allow silencing warnings

Author: e2

lib/ruby_dep/warning.rb

@@ -6,12 +6,16 @@ class Warning
     MSG_INSECURE = 'RubyDep: WARNING: your Ruby has security vulnerabilities!'\
       ' Please upgrade!'.freeze
 
+    MSG_HOW_TO_DISABLE = ' (To disable warnings, set'\
+      ' RUBY_DEP_GEM_SILENCE_WARNINGS=1)'.freeze
+
     def show_warnings
+      return if silenced?
       case check_ruby
       when :insecure
-        STDERR.puts MSG_INSECURE
+        STDERR.puts MSG_INSECURE + MSG_HOW_TO_DISABLE
       when :buggy
-        STDERR.puts MSG_BUGGY
+        STDERR.puts MSG_BUGGY + MSG_HOW_TO_DISABLE
       when :unknown
       else
         raise "Unknown problem type: #{problem.inspect}"
@@ -37,5 +41,10 @@ def check_ruby
       end
       :insecure
     end
+
+    def silenced?
+      value = ENV['RUBY_DEP_GEM_SILENCE_WARNINGS']
+      (value || '0') !~ /^0|false|no|n$/
+    end
   end
 end

spec/lib/ruby_dep/warning_spec.rb

@@ -7,40 +7,57 @@
   end
 
   describe '#show_warnings' do
-    context 'with an up-to-date Ruby' do
-      let(:ruby_version) { '2.3.1' }
-      it 'does not show warning' do
-        expect(STDERR).to_not receive(:puts)
-        subject.show_warnings
+    context 'when silenced' do
+      around do |example|
+        old = ENV['RUBY_DEP_GEM_SILENCE_WARNINGS']
+        ENV['RUBY_DEP_GEM_SILENCE_WARNINGS'] = '1'
+        example.run
+        ENV['RUBY_DEP_GEM_SILENCE_WARNINGS'] = old
       end
-    end
 
-    context 'with a secure but buggy Ruby' do
-      let(:ruby_version) { '2.2.4' }
-      it 'shows warning about bugs' do
-        expect(STDERR).to receive(:puts).with(
-          'RubyDep: WARNING: your Ruby is outdated/buggy. Please upgrade.')
-        subject.show_warnings
+      context 'with any outdated Ruby' do
+        let(:ruby_version) { '1.9.3' }
+        it 'does not show warning' do
+          expect(STDERR).to_not receive(:puts)
+          subject.show_warnings
+        end
       end
     end
 
-    context 'with an insecure Ruby' do
-      let(:ruby_version) { '2.2.3' }
-      it 'shows warning about vulnerability' do
-        expect(STDERR).to receive(:puts).with(
-          'RubyDep: WARNING: your Ruby has security vulnerabilities!'\
-          ' Please upgrade!')
-        subject.show_warnings
+    context 'when not silenced' do
+      context 'with an up-to-date Ruby' do
+        let(:ruby_version) { '2.3.1' }
+        it 'does not show warning' do
+          expect(STDERR).to_not receive(:puts)
+          subject.show_warnings
+        end
+      end
+
+      context 'with a secure but buggy Ruby' do
+        let(:ruby_version) { '2.2.4' }
+        it 'shows warning about bugs' do
+          expect(STDERR).to receive(:puts).with(
+            %r{RubyDep: WARNING: your Ruby is outdated\/buggy.})
+          subject.show_warnings
+        end
+      end
+
+      context 'with an insecure Ruby' do
+        let(:ruby_version) { '2.2.3' }
+        it 'shows warning about vulnerability' do
+          expect(STDERR).to receive(:puts).with(
+            /RubyDep: WARNING: your Ruby has security vulnerabilities!/)
+          subject.show_warnings
+        end
       end
-    end
 
-    context 'with an unsupported Ruby' do
-      let(:ruby_version) { '1.9.3' }
-      it 'shows warning about vulnerability' do
-        expect(STDERR).to receive(:puts).with(
-          'RubyDep: WARNING: your Ruby has security vulnerabilities!'\
-          ' Please upgrade!')
-        subject.show_warnings
+      context 'with an unsupported Ruby' do
+        let(:ruby_version) { '1.9.3' }
+        it 'shows warning about vulnerability' do
+          expect(STDERR).to receive(:puts).with(
+            /RubyDep: WARNING: your Ruby has security vulnerabilities!/)
+          subject.show_warnings
+        end
       end
     end
   end