tested MAIL_SENDER more thoroughly

spec/mailers/publication_mailer_spec.rb

@@ -21,6 +21,44 @@
       expect(mail.from).to eq(['sender@example.com'])
     end
 
+    context 'when MAIL_SENDER has name and email' do
+      before do
+        allow(ENV).to receive(:fetch).with('MAIL_SENDER').and_return('Sender Name <sender@example.com>')
+      end
+
+      let(:mail) { described_class.publication_submit(submitter, publication).deliver_now }
+
+      it 'uses the name and email in the from field' do
+        expect(mail.from).to eq(['sender@example.com'])
+        expect(mail[:from].display_names).to eq(['Sender Name'])
+      end
+    end
+
+    context 'when MAIL_SENDER is only an email' do
+      before do
+        allow(ENV).to receive(:fetch).with('MAIL_SENDER').and_return('sender@example.com')
+      end
+
+      let(:mail) { described_class.publication_submit(submitter, publication).deliver_now }
+
+      it 'uses just the email in the from field' do
+        expect(mail.from).to eq(['sender@example.com'])
+      end
+    end
+
+    context 'when MAIL_SENDER is empty' do
+      before do
+        allow(ENV).to receive(:fetch).with('MAIL_SENDER').and_return('')
+      end
+
+      let(:mail) { described_class.publication_submit(submitter, publication).deliver_now }
+
+      it 'raises an error' do
+        expect { mail }.to raise_error(ArgumentError, /SMTP From address may not be blank/)
+      end
+
+    end
+
     it 'sends to the correct recipients' do
       expect(mail.to).to eq(['submitter@example.com'])
       expect(mail.bcc).to eq(['sender@example.com'])