Merge pull request #7 from sql-rb/literals

Add literal node

Author: solnic

lib/sql/composer/compiler.rb

@@ -42,6 +42,10 @@ def visit(node)
         self
       end
 
+      def visit_literal(node)
+        add_node(Nodes::Literal, value: node[0])
+      end
+
       def visit_from(node)
         source, _ = node
         add_node(Nodes::From, source: source)

lib/sql/composer/dsl.rb

@@ -4,6 +4,7 @@
 
 require "sql/composer/compiler"
 require "sql/composer/tokens"
+require "sql/composer/nodes/literal"
 
 module SQL
   module Composer
@@ -31,6 +32,12 @@ def call
         compiler.(ast)
       end
 
+      def `(value)
+        Nodes::Literal.new(value: value)
+      end
+
+      private
+
       def method_missing(name, *args)
         ast << [name.to_s.downcase, *args]
         self

lib/sql/composer/nodes.rb

@@ -1,5 +1,6 @@
 # frozen_string_literal: true
 
+require "sql/composer/nodes/literal"
 require "sql/composer/nodes/identifier"
 require "sql/composer/nodes/select"
 require "sql/composer/nodes/from"

lib/sql/composer/nodes/literal.rb

@@ -0,0 +1,16 @@
+# frozen_string_literal: true
+
+require "sql/composer/nodes/core"
+
+module SQL
+  module Composer
+    module Nodes
+      class Literal < Core
+        def value
+          fetch(:value)
+        end
+        alias_method :to_s, :value
+      end
+    end
+  end
+end

spec/integration/sql/compose_spec.rb

@@ -27,6 +27,24 @@ def compose(&block)
   end
 
   describe "SELECT" do
+    context "with literals" do
+      let(:query) do
+        compose {
+          SELECT `"users"."id"`, `"users"."name"`
+          FROM `"users"`
+        }
+      end
+
+      specify do
+        expect(result).to eql(
+          <<~SQL.strip
+            SELECT "users"."id", "users"."name"
+            FROM "users"
+          SQL
+        )
+      end
+    end
+
     context "without WHERE" do
       let(:query) do
         compose { |users|