Use templates for issue e-mail subject and body (#8329)

* Add template capability for issue mail subject

* Remove test string

* Fix trim subject length

* Add comment to template and run make fmt

* Add information for the template

* Rename defaultMailSubject() to fallbackMailSubject()

* General rewrite of the mail template code

* Fix .Doer name

* Use text/template for subject instead of html

* Fix subject Re: prefix

* Fix mail tests

* Fix static templates

* [skip ci] Updated translations via Crowdin

* Expose db.SetMaxOpenConns and allow non MySQL dbs to set conn pool params (#8528)

* Expose db.SetMaxOpenConns and allow other dbs to set their connection params
* Add note about port exhaustion

Co-Authored-By: guillep2k <18600385+guillep2k@users.noreply.github.com>

* Prevent .code-view from overriding font on icon fonts (#8614)

* Correct some outdated statements in the contributing guidelines (#8612)

* More information for drone-cli in CONTRIBUTING.md

* Increases the version of drone-cli to 1.2.0
* Adds a note for the Docker Toolbox on Windows

Signed-off-by: LukBukkit <luk.bukkit@gmail.com>

* Fix the url for the blog repository (now on gitea.com)

Signed-off-by: LukBukkit <luk.bukkit@gmail.com>

* Remove TrN due to lack of lang context

* Redo templates to match previous code

* Fix extra character in template

* Unify PR & Issue tempaltes, fix format

* Remove default subject

* Add template tests

* Fix template

* Remove replaced function

* Provide User as models.User for better consistency

* Add docs

* Fix doc inaccuracies, improve examples

* Change mail footer to math AppName

* Add test for mail subject/body template separation

* Add support for code review comments

* Update docs/content/doc/advanced/mail-templates-us.md

Co-Authored-By: 6543 <24977596+6543@users.noreply.github.com>

4 files changed, 264 insertions, 96 deletions

diff --git a/services/mailer/mail.go b/services/mailer/mail.go
index bc2aff7314..fc892f6076 100644
--- a/services/mailer/mail.go
+++ b/services/mailer/mail.go
@@ -9,7 +9,11 @@ import (
 	"bytes"
 	"fmt"
 	"html/template"
+	"mime"
 	"path"
+	"regexp"
+	"strings"
+	texttmpl "text/template"
 
 	"code.gitea.io/gitea/models"
 	"code.gitea.io/gitea/modules/base"
@@ -28,18 +32,22 @@ const (
 	mailAuthResetPassword  base.TplName = "auth/reset_passwd"
 	mailAuthRegisterNotify base.TplName = "auth/register_notify"
 
-	mailIssueComment  base.TplName = "issue/comment"
-	mailIssueMention  base.TplName = "issue/mention"
-	mailIssueAssigned base.TplName = "issue/assigned"
-
 	mailNotifyCollaborator base.TplName = "notify/collaborator"
+
+	// There's no actual limit for subject in RFC 5322
+	mailMaxSubjectRunes = 256
 )
 
-var templates *template.Template
+var (
+	bodyTemplates       *template.Template
+	subjectTemplates    *texttmpl.Template
+	subjectRemoveSpaces = regexp.MustCompile(`[\s]+`)
+)
 
 // InitMailRender initializes the mail renderer
-func InitMailRender(tmpls *template.Template) {
-	templates = tmpls
+func InitMailRender(subjectTpl *texttmpl.Template, bodyTpl *template.Template) {
+	subjectTemplates = subjectTpl
+	bodyTemplates = bodyTpl
 }
 
