Add danger missing test coverage

- for 100% coverage

lib/gitlab/danger/commit_linter.rb

@@ -114,15 +114,11 @@ module Gitlab
         end
 
         details&.each_line do |line|
-          line = line.strip
-
-          next unless line_too_long?(line)
-
-          url_size = line.scan(%r((https?://\S+))).sum { |(url)| url.length }
+          line_without_urls = line.strip.gsub(%r{https?://\S+}, '')
 
           # If the line includes a URL, we'll allow it to exceed MAX_LINE_LENGTH characters, but
           # only if the line _without_ the URL does not exceed this limit.
-          next unless line_too_long?(line.length - url_size)
+          next unless line_too_long?(line_without_urls)
 
           add_problem(:details_line_too_long)
           break
@@ -172,14 +168,7 @@ module Gitlab
       end
 
       def line_too_long?(line)
-        case line
-        when String
         line.length > MAX_LINE_LENGTH
-        when Integer
-          line > MAX_LINE_LENGTH
-        else
-          raise ArgumentError, "The line argument (#{line}) should be a String or an Integer! #{line.class} given."
-        end
       end
 
       def subject_too_short?

lib/gitlab/danger/helper.rb

@@ -64,7 +64,7 @@ module Gitlab
         # - respond_to?(:gitlab)
         # - respond_to?(:gitlab, true)
         gitlab
-      rescue NoMethodError
+      rescue NameError
         nil
       end
 

spec/lib/gitlab/danger/commit_linter_spec.rb

@@ -300,8 +300,10 @@ RSpec.describe Gitlab::Danger::CommitLinter do
         end
       end
 
-      context 'when details exceeds the max line length including a URL' do
-        let(:commit_message) { "A B C\n\nhttps://gitlab.com" + 'D' * described_class::MAX_LINE_LENGTH }
+      context 'when details exceeds the max line length including URLs' do
+        let(:commit_message) do
+          "A B C\n\nsome message with https://example.com and https://gitlab.com" + 'D' * described_class::MAX_LINE_LENGTH
+        end
 
         it_behaves_like 'a valid commit'
       end

spec/lib/gitlab/danger/helper_spec.rb

@@ -33,6 +33,16 @@ RSpec.describe Gitlab::Danger::Helper do
         expect(helper.gitlab_helper).to eq(fake_gitlab)
       end
     end
+
+    context 'when danger gitlab plugin is not available' do
+      it 'returns nil' do
+        invalid_danger = Class.new do
+          include Gitlab::Danger::Helper
+        end.new
+
+        expect(invalid_danger.gitlab_helper).to be_nil
+      end
+    end
   end
 
   describe '#release_automation?' do