Updating aws_iam_user with exists? function. (#115)

* Updating aws_iam_user with exists? function. Solves #114

Signed-off-by: Nick Rycar <rycar@chef.io>

* Disabling class length rubocop rule.

Signed-off-by: Nick Rycar <rycar@chef.io>

libraries/aws_iam_user.rb

@@ -24,6 +24,10 @@ def initialize(
     @access_key_factory = access_key_factory
   end
 
+  def exists?
+    @aws_user_details_provider.exists?
+  end
+
   def has_mfa_enabled?
     @aws_user_details_provider.has_mfa_enabled?
   end

libraries/aws_iam_user_details_provider.rb

@@ -7,6 +7,10 @@ def initialize(user)
       @aws_user = user
     end
 
+    def exists?
+      @aws_user.exists?
+    end
+
     def name
       @aws_user.name
     end

test/unit/resources/aws_iam_user_details_provider_test.rb

@@ -13,6 +13,18 @@ def setup
     @mock_iam_resource_user = Minitest::Mock.new
   end
 
+  def test_exists_returns_true
+    @mock_iam_resource_user.expect :exists?, true
+    provider = AwsIam::UserDetailsProvider.new(@mock_iam_resource_user)
+    assert provider.exists?
+  end
+
+  def test_exists_returns_false
+    @mock_iam_resource_user.expect :exists?, false
+    provider = AwsIam::UserDetailsProvider.new(@mock_iam_resource_user)
+    refute provider.exists?
+  end
+
   def test_has_mfa_enabled_returns_true
     @mock_iam_resource_user.expect :mfa_devices, ['device']
     provider = AwsIam::UserDetailsProvider.new(@mock_iam_resource_user)

test/unit/resources/aws_iam_user_test.rb

@@ -3,6 +3,7 @@
 require 'helper'
 require 'aws_iam_user'
 
+# rubocop:disable Metrics/ClassLength
 class AwsIamUserTest < Minitest::Test
   Username = 'test'.freeze
 
@@ -13,6 +14,28 @@ def setup
     @mock_user = { name: Username }
   end
 
+  def test_that_exists_returns_true_if_user_exists
+    @mock_user_provider.expect :user, @mock_user, [Username]
+    @mock_dets_provider.expect :exists?, true
+    @mock_dets_prov_ini.expect :create, @mock_dets_provider, [@mock_user]
+    assert AwsIamUser.new(
+      @mock_user,
+      @mock_user_provider,
+      @mock_dets_prov_ini,
+    ).exists?
+  end
+
+  def test_that_exists_returns_false_if_user_does_not_exist
+    @mock_user_provider.expect :user, @mock_user, [Username]
+    @mock_dets_provider.expect :exists?, false
+    @mock_dets_prov_ini.expect :create, @mock_dets_provider, [@mock_user]
+    refute AwsIamUser.new(
+      @mock_user,
+      @mock_user_provider,
+      @mock_dets_prov_ini,
+    ).exists?
+  end
+
   def test_that_mfa_enable_returns_true_if_mfa_enabled
     @mock_user_provider.expect :user, @mock_user, [Username]
     @mock_dets_provider.expect :has_mfa_enabled?, true