Don't use tap so return value is that of yield

src/db.cr

@@ -102,14 +102,13 @@ module DB
 
   # Same as `#open` but the database is yielded and closed automatically.
   def self.open(uri : URI | String, &block)
-    build_database(uri).tap do |db|
+    db = build_database(uri)
     begin
       yield db
     ensure
       db.close
     end
   end
-  end
 
   private def self.build_database(connection_string : String)
     build_database(URI.parse(connection_string))

src/db/query_methods.cr

@@ -31,13 +31,8 @@ module DB
     # The `ResultSet` is closed automatically.
     def query(query, *args)
       # CHECK prepare(query).query(*args, &block)
-      query(query, *args).tap do |rs|
+      rs = query(query, *args)
-        begin
+      yield rs ensure rs.close
-          yield rs
-        ensure
-          rs.close
-        end
-      end
     end
 
     # Performs the `query` and returns an `ExecResult`

src/db/statement.cr

@@ -69,19 +69,14 @@ module DB
 
     # See `QueryMethods#query`
     def query(*args)
-      query(*args).tap do |rs|
+      rs = query(*args)
-        begin
+      yield rs ensure rs.close
-          yield rs
-        ensure
-          rs.close
-        end
-      end
     end
 
     private def perform_exec_and_release(args : Enumerable) : ExecResult
-      perform_exec(args).tap do
+      res = perform_exec(args)
       release_connection
-      end
+      res
     end
 
     protected abstract def perform_query(args : Enumerable) : ResultSet