings: ``,
 			wantNotes:    ``,
 		},
 		{
 			title: `a bad commit message title.`,
 			body:  goodCommitBody,
 			wantFindings: `  1. The commit title should start with the primary affected package name followed by a colon, like "net/http: improve [...]".
   2. The first word in the commit title after the package should be a lowercase English word (usually a verb).
   3. The commit title should not end with a period.
 `,
 			wantNotes: commitMessageAdvice,
 		},
 		{
 			title: `A bad vscode-go commit title`, // This verifies we complain about a "component" rather than "package".
 			repo:  "vscode-go",
 			body:  "This includes a bad bug format for vscode-go repo.\nFixes #1234",
 			wantFindings: `  1. The commit title should start with the primary affected component name followed by a colon, like "src/goInstallTools: improve [...]".
   2. The first word in the commit title after the component should be a lowercase English word (usually a verb).
   3. Do you have the right bug reference format? For the vscode-go repo, the format is usually 'Fixes golang/vscode-go#1234' or 'Updates golang/vscode-go#1234' at the end of the commit message.
 `,
 			wantNotes: commitMessageAdvice,
 		},
 		{
 			title:        `A bad wiki commit title we allow`, // We ignore the wiki repo.
 			repo:         "wiki",
 			body:         "A bad body we allow",
 			wantFindings: "",
 			wantNotes:    "",
 		},
 		{
 			title:        goodCommitTitle,
 			body:         "This commit body is missing a bug reference.",
 			wantFindings: "  1. You usually need to reference a bug number for all but trivial or cosmetic fixes. For this repo, the format is usually 'Fixes #12345' or 'Updates #12345' at the end of the commit message. Should you have a bug reference?\n",
 			wantNotes:    commitMessageAdvice,
 		},
 		{
 			title: goodCommitTitle,
 			body:  "Some `backticks`\n" + strings.Repeat("long line", 20) + "\n" + goodCommitBody,
 			wantFindings: `  1. You have a long 180 character line in the commit message body. Please add line breaks to long lines that should be wrapped. Lines in the commit message body should be wrapped at ~76 characters unless needed for things like URLs or tables. (Note: GitHub might render long lines as soft-wrapped, so double-check in the Gerrit commit message shown above.)
   2. It looks like you are using markdown in the commit message. If so, please remove it. Be sure to double-check the plain text shown in the Gerrit commit message above for any markdown backticks, markdown links, or other markdown formatting.
 `,
 			wantNotes: commitMessageAdvice,
 		},
 	}
 	for _, tt := range tests {
 		t.Run("title "+tt.title, func(t *testing.T) {
 			commit := commitMessage(tt.title, tt.body, goodCommitFooters)
 			repo := "go"
 			if tt.repo != "" {
 				repo = tt.repo
 			}
 			change, err := ParseCommitMessage(repo, commit)
 			if err != nil {
 				t.Fatalf("ParseCommitMessage failed: %v", err)
 			}
 			results := Check(change)
 			gotFindings, gotNotes := FormatResults(results)
 			t.Log("FormatResults:\n" + gotFindings)

 			if diff := cmp.Diff(tt.wantFindings, gotFindings); diff != "" {
 				t.Errorf("checkRules() findings mismatch (-want +got):\n%s", diff)
 			}
 			if diff := cmp.Diff(tt.wantNotes, gotNotes); diff != "" {
 				t.Errorf("checkRules() notes mismatch (-want +got):\n%s", diff)
 			}
 		})
 	}
 }

 func TestTitleRules(t *testing.T) {
 	tests := []struct {
 		title string
 		repo  string // if empty string, treated as "go" repo
 		body  string
 		want  []string
 	}{
 		// We consider these good titles.
 		{
 			title: "fmt: good",
 			want:  nil,
 		},
 		{
 			title: "go/types, types2: good",
 			want:  nil,
 		},
 		{
 			title: "go/types, types2, types3: good",
 			want:  nil,
 		},
 		{
 			title: "fmt: improve & make: Good",
 			want:  nil,
 		},
 		{
 			title: "README: fix something",
 			want:  nil,
 		},
 		{
 			title: "_content/doc/go1.21: fix something",
 			repo:  "website",
 			want:  nil,
 		},
 		{
 			title: "Fix a proposal", // We are lenient with proposal repo titles.
 			repo:  "proposal",
 			want:  nil,
 		},

