IrreversibleMigration: Ignore methods that are part of another meth…

…od call (#49)

config/default.yml

@@ -17,7 +17,7 @@ Sequel/IrreversibleMigration:
   Reference: https://www.rubydoc.info/gems/rubocop-sequel/RuboCop/Cop/Sequel/IrreversibleMigration
   Enabled: true
   VersionAdded: 0.3.5
-  VersionChanged: 0.3.7
+  VersionChanged: 0.3.8
 
 Sequel/JSONColumn:
   Description: >-

lib/rubocop/cop/sequel/irreversible_migration.rb

@@ -28,7 +28,7 @@ class IrreversibleMigration < Base
           set_column_allow_null
         ].freeze
 
-        MSG = 'Avoid using "%<name>s" inside a "change" block. Use "up" & "down" blocks instead.'
+        MSG = 'Using "%<name>s" inside a "change" block may cause an irreversible migration. Use "up" & "down" instead.'
         PRIMARY_KEY_MSG = 'Avoid using "add_primary_key" with an array argument inside a "change" block.'
 
         def on_block(node)
@@ -46,6 +46,8 @@ def on_block(node)
         def validate_node(node)
           return if within_create_table_block?(node)
 
+          return if part_of_method_call?(node)
+
           add_offense(node.loc.selector, message: format(MSG, name: node.method_name)) unless valid_change_method?(node)
 
           add_offense(node.loc.selector, message: PRIMARY_KEY_MSG) if invalid_primary_key_method?(node)
@@ -68,6 +70,10 @@ def within_create_table_block?(node)
             ancestor.method_name == :create_table
           end
         end
+
+        def part_of_method_call?(node)
+          node.each_ancestor(:send).count.positive?
+        end
       end
     end
   end

lib/rubocop/sequel/version.rb

@@ -4,7 +4,7 @@ module RuboCop
   module Sequel
     # This module holds the RuboCop Sequel version information.
     module Version
-      STRING = '0.3.7'
+      STRING = '0.3.8'
     end
   end
 end

spec/rubocop/cop/sequel/irreversible_migration_spec.rb

@@ -103,6 +103,52 @@
         expect(offenses.size).to eq(1)
       end
     end
+
+    describe 'and a method is used within an argument' do
+      let(:source) do
+        <<~SOURCE
+          change do
+            alter_table(:stores) do
+              add_column(:products, JSON, null: false, default: Sequel.pg_json({}))
+              add_constraint(
+                :only_one_user,
+                (
+                  Sequel.cast(Sequel.~(user_id: nil), Integer) +
+                  Sequel.cast(Sequel.~(owner_id: nil), Integer)
+                ) => 1,
+              )
+            end
+          end
+        SOURCE
+      end
+
+      it 'does not register an offense with valid methods' do
+        offenses = inspect_source_within_migration(source)
+        expect(offenses).to be_empty
+      end
+    end
+
+    describe 'and an invalid change method contains another invalid change method as an argument' do
+      let(:source) do
+        <<~SOURCE
+          change do
+            alter_table(:stores) do
+              drop_column(:products, JSON, null: false, default: Sequel.pg_json({}))
+            end
+          end
+        SOURCE
+      end
+
+      it 'only registers 1 offense' do
+        offenses = inspect_source_within_migration(source)
+        expect(offenses.size).to eq(1)
+      end
+
+      it 'only registers an offense for the parent method' do
+        offenses = inspect_source_within_migration(source)
+        expect(offenses.first.message).to include('drop_column')
+      end
+    end
   end
 
   context 'when inside an up block' do