Do not track associations by default

[Fixes #740]

CHANGELOG.md

@@ -5,6 +5,8 @@
 - [#758](https://github.com/airblade/paper_trail/pull/758) -
   `PaperTrail.config.track_associations` getter method removed,
   use `track_associations?` instead.
+- [#740](https://github.com/airblade/paper_trail/issues/740) -
+  `PaperTrail.config.track_associations?` now defaults to false
 - [#723](https://github.com/airblade/paper_trail/pull/723) -
   `PaperTrail.enabled=` now affects all threads
 - [#556](https://github.com/airblade/paper_trail/pull/556) /

lib/paper_trail/config.rb

@@ -34,9 +34,19 @@ module PaperTrail
       )
     end
 
+    # Previously, we checked `PaperTrail::VersionAssociation.table_exists?`
+    # here, but that proved to be problematic in situations when the database
+    # connection had not been established, or when the database does not exist
+    # yet (as with `rake db:create`).
     def track_associations?
       if @track_associations.nil?
-        PaperTrail::VersionAssociation.table_exists?
+        ActiveSupport::Deprecation.warn <<-EOS.strip_heredoc.gsub(/\s+/, " ")
+          PaperTrail.track_associations has not been set. As of PaperTrail 5, it
+          defaults to false. Tracking associations is an experimental feature so
+          we recommend setting PaperTrail.config.track_associations = false in
+          your config/initializers/paper_trail.rb
+        EOS
+        false
       else
         @track_associations
       end

spec/paper_trail/config_spec.rb

@@ -13,5 +13,21 @@ module PaperTrail
         expect { described_class.new }.to raise_error(NoMethodError)
       end
     end
+
+    describe "track_associations?" do
+      context "@track_associations is nil" do
+        after do
+          PaperTrail.config.track_associations = true
+        end
+
+        it "returns false and prints a deprecation warning" do
+          config = described_class.instance
+          config.track_associations = nil
+          expect {
+            expect(config.track_associations?).to eq(false)
+          }.to output(/DEPRECATION WARNING/).to_stderr
+        end
+      end
+    end
   end
 end

test/dummy/config/initializers/paper_trail.rb

@@ -1,5 +1,4 @@
-# Turn on associations tracking when the test suite is run on Travis CI
-PaperTrail.config.track_associations = true if ENV["TRAVIS"]
+PaperTrail.config.track_associations = true
 
 module PaperTrail
   class Version < ActiveRecord::Base