 		// We consider these bad titles.
 		{
 			title: "bad.",
 			want: []string{
 				"title: no package found",
 				"title: no lowercase word after a first colon",
 				"title: ends with period",
 			},
 		},
 		{
 			title: "bad",
 			want: []string{
 				"title: no package found",
 				"title: no lowercase word after a first colon",
 			},
 		},
 		{
 			title: "fmt: bad.",
 			want: []string{
 				"title: ends with period",
 			},
 		},
 		{
 			title: "Fmt: bad",
 			want: []string{
 				"title: no package found",
 			},
 		},
 		{
 			title: "fmt: Bad",
 			want: []string{
 				"title: no lowercase word after a first colon",
 			},
 		},
 		{
 			title: "fmt:  bad",
 			want: []string{
 				"title: no colon then single space after package",
 			},
 		},
 		{
 			title: "fmt:  Bad",
 			want: []string{
 				"title: no colon then single space after package",
 				"title: no lowercase word after a first colon",
 			},
 		},
 		{
 			title: "fmt:bad",
 			want: []string{
 				"title: no colon then single space after package",
 			},
 		},
 		{
 			title: "fmt : bad",
 			want: []string{
 				"title: no package found",
 			},
 		},
 		{
 			title: ": bad",
 			want: []string{
 				"title: no package found",
 			},
 		},
 		{
 			title: " : bad",
 			want: []string{
 				"title: no package found",
 			},
 		},
 		{
 			title: "go/types types2: bad",
 			want: []string{
 				"title: no package found",
 			},
 		},
 		{
 			title: "a sentence, with a comma and colon: bad",
 			want: []string{
 				"title: no package found",
 			},
 		},
 		{
 			title: "a sentence with a colon: and a wrongly placed package fmt: bad",
 			want: []string{
 				"title: no package found",
 			},
 		},
 		{
 			title: "",
 			want: []string{
 				"title: no package found",
 				"title: no lowercase word after a first colon",
 			},
 		},

 		// We allow these titles (in interests of simplicity or leniency).
 		// TODO: are some of these considered an alternative good style?
 		{
 			title: "go/types,types2: we allow",
 			want:  nil,
 		},
 		{
 			title: "cmd/{compile,link}: we allow",
 			want:  nil,
 		},
 		{
 			title: "cmd/{compile, link}: we allow",
 			want:  nil,
 		},
 	}
 	for _, tt := range tests {
 		t.Run("title "+tt.title, func(t *testing.T) {
 			commit := commitMessage(tt.title, goodCommitBody, goodCommitFooters)
 			repo := "go"
 			if tt.repo != "" {
 				repo = tt.repo
 			}
 			change, err := ParseCommitMessage(repo, commit)
 			if err != nil {
 				t.Fatalf("ParseCommitMessage failed: %v", err)
 			}
 			results := Check(change)

 			var got []string
 			for _, r := range results {
 				got = append(got, r.Name)
 			}

 			if diff := cmp.Diff(tt.want, got); diff != "" {
 				t.Errorf("checkRules() mismatch (-want +got):\n%s", diff)
 			}
 		})
 	}
 }

 func TestBodyRules(t *testing.T) {
 	tests := []struct {
 		name  string
 		title string // if empty string, we use goodCommitTitle
 		repo  string // if empty string, treated as "go" repo
 		body  string
 		want  []string
 	}{
 		// We consider these good bodies.
 		{
 			name: "good",
 			body: goodCommitBody,
 			want: nil,
 		},
 		{
 			name: "good bug format for go repo",
 			repo: "go",
 			body: "This is This is body text.\n\nFixes #1234",
 			want: nil,
 		},
 		{
 			name: "good bug format for tools repo",
 			repo: "tools",
 			body: "This is This is body text.\n\nFixes golang/go#1234",
 			want: nil,
 		},
 		{
 			name: "good bug format for vscode-go",
 			repo: "vscode-go",
 			body: "This is This is body text.\n\nFixes golang/vscode-go#1234",
 			want: nil,
 		},
 		{
 			name: "good bug format for unknown repo",
 			repo: "some-future-repo",
 			body: "This is This is body text.\n\nFixes golang/go#1234",
 			want: nil,
 		},
 		{
 			name: "allowed long lines for benchstat output",
 			body: "Encode/format=json-48   1.718µ ± 1%   1.423µ ± 1%  -17.20% (p=0.000 n=10)" +
 				strings.Repeat("Hello. ", 100) + "\n" + goodCommitBody,
 			want: nil,
 		},
 		{
 			name:  "a trival fix",
 			title: "fmt: fix spelling mistakes",
 			body:  "",
 			want:  nil, // we don't flag short body or missing bug reference because "spelling" is in title
 		},

