add test for token in options

spec/unit/fetcher_spec.rb

@@ -1,4 +1,5 @@
 describe GitHubChangelogGenerator::Fetcher do
+  VALID_TOKEN = "0123456789abcdef"
   before(:all) do
     @fetcher = GitHubChangelogGenerator::Fetcher.new
   end
@@ -6,14 +7,30 @@ describe GitHubChangelogGenerator::Fetcher do
   describe "#fetch_github_token" do
     token = GitHubChangelogGenerator::Fetcher::CHANGELOG_GITHUB_TOKEN
     context "when token in ENV exist" do
-      before { stub_const("ENV", ENV.to_hash.merge(token => "0123456789abcdef")) }
+      before { stub_const("ENV", ENV.to_hash.merge(token => VALID_TOKEN)) }
       subject { @fetcher.fetch_github_token }
-      it { is_expected.to eq("0123456789abcdef") }
+      it { is_expected.to eq(VALID_TOKEN) }
     end
     context "when token in ENV is nil" do
       before { stub_const("ENV", ENV.to_hash.merge(token => nil)) }
       subject { @fetcher.fetch_github_token }
       it { is_expected.to be_nil }
     end
+    context "when token in options and ENV is nil" do
+      before do
+        stub_const("ENV", ENV.to_hash.merge(token => nil))
+        @fetcher = GitHubChangelogGenerator::Fetcher.new(token: VALID_TOKEN)
+      end
+      subject { @fetcher.fetch_github_token }
+      it { is_expected.to eq(VALID_TOKEN) }
+    end
+    context "when token in options and ENV specified" do
+      before do
+        stub_const("ENV", ENV.to_hash.merge(token => "no_matter_what"))
+        @fetcher = GitHubChangelogGenerator::Fetcher.new(token: VALID_TOKEN)
+      end
+      subject { @fetcher.fetch_github_token }
+      it { is_expected.to eq(VALID_TOKEN) }
+    end
   end
 end