Comments are welcome!

lib/empanada_record.rb

@@ -1,16 +1,53 @@
 require 'sqlite_adapter'
+require 'missing_empanada_record'
+require 'empanada_record_attributes'
 
 module EmpanadaRecord
   class Base
+    ATTRIBUTES = ['id', 'name']
     @@adapter = SqliteAdapter.new
-
+
+    class << self
+      ATTRIBUTES.each do |attr|
+        define_method "find_by_#{attr}" do |argument|
+          results = @@adapter.run("SELECT * FROM #{table_name} WHERE #{attr} = '#{argument}'")
+          results.any? ? self.new(*results.first) : MissingEmpanadaRecord.new
+        end
+      end
+    end
+
+    def method_missing(name, *args) "Not method available for empanada record" end
+
     def self.find(id)
       results = @@adapter.run("SELECT * FROM #{table_name} WHERE id=#{id.to_i}")
-      if results.any?
-        self.new(*results.first)
-      else
-        raise 'EmpanadaRecordError: Record Not Found!'
-      end
+      results.any? ? self.new(*results.first) : MissingEmpanadaRecord.new
+    end
+
+    def self.first
+      result = @@adapter.run("SELECT * FROM #{table_name} LIMIT 1")
+      result.any? ? self.new(*result.first) : MissingEmpanadaRecord.new
+    end
+
+    def self.all
+      results = @@adapter.run("SELECT * FROM #{table_name}")
+      results.any? ? results.map! {|product| self.new(*product)} : [MissingEmpanadaRecord.new]
+    end
+
+    def self.count
+      result = @@adapter.run("SELECT COUNT(*) FROM #{table_name}")
+      result.flatten.first
+    end
+
+    def self.where(args)
+      attributes = EmpanadaRecordAttributes.new(args.keys)
+      valid_attributes = attributes.validate
+      raise ArgumentError.new(valid_attributes) if valid_attributes.is_a? String
+
+      conditions = []
+      args.each{ |key, value| conditions << "#{key} = '#{value}'"}
+
+      results = @@adapter.run("SELECT * FROM #{table_name} WHERE #{conditions.join(" AND ")}")
+      results.any? ? results.map! {|product| self.new(*product)} : [MissingEmpanadaRecord.new]
     end
 
     def self.table_name

lib/empanada_record_attributes.rb

@@ -0,0 +1,17 @@
+class EmpanadaRecordAttributes
+  attr_accessor :attributes
+  ATTRIBUTES = ['id', 'name']
+
+  def initialize(attributes)
+    @attributes = attributes.collect(&:to_s)
+  end
+
+  def validate
+    invalid_attributes = @attributes.select{ |attr| !ATTRIBUTES.include?(attr) }
+    invalid_attributes.any? ? invalid_attributes_message(invalid_attributes) : true
+  end
+
+  def invalid_attributes_message(attributes)
+    "Next attributes doesn't exist: #{attributes.join(',')}"
+  end
+end

lib/missing_empanada_record.rb

@@ -0,0 +1,14 @@
+class MissingEmpanadaRecord
+  ATTRIBUTES = [:id, :name]
+
+  ATTRIBUTES.each do |attr|
+    define_method "#{attr}" do get_message end
+  end
+
+  def method_missing(name, *args) get_message end
+
+  private
+  def get_message
+    "EmpanadaRecordError: Record Not Found!"
+  end
+end

test/test_product.rb

@@ -13,9 +13,85 @@ def test_find_by_id
   end
 
   def test_find_no_records
-    err = assert_raises RuntimeError do
-      Product.find(999)
-    end
-    assert_equal err.message, 'EmpanadaRecordError: Record Not Found!'
+    product = Product.find(9929)
+    assert_instance_of MissingEmpanadaRecord, product
+    assert_equal product.name, 'EmpanadaRecordError: Record Not Found!'    
   end
+
+  def test_find_first_record
+    product = Product.first
+
+    refute_nil product
+    assert_equal product.id, 20
+  end
+
+  def test_find_all_records
+    products = Product.all
+
+    refute_nil products
+    assert_equal products.class, Array
+    assert_equal products.size, 2
+  end
+
+  def test_count_records
+    number_of_products = Product.count
+
+    assert_equal Fixnum, number_of_products.class
+    assert_equal number_of_products, 2
+  end
+
+  def test_find_by_id
+    product = Product.find_by_id("20")
+
+    assert_equal product.id, 20
+    assert_equal product.name, 'Portatil'
+    assert_instance_of Product, product
+  end
+
+  def test_find_by_name
+    product = Product.find_by_name("Portatil")
+
+    assert_equal product.id, 20
+    assert_equal product.name, 'Portatil'
+    assert_instance_of Product, product
+  end
+
+  def test_find_by_id_no_record_found
+    product = Product.find_by_id("20123")
+
+    assert_instance_of MissingEmpanadaRecord, product
+    assert_equal product.id, 'EmpanadaRecordError: Record Not Found!'
+    assert_equal product.name, 'EmpanadaRecordError: Record Not Found!'
+  end
+
+  def test_find_by_name_no_record_found
+    product = Product.find_by_name("Empanada")
+
+    assert_instance_of MissingEmpanadaRecord, product
+    assert_equal product.id, 'EmpanadaRecordError: Record Not Found!'
+    assert_equal product.name, 'EmpanadaRecordError: Record Not Found!'
+  end
+
+  def test_where_method
+    products = Product.where(:id => 20, :name => "Portatil")
+
+    assert_equal products.size, 1
+    assert_equal products.first.id, 20
+    assert_equal products.first.name, 'Portatil'
+    assert_instance_of Product, products.first
+  end
+
+  def test_where_method_invalid_attributes
+    assert_raises(ArgumentError) {
+      products = Product.where(:random_attribute => 20, :nmas => "Portatil")
+    }
+  end
+
+  def test_where_method_no_records_found
+    products = Product.where(:id => 220, :name => "Empanada")
+
+    assert_equal products.first.id, 'EmpanadaRecordError: Record Not Found!'
+    assert_equal products.first.name, 'EmpanadaRecordError: Record Not Found!'
+    assert_instance_of MissingEmpanadaRecord, products.first
+  end  
 end