 		// Now we consider some bad bodies.
 		// First, some basic mistakes.
 		{
 			name: "too short",
 			body: "Short body",
 			want: []string{
 				"body: short",
 				"body: no bug reference candidate found",
 			},
 		},
 		{
 			name: "missing body",
 			body: "",
 			want: []string{
 				"body: short",
 				"body: no bug reference candidate found",
 			},
 		},
 		{
 			name: "not word wrapped",
 			body: strings.Repeat("Hello. ", 100) + "\n" + goodCommitBody,
 			want: []string{
 				"body: long lines",
 			},
 		},
 		{
 			name: "not a sentence",
 			body: "This is missing a period",
 			want: []string{
 				"body: no sentence candidates found",
 				"body: no bug reference candidate found",
 			},
 		},
 		{
 			name: "Signed-off-by",
 			body: "Signed-off-by: bad\n\n" + goodCommitBody,
 			want: []string{
 				"body: contains Signed-off-by",
 			},
 		},
 		{
 			name: "PR instructions",
 			body: "Delete these instructions once you have read and applied them.\n",
 			want: []string{
 				"body: still contains PR instructions",
 				"body: no bug reference candidate found",
 			},
 		},

 		// Next, mistakes in the repo-specific format or location of bug references.
 		{
 			name: "bad bug format for go repo",
 			repo: "go",
 			body: "This is body text.\n\nFixes golang/go#1234",
 			want: []string{
 				"body: bug format looks incorrect",
 			},
 		},
 		{
 			name: "bad bug format for tools repo",
 			repo: "tools",
 			body: "This is body text.\n\nFixes #1234",
 			want: []string{
 				"body: bug format looks incorrect",
 			},
 		},
 		{
 			name: "bad bug format for vscode-go",
 			repo: "vscode-go",
 			body: "This is body text.\n\nFixes #1234",
 			want: []string{
 				"body: bug format looks incorrect",
 			},
 		},
 		{
 			name: "bad bug format for unknown repo",
 			repo: "some-future-repo",
 			body: "This is body text.\n\nFixes #1234",
 			want: []string{
 				"body: bug format looks incorrect",
 			},
 		},
 		{
 			name: "bad bug location",
 			body: "This is body text.\nFixes #1234\nAnd a final line we should not have.",
 			want: []string{
 				"body: no bug reference candidate at end",
 			},
 		},

 		// We next have some good bodies that are markdown-ish,
 		// but we allow them.
 		{
 			name:  "allowed markdown: mention regex in title",
 			title: "regexp: fix something",
 			body:  "Example `.*`.\n" + goodCommitBody,
 			want:  nil,
 		},
 		{
 			name: "allowed markdown: mention regex in body",
 			body: "A regex `.*`.\n" + goodCommitBody,
 			want: nil,
 		},
 		{
 			name: "allowed markdown: mention markdown",
 			body: "A markdown bug `and this is ok`.\n" + goodCommitBody,
 			want: nil,
 		},
 		{
 			name: "allowed markdown: might be go code",
 			body: " s := `raw`\n" + goodCommitBody,
 			want: nil,
 		},

