Add spaces between functions and triggers in schema.rb (#195)

I've been dealing with the changes to schema_dumper in Rails 8.1 and
Senic 1.9 and found that it's most common for their methods not to emit
a newline after their last operation.

Hence I think it's safe to assume that functions() and triggers() should
emit a newline before their loops and within their loops, up to the last
iteration.
And, not having these functions emit a final newline holds with the
pattern used by the Rails and Scenic schema_dumpers.

I've tested this in my own apps with a patch on this gem and the spacing
is correct with the new Rails 8.1 schema changes (and with Scenic
emitting `create_view` statements before the `create_function` and
`create_trigger` statements).

Author: chiperific

lib/fx/schema_dumper.rb

@@ -21,20 +21,16 @@ def functions(stream)
       dumpable_functions_in_database = Fx.database.functions
 
       dumpable_functions_in_database.each do |function|
+        stream.puts
         stream.puts(function.to_schema)
       end
-
-      stream.puts if dumpable_functions_in_database.any?
     end
 
     def triggers(stream)
       dumpable_triggers_in_database = Fx.database.triggers
 
-      if dumpable_triggers_in_database.any?
-        stream.puts
-      end
-
       dumpable_triggers_in_database.each do |trigger|
+        stream.puts
         stream.puts(trigger.to_schema)
       end
     end

spec/fx/schema_dumper_spec.rb

@@ -159,6 +159,64 @@
     connection.schema_search_path = "public"
   end
 
+  it "puts a blank line before each function and trigger" do
+    connection.create_table :users do |t|
+      t.string :name
+      t.string :upper_name
+      t.string :down_name
+    end
+    Fx.database.create_function <<~SQL
+      CREATE OR REPLACE FUNCTION uppercase_users_name()
+      RETURNS trigger AS $$
+      BEGIN
+        NEW.upper_name = UPPER(NEW.name);
+        RETURN NEW;
+      END;
+      $$ LANGUAGE plpgsql;
+    SQL
+    sql_definition = <<~SQL
+      CREATE TRIGGER uppercase_users_name
+          BEFORE INSERT ON users
+          FOR EACH ROW
+          EXECUTE FUNCTION uppercase_users_name();
+    SQL
+    connection.create_trigger(
+      :uppercase_users_name,
+      sql_definition: sql_definition
+    )
+    Fx.database.create_function <<~SQL
+      CREATE OR REPLACE FUNCTION downcase_users_name()
+      RETURNS trigger AS $$
+      BEGIN
+        NEW.down_name = LOWER(NEW.name);
+        RETURN NEW;
+      END;
+      $$ LANGUAGE plpgsql;
+    SQL
+    sql_definition = <<~SQL
+      CREATE TRIGGER downcase_users_name
+          BEFORE INSERT ON users
+          FOR EACH ROW
+          EXECUTE FUNCTION downcase_users_name();
+    SQL
+    connection.create_trigger(
+      :downcase_users_name,
+      sql_definition: sql_definition
+    )
+    stream = StringIO.new
+    output = stream.string
+
+    dump(connection: connection, stream: stream)
+
+    pattern = /(?<delimiter>end|SQL)\n\n  (?<statement>create_function|create_trigger)/
+    # a blank line between:
+    # - the table and the uppercase_users_name function,
+    # - the uppercase_users_name function and the downcase_users_name function,
+    # - the downcase_users_name function and the uppercase_users_name trigger,
+    # - the uppercase_users_name trigger and the downcase_users_name trigger,
+    expect(output.scan(pattern).size).to eq(4)
+  end
+
   def dump(connection:, stream:)
     if Rails.version >= "7.2"
       ActiveRecord::SchemaDumper.dump(connection.pool, stream)