Add Where#merge

Author: solnic

lib/sql/composer/nodes/where.rb

@@ -36,6 +36,10 @@ def append(hash = {}, &block)
           with(operations: operations + new_operations)
         end
 
+        def merge(other)
+          with(operations: operations + other.operations)
+        end
+
         def to_ast
           [:where, operations.map(&:to_ast)]
         end

lib/sql/composer/statement.rb

@@ -20,9 +20,9 @@ def each(&block)
       def append(type, *args, &block)
         new_dsl =
           if block
-            dsl.new(&block)
+            dsl.new(ast: [], &block)
           else
-            dsl.new.__send__(type, *args)
+            dsl.new(ast: []).__send__(type, *args)
           end
 
         left = self

spec/integration/sql/compose_spec.rb

@@ -442,6 +442,22 @@
         end
       end
 
+      context "with existing :where" do
+        let(:query) do
+          source_query.append(:where, name: "Jane").append(:where, id: 1)
+        end
+
+        specify do
+          expect(result).to eql(
+            <<~SQL.strip.gsub("\n", " ")
+              SELECT id, name
+              FROM users
+              WHERE name = 'Jane' AND id = 1
+            SQL
+          )
+        end
+      end
+
       context "with a block" do
         let(:query) do
           source_query.append(:order) { WHERE(`name` == "Jane") }