[Feature - Max Attachment Size] - UI check and notice implemented. BE validation added. ENV added. Tests added. Readme updated.

Author: milos-dukic

README.md

@@ -28,6 +28,7 @@ To configure additional features, you can set the following environment variable
   `/script/admin/create-vapid-key`
 - `SENTRY_DSN` - to enable error reporting to sentry in production, supply your
   DSN here
+- `MAX_ATTACHMENT_SIZE_IN_BYTES` - sets maximum size in bytes, per attachment, if not defined there is no limit in size
 
 For example:
 

app/assets/stylesheets/composer.css

@@ -4,6 +4,24 @@
   padding: var(--block-space-half) calc(var(--inline-space) + 1vw);
 }
 
+.composer-notice {
+  text-align: right;
+  color: red;
+  font-size: 12px;
+  opacity: 0;
+}
+
+.composer-notice-show {
+   animation: flashMaxAttachmentNotice 2s ease-in
+}
+
+@keyframes flashMaxAttachmentNotice
+{
+  0% { opacity: 1; }
+  95% { opacity: 1; }
+  100% { opacity: 0; }
+}
+
 .composer__input-hint,
 .composer__context-btn {
   .composer:has(.composer__input:focus-within) & {

app/helpers/application_helper.rb

@@ -22,6 +22,22 @@ def body_classes
     [ @body_class, admin_body_class, account_logo_body_class ].compact.join(" ")
   end
 
+  def is_attachment_size_valid(attachment_size_in_bytes)
+    return true unless max_attachment_size_enabled?
+
+    attachment_size_in_bytes <= max_attachment_size_in_bytes
+  end
+
+  def max_attachment_size_enabled?
+    ENV.fetch("MAX_ATTACHMENT_SIZE_IN_BYTES", nil).present? && Integer(ENV.fetch("MAX_ATTACHMENT_SIZE_IN_BYTES", nil)).positive?
+  end
+
+  def max_attachment_size_in_bytes
+    return nil unless max_attachment_size_enabled?
+
+    Integer(ENV["MAX_ATTACHMENT_SIZE_IN_BYTES"])
+  end
+
   def link_back
     back_url = request.referrer
     back_url = root_path if back_url.nil? || back_url == request.url

app/helpers/rooms_helper.rb

@@ -66,7 +66,9 @@ def composer_data_options(room)
         controller: "composer drop-target",
         action: composer_data_actions,
         composer_messages_outlet: "#message-area",
-        composer_toolbar_class: "composer--rich-text", composer_room_id_value: room.id
+        composer_toolbar_class: "composer--rich-text",
+        composer_room_id_value: room.id,
+        composer_max_attachment_size_in_bytes_value: max_attachment_size_in_bytes
       }
     end
 

app/javascript/controllers/composer_controller.js

@@ -5,8 +5,8 @@ import { escapeHTML } from "helpers/dom_helpers"
 
 export default class extends Controller {
   static classes = ["toolbar"]
-  static targets = [ "clientid", "fields", "fileList", "text" ]
-  static values = { roomId: Number }
+  static targets = [ "clientid", "fields", "fileList", "text", "attachmentNotice" ]
+  static values = { roomId: Number, maxAttachmentSizeInBytes: Number }
   static outlets = [ "messages" ]
 
   #files = []
@@ -65,7 +65,14 @@ export default class extends Controller {
 
   filePicked(event) {
     for (const file of event.target.files) {
-      this.#files.push(file)
+      if(this.maxAttachmentSizeInBytesValue === null || file.size <= this.maxAttachmentSizeInBytesValue) {
+        this.#files.push(file)
+      } else {
+        this.attachmentNoticeTarget.addEventListener("animationend", () => {
+          this.attachmentNoticeTarget.classList.remove("composer-notice-show")
+        });
+        this.attachmentNoticeTarget.classList.add("composer-notice-show")
+      }
     }
     event.target.value = null
     this.#updateFileList()

app/models/message.rb

@@ -1,6 +1,8 @@
 class Message < ApplicationRecord
   include Attachment, Broadcasts, Mentionee, Pagination, Searchable
 
+  validate :attachment_size
+
   belongs_to :room, touch: true
   belongs_to :creator, class_name: "User", default: -> { Current.user }
 
@@ -41,4 +43,11 @@ def sound
       Sound.find_by_name match[:name]
     end
   end
+
+  private
+    def attachment_size
+      if attachment? && !ApplicationController.helpers.is_attachment_size_valid(attachment.blob.byte_size)
+        errors.add(:attachment, "Attachment exceeds max size: #{ApplicationController.helpers.max_attachment_size_in_bytes}")
+      end
+    end
 end

app/views/rooms/show/_composer.html.erb

@@ -50,7 +50,7 @@
             </div>
           </div>
         </fieldset>
-
+        <div class="composer-notice" data-composer-target="attachmentNotice">File exceeds max attachment size (<%= max_attachment_size_in_bytes %> bytes)</div>
         <div class="typing-indicator gap txt-small align-center flex-inline" data-typing-notifications-target="indicator">
           <div class="typing-indicator__author spinner" data-typing-notifications-target="author"></div>
         </div>

test/models/message/attachment_test.rb

@@ -19,6 +19,23 @@ class Message::AttachmentTest < ActiveSupport::TestCase
     assert_equal message.plain_text_body, "moon.jpg"
   end
 
+  test "creating a blank message with attachment that exceeds max attachment limit" do
+    ApplicationController.helpers.expects(:is_attachment_size_valid).returns(false)
+
+    assert_raises(ActiveRecord::RecordInvalid) do
+      create_attachment_message("moon.jpg", "image/jpeg")
+    end
+  end
+
+  test "creating a blank message with attachment that doesn't exceed max attachment limit" do
+    ApplicationController.helpers.expects(:is_attachment_size_valid).returns(true)
+
+    assert_nothing_raised do
+      create_attachment_message("moon.jpg", "image/jpeg")
+    end
+  end
+
+
 
   private
     def create_attachment_message(file, content_type)