 		// Examples of using markdown that we flag.
 		{
 			name: "markdown backticks",
 			body: "A variable `foo`.\n" + goodCommitBody,
 			want: []string{
 				"body: might use markdown",
 			},
 		},
 		{
 			name: "markdown block quote",
 			body: "Some code:\n```\nx := y\n```\n" + goodCommitBody,
 			want: []string{
 				"body: might use markdown",
 			},
 		},
 		{
 			name: "markdown link",
 			body: "[click here](https://example.com)\n" + goodCommitBody,
 			want: []string{
 				"body: might use markdown",
 			},
 		},
 	}
 	for _, tt := range tests {
 		t.Run(tt.name, func(t *testing.T) {
 			title := goodCommitTitle
 			if tt.title != "" {
 				title = tt.title
 			}
 			commit := commitMessage(title, tt.body, goodCommitFooters)
 			repo := "go"
 			if tt.repo != "" {
 				repo = tt.repo
 			}
 			change, err := ParseCommitMessage(repo, commit)
 			if err != nil {
 				t.Fatalf("ParseCommitMessage failed: %v", err)
 			}
 			results := Check(change)

 			var got []string
 			for _, r := range results {
 				got = append(got, r.Name)
 			}

 			if diff := cmp.Diff(tt.want, got); diff != "" {
 				t.Errorf("checkRules() mismatch (-want +got):\n%s", diff)
 			}
 		})
 	}
 }

 func TestParseCommitMessage(t *testing.T) {
 	tests := []struct {
 		name    string
 		repo    string
 		text    string
 		want    Change
 		wantErr bool
 	}{
 		// Bad examples.
 		{
 			name:    "not enough lines",
 			text:    "title",
 			want:    Change{},
 			wantErr: true,
 		},
 		{
 			name:    "second line not blank",
 			text:    "title\nbad line\nBody 1",
 			want:    Change{},
 			wantErr: true,
 		},
 		{
 			name:    "no footer",
 			text:    "title\n\nBody 1\n",
 			want:    Change{},
 			wantErr: true,
 		},
 		{
 			name:    "no footer and no body",
 			text:    "title\n\n\n",
 			want:    Change{},
 			wantErr: true,
 		},

 		// Good examples.
 		{
 			name: "good",
 			text: "title\n\nBody 1\n\nFooter: 1\n",
 			want: Change{
 				Title: "title",
 				Body:  "Body 1",
 			},
 			wantErr: false,
 		},
 		{
 			name: "good with two body lines",
 			text: "title\n\nBody 1\nBody 2\n\nFooter: 1\n",
 			want: Change{
 				Title: "title",
 				Body:  "Body 1\nBody 2",
 			},
 			wantErr: false,
 		},
 		{
 			name: "good with empty body",
 			text: "title\n\nFooter: 1\n",
 			want: Change{
 				Title: "title",
 				Body:  "",
 			},
 			wantErr: false,
 		},
 		{
 			name: "good with extra blank lines after footer",
 			text: "title\n\nBody 1\n\nFooter: 1\n\n\n",
 			want: Change{
 				Title: "title",
 				Body:  "Body 1",
 			},
 			wantErr: false,
 		},
 		{
 			name: "good with body line that looks like footer",
 			text: "title\n\nBody 1\nLink: example.com\n\nFooter: 1\n\n\n",
 			want: Change{
 				Title: "title",
 				Body:  "Body 1\nLink: example.com",
 			},
 			wantErr: false,
 		},
 		{
 			name: "allowed cherry pick in footer", // Example from CL 346093.
 			text: "title\n\nBody 1\n\nFooter: 1\n(cherry picked from commit ebd07b13caf35114b32e7d6783b27902af4829ce)\n",
 			want: Change{
 				Title: "title",
 				Body:  "Body 1",
 			},
 			wantErr: false,
 		},
 	}
 	for _, tt := range tests {
 		t.Run(tt.name, func(t *testing.T) {
 			got, err := ParseCommitMessage(tt.repo, tt.text)
 			if (err != nil) != tt.wantErr {
 				t.Errorf("ParseCommitMessage() error = %v, wantErr %v", err, tt.wantErr)
 				return
 			}
 			if diff := cmp.Diff(tt.want, got); diff != "" {
 				t.Errorf("checkRules() mismatch (-want +got):\n%s", diff)
 			}
 		})
 	}
 }

 // commitMessage helps us create valid commit messages while testing.
 func commitMessage(title, body, footers string) string {
 	return title + "\n\n" + body + "\n\n" + footers
 }

