[MM-4819] Add MinimumHashtagLength config (#10248)

#### Summary
Add `MinimumHashtagLength` config

#### Ticket Link
#9156 
https://mattermost.atlassian.net/browse/MM-4819

#### Checklist
N/A

app/diagnostics.go

@@ -278,6 +278,7 @@ func (a *App) trackConfig() {
 		"time_between_user_typing_updates_milliseconds":           *cfg.ServiceSettings.TimeBetweenUserTypingUpdatesMilliseconds,
 		"cluster_log_timeout_milliseconds":                        *cfg.ServiceSettings.ClusterLogTimeoutMilliseconds,
 		"enable_post_search":                                      *cfg.ServiceSettings.EnablePostSearch,
+		"minimum_hashtag_length":                                  *cfg.ServiceSettings.MinimumHashtagLength,
 		"enable_user_statuses":                                    *cfg.ServiceSettings.EnableUserStatuses,
 		"close_unused_direct_messages":                            *cfg.ServiceSettings.CloseUnusedDirectMessages,
 		"enable_preview_features":                                 *cfg.ServiceSettings.EnablePreviewFeatures,

config/client.go

@@ -35,6 +35,7 @@ func GenerateClientConfig(c *model.Config, diagnosticId string, license *model.L
 	props["EnableTesting"] = strconv.FormatBool(*c.ServiceSettings.EnableTesting)
 	props["EnableDeveloper"] = strconv.FormatBool(*c.ServiceSettings.EnableDeveloper)
 	props["PostEditTimeLimit"] = fmt.Sprintf("%v", *c.ServiceSettings.PostEditTimeLimit)
+	props["MinimumHashtagLength"] = fmt.Sprintf("%v", *c.ServiceSettings.MinimumHashtagLength)
 	props["CloseUnusedDirectMessages"] = strconv.FormatBool(*c.ServiceSettings.CloseUnusedDirectMessages)
 	props["EnablePreviewFeatures"] = strconv.FormatBool(*c.ServiceSettings.EnablePreviewFeatures)
 	props["EnableTutorial"] = strconv.FormatBool(*c.ServiceSettings.EnableTutorial)

config/default.json

@@ -61,6 +61,7 @@
         "ExperimentalEnableAuthenticationTransfer": true,
         "TimeBetweenUserTypingUpdatesMilliseconds": 5000,
         "EnablePostSearch": true,
+        "MinimumHashtagLength": 3,
         "EnableUserTypingMessages": true,
         "EnableChannelViewedMessages": true,
         "EnableUserStatuses": true,

model/config.go

@@ -267,6 +267,7 @@ type ServiceSettings struct {
 	PostEditTimeLimit                                 *int
 	TimeBetweenUserTypingUpdatesMilliseconds          *int64
 	EnablePostSearch                                  *bool
+	MinimumHashtagLength                              *int
 	EnableUserTypingMessages                          *bool
 	EnableChannelViewedMessages                       *bool
 	EnableUserStatuses                                *bool
@@ -436,6 +437,10 @@ func (s *ServiceSettings) SetDefaults() {
 		s.EnablePostSearch = NewBool(true)
 	}
 
+	if s.MinimumHashtagLength == nil {
+		s.MinimumHashtagLength = NewInt(3)
+	}
+
 	if s.EnableUserTypingMessages == nil {
 		s.EnableUserTypingMessages = NewBool(true)
 	}

tests/test-config.json

@@ -49,6 +49,7 @@
         "PostEditTimeLimit": -1,
         "TimeBetweenUserTypingUpdatesMilliseconds": 5000,
         "EnablePostSearch": true,
+        "MinimumHashtagLength": 3,
         "EnableUserTypingMessages": true,
         "EnableChannelViewedMessages": true,
         "EnableUserStatuses": true,