Fix error in Blowfish, SHA1 password strategies

* Bug report:
  thoughtbot#222
* Remove duplication in spec suite.
* Extract `fake_model_with_password_strategy` spec helper method.

lib/clearance/password_strategies/blowfish.rb

@@ -30,9 +30,13 @@ def generate_hash(string)
 
       def initialize_salt_if_necessary
         if salt.blank?
-          self.salt = generate_random_code
+          self.salt = generate_salt
         end
       end
+
+      def generate_salt
+        SecureRandom.hex(20).encode('UTF-8')
+      end
     end
   end
 end

lib/clearance/password_strategies/sha1.rb

@@ -30,9 +30,13 @@ def generate_hash(string)
 
       def initialize_salt_if_necessary
         if salt.blank?
-          self.salt = generate_random_code
+          self.salt = generate_salt
         end
       end
+
+      def generate_salt
+        SecureRandom.hex(20).encode('UTF-8')
+      end
     end
   end
 end

spec/models/bcrypt_migration_from_sha1_spec.rb

@@ -2,12 +2,9 @@
 
 describe Clearance::PasswordStrategies::BCryptMigrationFromSHA1 do
   subject do
-    Class.new do
-      attr_reader :password
-      attr_accessor :encrypted_password
-      attr_accessor :salt
-      include Clearance::PasswordStrategies::BCryptMigrationFromSHA1
-    end.new
+    fake_model_with_password_strategy(
+      Clearance::PasswordStrategies::BCryptMigrationFromSHA1
+    )
   end
 
   describe '#password=' do
@@ -86,5 +83,4 @@
       end
     end
   end
-
 end

spec/models/bcrypt_spec.rb

@@ -2,10 +2,7 @@
 
 describe Clearance::PasswordStrategies::BCrypt do
   subject do
-    Class.new do
-      attr_accessor :encrypted_password
-      include Clearance::PasswordStrategies::BCrypt
-    end.new
+    fake_model_with_password_strategy(Clearance::PasswordStrategies::BCrypt)
   end
 
   describe '#password=' do

spec/models/blowfish_spec.rb

@@ -2,12 +2,7 @@
 
 describe Clearance::PasswordStrategies::Blowfish do
   subject do
-    Class.new do
-      attr_accessor :salt, :encrypted_password
-      include Clearance::PasswordStrategies::Blowfish
-
-      def generate_random_code; 'code'; end
-    end.new
+    fake_model_with_password_strategy(Clearance::PasswordStrategies::Blowfish)
   end
 
   describe '#password=' do

spec/models/sha1_spec.rb

@@ -2,12 +2,7 @@
 
 describe Clearance::PasswordStrategies::SHA1 do
   subject do
-    Class.new do
-      attr_accessor :salt, :encrypted_password
-      include Clearance::PasswordStrategies::SHA1
-
-      def generate_random_code; "code"; end
-    end.new
+    fake_model_with_password_strategy(Clearance::PasswordStrategies::SHA1)
   end
 
   describe '#password=' do

spec/support/fake_model_with_password_strategy.rb

@@ -0,0 +1,14 @@
+module FakeModelWithPasswordStrategy
+  def fake_model_with_password_strategy(password_strategy)
+    Class.new do
+      attr_reader :password
+      attr_accessor :encrypted_password, :salt
+
+      include password_strategy
+    end.new
+  end
+end
+
+RSpec.configure do |config|
+  config.include FakeModelWithPasswordStrategy
+end