 // Some auxiliary testing variables available for use when creating commit messages.
 var (
 	goodCommitTitle   = "pkg: a title that does not trigger any rules"
 	goodCommitBody    = "A commit message body that does not trigger any rules.\n\nFixes #1234"
 	goodCommitFooters = `Change-Id: I1d8d10b142358983194ef2c389de4d9862d4ce97
 GitHub-Last-Rev: 6d27e1471ee5dac0323a10b46e6e64e647068ecf
 GitHub-Pull-Request: golang/build#69`
 )
	// Copyright 2023 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 rules

	import (
	"strings"
	"testing"

	"github.com/google/go-cmp/cmp"
	)

	func TestFormatRuleResults(t *testing.T) {
	tests := []struct {
	title string
	repo string // if empty string, treated as "go" repo
	body string
	wantFindings string
	wantNotes string
	}{
	{
	title: `fmt: improve some things`, // We consider this a good commit message title.
	body: goodCommitBody,
	wantFindings: ``,
	wantNotes: ``,
	},
	{
	title: `a bad commit message title.`,
	body: goodCommitBody,
	wantFindings: ` 1. The commit title should start with the primary affected package name followed by a colon, like "net/http: improve [...]".
	2. The first word in the commit title after the package should be a lowercase English word (usually a verb).
	3. The commit title should not end with a period.
	`,
	wantNotes: commitMessageAdvice,
	},
	{
	title: `A bad vscode-go commit title`, // This verifies we complain about a "component" rather than "package".
	repo: "vscode-go",
	body: "This includes a bad bug format for vscode-go repo.\nFixes #1234",
	wantFindings: ` 1. The commit title should start with the primary affected component name followed by a colon, like "src/goInstallTools: improve [...]".
	2. The first word in the commit title after the component should be a lowercase English word (usually a verb).
	3. Do you have the right bug reference format? For the vscode-go repo, the format is usually 'Fixes golang/vscode-go#1234' or 'Updates golang/vscode-go#1234' at the end of the commit message.
	`,
	wantNotes: commitMessageAdvice,
	},
	{
	title: `A bad wiki commit title we allow`, // We ignore the wiki repo.
	repo: "wiki",
	body: "A bad body we allow",
	wantFindings: "",
	wantNotes: "",
	},
	{
	title: goodCommitTitle,
	body: "This commit body is missing a bug reference.",
	wantFindings: " 1. You usually need to reference a bug number for all but trivial or cosmetic fixes. For this repo, the format is usually 'Fixes #12345' or 'Updates #12345' at the end of the commit message. Should you have a bug reference?\n",
	wantNotes: commitMessageAdvice,
	},
	{
	title: goodCommitTitle,
	body: "Some `backticks`\n" + strings.Repeat("long line", 20) + "\n" + goodCommitBody,
	wantFindings: ` 1. You have a long 180 character line in the commit message body. Please add line breaks to long lines that should be wrapped. Lines in the commit message body should be wrapped at ~76 characters unless needed for things like URLs or tables. (Note: GitHub might render long lines as soft-wrapped, so double-check in the Gerrit commit message shown above.)
	2. It looks like you are using markdown in the commit message. If so, please remove it. Be sure to double-check the plain text shown in the Gerrit commit message above for any markdown backticks, markdown links, or other markdown formatting.
	`,
	wantNotes: commitMessageAdvice,
	},
	}
	for _, tt := range tests {
	t.Run("title "+tt.title, func(t *testing.T) {
	commit := commitMessage(tt.title, tt.body, goodCommitFooters)
	repo := "go"
	if tt.repo != "" {
	repo = tt.repo
	}
	change, err := ParseCommitMessage(repo, commit)
	if err != nil {
	t.Fatalf("ParseCommitMessage failed: %v", err)
	}
	results := Check(change)
	gotFindings, gotNotes := FormatResults(results)
	t.Log("FormatResults:\n" + gotFindings)

	if diff := cmp.Diff(tt.wantFindings, gotFindings); diff != "" {
	t.Errorf("checkRules() findings mismatch (-want +got):\n%s", diff)
	}
	if diff := cmp.Diff(tt.wantNotes, gotNotes); diff != "" {
	t.Errorf("checkRules() notes mismatch (-want +got):\n%s", diff)
	}
	})
	}
	}