 // SendTestMail sends a test mail
@@ -58,7 +66,7 @@ func SendUserMail(language string, u *models.User, tpl base.TplName, code, subje
 
 	var content bytes.Buffer
 
-	if err := templates.ExecuteTemplate(&content, string(tpl), data); err != nil {
+	if err := bodyTemplates.ExecuteTemplate(&content, string(tpl), data); err != nil {
 		log.Error("Template: %v", err)
 		return
 	}
@@ -96,7 +104,7 @@ func SendActivateEmailMail(locale Locale, u *models.User, email *models.EmailAdd
 
 	var content bytes.Buffer
 
-	if err := templates.ExecuteTemplate(&content, string(mailAuthActivateEmail), data); err != nil {
+	if err := bodyTemplates.ExecuteTemplate(&content, string(mailAuthActivateEmail), data); err != nil {
 		log.Error("Template: %v", err)
 		return
 	}
@@ -121,7 +129,7 @@ func SendRegisterNotifyMail(locale Locale, u *models.User) {
 
 	var content bytes.Buffer
 
-	if err := templates.ExecuteTemplate(&content, string(mailAuthRegisterNotify), data); err != nil {
+	if err := bodyTemplates.ExecuteTemplate(&content, string(mailAuthRegisterNotify), data); err != nil {
 		log.Error("Template: %v", err)
 		return
 	}
@@ -145,7 +153,7 @@ func SendCollaboratorMail(u, doer *models.User, repo *models.Repository) {
 
 	var content bytes.Buffer
 
-	if err := templates.ExecuteTemplate(&content, string(mailNotifyCollaborator), data); err != nil {
+	if err := bodyTemplates.ExecuteTemplate(&content, string(mailNotifyCollaborator), data); err != nil {
 		log.Error("Template: %v", err)
 		return
 	}
@@ -156,40 +164,70 @@ func SendCollaboratorMail(u, doer *models.User, repo *models.Repository) {
 	SendAsync(msg)
 }
 
-func composeTplData(subject, body, link string) map[string]interface{} {
-	data := make(map[string]interface{}, 10)
-	data["Subject"] = subject
-	data["Body"] = body
-	data["Link"] = link
-	return data
-}
+func composeIssueCommentMessage(issue *models.Issue, doer *models.User, actionType models.ActionType, fromMention bool,
+	content string, comment *models.Comment, tos []string, info string) *Message {
+
+	if err := issue.LoadPullRequest(); err != nil {
+		log.Error("LoadPullRequest: %v", err)
+		return nil
+	}
+
+	var (
+		subject string
+		link    string
+		prefix  string
+		// Fall back subject for bad templates, make sure subject is never empty
+		fallback string
+	)
 
-func composeIssueCommentMessage(issue *models.Issue, doer *models.User, content string, comment *models.Comment, tplName base.TplName, tos []string, info string) *Message {
-	var subject string
+	commentType := models.CommentTypeComment
 	if comment != nil {
-		subject = "Re: " + mailSubject(issue)
+		prefix = "Re: "
+		commentType = comment.Type
+		link = issue.HTMLURL() + "#" + comment.HashTag()
 	} else {
-		subject = mailSubject(issue)
-	}
-	err := issue.LoadRepo()
-	if err != nil {
-		log.Error("LoadRepo: %v", err)
+		link = issue.HTMLURL()
 	}
+
+	fallback = prefix + fallbackMailSubject(issue)
+
+	// This is the body of the new issue or comment, not the mail body
 	body := string(markup.RenderByType(markdown.MarkupName, []byte(content), issue.Repo.HTMLURL(), issue.Repo.ComposeMetas()))
 
-	var data = make(map[string]interface{}, 10)
-	if comment != nil {
-		data = composeTplData(subject, body, issue.HTMLURL()+"#"+comment.HashTag())
+	actType, actName, tplName := actionToTemplate(issue, actionType, commentType)
+
+	mailMeta := map[string]interface{}{
+		"FallbackSubject": fallback,
+		"Body":            body,
+		"Link":            link,
+		"Issue":           issue,
+		"Comment":         comment,
+		"IsPull":          issue.IsPull,
+		"User":            issue.Repo.MustOwner(),
+		"Repo":            issue.Repo.FullName(),
+		"Doer":            doer,
+		"IsMention":       fromMention,
+		"SubjectPrefix":   prefix,
+		"ActionType":      actType,
+		"ActionName":      actName,
+	}
+
+	var mailSubject bytes.Buffer
+	if err := subjectTemplates.ExecuteTemplate(&mailSubject, string(tplName), mailMeta); err == nil {
+		subject = sanitizeSubject(mailSubject.String())
 	} else {
-		data = composeTplData(subject, body, issue.HTMLURL())
+		log.Error("ExecuteTemplate [%s]: %v", string(tplName)+"/subject", err)
+	}
+
+	if subject == "" {
+		subject = fallback
 	}
-	data["Doer"] = doer
-	data["Issue"] = issue
+	mailMeta["Subject"] = subject
 
