Use read_attribute_for_database when generating cached INSERTs

lib/fixture_kit/coders/active_record_coder.rb

@@ -74,7 +74,7 @@ def generate_statements(models)
         rows = []
         model.unscoped.order(:id).find_each do |record|
           row_values = column_names.map do |col|
-            value = record.read_attribute_before_type_cast(col)
+            value = record.read_attribute_for_database(col)
             model.connection.quote(value)
           end
           rows << "(#{row_values.join(", ")})"

spec/dummy/app/models/binary_blob.rb

@@ -0,0 +1,6 @@
+# frozen_string_literal: true
+
+class BinaryBlob < ActiveRecord::Base
+  has_many :children, class_name: "BinaryBlobChild"
+  encrypts :secret_note
+end

spec/dummy/app/models/binary_blob_child.rb

@@ -0,0 +1,5 @@
+# frozen_string_literal: true
+
+class BinaryBlobChild < ActiveRecord::Base
+  belongs_to :binary_blob
+end

spec/dummy/config/application.rb

@@ -20,5 +20,9 @@ class Application < Rails::Application
 
     # Minimal config for testing
     config.active_record.maintain_test_schema = false
+
+    config.active_record.encryption.primary_key = "test_primary_key_32_bytes_padding"
+    config.active_record.encryption.deterministic_key = "test_deterministic_key_32_padding"
+    config.active_record.encryption.key_derivation_salt = "test_key_derivation_salt_padding"
   end
 end

spec/support/dummy_rails_helper.rb

@@ -82,6 +82,8 @@ def setup_databases
     ActiveRecord::Base.connection.drop_table(:vehicles, if_exists: true, force: :cascade)
     ActiveRecord::Base.connection.drop_table(:gadgets, if_exists: true, force: :cascade)
     ActiveRecord::Base.connection.drop_table(:computed_widgets, if_exists: true, force: :cascade)
+    ActiveRecord::Base.connection.drop_table(:binary_blob_children, if_exists: true, force: :cascade)
+    ActiveRecord::Base.connection.drop_table(:binary_blobs, if_exists: true, force: :cascade)
   end
 
   AnalyticsRecord.connection.disable_referential_integrity do
@@ -143,6 +145,20 @@ def setup_databases
     t.timestamps
   end
 
+  ActiveRecord::Base.connection.create_table :binary_blobs, force: true do |t|
+    t.binary :payload, limit: 16, null: false
+    t.string :label, null: false
+    t.json :metadata
+    t.text :secret_note
+    t.timestamps
+  end
+
+  ActiveRecord::Base.connection.create_table :binary_blob_children, force: true do |t|
+    t.binary :payload, limit: 16, null: false
+    t.references :binary_blob, null: false, foreign_key: true
+    t.timestamps
+  end
+
   # Analytics database schema
   AnalyticsRecord.connection.create_table :activity_logs, force: true do |t|
     t.integer :external_user_id, null: false

spec/unit/coders/active_record_coder_spec.rb

@@ -115,6 +115,71 @@ def upsert_all_options(model)
     end
   end
 
+  describe "binary column encoding" do
+    let(:raw_bytes) { (240..255).map(&:chr).join.force_encoding(Encoding::ASCII_8BIT) }
+
+    it "preserves exact bytes when fixtures are mounted from cache" do
+      result = coder.generate { BinaryBlob.create!(payload: raw_bytes, label: "first") }
+
+      coder.mount(result)
+
+      replayed = BinaryBlob.find_by!(label: "first")
+      expect(replayed.payload.b).to eq(raw_bytes)
+    end
+
+    it "round-trips multiple rows with different payloads" do
+      other_bytes = (128..143).map(&:chr).join.force_encoding(Encoding::ASCII_8BIT)
+      result = coder.generate do
+        BinaryBlob.create!(payload: raw_bytes, label: "first")
+        BinaryBlob.create!(payload: other_bytes, label: "second")
+      end
+
+      coder.mount(result)
+
+      expect(BinaryBlob.find_by!(label: "first").payload.b).to eq(raw_bytes)
+      expect(BinaryBlob.find_by!(label: "second").payload.b).to eq(other_bytes)
+    end
+
+    it "round-trips a JSON column alongside binary data" do
+      metadata = {"version" => 2, "tags" => ["alpha", "beta"]}
+      result = coder.generate do
+        BinaryBlob.create!(payload: raw_bytes, label: "with-json", metadata: metadata)
+      end
+
+      coder.mount(result)
+
+      replayed = BinaryBlob.find_by!(label: "with-json")
+      expect(replayed.payload.b).to eq(raw_bytes)
+      expect(replayed.metadata).to eq(metadata)
+    end
+
+    it "stores ciphertext, not cleartext, for encrypts attributes" do
+      cleartext = "shhh-this-is-private-#{SecureRandom.hex(4)}"
+      result = coder.generate { BinaryBlob.create!(payload: raw_bytes, label: "encrypted", secret_note: cleartext) }
+
+      sql = result[BinaryBlob]
+      expect(sql).not_to include(cleartext)
+
+      coder.mount(result)
+
+      replayed = BinaryBlob.find_by!(label: "encrypted")
+      expect(replayed.secret_note).to eq(cleartext)
+    end
+
+    it "replays a foreign key relationship without integrity errors" do
+      result = coder.generate do
+        parent = BinaryBlob.create!(payload: raw_bytes, label: "parent")
+        BinaryBlobChild.create!(binary_blob: parent, payload: raw_bytes)
+      end
+
+      coder.mount(result)
+
+      parent = BinaryBlob.find_by!(label: "parent")
+      expect(parent.children.count).to eq(1)
+      expect(parent.children.first.payload.b).to eq(raw_bytes)
+    end
+  end
+
   describe "#mount" do
     it "documents that connection execute_batch is currently private" do
       connection = User.connection