Add MIN_COMMENT_SIZE parameter

backend/app/cmd/server.go

@@ -65,6 +65,7 @@ type ServerCommand struct {
 	BackupLocation             string        `long:"backup" env:"BACKUP_PATH" default:"./var/backup" description:"backups location"`
 	MaxBackupFiles             int           `long:"max-back" env:"MAX_BACKUP_FILES" default:"10" description:"max backups to keep"`
 	LegacyImageProxy           bool          `long:"img-proxy" env:"IMG_PROXY" description:"[deprecated, use image-proxy.http2https] enable image proxy"`
+	MinCommentSize             int           `long:"min-comment" env:"MIN_COMMENT_SIZE" default:"0" description:"min comment size"`
 	MaxCommentSize             int           `long:"max-comment" env:"MAX_COMMENT_SIZE" default:"2048" description:"max comment size"`
 	MaxVotes                   int           `long:"max-votes" env:"MAX_VOTES" default:"-1" description:"maximum number of votes per comment"`
 	RestrictVoteIP             bool          `long:"votes-ip" env:"VOTES_IP" description:"restrict votes from the same ip"`
@@ -502,6 +503,7 @@ func (s *ServerCommand) newServerApp(ctx context.Context) (*serverApp, error) {
 		EditDuration:           s.EditDuration,
 		AdminEdits:             s.AdminEdit,
 		AdminStore:             adminStore,
+		MinCommentSize:         s.MinCommentSize,
 		MaxCommentSize:         s.MaxCommentSize,
 		MaxVotes:               s.MaxVotes,
 		PositiveScore:          s.PositiveScore,

backend/app/rest/api/rest.go

@@ -419,6 +419,7 @@ func (s *Rest) configCtrl(w http.ResponseWriter, r *http.Request) {
 		Version               string   `json:"version"`
 		EditDuration          int      `json:"edit_duration"`
 		AdminEdit             bool     `json:"admin_edit"`
+		MinCommentSize        int      `json:"min_comment_size"`
 		MaxCommentSize        int      `json:"max_comment_size"`
 		Admins                []string `json:"admins"`
 		AdminEmail            string   `json:"admin_email"`
@@ -439,6 +440,7 @@ func (s *Rest) configCtrl(w http.ResponseWriter, r *http.Request) {
 		Version:               s.Version,
 		EditDuration:          int(s.DataService.EditDuration.Seconds()),
 		AdminEdit:             s.DataService.AdminEdits,
+		MinCommentSize:        s.DataService.MinCommentSize,
 		MaxCommentSize:        s.DataService.MaxCommentSize,
 		Admins:                admins,
 		AdminEmail:            emails,

backend/app/store/service/service.go

@@ -27,6 +27,7 @@ type DataStore struct {
 	Engine              engine.Interface
 	EditDuration        time.Duration
 	AdminStore          admin.Store
+	MinCommentSize      int
 	MaxCommentSize      int
 	MaxVotes            int
 	RestrictSameIPVotes struct {
@@ -69,7 +70,7 @@ type PostMetaData struct {
 	ReadOnly bool   `json:"read_only"`
 }
 
-const defaultCommentMaxSize = 2000
+const defaultCommentMaxSize = 2048
 const maxLastCommentsReply = 5000
 
 // UnlimitedVotes doesn't restrict MaxVotes
@@ -639,8 +640,12 @@ func (s *DataStore) ValidateComment(c *store.Comment) error {
 	if c.Orig == "" {
 		return fmt.Errorf("empty comment text")
 	}
-	if len([]rune(c.Orig)) > maxSize {
-		return fmt.Errorf("comment text exceeded max allowed size %d (%d)", maxSize, len([]rune(c.Orig)))
+	commentLength := len([]rune(c.Orig))
+	if commentLength > maxSize {
+		return fmt.Errorf("comment text exceeded max allowed size %d (%d)", maxSize, commentLength)
+	}
+	if s.MinCommentSize > 0 && commentLength < s.MinCommentSize {
+		return fmt.Errorf("comment text is smaller than min allowed size %d (%d)", s.MinCommentSize, commentLength)
 	}
 	if c.User.ID == "" || c.User.Name == "" {
 		return fmt.Errorf("empty user info")

backend/app/store/service/service_test.go

@@ -924,7 +924,7 @@ func TestService_EditCommentAdmin(t *testing.T) {
 }
 
 func TestService_ValidateComment(t *testing.T) {
-	b := DataStore{MaxCommentSize: 2000, AdminStore: admin.NewStaticKeyStore("secret 123")}
+	b := DataStore{MinCommentSize: 6, MaxCommentSize: 2000, AdminStore: admin.NewStaticKeyStore("secret 123")}
 	longText := fmt.Sprintf("%4000s", "X")
 
 	tbl := []struct {
@@ -934,6 +934,7 @@ func TestService_ValidateComment(t *testing.T) {
 		{inp: store.Comment{}, err: "empty comment text"},
 		{inp: store.Comment{Orig: "something blah", User: store.User{ID: "myid", Name: "name"}}, err: ""},
 		{inp: store.Comment{Orig: "something blah", User: store.User{ID: "myid"}}, err: "empty user info"},
+		{inp: store.Comment{Orig: "short", User: store.User{ID: "myid", Name: "name"}}, err: "comment text is smaller than min allowed size 6 (5)"},
 		{inp: store.Comment{Orig: longText, User: store.User{ID: "myid", Name: "name"}}, err: "comment text exceeded max allowed size 2000 (4000)"},
 		{inp: store.Comment{Orig: "here is a link with relative URL: [google.com](url)", User: store.User{ID: "myid", Name: "name"}}, err: "links should start with mailto:, http:// or https://"},
 		{inp: store.Comment{Orig: "here is a link with relative URL: [google.com](url)", User: store.User{ID: "myid", Name: "name"}}, err: "links should start with mailto:, http:// or https://"},

site/src/docs/configuration/parameters/index.md

@@ -135,6 +135,7 @@ services:
 | ssl.acme-location              | SSL_ACME_LOCATION              | `./var/acme`             | dir where obtained le-certs will be stored                |
 | ssl.acme-email                 | SSL_ACME_EMAIL                 |                          | admin email for receiving notifications from LE           |
 | max-comment                    | MAX_COMMENT_SIZE               | `2048`                   | comment's size limit                                      |
+| min-comment                    | MIN_COMMENT_SIZE               | `0`                      | comment's minimal size limit, `0` - unlimited             |
 | max-votes                      | MAX_VOTES                      | `-1`                     | votes limit per comment, `-1` - unlimited                 |
 | votes-ip                       | VOTES_IP                       | `false`                  | restrict votes from the same IP                           |
 | anon-vote                      | ANON_VOTE                      | `false`                  | allow voting for anonymous users, require VOTES_IP to be enabled as well |