First aproach

lib/boot.rb

@@ -0,0 +1,10 @@
+$LOAD_PATH.unshift(File.join(File.dirname(__FILE__), '..', 'lib'))
+$LOAD_PATH.unshift(File.dirname(__FILE__))
+
+require 'sqlite_adapter'
+require 'empanada_record'
+require "product"
+
+p Product.first
+p Product.last
+p Product.where("id = 20")

lib/empanada_record.rb

@@ -3,7 +3,8 @@
 module EmpanadaRecord
   class Base
     @@adapter = SqliteAdapter.new
-
+
+    # Finder methdos
     def self.find(id)
       results = @@adapter.run("SELECT * FROM #{table_name} WHERE id=#{id.to_i}")
       if results.any?
@@ -13,8 +14,64 @@ def self.find(id)
       end
     end
 
+    def self.all
+      resultset = @@adapter.run("SELECT * FROM #{table_name}")
+      resultset.map { |ary| self.new(*ary)}
+    end
+
+    def self.count
+      resultset = @@adapter.run("SELECT COUNT(*) FROM #{table_name}")
+      resultset.flatten.first
+    end
+
+    def self.first
+      resultset = @@adapter.run("SELECT * FROM #{table_name} LIMIT 1 OFFSET 0")
+      if resultset.any?
+        self.new(*resultset.first)
+      else
+        nil
+      end
+    end
+
+    def self.last
+      resultset = @@adapter.run("SELECT * FROM #{table_name} ORDER BY rowid DESC LIMIT 1 OFFSET 0")
+      if resultset.any?
+        self.new(*resultset.first)
+      else
+        nil
+      end
+    end
+
+    def self.where(query)
+      resultset = @@adapter.run("SELECT * FROM #{table_name} WHERE #{query}")
+      resultset.map { |ary| self.new(*ary)}
+    end
+
     def self.table_name
       self.name + "s"
     end
+
+    def self.find_by(attribute, data )
+      #Object.const_get("Product")
+      if respond_to?(attribute.to_s)
+        results = @@adapter.run("SELECT * FROM #{table_name} WHERE #{attribute} = '#{data}'")
+        if results.any?
+          results.map { |ary| self.new(*ary)}
+        else
+          raise 'EmpanadaRecordError: Record Not Found!'
+        end
+      else
+        raise "EmpanadaRecordError: undefined method '#{attribute}'"
+      end
+    end
+
+    def self.attributes
+      attrs = @@adapter.run("pragma table_info(#{table_name})")
+      attrs.map {|attr| attr[1]}
+    end
+
+    def self.respond_to?(attribute)
+      attributes.include? attribute
+    end
   end
 end

test/test_product.rb

@@ -18,4 +18,40 @@ def test_find_no_records
     end
     assert_equal err.message, 'EmpanadaRecordError: Record Not Found!'
   end
+
+  def test_all
+    ids = Product.all.map { |p| p.id }
+    assert_equal ids.sort, [10, 20]
+  end
+
+  def test_count
+    count = Product.count
+    assert_equal count, 2
+  end
+
+  def test_first
+    assert_equal Product.first.id, 20
+  end
+
+  def test_last
+    assert_equal Product.last.id, 10
+  end
+
+  def test_where
+    product = Product.where("id = 20")
+    assert_equal product.first.id, 20
+  end
+
+  def test_find_by
+    products = Product.find_by("name", "Portatil")
+    assert_operator products.count, :>=, 1
+  end
+
+  def test_attributes
+    assert_equal Product.attributes.sort, ["id", "name"]
+  end
+
+  def test_respond_to?
+    assert_equal Product.respond_to?("name"), true
+  end
 end