	func TestTitleRules(t *testing.T) {
	tests := []struct {
	title string
	repo string // if empty string, treated as "go" repo
	body string
	want []string
	}{
	// We consider these good titles.
	{
	title: "fmt: good",
	want: nil,
	},
	{
	title: "go/types, types2: good",
	want: nil,
	},
	{
	title: "go/types, types2, types3: good",
	want: nil,
	},
	{
	title: "fmt: improve & make: Good",
	want: nil,
	},
	{
	title: "README: fix something",
	want: nil,
	},
	{
	title: "_content/doc/go1.21: fix something",
	repo: "website",
	want: nil,
	},
	{
	title: "Fix a proposal", // We are lenient with proposal repo titles.
	repo: "proposal",
	want: nil,
	},

	// We consider these bad titles.
	{
	title: "bad.",
	want: []string{
	"title: no package found",
	"title: no lowercase word after a first colon",
	"title: ends with period",
	},
	},
	{
	title: "bad",
	want: []string{
	"title: no package found",
	"title: no lowercase word after a first colon",
	},
	},
	{
	title: "fmt: bad.",
	want: []string{
	"title: ends with period",
	},
	},
	{
	title: "Fmt: bad",
	want: []string{
	"title: no package found",
	},
	},
	{
	title: "fmt: Bad",
	want: []string{
	"title: no lowercase word after a first colon",
	},
	},
	{
	title: "fmt: bad",
	want: []string{
	"title: no colon then single space after package",
	},
	},
	{
	title: "fmt: Bad",
	want: []string{
	"title: no colon then single space after package",
	"title: no lowercase word after a first colon",
	},
	},
	{
	title: "fmt:bad",
	want: []string{
	"title: no colon then single space after package",
	},
	},
	{
	title: "fmt : bad",
	want: []string{
	"title: no package found",
	},
	},
	{
	title: ": bad",
	want: []string{
	"title: no package found",
	},
	},
	{
	title: " : bad",
	want: []string{
	"title: no package found",
	},
	},
	{
	title: "go/types types2: bad",
	want: []string{
	"title: no package found",
	},
	},
	{
	title: "a sentence, with a comma and colon: bad",
	want: []string{
	"title: no package found",
	},
	},
	{
	title: "a sentence with a colon: and a wrongly placed package fmt: bad",
	want: []string{
	"title: no package found",
	},
	},
	{
	title: "",
	want: []string{
	"title: no package found",
	"title: no lowercase word after a first colon",
	},
	},

	// We allow these titles (in interests of simplicity or leniency).
	// TODO: are some of these considered an alternative good style?
	{
	title: "go/types,types2: we allow",
	want: nil,
	},
	{
	title: "cmd/{compile,link}: we allow",
	want: nil,
	},
	{
	title: "cmd/{compile, link}: we allow",
	want: nil,
	},
	}
	for _, tt := range tests {
	t.Run("title "+tt.title, func(t *testing.T) {
	commit := commitMessage(tt.title, goodCommitBody, goodCommitFooters)
	repo := "go"
	if tt.repo != "" {
	repo = tt.repo
	}
	change, err := ParseCommitMessage(repo, commit)
	if err != nil {
	t.Fatalf("ParseCommitMessage failed: %v", err)
	}
	results := Check(change)

	var got []string
	for _, r := range results {
	got = append(got, r.Name)
	}

	if diff := cmp.Diff(tt.want, got); diff != "" {
	t.Errorf("checkRules() mismatch (-want +got):\n%s", diff)
	}
	})
	}
	}

