docs: add note about with_meta vs after_commit callbacks

Closes #236

README.md

@@ -337,6 +337,8 @@ end
 
 **Important:** If you use connection pooling (e.g., PgBouncer), using `.with_meta` without a transaction may lead to unexpected results (since meta is set for a connection). Without a transaction, we cannot guarantee that the same connection will be used for queries (including metadata cleanup).
 
+**Important**: In Rails, `after_commit` callbacks are executed after transaction is committed, and, thus, after `with_meta` block is executed—the meta wouldn't be added to changes captured in the `after_commit` phase. One particular scenario is having associations with `touch: true` (_touch_ updates are executed after commit).
+
 ### Track responsibility
 
 A special application of meta information is storing the author of the change, which is called _Responsible ID_. There is more likely that you would like to store the `current_user.id` that way.

spec/dummy/app/models/article.rb

@@ -3,6 +3,6 @@
 class Article < ActiveRecord::Base
   has_logidze
 
-  belongs_to :user, optional: true
+  belongs_to :user, optional: true, touch: :time
   has_many :comments
 end

spec/integration/meta_spec.rb

@@ -20,7 +20,7 @@
   let(:meta2) { {"other_key" => "other_val"} }
 
   describe ".with_meta" do
-    subject { User.create!(name: "test", age: 10, active: false) }
+    subject(:user) { User.create!(name: "test", age: 10, active: false) }
 
     context "insert" do
       it "doesn't set meta if it's not provided" do
@@ -209,6 +209,19 @@
         expect(subject.at_version(2)).to be_nil
         expect(subject.at_version(3).meta).to eq meta2
       end
+
+      # See https://github.com/palkan/logidze/issues/236
+      context "with Rails touch:true" do
+        let!(:article) { Article.create!(title: "test", user: user) }
+
+        it "updating a record updates the parent record's log_data with the correct meta" do
+          Logidze.with_meta(meta, transactional: false) do
+            article.touch(time: 1.minute.since)
+          end
+
+          expect(user.reload.log_data.meta).to eq(meta)
+        end
+      end
     end
 
     context "when transactional:false" do

spec/support/acceptance_helpers.rb

@@ -32,7 +32,7 @@ def run_command(cmd, env: {}, success: true)
         )
 
       if ENV["LOG"]
-        puts "\n\nCOMMAND:\n#{command}\n\nOUTPUT:\n#{output}\nERROR:\n#{err}\n"
+        puts "\n\nCOMMAND:\n#{cmd}\n\nOUTPUT:\n#{output}\nERROR:\n#{err}\n"
       end
 
       [status, output, err]