fix(iam): Don't leak constants

The IAMTokenManager class declared its constants outside the class
definition, which caused undesired side-effect on pieces of code that
also relied on these contants names.

Fixes #22

Author: Luiz Aoqui

lib/ibm_watson/iam_token_manager.rb

@@ -5,16 +5,16 @@
 require("rbconfig")
 require_relative("./version.rb")
 
-DEFAULT_IAM_URL = "https://iam.bluemix.net/identity/token"
-CONTENT_TYPE = "application/x-www-form-urlencoded"
-ACCEPT = "application/json"
-DEFAULT_AUTHORIZATION = "Basic Yng6Yng="
-REQUEST_TOKEN_GRANT_TYPE = "urn:ibm:params:oauth:grant-type:apikey"
-REQUEST_TOKEN_RESPONSE_TYPE = "cloud_iam"
-REFRESH_TOKEN_GRANT_TYPE = "refresh_token"
-
 # Class to manage IAM Token Authentication
 class IAMTokenManager
+  DEFAULT_IAM_URL = "https://iam.bluemix.net/identity/token"
+  CONTENT_TYPE = "application/x-www-form-urlencoded"
+  ACCEPT = "application/json"
+  DEFAULT_AUTHORIZATION = "Basic Yng6Yng="
+  REQUEST_TOKEN_GRANT_TYPE = "urn:ibm:params:oauth:grant-type:apikey"
+  REQUEST_TOKEN_RESPONSE_TYPE = "cloud_iam"
+  REFRESH_TOKEN_GRANT_TYPE = "refresh_token"
+
   attr_accessor :token_info, :user_access_token
   def initialize(iam_apikey: nil, iam_access_token: nil, iam_url: nil)
     @iam_apikey = iam_apikey

test/unit/test_iam_token_manager.rb

@@ -162,4 +162,14 @@ def test_get_token
     token = token_manager._token
     assert_equal("dummy", token)
   end
+
+  def test_dont_leak_constants
+    assert_nil(defined? DEFAULT_IAM_URL)
+    assert_nil(defined? CONTENT_TYPE)
+    assert_nil(defined? ACCEPT)
+    assert_nil(defined? DEFAULT_AUTHORIZATION)
+    assert_nil(defined? REQUEST_TOKEN_GRANT_TYPE)
+    assert_nil(defined? REQUEST_TOKEN_RESPONSE_TYPE)
+    assert_nil(defined? REFRESH_TOKEN_GRANT_TYPE)
+  end
 end