 	var mailBody bytes.Buffer
 
-	if err := templates.ExecuteTemplate(&mailBody, string(tplName), data); err != nil {
-		log.Error("Template: %v", err)
+	if err := bodyTemplates.ExecuteTemplate(&mailBody, string(tplName), mailMeta); err != nil {
+		log.Error("ExecuteTemplate [%s]: %v", string(tplName)+"/body", err)
 	}
 
 	msg := NewMessageFrom(tos, doer.DisplayName(), setting.MailService.FromEmail, subject, mailBody.String())
@@ -206,24 +244,81 @@ func composeIssueCommentMessage(issue *models.Issue, doer *models.User, content
 	return msg
 }
 
+func sanitizeSubject(subject string) string {
+	runes := []rune(strings.TrimSpace(subjectRemoveSpaces.ReplaceAllLiteralString(subject, " ")))
+	if len(runes) > mailMaxSubjectRunes {
+		runes = runes[:mailMaxSubjectRunes]
+	}
+	// Encode non-ASCII characters
+	return mime.QEncoding.Encode("utf-8", string(runes))
+}
+
 // SendIssueCommentMail composes and sends issue comment emails to target receivers.
-func SendIssueCommentMail(issue *models.Issue, doer *models.User, content string, comment *models.Comment, tos []string) {
+func SendIssueCommentMail(issue *models.Issue, doer *models.User, actionType models.ActionType, content string, comment *models.Comment, tos []string) {
 	if len(tos) == 0 {
 		return
 	}
 
-	SendAsync(composeIssueCommentMessage(issue, doer, content, comment, mailIssueComment, tos, "issue comment"))
+	SendAsync(composeIssueCommentMessage(issue, doer, actionType, false, content, comment, tos, "issue comment"))
 }
 
 // SendIssueMentionMail composes and sends issue mention emails to target receivers.
-func SendIssueMentionMail(issue *models.Issue, doer *models.User, content string, comment *models.Comment, tos []string) {
+func SendIssueMentionMail(issue *models.Issue, doer *models.User, actionType models.ActionType, content string, comment *models.Comment, tos []string) {
 	if len(tos) == 0 {
 		return
 	}
-	SendAsync(composeIssueCommentMessage(issue, doer, content, comment, mailIssueMention, tos, "issue mention"))
+	SendAsync(composeIssueCommentMessage(issue, doer, actionType, true, content, comment, tos, "issue mention"))
+}
+
+// actionToTemplate returns the type and name of the action facing the user
+// (slightly different from models.ActionType) and the name of the template to use (based on availability)
+func actionToTemplate(issue *models.Issue, actionType models.ActionType, commentType models.CommentType) (typeName, name, template string) {
+	if issue.IsPull {
+		typeName = "pull"
+	} else {
+		typeName = "issue"
+	}
+	switch actionType {
+	case models.ActionCreateIssue, models.ActionCreatePullRequest:
+		name = "new"
+	case models.ActionCommentIssue:
+		name = "comment"
+	case models.ActionCloseIssue, models.ActionClosePullRequest:
+		name = "close"
+	case models.ActionReopenIssue, models.ActionReopenPullRequest:
+		name = "reopen"
+	case models.ActionMergePullRequest:
+		name = "merge"
+	default:
+		switch commentType {
+		case models.CommentTypeReview:
+			name = "review"
+		case models.CommentTypeCode:
+			name = "code"
+		case models.CommentTypeAssignees:
+			name = "assigned"
+		default:
+			name = "default"
+		}
+	}
+
+	template = typeName + "/" + name
+	ok := bodyTemplates.Lookup(template) != nil
+	if !ok && typeName != "issue" {
+		template = "issue/" + name
+		ok = bodyTemplates.Lookup(template) != nil
+	}
+	if !ok {
+		template = typeName + "/default"
+		ok = bodyTemplates.Lookup(template) != nil
+	}
+	if !ok {
+		template = "issue/default"
+	}
+	return
 }
 
