cmd/watchflakes/github.go - build - Git at Google

 // Copyright 2024 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 main

 import (
 	"fmt"
 	"log"
 	"regexp"
 	"sort"
 	"strings"

 	"golang.org/x/build/cmd/watchflakes/internal/script"
 	"rsc.io/github"
 )

 // An Issue is a single GitHub issue in the Test Flakes project:
 // a plain github.Issue plus our associated data.
 type Issue struct {
 	*github.Issue
 	ScriptText string         // extracted watchflakes script
 	Script     *script.Script // compiled script

 	// initialized by readComments
 	Stale    bool                   // issue comments may be stale
 	Comments []*github.IssueComment // all issue comments
 	NewBody  bool                   // issue body (containing script) is newer than last watchflakes comment
 	Mentions map[string]bool        // log URLs that have already been posted in watchflakes comments

 	// what to send back to the issue
 	Error string         // error message (markdown) to post back to issue
 	Post  []*FailurePost // failures to post back to issue
 }

 func (i *Issue) String() string { return fmt.Sprintf("#%d", i.Number) }

 var (
 	gh         *github.Client
 	repo       *github.Repo
 	labels     map[string]*github.Label
 	testFlakes *github.Project
 )

 var scriptRE = regexp.MustCompile(`(?m)(^( {4}|\t)#!watchflakes\n((( {4}|\t).*)?\n)+|^\x60{3}\n#!watchflakes\n(([^\x60].*)?\n)+\x60{3}\n)`)

 // readIssues reads the GitHub issues in the Test Flakes project.
 // It also sets up the repo, labels, and testFlakes variables for
 // use by other functions below.
 func readIssues(old []*Issue) ([]*Issue, error) {
 	var err error
 	gh, err = github.Dial("gopherbot")
 	if err != nil {
 		gh, err = github.Dial("")
 		if err != nil {
 			return nil, err
 		}
 	}

 	// Find repo.
 	r, err := gh.Repo("golang", "go")
 	if err != nil {
 		return nil, err
 	}
 	repo = r

 	// Find labels.
 	list, err := gh.SearchLabels("golang", "go", "")
 	if err != nil {
 		return nil, err
 	}
 	labels = make(map[string]*github.Label)
 	for _, label := range list {
 		labels[label.Name] = label
 	}

 	// Find Test Flakes project.
 	ps, err := gh.Projects("golang", "")
 	if err != nil {
 		return nil, err
 	}
 	for _, p := range ps {
 		if p.Title == "Test Flakes" {
 			testFlakes = p
 			break
 		}
 	}
 	if testFlakes == nil {
 		return nil, fmt.Errorf("cannot find Test Flakes project")
 	}

 	cache := make(map[int]*Issue)
 	for _, issue := range old {
 		cache[issue.Number] = issue
 	}
 	// Read all issues in Test Flakes.
 	var issues []*Issue
 	items, err := gh.ProjectItems(testFlakes)
 	if err != nil {
 		return nil, err
 	}
 	for _, item := range items {
 		if item.Issue != nil {
 			issue := &Issue{Issue: item.Issue, NewBody: true, Stale: true}
 			if c := cache[item.Issue.Number]; c != nil {
 				// Carry conservative NewBody, Mentions data forward
 				// to avoid round trips about things we already know.
 				if c.Issue.LastEditedAt.Equal(item.Issue.LastEditedAt) {
 					issue.NewBody = c.NewBody
 				}
 				issue.Mentions = c.Mentions
 			}
 			issues = append(issues, issue)
 		}
 	}
 	sort.Slice(issues, func(i, j int) bool {
 		return issues[i].Number < issues[j].Number
 	})

 	return issues, nil
 }

 // findScripts finds the scripts in the issues,
 // initializing issue.Script and .ScriptText or else .Error
 // in each issue.
 func findScripts(issues []*Issue) {
 	for _, issue := range issues {
 		findScript(issue)
 	}
 }

 var noScriptError = `
 Sorry, but I can't find a watchflakes script at the start of the issue description.
 See https://go.dev/wiki/Watchflakes for details.
 `

 var parseScriptError = `
 Sorry, but there were parse errors in the watch flakes script.
 The script I found was:

 %s

 And the problems were:

 %s

 See https://go.dev/wiki/Watchflakes for details.
 `

 // findScript finds the script in issue and parses it.
 // If the script is not found or has any parse errors,
 // issue.Error is filled in.
 // Otherwise issue.ScriptText and issue.Script are filled in.
 func findScript(issue *Issue) {
 	// Extract ```-fenced or indented code block at start of issue description (body).
 	body := strings.ReplaceAll(issue.Body, "\r\n", "\n")
 	lines := strings.SplitAfter(body, "\n")
 	for len(lines) > 0 && strings.TrimSpace(lines[0]) == "" {
 		lines = lines[1:]
 	}
 	text := ""
 	if len(lines) > 0 && strings.HasPrefix(lines[0], "```") {
 		marker := lines[0]
 		n := 0
 		for n < len(marker) && marker[n] == '`' {
 			n++
 		}
 		marker = marker[:n]
 		i := 1
 		for i := 1; i < len(lines); i++ {
 			if strings.HasPrefix(lines[i], marker) && strings.TrimSpace(strings.TrimLeft(lines[i], "`")) == "" {
 				text = strings.Join(lines[1:i], "")
 				break
 			}
 		}
 		if i < len(lines) {
 		}
 	} else if strings.HasPrefix(lines[0], "\t") || strings.HasPrefix(lines[0], "    ") {
 		i := 1
 		for i < len(lines) && (strings.HasPrefix(lines[i], "\t") || strings.HasPrefix(lines[i], "    ")) {
 			i++
 		}
 		text = strings.Join(lines[:i], "")
 	}

 	// Must start with #!watchflakes so we're sure it is for us.
 	hdr, _, _ := strings.Cut(text, "\n")
 	hdr = strings.TrimSpace(hdr)
 	if hdr != "#!watchflakes" {
 		issue.Error = noScriptError
 		return
 	}

 	// Parse script.
 	issue.ScriptText = text
 	s, errs := script.Parse("script", text, fields)
 	if len(errs) > 0 {
 		var errtext strings.Builder
 		for _, err := range errs {
 			errtext.WriteString(err.Error())
 			errtext.WriteString("\n")
 		}
 		issue.Error = fmt.Sprintf(parseScriptError, indent("\t", text), indent("\t", errtext.String()))
 		return
 	}

 	issue.Script = s
 }

 func postIssueErrors(issues []*Issue) []error {
 	var errors []error
 	for _, issue := range issues {
 		if issue.Error != "" && issue.NewBody {
 			readComments(issue)
 			if issue.NewBody {
 				fmt.Printf(" - #%d script error\n", issue.Number)
 				if *verbose {
 					fmt.Printf("\n%s\n", indent(spaces[:7], issue.Error))
 				}
 				if *post {
 					if err := postComment(issue, issue.Error); err != nil {
 						errors = append(errors, err)
 						continue
 					}
 					issue.NewBody = false
 				}
 			}
 		}
 	}
 	return errors
 }

 // updateText returns the text for the GitHub update on issue.
 func updateText(issue *Issue) string {
 	if len(issue.Post) == 0 {
 		return ""
 	}

 	var b strings.Builder
 	fmt.Fprintf(&b, "Found new dashboard test flakes for:\n\n%s", indent(spaces[:4], issue.ScriptText))
 	for _, f := range issue.Post {
 		b.WriteString("\n")
 		_ = f
 		b.WriteString(f.Markdown())
 	}
 	return b.String()
 }

 // reportNew creates and returns a new issue for reporting the failure.
 // If *post is false, reportNew returns a fake issue with number 0.
 func reportNew(fp *FailurePost) (*Issue, error) {
 	var pattern, title string
 	if fp.Pkg != "" {
 		pattern = fmt.Sprintf("pkg == %q && test == %q", fp.Pkg, fp.Test)
 		test := fp.Test
 		if test == "" {
 			test = "unrecognized"
 		}
 		title = shortPkg(fp.Pkg) + ": " + test + " failures"
 	} else if fp.Test != "" {
 		pattern = fmt.Sprintf("repo == %q && pkg == %q && test == %q", fp.Repo, "", fp.Test)
 		title = "build: " + fp.Test + " failures"
 	} else if fp.IsBuildFailure() {
 		pattern = fmt.Sprintf("builder == %q && repo == %q && mode == %q", fp.Builder, fp.Repo, "build")
 		title = "build: build failure on " + fp.Builder
 	} else {
 		pattern = fmt.Sprintf("builder == %q && repo == %q && pkg == %q && test == %q", fp.Builder, fp.Repo, "", "")
 		title = "build: unrecognized failures on " + fp.Builder
 	}

 	var msg strings.Builder
 	fmt.Fprintf(&msg, "```\n#!watchflakes\ndefault <- %s\n```\n\n", pattern)
 	fmt.Fprintf(&msg, "Issue created automatically to collect these failures.\n\n")
 	fmt.Fprintf(&msg, "Example ([log](%s)):\n\n%s", fp.URL, indent(spaces[:4], fp.Snippet))

