Add emails sent inspect

Author: ka8725

lib/rspec/rails/matchers/send_email.rb

@@ -7,6 +7,8 @@ module Matchers
       #
       # @see RSpec::Rails::Matchers#send_email
       class SendEmail < RSpec::Rails::Matchers::BaseMatcher
+        INSPECT_EMAIL_ATTRIBUTES = %i[subject from to cc bcc].freeze
+
         def initialize(criteria)
           @criteria = criteria
         end
@@ -39,11 +41,13 @@ def match_when_negated(block)
         end
 
         def failure_message
-          if multiple_match?
-            'More than 1 matching emails were sent.'
-          else
-            'No matching emails were sent.'
-          end
+          result =
+            if multiple_match?
+              'More than 1 matching emails were sent.'
+            else
+              'No matching emails were sent.'
+            end
+          "#{result}#{sent_emails_message}"
         end
 
         def failure_message_when_negated
@@ -85,6 +89,19 @@ def matched_email?(email)
         def multiple_match?
           @matched_emails.many?
         end
+
+        def sent_emails_message
+          if @diff.empty?
+            "\n\nNo emails were sent."
+          else
+            sent_emails =
+              @diff.map do |email|
+                inspected = INSPECT_EMAIL_ATTRIBUTES.map { |attr| "#{attr}: #{email.public_send(attr)}" }.join(", ")
+                "- #{inspected}"
+              end.join("\n")
+            "\n\nThe following emails were sent:\n#{sent_emails}"
+          end
+        end
       end
 
       # @api public

spec/rspec/rails/matchers/send_email_spec.rb

@@ -29,7 +29,22 @@
   it "fails with a clear message" do
     expect {
       expect { TestMailer.test_email.deliver_now }.to send_email(from: '[email protected]')
-    }.to raise_error(RSpec::Expectations::ExpectationNotMetError, "No matching emails were sent.")
+    }.to raise_error(RSpec::Expectations::ExpectationNotMetError, <<~MSG.strip)
+      No matching emails were sent.
+
+      The following emails were sent:
+      - subject: Test email, from: ["[email protected]"], to: ["[email protected]"], cc: ["[email protected]"], bcc: ["[email protected]"]
+    MSG
+  end
+
+  it "fails with a clear message when no emails were sent" do
+    expect {
+      expect { }.to send_email
+    }.to raise_error(RSpec::Expectations::ExpectationNotMetError, <<~MSG.strip)
+      No matching emails were sent.
+
+      No emails were sent.
+    MSG
   end
 
   it "fails with a clear message for negated version" do
@@ -41,6 +56,12 @@
   it "fails for multiple matches" do
     expect {
       expect { 2.times { TestMailer.test_email.deliver_now } }.to send_email(from: '[email protected]')
-    }.to raise_error(RSpec::Expectations::ExpectationNotMetError, "More than 1 matching emails were sent.")
+    }.to raise_error(RSpec::Expectations::ExpectationNotMetError, <<~MSG.strip)
+      More than 1 matching emails were sent.
+
+      The following emails were sent:
+      - subject: Test email, from: ["[email protected]"], to: ["[email protected]"], cc: ["[email protected]"], bcc: ["[email protected]"]
+      - subject: Test email, from: ["[email protected]"], to: ["[email protected]"], cc: ["[email protected]"], bcc: ["[email protected]"]
+    MSG
   end
 end