Merge pull request #330: bound attachment preview work

Reviewed and merged by GPT on behalf of DHH. Keep both boost-cache and preview-loading regressions.

test/controllers/messages_caching_test.rb

@@ -67,6 +67,22 @@ class MessagesCachingTest < ActionDispatch::IntegrationTest
     assert_equal in_order, css_select("##{dom_id(messages(:fourth), :boosts)} .boost").map { it["id"] }
   end
 
+  test "a page of messages loads whether their previews were made along with the messages, not one at a time" do
+    room = rooms(:watercooler)
+    2.times do |copy|
+      { "moon.jpg" => "image/jpeg", "alpha-centuri.mov" => "video/quicktime" }.each do |file, content_type|
+        room.messages.create_with_attachment! creator: users(:david), client_message_id: "#{copy}-#{file}", attachment: fixture_file_upload(file, content_type)
+      end
+    end
+
+    assert_no_queries_match(/"active_storage_\w+"\."(id|blob_id|record_id)" = \?/) do
+      get room_messages_url(room)
+    end
+    assert_response :success
+    assert_select "img[src*='moon.jpg']", count: 2
+    assert_select "video[poster]", count: 2
+  end
+
   private
     def with_memory_cache
       old_cache = Rails.cache

test/helpers/messages_helper_test.rb

@@ -24,4 +24,52 @@ class MessagesHelperTest < ActionView::TestCase
     assert_match /<a href="https:\/\/example\.com"[^>]*>example<\/a>/, presentation
     assert_match /<strong>bold<\/strong>/, presentation
   end
+
+  test "message_presentation shows an image's thumbnail made when it was posted" do
+    presentation = view.message_presentation(attachment_message("moon.jpg", "image/jpeg", processed: true))
+
+    assert_match %r{<img[^>]+src="[^"]*/representations/[^"]*moon\.jpg"}, presentation
+  end
+
+  test "message_presentation links an image whose thumbnail wasn't made, rather than making it on view" do
+    presentation = view.message_presentation(attachment_message("moon.jpg", "image/jpeg", processed: false))
+
+    assert_no_match %r{/representations/}, presentation
+    assert_match %r{<span>moon\.jpg</span>}, presentation
+  end
+
+  test "message_presentation gives a video the poster made when it was posted" do
+    presentation = view.message_presentation(attachment_message("alpha-centuri.mov", "video/quicktime", processed: true))
+
+    assert_match %r{<video[^>]+poster="[^"]*/representations/[^"]*alpha-centuri}, presentation
+  end
+
+  test "message_presentation shows a video whose poster wasn't made without one, rather than making it on view" do
+    presentation = view.message_presentation(attachment_message("alpha-centuri.mov", "video/quicktime", processed: false))
+
+    assert_match %r{<video[^>]+src="[^"]*alpha-centuri\.mov"}, presentation
+    assert_no_match %r{poster=|/representations/}, presentation
+  end
+
+  test "message_presentation shows a video whose frame was drawn but whose poster wasn't made without one" do
+    message = attachment_message("alpha-centuri.mov", "video/quicktime", processed: false)
+    message.attachment.preview(format: :jpg).processed
+    assert message.attachment.preview(:poster).processed?
+
+    presentation = view.message_presentation(message.reload)
+
+    assert_match %r{<video[^>]+src="[^"]*alpha-centuri\.mov"}, presentation
+    assert_no_match %r{poster=|/representations/}, presentation
+  end
+
+  private
+    def attachment_message(file, content_type, processed:)
+      attributes = { creator: users(:jason), client_message_id: "0015", attachment: fixture_file_upload(file, content_type) }
+
+      if processed
+        rooms(:pets).messages.create_with_attachment!(attributes)
+      else
+        rooms(:pets).messages.create!(attributes)
+      end
+    end
 end

test/models/message/attachment_test.rb

@@ -34,7 +34,68 @@ class Message::AttachmentTest < ActiveSupport::TestCase
     assert_not message.attachment.preview(format: :webp).image.attached?
   end
 
+  test "creating a message makes the video poster that the room shows" do
+    message = create_attachment_message("alpha-centuri.mov", "video/quicktime")
+
+    assert_no_difference -> { ActiveStorage::VariantRecord.count } do
+      message.reload.attachment.preview(:poster).processed
+    end
+  end
+
+  test "video previews are drawn by the previewer with a time limit, from a frame within the first 5 seconds" do
+    assert_includes ActiveStorage.previewers, TimeLimitedVideoPreviewer
+    assert_not_includes ActiveStorage.previewers, ActiveStorage::Previewer::VideoPreviewer
+    assert_includes ActiveStorage.video_preview_arguments, "gte(t\\,5)"
+  end
+
+  test "creating a message gives up on a video preview that takes longer than the time limit" do
+    started = nil
+    message = nil
+
+    with_ffmpeg_sleeping(5.seconds) do
+      stub_const(TimeLimitedVideoPreviewer, :TIME_LIMIT, 0.2) do
+        started = Process.clock_gettime(Process::CLOCK_MONOTONIC)
+        message = create_attachment_message("alpha-centuri.mov", "video/quicktime")
+      end
+    end
+
+    assert_operator Process.clock_gettime(Process::CLOCK_MONOTONIC) - started, :<, 2
+    assert_not message.reload.attachment.preview(format: :webp).image.attached?
+  end
+
+  test "creating a message makes no thumbnail of an image with more pixels than the limit" do
+    moon = Vips::Image.new_from_file(file_fixture("moon.jpg").to_s)
+
+    stub_const(Message::Attachment, :THUMBNAIL_MAX_PIXELS, moon.width * moon.height) do
+      assert create_attachment_message("moon.jpg", "image/jpeg").attachment.representation(:thumb).processed?
+    end
+
+    stub_const(Message::Attachment, :THUMBNAIL_MAX_PIXELS, moon.width * moon.height - 1) do
+      assert_not create_attachment_message("moon.jpg", "image/jpeg").attachment.representation(:thumb).processed?
+    end
+  end
+
+  test "creating a message makes no preview of a video with more pixels than the limit" do
+    stub_const(Message::Attachment, :THUMBNAIL_MAX_PIXELS, 1) do
+      message = create_attachment_message("alpha-centuri.mov", "video/quicktime")
+      assert_not message.reload.attachment.preview(format: :webp).image.attached?
+    end
+  end
+
   private
+    def with_ffmpeg_sleeping(duration)
+      Tempfile.create("ffmpeg") do |ffmpeg|
+        ffmpeg.write "#!/bin/sh\n[ \"$1\" = \"-version\" ] && exit 0\nexec sleep #{duration.to_i}\n"
+        ffmpeg.close
+        File.chmod 0o755, ffmpeg.path
+
+        previous, ActiveStorage.paths[:ffmpeg] = ActiveStorage.paths[:ffmpeg], ffmpeg.path
+        yield
+      ensure
+        ActiveStorage.paths[:ffmpeg] = previous
+      end
+    end
+
     def create_attachment_message(file, content_type)
       rooms(:hq).messages.create_with_attachment! \
         creator: users(:david),