 	// TODO: for a single test failure, add a link to LUCI history page.

 	fmt.Printf("# new issue: %s\n%s\n%s\n%s\n\n%s\n", title, fp.String(), fp.URL, pattern, fp.Snippet)
 	if *verbose {
 		fmt.Printf("\n%s\n", indent(spaces[:3], msg.String()))
 	}

 	issue := new(Issue)
 	if *post {
 		issue.Issue = newIssue(title, msg.String())
 	} else {
 		issue.Issue = &github.Issue{Title: title, Body: msg.String()}
 	}
 	findScript(issue)
 	if issue.Error != "" {
 		return nil, fmt.Errorf("cannot find script in generated issue:\nBody:\n%s\n\nError:\n%s", issue.Body, issue.Error)
 	}
 	issue.Post = append(issue.Post, fp)
 	return issue, nil
 }

 // signature is the signature we add to the end of every comment or issue body
 // we post on GitHub. It links to documentation for users, and it also serves as
 // a way to identify the comments that we posted, since watchflakes can be run
 // as gopherbot or as an ordinary user.
 const signature = "\n\n— [watchflakes](https://go.dev/wiki/Watchflakes)\n"

 // keep in sync with buildURL function in luci.go
 // An older version reported ci.chromium.org/ui/b instead of ci.chromium.org/b,
 // match them as well.
 var buildUrlRE = regexp.MustCompile(`[("']https://ci.chromium.org/(ui/)?b/[0-9]+['")]`)

 // readComments loads the comments for the given issue,
 // setting the Comments, NewBody, and Mentions fields.
 func readComments(issue *Issue) {
 	if issue.Number == 0 || !issue.Stale {
 		return
 	}
 	log.Printf("readComments %d", issue.Number)
 	comments, err := gh.IssueComments(issue.Issue)
 	if err != nil {
 		log.Fatal(err)
 	}
 	issue.Comments = comments
 	mtime := issue.LastEditedAt
 	if mtime.IsZero() {
 		mtime = issue.CreatedAt
 	}
 	issue.Mentions = make(map[string]bool)
 	issue.NewBody = true // until proven otherwise
 	for _, com := range comments {
 		// Only consider comments we signed.
 		if !strings.Contains(com.Body, "\n— watchflakes") && !strings.Contains(com.Body, "\n— [watchflakes](") {
 			continue
 		}
 		if com.CreatedAt.After(issue.LastEditedAt) {
 			issue.NewBody = false
 		}
 		for _, link := range buildUrlRE.FindAllString(com.Body, -1) {
 			l := strings.Trim(link, "()\"'")
 			issue.Mentions[l] = true
 			// An older version reported ci.chromium.org/ui/b instead of ci.chromium.org/b,
 			// match them as well.
 			issue.Mentions[strings.Replace(l, "ci.chromium.org/ui/b/", "ci.chromium.org/b/", 1)] = true
 		}
 	}
 	issue.Stale = false
 }

 // newIssue creates a new issue with the given title and body,
 // setting the NeedsInvestigation label and placing the issue int
 // the Test Flakes project.
 // It automatically adds signature to the body.
 func newIssue(title, body string) *github.Issue {
 	var args []any
 	if lab := labels["NeedsInvestigation"]; lab != nil {
 		args = append(args, lab)
 	}
 	args = append(args, testFlakes)

 	issue, err := gh.CreateIssue(repo, title, body+signature, args...)
 	if err != nil {
 		log.Fatal(err)
 	}
 	return issue
 }

