Add scope to unique

README.md

@@ -77,6 +77,16 @@ Prefix your method call with `unique`. For example:
 Faker::Name.unique.name # This will return a unique name every time it is called
 ```
 
+You can also provide a scope for the unique generator.
+
+```ruby
+Faker::Name.unique(scope: :user).name # This will return a unique name for the :user scope
+Faker::Name.unique(scope: :customer).name # This will return a unique name for the :customer scope. This value may have already been returned in the :user scope.
+
+# The unique scope can be any ruby Object so you can make a scope for a particular class attribute like this:
+Faker::Name.unique(scope: [:customer, :name]).name
+```
+
 If too many unique values are requested from a generator that has a limited
 number of potential values, a `Faker::UniqueGenerator::RetryLimitExceeded`
 exception may be raised. It is possible to clear the record of unique values

lib/faker.rb

@@ -217,9 +217,11 @@ def resolve(value)
       # Return unique values from the generator every time.
       #
       # @param max_retries [Integer] The max number of retries that should be done before giving up.
+      # @param scope [Object] The scope of the unique values
       # @return [self]
-      def unique(max_retries = 10_000)
-        @unique ||= UniqueGenerator.new(self, max_retries)
+      def unique(max_retries = 10_000, scope: DefaultUniqueScope)
+        @unique ||= {}
+        @unique[scope] ||= UniqueGenerator.new(self, max_retries)
       end
 
       def sample(list, num = nil)
@@ -258,6 +260,8 @@ def disable_enforce_available_locales
 
       private
 
+      class DefaultUniqueScope; end
+
       def warn_for_deprecated_arguments
         keywords = []
         yield(keywords)

test/test_faker.rb

@@ -117,10 +117,28 @@ def test_rand_for_range
   end
 
   def test_unique
+    Faker::Base.unique.clear
+
     unique_numbers = Array.new(8) do
       Faker::Base.unique.numerify('#')
     end
 
     assert_equal(unique_numbers.uniq, unique_numbers)
   end
+
+  def test_unique_scope
+    Faker::Base.unique.clear
+    Faker::Base.unique(scope: :other).clear
+
+    unique_numbers_default_scope = Array.new(8) do
+      Faker::Base.unique.numerify('#')
+    end
+
+    unique_numbers_other_scope = Array.new(8) do
+      Faker::Base.unique(scope: :other).numerify('#')
+    end
+
+    # Assert that the intersection of the "default" scope and the "other" scope is not empty
+    assert !(unique_numbers_default_scope & unique_numbers_other_scope).empty?
+  end
 end