1 files changed, 86 insertions, 0 deletions
diff --git a/spec/initializers/mail_starttls_patch_spec.rb b/spec/initializers/mail_starttls_patch_spec.rb
new file mode 100644
index 00000000000..126ffb98f0e
--- /dev/null
+++ b/spec/initializers/mail_starttls_patch_spec.rb
@@ -0,0 +1,86 @@
+# frozen_string_literal: true
+
+# rubocop:disable RSpec/VariableDefinition, RSpec/VariableName
+
+require 'spec_helper'
+require 'mail'
+require_relative '../../config/initializers/mail_starttls_patch'
+
+RSpec.describe 'Mail STARTTLS patch', feature_category: :integrations do
+  using RSpec::Parameterized::TableSyntax
+
+  let(:message) do
+    Mail.new do
+      from    'sender@example.com'
+      to      'receiver@example.com'
+      subject 'test mesage'
+    end
+  end
+
+  # Taken from https://github.com/mikel/mail/pull/1536#issue-1490438378
+  where(:ssl, :tls, :enable_starttls, :enable_starttls_auto, :smtp_tls, :smtp_starttls_mode) do
+    true  | nil   | nil     | nil   | true  | false
+    nil   | false | nil     | nil   | false | :auto
+    nil   | false | nil     | true  | false | :auto
+    false | false | true    | false | false | :always
+    false | nil   | false   | false | false | false
+    false | false | false   | nil   | false | false
+    false | nil   | :always | nil   | false | :always
+    false | nil   | :auto   | nil   | false | :auto
+  end
+
+  with_them do
+    let(:values) do
+      {
+        ssl: ssl,
+        tls: tls,
+        enable_starttls: enable_starttls,
+        enable_starttls_auto: enable_starttls_auto
+      }
+    end
+
+    let(:mail) { Mail::SMTP.new(values) }
+    let(:smtp) { double }
+
+    it 'sets TLS and STARTTLS settings properly' do
+      expect(smtp).to receive(:open_timeout=)
+      expect(smtp).to receive(:read_timeout=)
+      expect(smtp).to receive(:start)
+
+      if smtp_tls
+        expect(smtp).to receive(:enable_tls)
+        expect(smtp).to receive(:disable_starttls)
+      else
+        expect(smtp).to receive(:disable_tls)
+
+        case smtp_starttls_mode
+        when :always
+          expect(smtp).to receive(:enable_starttls)
+        when :auto
+          expect(smtp).to receive(:enable_starttls_auto)
+        when false
+          expect(smtp).to receive(:disable_starttls)
+        end
+      end
+
+      allow(Net::SMTP).to receive(:new).and_return(smtp)
+      mail.deliver!(message)
+    end
+  end
+
+  context 'when enable_starttls and tls are enabled' do
+    let(:values) do
+      {
+        tls: true,
+        enable_starttls: true
+      }
+    end
+
+    let(:mail) { Mail::SMTP.new(values) }
+
+    it 'raises an argument exception' do
+      expect { mail.deliver!(message) }.to raise_error(ArgumentError)
+    end
+  end
+end
+# rubocop:enable RSpec/VariableDefinition, RSpec/VariableName