Add minimum channel name length in rename modal (#7308)

webapp/components/rename_channel_modal.jsx

@@ -139,6 +139,17 @@ export class RenameChannelModal extends React.Component {
         } else if (channel.display_name.length > Constants.MAX_CHANNELNAME_LENGTH) {
             state.displayNameError = formatMessage(holders.maxLength, {maxLength: Constants.MAX_CHANNELNAME_LENGTH});
             state.invalid = true;
+        } else if (channel.display_name.length < Constants.MIN_CHANNELNAME_LENGTH) {
+            state.displayNameError = (
+                <FormattedMessage
+                    id='rename_channel.minLength'
+                    defaultMessage='Channel name must be {minLength, number} or more characters'
+                    values={{
+                        minLength: Constants.MIN_CHANNELNAME_LENGTH
+                    }}
+                />
+            );
+            state.invalid = true;
         } else {
             state.displayNameError = '';
         }

webapp/i18n/en.json

@@ -2063,6 +2063,7 @@
   "rename_channel.handleHolder": "lowercase alphanumeric characters",
   "rename_channel.lowercase": "Must be lowercase alphanumeric characters",
   "rename_channel.maxLength": "This field must be less than {maxLength, number} characters",
+  "rename_channel.minLength": "Channel name must be {minLength, number} or more characters",
   "rename_channel.required": "This field is required",
   "rename_channel.save": "Save",
   "rename_channel.title": "Rename Channel",