 // SendIssueAssignedMail composes and sends issue assigned email
 func SendIssueAssignedMail(issue *models.Issue, doer *models.User, content string, comment *models.Comment, tos []string) {
-	SendAsync(composeIssueCommentMessage(issue, doer, content, comment, mailIssueAssigned, tos, "issue assigned"))
+	SendAsync(composeIssueCommentMessage(issue, doer, models.ActionType(0), false, content, comment, tos, "issue assigned"))
 }
diff --git a/services/mailer/mail_comment.go b/services/mailer/mail_comment.go
index d306c14f42..6469eb1fa1 100644
--- a/services/mailer/mail_comment.go
+++ b/services/mailer/mail_comment.go
@@ -31,24 +31,8 @@ func mailParticipantsComment(ctx models.DBContext, c *models.Comment, opType mod
 	for i, u := range userMentions {
 		mentions[i] = u.LowerName
 	}
-	if len(c.Content) > 0 {
-		if err = mailIssueCommentToParticipants(issue, c.Poster, c.Content, c, mentions); err != nil {
-			log.Error("mailIssueCommentToParticipants: %v", err)
-		}
+	if err = mailIssueCommentToParticipants(issue, c.Poster, opType, c.Content, c, mentions); err != nil {
+		log.Error("mailIssueCommentToParticipants: %v", err)
 	}
-
-	switch opType {
-	case models.ActionCloseIssue:
-		ct := fmt.Sprintf("Closed #%d.", issue.Index)
-		if err = mailIssueCommentToParticipants(issue, c.Poster, ct, c, mentions); err != nil {
-			log.Error("mailIssueCommentToParticipants: %v", err)
-		}
-	case models.ActionReopenIssue:
-		ct := fmt.Sprintf("Reopened #%d.", issue.Index)
-		if err = mailIssueCommentToParticipants(issue, c.Poster, ct, c, mentions); err != nil {
-			log.Error("mailIssueCommentToParticipants: %v", err)
-		}
-	}
-
 	return nil
 }
diff --git a/services/mailer/mail_issue.go b/services/mailer/mail_issue.go
index a5f3251807..32b21b1324 100644
--- a/services/mailer/mail_issue.go
+++ b/services/mailer/mail_issue.go
@@ -14,7 +14,7 @@ import (
 	"github.com/unknwon/com"
 )
 
-func mailSubject(issue *models.Issue) string {
+func fallbackMailSubject(issue *models.Issue) string {
 	return fmt.Sprintf("[%s] %s (#%d)", issue.Repo.FullName(), issue.Title, issue.Index)
 }
 
@@ -22,7 +22,7 @@ func mailSubject(issue *models.Issue) string {
 // This function sends two list of emails:
 // 1. Repository watchers and users who are participated in comments.
 // 2. Users who are not in 1. but get mentioned in current issue/comment.
-func mailIssueCommentToParticipants(issue *models.Issue, doer *models.User, content string, comment *models.Comment, mentions []string) error {
+func mailIssueCommentToParticipants(issue *models.Issue, doer *models.User, actionType models.ActionType, content string, comment *models.Comment, mentions []string) error {
 
 	watchers, err := models.GetWatchers(issue.RepoID)
 	if err != nil {
@@ -89,7 +89,7 @@ func mailIssueCommentToParticipants(issue *models.Issue, doer *models.User, cont
 	}
 
 	for _, to := range tos {
-		SendIssueCommentMail(issue, doer, content, comment, []string{to})
+		SendIssueCommentMail(issue, doer, actionType, content, comment, []string{to})
 	}
 
