Allow `to_table` in `invert_remove_foreign_key`

remove_foreign_key supports
- remove_foreign_key :accounts, :branches
- remove_foreign_key :accounts, to_table: :branches

but the second one is not reversible.

This branch is to fix and allow second one to be reversible.

[Nikolay Epifanov, Rich Chen]

4 files changed, 36 insertions, 4 deletions

diff --git a/activerecord/CHANGELOG.md b/activerecord/CHANGELOG.md
index d1ae41ab97..06ce2e6d4f 100644
--- a/activerecord/CHANGELOG.md
+++ b/activerecord/CHANGELOG.md
@@ -73,5 +73,9 @@
 
     *DHH*
 
+*   Allow `to_table` in `invert_remove_foreign_key`.
+
+    *Nikolay Epifanov*, *Rich Chen*
+
 
 Please check [5-2-stable](https://github.com/rails/rails/blob/5-2-stable/activerecord/CHANGELOG.md) for previous changes.
diff --git a/activerecord/lib/active_record/connection_adapters/abstract/schema_statements.rb b/activerecord/lib/active_record/connection_adapters/abstract/schema_statements.rb
index 3be0906f2a..fd9bf48ab5 100644
--- a/activerecord/lib/active_record/connection_adapters/abstract/schema_statements.rb
+++ b/activerecord/lib/active_record/connection_adapters/abstract/schema_statements.rb
@@ -980,11 +980,18 @@ module ActiveRecord
       #
       #   remove_foreign_key :accounts, column: :owner_id
       #
+      # Removes the foreign key on +accounts.owner_id+. in a reversible manner
+      #
+      #   remove_foreign_key :accounts, column: :owner_id, to_table: :owners
+      #
       # Removes the foreign key named +special_fk_name+ on the +accounts+ table.
       #
       #   remove_foreign_key :accounts, name: :special_fk_name
       #
-      # The +options+ hash accepts the same keys as SchemaStatements#add_foreign_key.
+      # The +options+ hash accepts the same keys as SchemaStatements#add_foreign_key
+      # with an addition of
+      # [<tt>:to_table</tt>]
+      #   The table contains the referenced primary key.
       def remove_foreign_key(from_table, options_or_to_table = {})
         return unless supports_foreign_keys?
 
diff --git a/activerecord/lib/active_record/migration/command_recorder.rb b/activerecord/lib/active_record/migration/command_recorder.rb
index 087632b10f..dea6d4ec08 100644
--- a/activerecord/lib/active_record/migration/command_recorder.rb
+++ b/activerecord/lib/active_record/migration/command_recorder.rb
@@ -214,11 +214,24 @@ module ActiveRecord
         end
 
         def invert_remove_foreign_key(args)
-          from_table, to_table, remove_options = args
-          raise ActiveRecord::IrreversibleMigration, "remove_foreign_key is only reversible if given a second table" if to_table.nil? || to_table.is_a?(Hash)
+          from_table, options_or_to_table, options_or_nil = args
+
+          to_table = if options_or_to_table.is_a?(Hash)
+            options_or_to_table[:to_table]
+          else
+            options_or_to_table
+          end
+
+          remove_options = if options_or_to_table.is_a?(Hash)
+            options_or_to_table.except(:to_table)
+          else
+            options_or_nil
+          end
+
+          raise ActiveRecord::IrreversibleMigration, "remove_foreign_key is only reversible if given a second table" if to_table.nil?
 
           reversed_args = [from_table, to_table]
-          reversed_args << remove_options if remove_options
+          reversed_args << remove_options if remove_options.present?
 
           [:add_foreign_key, reversed_args]
         end
diff --git a/activerecord/test/cases/migration/command_recorder_test.rb b/activerecord/test/cases/migration/command_recorder_test.rb
index 3a11bb081b..daca296ade 100644
--- a/activerecord/test/cases/migration/command_recorder_test.rb
+++ b/activerecord/test/cases/migration/command_recorder_test.rb
@@ -334,6 +334,14 @@ module ActiveRecord
         assert_equal [:add_foreign_key, [:dogs, :people, on_delete: :nullify, on_update: :cascade]], enable
       end
 
+      def test_invert_remove_foreign_key_with_to_table_in_options
+        enable = @recorder.inverse_of :remove_foreign_key, [:dogs, to_table: :people]
+        assert_equal [:add_foreign_key, [:dogs, :people]], enable
+
+        enable = @recorder.inverse_of :remove_foreign_key, [:dogs, to_table: :people, column: :owner_id]
+        assert_equal [:add_foreign_key, [:dogs, :people, column: :owner_id]], enable
+      end
+
       def test_invert_remove_foreign_key_is_irreversible_without_to_table
         assert_raises ActiveRecord::IrreversibleMigration do
           @recorder.inverse_of :remove_foreign_key, [:dogs, column: "owner_id"]