 // postComment posts a new comment on the issue.
 // It automatically adds signature to the comment.
 func postComment(issue *Issue, body string) error {
 	if len(body) > 50000 {
 		// Apparently GitHub GraphQL API limits comment length to 65536.
 		body = body[:50000] + "\n</details>\n(... long comment truncated ...)\n"
 	}
 	if issue.Issue.Closed {
 		reopen := false
 		for _, p := range issue.Post {
 			_ = p
 			if p.Time.After(issue.ClosedAt) {
 				reopen = true
 				break
 			}
 		}
 		if reopen {
 			if err := gh.ReopenIssue(issue.Issue); err != nil {
 				return err
 			}
 		}
 	}
 	return gh.AddIssueComment(issue.Issue, body+signature)
 }
	// Copyright 2024 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 main

	import (
	"fmt"
	"log"
	"regexp"
	"sort"
	"strings"

	"golang.org/x/build/cmd/watchflakes/internal/script"
	"rsc.io/github"
	)

	// An Issue is a single GitHub issue in the Test Flakes project:
	// a plain github.Issue plus our associated data.
	type Issue struct {
	*github.Issue
	ScriptText string // extracted watchflakes script
	Script *script.Script // compiled script

	// initialized by readComments
	Stale bool // issue comments may be stale
	Comments []*github.IssueComment // all issue comments
	NewBody bool // issue body (containing script) is newer than last watchflakes comment
	Mentions map[string]bool // log URLs that have already been posted in watchflakes comments

	// what to send back to the issue
	Error string // error message (markdown) to post back to issue
	Post []*FailurePost // failures to post back to issue
	}

	func (i *Issue) String() string { return fmt.Sprintf("#%d", i.Number) }

	var (
	gh *github.Client
	repo *github.Repo
	labels map[string]*github.Label
	testFlakes *github.Project
	)

	var scriptRE = regexp.MustCompile(`(?m)(^( {4}\|\t)#!watchflakes\n((( {4}\|\t).)?\n)+\|^\x60{3}\n#!watchflakes\n(([^\x60].)?\n)+\x60{3}\n)`)

	// readIssues reads the GitHub issues in the Test Flakes project.
	// It also sets up the repo, labels, and testFlakes variables for
	// use by other functions below.
	func readIssues(old []Issue) ([]Issue, error) {
	var err error
	gh, err = github.Dial("gopherbot")
	if err != nil {
	gh, err = github.Dial("")
	if err != nil {
	return nil, err
	}
	}

	// Find repo.
	r, err := gh.Repo("golang", "go")
	if err != nil {
	return nil, err
	}
	repo = r

	// Find labels.
	list, err := gh.SearchLabels("golang", "go", "")
	if err != nil {
	return nil, err
	}
	labels = make(map[string]*github.Label)
	for _, label := range list {
	labels[label.Name] = label
	}

	// Find Test Flakes project.
	ps, err := gh.Projects("golang", "")
	if err != nil {
	return nil, err
	}
	for _, p := range ps {
	if p.Title == "Test Flakes" {
	testFlakes = p
	break
	}
	}
	if testFlakes == nil {
	return nil, fmt.Errorf("cannot find Test Flakes project")
	}

	cache := make(map[int]*Issue)
	for _, issue := range old {
	cache[issue.Number] = issue
	}
	// Read all issues in Test Flakes.
	var issues []*Issue
	items, err := gh.ProjectItems(testFlakes)
	if err != nil {
	return nil, err
	}
	for _, item := range items {
	if item.Issue != nil {
	issue := &Issue{Issue: item.Issue, NewBody: true, Stale: true}
	if c := cache[item.Issue.Number]; c != nil {
	// Carry conservative NewBody, Mentions data forward
	// to avoid round trips about things we already know.
	if c.Issue.LastEditedAt.Equal(item.Issue.LastEditedAt) {
	issue.NewBody = c.NewBody
	}
	issue.Mentions = c.Mentions
	}
	issues = append(issues, issue)
	}
	}
	sort.Slice(issues, func(i, j int) bool {
	return issues[i].Number < issues[j].Number
	})

	return issues, nil
	}

	// findScripts finds the scripts in the issues,
	// initializing issue.Script and .ScriptText or else .Error
	// in each issue.
	func findScripts(issues []*Issue) {
	for _, issue := range issues {
	findScript(issue)
	}
	}

	var noScriptError = `
	Sorry, but I can't find a watchflakes script at the start of the issue description.
	See https://go.dev/wiki/Watchflakes for details.
	`

	var parseScriptError = `
	Sorry, but there were parse errors in the watch flakes script.
	The script I found was:

	%s

	And the problems were:

	%s

	See https://go.dev/wiki/Watchflakes for details.
	`

	// findScript finds the script in issue and parses it.
	// If the script is not found or has any parse errors,
	// issue.Error is filled in.
	// Otherwise issue.ScriptText and issue.Script are filled in.
	func findScript(issue *Issue) {
	// Extract ```-fenced or indented code block at start of issue description (body).
	body := strings.ReplaceAll(issue.Body, "\r\n", "\n")
	lines := strings.SplitAfter(body, "\n")
	for len(lines) > 0 && strings.TrimSpace(lines[0]) == "" {
	lines = lines[1:]
	}
	text := ""
	if len(lines) > 0 && strings.HasPrefix(lines[0], "```") {
	marker := lines[0]
	n := 0
	for n < len(marker) && marker[n] == '`' {
	n++
	}
	marker = marker[:n]
	i := 1
	for i := 1; i < len(lines); i++ {
	if strings.HasPrefix(lines[i], marker) && strings.TrimSpace(strings.TrimLeft(lines[i], "`")) == "" {
	text = strings.Join(lines[1:i], "")
	break
	}
	}
	if i < len(lines) {
	}
	} else if strings.HasPrefix(lines[0], "\t") \|\| strings.HasPrefix(lines[0], " ") {
	i := 1
	for i < len(lines) && (strings.HasPrefix(lines[i], "\t") \|\| strings.HasPrefix(lines[i], " ")) {
	i++
	}
	text = strings.Join(lines[:i], "")
	}

	// Must start with #!watchflakes so we're sure it is for us.
	hdr, _, _ := strings.Cut(text, "\n")
	hdr = strings.TrimSpace(hdr)
	if hdr != "#!watchflakes" {
	issue.Error = noScriptError
	return
	}

	// Parse script.
	issue.ScriptText = text
	s, errs := script.Parse("script", text, fields)
	if len(errs) > 0 {
	var errtext strings.Builder
	for _, err := range errs {
	errtext.WriteString(err.Error())
	errtext.WriteString("\n")
	}
	issue.Error = fmt.Sprintf(parseScriptError, indent("\t", text), indent("\t", errtext.String()))
	return
	}

	issue.Script = s
	}

	func postIssueErrors(issues []*Issue) []error {
	var errors []error
	for _, issue := range issues {
	if issue.Error != "" && issue.NewBody {
	readComments(issue)
	if issue.NewBody {
	fmt.Printf(" - #%d script error\n", issue.Number)
	if *verbose {
	fmt.Printf("\n%s\n", indent(spaces[:7], issue.Error))
	}
	if *post {
	if err := postComment(issue, issue.Error); err != nil {
	errors = append(errors, err)
	continue
	}
	issue.NewBody = false
	}
	}
	}
	}
	return errors
	}

	// updateText returns the text for the GitHub update on issue.
	func updateText(issue *Issue) string {
	if len(issue.Post) == 0 {
	return ""
	}

	var b strings.Builder
	fmt.Fprintf(&b, "Found new dashboard test flakes for:\n\n%s", indent(spaces[:4], issue.ScriptText))
	for _, f := range issue.Post {
	b.WriteString("\n")
	_ = f
	b.WriteString(f.Markdown())
	}
	return b.String()
	}

	// reportNew creates and returns a new issue for reporting the failure.
	// If *post is false, reportNew returns a fake issue with number 0.
	func reportNew(fp FailurePost) (Issue, error) {
	var pattern, title string
	if fp.Pkg != "" {
	pattern = fmt.Sprintf("pkg == %q && test == %q", fp.Pkg, fp.Test)
	test := fp.Test
	if test == "" {
	test = "unrecognized"
	}
	title = shortPkg(fp.Pkg) + ": " + test + " failures"
	} else if fp.Test != "" {
	pattern = fmt.Sprintf("repo == %q && pkg == %q && test == %q", fp.Repo, "", fp.Test)
	title = "build: " + fp.Test + " failures"
	} else if fp.IsBuildFailure() {
	pattern = fmt.Sprintf("builder == %q && repo == %q && mode == %q", fp.Builder, fp.Repo, "build")
	title = "build: build failure on " + fp.Builder
	} else {
	pattern = fmt.Sprintf("builder == %q && repo == %q && pkg == %q && test == %q", fp.Builder, fp.Repo, "", "")
	title = "build: unrecognized failures on " + fp.Builder
	}

	var msg strings.Builder
	fmt.Fprintf(&msg, "```\n#!watchflakes\ndefault <- %s\n```\n\n", pattern)
	fmt.Fprintf(&msg, "Issue created automatically to collect these failures.\n\n")
	fmt.Fprintf(&msg, "Example ([log](%s)):\n\n%s", fp.URL, indent(spaces[:4], fp.Snippet))