	func TestBodyRules(t *testing.T) {
	tests := []struct {
	name string
	title string // if empty string, we use goodCommitTitle
	repo string // if empty string, treated as "go" repo
	body string
	want []string
	}{
	// We consider these good bodies.
	{
	name: "good",
	body: goodCommitBody,
	want: nil,
	},
	{
	name: "good bug format for go repo",
	repo: "go",
	body: "This is This is body text.\n\nFixes #1234",
	want: nil,
	},
	{
	name: "good bug format for tools repo",
	repo: "tools",
	body: "This is This is body text.\n\nFixes golang/go#1234",
	want: nil,
	},
	{
	name: "good bug format for vscode-go",
	repo: "vscode-go",
	body: "This is This is body text.\n\nFixes golang/vscode-go#1234",
	want: nil,
	},
	{
	name: "good bug format for unknown repo",
	repo: "some-future-repo",
	body: "This is This is body text.\n\nFixes golang/go#1234",
	want: nil,
	},
	{
	name: "allowed long lines for benchstat output",
	body: "Encode/format=json-48 1.718µ ± 1% 1.423µ ± 1% -17.20% (p=0.000 n=10)" +
	strings.Repeat("Hello. ", 100) + "\n" + goodCommitBody,
	want: nil,
	},
	{
	name: "a trival fix",
	title: "fmt: fix spelling mistakes",
	body: "",
	want: nil, // we don't flag short body or missing bug reference because "spelling" is in title
	},

	// Now we consider some bad bodies.
	// First, some basic mistakes.
	{
	name: "too short",
	body: "Short body",
	want: []string{
	"body: short",
	"body: no bug reference candidate found",
	},
	},
	{
	name: "missing body",
	body: "",
	want: []string{
	"body: short",
	"body: no bug reference candidate found",
	},
	},
	{
	name: "not word wrapped",
	body: strings.Repeat("Hello. ", 100) + "\n" + goodCommitBody,
	want: []string{
	"body: long lines",
	},
	},
	{
	name: "not a sentence",
	body: "This is missing a period",
	want: []string{
	"body: no sentence candidates found",
	"body: no bug reference candidate found",
	},
	},
	{
	name: "Signed-off-by",
	body: "Signed-off-by: bad\n\n" + goodCommitBody,
	want: []string{
	"body: contains Signed-off-by",
	},
	},
	{
	name: "PR instructions",
	body: "Delete these instructions once you have read and applied them.\n",
	want: []string{
	"body: still contains PR instructions",
	"body: no bug reference candidate found",
	},
	},

	// Next, mistakes in the repo-specific format or location of bug references.
	{
	name: "bad bug format for go repo",
	repo: "go",
	body: "This is body text.\n\nFixes golang/go#1234",
	want: []string{
	"body: bug format looks incorrect",
	},
	},
	{
	name: "bad bug format for tools repo",
	repo: "tools",
	body: "This is body text.\n\nFixes #1234",
	want: []string{
	"body: bug format looks incorrect",
	},
	},
	{
	name: "bad bug format for vscode-go",
	repo: "vscode-go",
	body: "This is body text.\n\nFixes #1234",
	want: []string{
	"body: bug format looks incorrect",
	},
	},
	{
	name: "bad bug format for unknown repo",
	repo: "some-future-repo",
	body: "This is body text.\n\nFixes #1234",
	want: []string{
	"body: bug format looks incorrect",
	},
	},
	{
	name: "bad bug location",
	body: "This is body text.\nFixes #1234\nAnd a final line we should not have.",
	want: []string{
	"body: no bug reference candidate at end",
	},
	},

	// We next have some good bodies that are markdown-ish,
	// but we allow them.
	{
	name: "allowed markdown: mention regex in title",
	title: "regexp: fix something",
	body: "Example `.*`.\n" + goodCommitBody,
	want: nil,
	},
	{
	name: "allowed markdown: mention regex in body",
	body: "A regex `.*`.\n" + goodCommitBody,
	want: nil,
	},
	{
	name: "allowed markdown: mention markdown",
	body: "A markdown bug `and this is ok`.\n" + goodCommitBody,
	want: nil,
	},
	{
	name: "allowed markdown: might be go code",
	body: " s := `raw`\n" + goodCommitBody,
	want: nil,
	},

