Add Blob#type as a StringInquirer

2 files changed, 20 insertions, 0 deletions

diff --git a/app/models/active_storage/blob.rb b/app/models/active_storage/blob.rb
index 6a7836b9e5..b2d5b2362c 100644
--- a/app/models/active_storage/blob.rb
+++ b/app/models/active_storage/blob.rb
@@ -84,6 +84,20 @@ class ActiveStorage::Blob < ActiveRecord::Base
     ActiveStorage::Filename.new(self[:filename])
   end
 
+  # Returns a `StringInquirer` based on the content_type that is broken into text, image, audio, video, pdf, or,
+  # the catch-all, file. Example: `messages.attachments.select(&:image?)`.
+  def type
+    @type ||=
+      case content_type
+      when /^text/  then 'text'
+      when /^image/ then 'image'
+      when /^audio/ then 'audio'
+      when /^video/ then 'video'
+      when /pdf/    then 'pdf'
+      else 'file'
+      end.inquiry
+  end
+
   # Returns a `ActiveStorage::Variant` instance with the set of `transformations` passed in. This is only relevant
   # for image files, and it allows any image to be transformed for size, colors, and the like. Example:
   #
diff --git a/test/models/blob_test.rb b/test/models/blob_test.rb
index a5b291d5db..b51be7a93b 100644
--- a/test/models/blob_test.rb
+++ b/test/models/blob_test.rb
@@ -11,6 +11,12 @@ class ActiveStorage::BlobTest < ActiveSupport::TestCase
     assert_equal Digest::MD5.base64digest(data), blob.checksum
   end
 
+  test "inquery type" do
+    blob = create_blob data: "Hello world!"
+    assert blob.type.text?
+    assert_not blob.type.audio?
+  end
+
   test "download yields chunks" do
     blob   = create_blob data: "a" * 75.kilobytes
     chunks = []