 	// Mail mentioned people and exclude watchers.
@@ -106,7 +106,7 @@ func mailIssueCommentToParticipants(issue *models.Issue, doer *models.User, cont
 	emails := models.GetUserEmailsByNames(tos)
 
 	for _, to := range emails {
-		SendIssueMentionMail(issue, doer, content, comment, []string{to})
+		SendIssueMentionMail(issue, doer, actionType, content, comment, []string{to})
 	}
 
 	return nil
@@ -131,32 +131,8 @@ func mailParticipants(ctx models.DBContext, issue *models.Issue, doer *models.Us
 	for i, u := range userMentions {
 		mentions[i] = u.LowerName
 	}
-
-	if len(issue.Content) > 0 {
-		if err = mailIssueCommentToParticipants(issue, doer, issue.Content, nil, mentions); err != nil {
-			log.Error("mailIssueCommentToParticipants: %v", err)
-		}
-	}
-
-	switch opType {
-	case models.ActionCreateIssue, models.ActionCreatePullRequest:
-		if len(issue.Content) == 0 {
-			ct := fmt.Sprintf("Created #%d.", issue.Index)
-			if err = mailIssueCommentToParticipants(issue, doer, ct, nil, mentions); err != nil {
-				log.Error("mailIssueCommentToParticipants: %v", err)
-			}
-		}
-	case models.ActionCloseIssue, models.ActionClosePullRequest:
-		ct := fmt.Sprintf("Closed #%d.", issue.Index)
-		if err = mailIssueCommentToParticipants(issue, doer, ct, nil, mentions); err != nil {
-			log.Error("mailIssueCommentToParticipants: %v", err)
-		}
-	case models.ActionReopenIssue, models.ActionReopenPullRequest:
-		ct := fmt.Sprintf("Reopened #%d.", issue.Index)
-		if err = mailIssueCommentToParticipants(issue, doer, ct, nil, mentions); err != nil {
-			log.Error("mailIssueCommentToParticipants: %v", err)
-		}
+	if err = mailIssueCommentToParticipants(issue, doer, opType, issue.Content, nil, mentions); err != nil {
+		log.Error("mailIssueCommentToParticipants: %v", err)
 	}
-
 	return nil
 }
diff --git a/services/mailer/mail_test.go b/services/mailer/mail_test.go
index c7a84d6b33..a10507e0e4 100644
--- a/services/mailer/mail_test.go
+++ b/services/mailer/mail_test.go
@@ -5,8 +5,10 @@
 package mailer
 
 import (
+	"bytes"
 	"html/template"
 	"testing"
+	texttmpl "text/template"
 
 	"code.gitea.io/gitea/models"
 	"code.gitea.io/gitea/modules/setting"
@@ -14,7 +16,11 @@ import (
 	"github.com/stretchr/testify/assert"
 )
 
-const tmpl = `
+const subjectTpl = `
+{{.SubjectPrefix}}[{{.Repo}}] @{{.Doer.Name}} #{{.Issue.Index}} - {{.Issue.Title}}
+`
+
+const bodyTpl = `
 <!DOCTYPE html>
 <html>
 <head>
@@ -47,17 +53,19 @@ func TestComposeIssueCommentMessage(t *testing.T) {
 	issue := models.AssertExistsAndLoadBean(t, &models.Issue{ID: 1, Repo: repo, Poster: doer}).(*models.Issue)
 	comment := models.AssertExistsAndLoadBean(t, &models.Comment{ID: 2, Issue: issue}).(*models.Comment)
 
-	email := template.Must(template.New("issue/comment").Parse(tmpl))
-	InitMailRender(email)
+	stpl := texttmpl.Must(texttmpl.New("issue/comment").Parse(subjectTpl))
+	btpl := template.Must(template.New("issue/comment").Parse(bodyTpl))
+	InitMailRender(stpl, btpl)
 
 	tos := []string{"test@gitea.com", "test2@gitea.com"}
-	msg := composeIssueCommentMessage(issue, doer, "test body", comment, mailIssueComment, tos, "issue comment")
+	msg := composeIssueCommentMessage(issue, doer, models.ActionCommentIssue, false, "test body", comment, tos, "issue comment")
 
 	subject := msg.GetHeader("Subject")
 	inreplyTo := msg.GetHeader("In-Reply-To")
 	references := msg.GetHeader("References")
 