	// Examples of using markdown that we flag.
	{
	name: "markdown backticks",
	body: "A variable `foo`.\n" + goodCommitBody,
	want: []string{
	"body: might use markdown",
	},
	},
	{
	name: "markdown block quote",
	body: "Some code:\n```\nx := y\n```\n" + goodCommitBody,
	want: []string{
	"body: might use markdown",
	},
	},
	{
	name: "markdown link",
	body: "[click here](https://example.com)\n" + goodCommitBody,
	want: []string{
	"body: might use markdown",
	},
	},
	}
	for _, tt := range tests {
	t.Run(tt.name, func(t *testing.T) {
	title := goodCommitTitle
	if tt.title != "" {
	title = tt.title
	}
	commit := commitMessage(title, tt.body, goodCommitFooters)
	repo := "go"
	if tt.repo != "" {
	repo = tt.repo
	}
	change, err := ParseCommitMessage(repo, commit)
	if err != nil {
	t.Fatalf("ParseCommitMessage failed: %v", err)
	}
	results := Check(change)

	var got []string
	for _, r := range results {
	got = append(got, r.Name)
	}

	if diff := cmp.Diff(tt.want, got); diff != "" {
	t.Errorf("checkRules() mismatch (-want +got):\n%s", diff)
	}
	})
	}
	}

	func TestParseCommitMessage(t *testing.T) {
	tests := []struct {
	name string
	repo string
	text string
	want Change
	wantErr bool
	}{
	// Bad examples.
	{
	name: "not enough lines",
	text: "title",
	want: Change{},
	wantErr: true,
	},
	{
	name: "second line not blank",
	text: "title\nbad line\nBody 1",
	want: Change{},
	wantErr: true,
	},
	{
	name: "no footer",
	text: "title\n\nBody 1\n",
	want: Change{},
	wantErr: true,
	},
	{
	name: "no footer and no body",
	text: "title\n\n\n",
	want: Change{},
	wantErr: true,
	},

	// Good examples.
	{
	name: "good",
	text: "title\n\nBody 1\n\nFooter: 1\n",
	want: Change{
	Title: "title",
	Body: "Body 1",
	},
	wantErr: false,
	},
	{
	name: "good with two body lines",
	text: "title\n\nBody 1\nBody 2\n\nFooter: 1\n",
	want: Change{
	Title: "title",
	Body: "Body 1\nBody 2",
	},
	wantErr: false,
	},
	{
	name: "good with empty body",
	text: "title\n\nFooter: 1\n",
	want: Change{
	Title: "title",
	Body: "",
	},
	wantErr: false,
	},
	{
	name: "good with extra blank lines after footer",
	text: "title\n\nBody 1\n\nFooter: 1\n\n\n",
	want: Change{
	Title: "title",
	Body: "Body 1",
	},
	wantErr: false,
	},
	{
	name: "good with body line that looks like footer",
	text: "title\n\nBody 1\nLink: example.com\n\nFooter: 1\n\n\n",
	want: Change{
	Title: "title",
	Body: "Body 1\nLink: example.com",
	},
	wantErr: false,
	},
	{
	name: "allowed cherry pick in footer", // Example from CL 346093.
	text: "title\n\nBody 1\n\nFooter: 1\n(cherry picked from commit ebd07b13caf35114b32e7d6783b27902af4829ce)\n",
	want: Change{
	Title: "title",
	Body: "Body 1",
	},
	wantErr: false,
	},
	}
	for _, tt := range tests {
	t.Run(tt.name, func(t *testing.T) {
	got, err := ParseCommitMessage(tt.repo, tt.text)
	if (err != nil) != tt.wantErr {
	t.Errorf("ParseCommitMessage() error = %v, wantErr %v", err, tt.wantErr)
	return
	}
	if diff := cmp.Diff(tt.want, got); diff != "" {
	t.Errorf("checkRules() mismatch (-want +got):\n%s", diff)
	}
	})
	}
	}

	// commitMessage helps us create valid commit messages while testing.
	func commitMessage(title, body, footers string) string {
	return title + "\n\n" + body + "\n\n" + footers
	}

	// Some auxiliary testing variables available for use when creating commit messages.
	var (
	goodCommitTitle = "pkg: a title that does not trigger any rules"
	goodCommitBody = "A commit message body that does not trigger any rules.\n\nFixes #1234"
	goodCommitFooters = `Change-Id: I1d8d10b142358983194ef2c389de4d9862d4ce97
	GitHub-Last-Rev: 6d27e1471ee5dac0323a10b46e6e64e647068ecf
	GitHub-Pull-Request: golang/build#69`
	)