Set default value for an argument of #issue_access_token

Author: mizoR

lib/line/bot/client.rb

@@ -62,7 +62,7 @@ def credentials
       # @param grant_type [String] Grant type
       #
       # @return [Net::HTTPResponse]
-      def issue_access_token(grant_type)
+      def issue_access_token(grant_type = 'client_credentials')
         payload = URI.encode_www_form(
           grant_type:    grant_type,
           client_id:     channel_id,

spec/line/bot/client_access_token_spec.rb

@@ -32,9 +32,7 @@ def generate_client
     stub_request(:post, uri_template).to_return { |request| {body: OAUTH_ACCESS_TOKEN_ISSUE_CONTENT, status: 200} }
 
     client = generate_client
-    grant_type = 'client_credentials'
-
-    response = client.issue_access_token(grant_type)
+    response = client.issue_access_token
 
     expect(response).to be_a(Net::HTTPOK)
     result = JSON.parse(response.body)