Addendum to #12891

* Fix incorrectly named tests
* Restore Object#to_param behavior
* Ensure param is derived from a squished and truncated string

2 files changed, 28 insertions, 8 deletions

diff --git a/activerecord/lib/active_record/integration.rb b/activerecord/lib/active_record/integration.rb
index f881fa74b2..951db5b756 100644
--- a/activerecord/lib/active_record/integration.rb
+++ b/activerecord/lib/active_record/integration.rb
@@ -86,12 +86,16 @@ module ActiveRecord
       #
       #   params[:id]               # => "123-fancy-pants"
       #   User.find(params[:id]).id # => 123
-      def to_param(method_name)
-        define_method :to_param do
-          if (default = super()) && (result = send(method_name).to_s).present?
-            "#{default}-#{result.truncate(20, separator: /\s/, omission: nil).parameterize}"
-          else
-            default
+      def to_param(method_name = nil)
+        if method_name.nil?
+          super()
+        else
+          define_method :to_param do
+            if (default = super()) && (result = send(method_name).to_s).present?
+              "#{default}-#{result.squish.truncate(20, separator: /\s/, omission: nil).parameterize}"
+            else
+              default
+            end
           end
         end
       end
diff --git a/activerecord/test/cases/integration_test.rb b/activerecord/test/cases/integration_test.rb
index 1f62433ea2..8097f6e36e 100644
--- a/activerecord/test/cases/integration_test.rb
+++ b/activerecord/test/cases/integration_test.rb
@@ -28,7 +28,19 @@ class IntegrationTest < ActiveRecord::TestCase
     assert_equal '4-flamboyant-software', firm.to_param
   end
 
-  def to_param_class_method_uses_default_if_blank
+  def test_to_param_class_method_truncates
+    firm = Firm.find(4)
+    firm.name = 'a ' * 100
+    assert_equal '4-a-a-a-a-a-a-a-a-a', firm.to_param
+  end
+
+  def test_to_param_class_method_squishes
+    firm = Firm.find(4)
+    firm.name = "ab \n" * 100
+    assert_equal '4-ab-ab-ab-ab-ab-ab', firm.to_param
+  end
+
+  def test_to_param_class_method_uses_default_if_blank
     firm = Firm.find(4)
     firm.name = nil
     assert_equal '4', firm.to_param
@@ -36,11 +48,15 @@ class IntegrationTest < ActiveRecord::TestCase
     assert_equal '4', firm.to_param
   end
 
-  def to_param_class_method_uses_default_if_not_persisted
+  def test_to_param_class_method_uses_default_if_not_persisted
     firm = Firm.new(name: 'Fancy Shirts')
     assert_equal nil, firm.to_param
   end
 
+  def test_to_param_with_no_arguments
+    assert_equal 'Firm', Firm.to_param
+  end
+
   def test_cache_key_for_existing_record_is_not_timezone_dependent
     utc_key = Developer.first.cache_key