-	assert.Equal(t, subject[0], "Re: "+mailSubject(issue), "Comment reply subject should contain Re:")
+	assert.Equal(t, "Re: ", subject[0][:4], "Comment reply subject should contain Re:")
+	assert.Equal(t, "Re: [user2/repo1] @user2 #1 - issue1", subject[0])
 	assert.Equal(t, inreplyTo[0], "<user2/repo1/issues/1@localhost>", "In-Reply-To header doesn't match")
 	assert.Equal(t, references[0], "<user2/repo1/issues/1@localhost>", "References header doesn't match")
 }
@@ -75,17 +83,122 @@ func TestComposeIssueMessage(t *testing.T) {
 	repo := models.AssertExistsAndLoadBean(t, &models.Repository{ID: 1, Owner: doer}).(*models.Repository)
 	issue := models.AssertExistsAndLoadBean(t, &models.Issue{ID: 1, Repo: repo, Poster: doer}).(*models.Issue)
 
-	email := template.Must(template.New("issue/comment").Parse(tmpl))
-	InitMailRender(email)
+	stpl := texttmpl.Must(texttmpl.New("issue/new").Parse(subjectTpl))
+	btpl := template.Must(template.New("issue/new").Parse(bodyTpl))
+	InitMailRender(stpl, btpl)
 
 	tos := []string{"test@gitea.com", "test2@gitea.com"}
-	msg := composeIssueCommentMessage(issue, doer, "test body", nil, mailIssueComment, tos, "issue create")
+	msg := composeIssueCommentMessage(issue, doer, models.ActionCreateIssue, false, "test body", nil, tos, "issue create")
 
 	subject := msg.GetHeader("Subject")
 	messageID := msg.GetHeader("Message-ID")
 
