Preserve existing metadata when analyzing a blob

Closes #31138.

3 files changed, 28 insertions, 3 deletions

diff --git a/activestorage/app/models/active_storage/blob.rb b/activestorage/app/models/active_storage/blob.rb
index 99823e14c6..2aa05d665e 100644
--- a/activestorage/app/models/active_storage/blob.rb
+++ b/activestorage/app/models/active_storage/blob.rb
@@ -249,7 +249,7 @@ class ActiveStorage::Blob < ActiveRecord::Base
   # You won't ordinarily need to call this method from a Rails application. New blobs are automatically and asynchronously
   # analyzed via #analyze_later when they're attached for the first time.
   def analyze
-    update! metadata: extract_metadata_via_analyzer
+    update! metadata: metadata.merge(extract_metadata_via_analyzer)
   end
 
   # Enqueues an ActiveStorage::AnalyzeJob which calls #analyze.
diff --git a/activestorage/test/models/attachments_test.rb b/activestorage/test/models/attachments_test.rb
index 47f2bd7911..96bc963cff 100644
--- a/activestorage/test/models/attachments_test.rb
+++ b/activestorage/test/models/attachments_test.rb
@@ -88,6 +88,16 @@ class ActiveStorage::AttachmentsTest < ActiveSupport::TestCase
     end
   end
 
+  test "preserve existing metadata when analyzing a newly-attached blob" do
+    blob = create_file_blob(metadata: { foo: "bar" })
+
+    perform_enqueued_jobs do
+      @user.avatar.attach blob
+    end
+
+    assert_equal "bar", blob.reload.metadata[:foo]
+  end
+
   test "purge attached blob" do
     @user.avatar.attach create_blob(filename: "funky.jpg")
     avatar_key = @user.avatar.key
@@ -193,6 +203,21 @@ class ActiveStorage::AttachmentsTest < ActiveSupport::TestCase
     end
   end
 
+  test "preserve existing metadata when analyzing newly-attached blobs" do
+    blobs = [
+      create_file_blob(filename: "racecar.jpg", content_type: "image/jpeg", metadata: { foo: "bar" }),
+      create_file_blob(filename: "video.mp4", content_type: "video/mp4", metadata: { foo: "bar" })
+    ]
+
+    perform_enqueued_jobs do
+      @user.highlights.attach(blobs)
+    end
+
+    blobs.each do |blob|
+      assert_equal "bar", blob.reload.metadata[:foo]
+    end
+  end
+
   test "purge attached blobs" do
     @user.highlights.attach create_blob(filename: "funky.jpg"), create_blob(filename: "wonky.jpg")
     highlight_keys = @user.highlights.collect(&:key)
diff --git a/activestorage/test/test_helper.rb b/activestorage/test/test_helper.rb
index 38408cdad3..55da781f2a 100644
--- a/activestorage/test/test_helper.rb
+++ b/activestorage/test/test_helper.rb
@@ -45,8 +45,8 @@ class ActiveSupport::TestCase
       ActiveStorage::Blob.create_after_upload! io: StringIO.new(data), filename: filename, content_type: content_type
     end
 
-    def create_file_blob(filename: "racecar.jpg", content_type: "image/jpeg")
-      ActiveStorage::Blob.create_after_upload! io: file_fixture(filename).open, filename: filename, content_type: content_type
+    def create_file_blob(filename: "racecar.jpg", content_type: "image/jpeg", metadata: nil)
+      ActiveStorage::Blob.create_after_upload! io: file_fixture(filename).open, filename: filename, content_type: content_type, metadata: metadata
     end
 
     def create_blob_before_direct_upload(filename: "hello.txt", byte_size:, checksum:, content_type: "text/plain")