	// TODO: for a single test failure, add a link to LUCI history page.

	fmt.Printf("# new issue: %s\n%s\n%s\n%s\n\n%s\n", title, fp.String(), fp.URL, pattern, fp.Snippet)
	if *verbose {
	fmt.Printf("\n%s\n", indent(spaces[:3], msg.String()))
	}

	issue := new(Issue)
	if *post {
	issue.Issue = newIssue(title, msg.String())
	} else {
	issue.Issue = &github.Issue{Title: title, Body: msg.String()}
	}
	findScript(issue)
	if issue.Error != "" {
	return nil, fmt.Errorf("cannot find script in generated issue:\nBody:\n%s\n\nError:\n%s", issue.Body, issue.Error)
	}
	issue.Post = append(issue.Post, fp)
	return issue, nil
	}

	// signature is the signature we add to the end of every comment or issue body
	// we post on GitHub. It links to documentation for users, and it also serves as
	// a way to identify the comments that we posted, since watchflakes can be run
	// as gopherbot or as an ordinary user.
	const signature = "\n\n— [watchflakes](https://go.dev/wiki/Watchflakes)\n"

	// keep in sync with buildURL function in luci.go
	// An older version reported ci.chromium.org/ui/b instead of ci.chromium.org/b,
	// match them as well.
	var buildUrlRE = regexp.MustCompile(`[("']https://ci.chromium.org/(ui/)?b/[0-9]+['")]`)

	// readComments loads the comments for the given issue,
	// setting the Comments, NewBody, and Mentions fields.
	func readComments(issue *Issue) {
	if issue.Number == 0 \|\| !issue.Stale {
	return
	}
	log.Printf("readComments %d", issue.Number)
	comments, err := gh.IssueComments(issue.Issue)
	if err != nil {
	log.Fatal(err)
	}
	issue.Comments = comments
	mtime := issue.LastEditedAt
	if mtime.IsZero() {
	mtime = issue.CreatedAt
	}
	issue.Mentions = make(map[string]bool)
	issue.NewBody = true // until proven otherwise
	for _, com := range comments {
	// Only consider comments we signed.
	if !strings.Contains(com.Body, "\n— watchflakes") && !strings.Contains(com.Body, "\n— [watchflakes](") {
	continue
	}
	if com.CreatedAt.After(issue.LastEditedAt) {
	issue.NewBody = false
	}
	for _, link := range buildUrlRE.FindAllString(com.Body, -1) {
	l := strings.Trim(link, "()\"'")
	issue.Mentions[l] = true
	// An older version reported ci.chromium.org/ui/b instead of ci.chromium.org/b,
	// match them as well.
	issue.Mentions[strings.Replace(l, "ci.chromium.org/ui/b/", "ci.chromium.org/b/", 1)] = true
	}
	}
	issue.Stale = false
	}

	// newIssue creates a new issue with the given title and body,
	// setting the NeedsInvestigation label and placing the issue int
	// the Test Flakes project.
	// It automatically adds signature to the body.
	func newIssue(title, body string) *github.Issue {
	var args []any
	if lab := labels["NeedsInvestigation"]; lab != nil {
	args = append(args, lab)
	}
	args = append(args, testFlakes)

	issue, err := gh.CreateIssue(repo, title, body+signature, args...)
	if err != nil {
	log.Fatal(err)
	}
	return issue
	}

	// postComment posts a new comment on the issue.
	// It automatically adds signature to the comment.
	func postComment(issue *Issue, body string) error {
	if len(body) > 50000 {
	// Apparently GitHub GraphQL API limits comment length to 65536.
	body = body[:50000] + "\n</details>\n(... long comment truncated ...)\n"
	}
	if issue.Issue.Closed {
	reopen := false
	for _, p := range issue.Post {
	_ = p
	if p.Time.After(issue.ClosedAt) {
	reopen = true
	break
	}
	}
	if reopen {
	if err := gh.ReopenIssue(issue.Issue); err != nil {
	return err
	}
	}
	}
	return gh.AddIssueComment(issue.Issue, body+signature)
	}