-	assert.Equal(t, subject[0], mailSubject(issue), "Subject not equal to issue.mailSubject()")
+	assert.Equal(t, "[user2/repo1] @user2 #1 - issue1", subject[0])
 	assert.Nil(t, msg.GetHeader("In-Reply-To"))
 	assert.Nil(t, msg.GetHeader("References"))
 	assert.Equal(t, messageID[0], "<user2/repo1/issues/1@localhost>", "Message-ID header doesn't match")
 }
+
+func TestTemplateSelection(t *testing.T) {
+	assert.NoError(t, models.PrepareTestDatabase())
+	var mailService = setting.Mailer{
+		From: "test@gitea.com",
+	}
+
+	setting.MailService = &mailService
+	setting.Domain = "localhost"
+
+	doer := models.AssertExistsAndLoadBean(t, &models.User{ID: 2}).(*models.User)
+	repo := models.AssertExistsAndLoadBean(t, &models.Repository{ID: 1, Owner: doer}).(*models.Repository)
+	issue := models.AssertExistsAndLoadBean(t, &models.Issue{ID: 1, Repo: repo, Poster: doer}).(*models.Issue)
+	tos := []string{"test@gitea.com"}
+
+	stpl := texttmpl.Must(texttmpl.New("issue/default").Parse("issue/default/subject"))
+	texttmpl.Must(stpl.New("issue/new").Parse("issue/new/subject"))
+	texttmpl.Must(stpl.New("pull/comment").Parse("pull/comment/subject"))
+	texttmpl.Must(stpl.New("issue/close").Parse("")) // Must default to fallback subject
+
+	btpl := template.Must(template.New("issue/default").Parse("issue/default/body"))
+	template.Must(btpl.New("issue/new").Parse("issue/new/body"))
+	template.Must(btpl.New("pull/comment").Parse("pull/comment/body"))
+	template.Must(btpl.New("issue/close").Parse("issue/close/body"))
+
+	InitMailRender(stpl, btpl)
+
+	expect := func(t *testing.T, msg *Message, expSubject, expBody string) {
+		subject := msg.GetHeader("Subject")
+		msgbuf := new(bytes.Buffer)
+		_, _ = msg.WriteTo(msgbuf)
+		wholemsg := msgbuf.String()
+		assert.Equal(t, []string{expSubject}, subject)
+		assert.Contains(t, wholemsg, expBody)
+	}
+
+	msg := composeIssueCommentMessage(issue, doer, models.ActionCreateIssue, false, "test body", nil, tos, "TestTemplateSelection")
+	expect(t, msg, "issue/new/subject", "issue/new/body")
+
+	comment := models.AssertExistsAndLoadBean(t, &models.Comment{ID: 2, Issue: issue}).(*models.Comment)
+	msg = composeIssueCommentMessage(issue, doer, models.ActionCommentIssue, false, "test body", comment, tos, "TestTemplateSelection")
+	expect(t, msg, "issue/default/subject", "issue/default/body")
+
+	pull := models.AssertExistsAndLoadBean(t, &models.Issue{ID: 2, Repo: repo, Poster: doer}).(*models.Issue)
+	comment = models.AssertExistsAndLoadBean(t, &models.Comment{ID: 4, Issue: pull}).(*models.Comment)
+	msg = composeIssueCommentMessage(pull, doer, models.ActionCommentIssue, false, "test body", comment, tos, "TestTemplateSelection")
+	expect(t, msg, "pull/comment/subject", "pull/comment/body")
+
+	msg = composeIssueCommentMessage(issue, doer, models.ActionCloseIssue, false, "test body", nil, tos, "TestTemplateSelection")
+	expect(t, msg, "[user2/repo1] issue1 (#1)", "issue/close/body")
+}
+
+func TestTemplateServices(t *testing.T) {
+	assert.NoError(t, models.PrepareTestDatabase())
+	var mailService = setting.Mailer{
+		From: "test@gitea.com",
+	}
+
+	setting.MailService = &mailService
+	setting.Domain = "localhost"
+
+	doer := models.AssertExistsAndLoadBean(t, &models.User{ID: 2}).(*models.User)
+	repo := models.AssertExistsAndLoadBean(t, &models.Repository{ID: 1, Owner: doer}).(*models.Repository)
+	issue := models.AssertExistsAndLoadBean(t, &models.Issue{ID: 1, Repo: repo, Poster: doer}).(*models.Issue)
+	comment := models.AssertExistsAndLoadBean(t, &models.Comment{ID: 2, Issue: issue}).(*models.Comment)
+	assert.NoError(t, issue.LoadRepo())
+
+	expect := func(t *testing.T, issue *models.Issue, comment *models.Comment, doer *models.User,
+		actionType models.ActionType, fromMention bool, tplSubject, tplBody, expSubject, expBody string) {
+
+		stpl := texttmpl.Must(texttmpl.New("issue/default").Parse(tplSubject))
+		btpl := template.Must(template.New("issue/default").Parse(tplBody))
+		InitMailRender(stpl, btpl)
+
+		tos := []string{"test@gitea.com"}
+		msg := composeIssueCommentMessage(issue, doer, actionType, fromMention, "test body", comment, tos, "TestTemplateServices")
+
+		subject := msg.GetHeader("Subject")
+		msgbuf := new(bytes.Buffer)
+		_, _ = msg.WriteTo(msgbuf)
+		wholemsg := msgbuf.String()
+
+		assert.Equal(t, []string{expSubject}, subject)
+		assert.Contains(t, wholemsg, "\r\n"+expBody+"\r\n")
+	}
+
+	expect(t, issue, comment, doer, models.ActionCommentIssue, false,
+		"{{.SubjectPrefix}}[{{.Repo}}]: @{{.Doer.Name}} commented on #{{.Issue.Index}} - {{.Issue.Title}}",
+		"//{{.ActionType}},{{.ActionName}},{{if .IsMention}}norender{{end}}//",
+		"Re: [user2/repo1]: @user2 commented on #1 - issue1",
+		"//issue,comment,//")
+
+	expect(t, issue, comment, doer, models.ActionCommentIssue, true,
+		"{{if .IsMention}}must render{{end}}",
+		"//subject is: {{.Subject}}//",
+		"must render",
+		"//subject is: must render//")
+
+	expect(t, issue, comment, doer, models.ActionCommentIssue, true,
+		"{{.FallbackSubject}}",
+		"//{{.SubjectPrefix}}//",
+		"Re: [user2/repo1] issue1 (#1)",
+		"//Re: //")
+}