[feature] add ability to reset collected emails

README.md

@@ -63,11 +63,15 @@ class MyTest extends KernelTestCase // or WebTestCase
             // Any \Symfony\Component\Mime\Email methods can be used
             $this->assertSame('value', $email->getHeaders()->get('X-SOME-HEADER')->getBodyAsString());
         });
+
+        // reset collected emails
+        $this->mailer()->reset();
     }
 }
 ```
 
-**NOTE**: Emails are persisted between kernel reboots within each test.
+**NOTE**: Emails are persisted between kernel reboots within each test. You can reset the
+collected emails with `$this->mailer()->reset()`.
 
 ### Custom TestEmail
 

src/TestMailer.php

@@ -43,9 +43,7 @@ public static function add(MessageEvent $event): void
 
     public function sentEmails(): SentEmails
     {
-        if (!self::$events) {
-            throw new \LogicException('Cannot access sent emails as email collection has not yet been started.');
-        }
+        self::ensureStarted();
 
         return SentEmails::fromEvents(self::$events);
     }
@@ -63,4 +61,22 @@ public function sentTestEmails(string $testEmailClass = TestEmail::class): array
 
         return \array_map(static fn(Email $email) => new $testEmailClass($email), $this->sentEmails()->all());
     }
+
+    /**
+     * Reset the collected emails.
+     */
+    public function reset(): self
+    {
+        self::ensureStarted();
+        self::start();
+
+        return $this;
+    }
+
+    private static function ensureStarted(): void
+    {
+        if (!self::$events) {
+            throw new \LogicException('Cannot access sent emails as email collection has not yet been started.');
+        }
+    }
 }

tests/InteractsWithMailerTest.php

@@ -190,6 +190,33 @@ public function emails_are_persisted_between_reboots(string $environment): void
         $this->mailer()->assertSentEmailCount(1);
     }
 
+    /**
+     * @test
+     * @dataProvider environmentProvider
+     */
+    public function can_reset_collected_emails(string $environment): void
+    {
+        self::bootKernel(['environment' => $environment]);
+
+        $this->mailer()->assertNoEmailSent();
+
+        self::$container->get('mailer')->send(new Email1());
+
+        $this->mailer()
+            ->assertSentEmailCount(1)
+            ->reset()
+            ->assertNoEmailSent()
+        ;
+
+        self::ensureKernelShutdown();
+
+        self::bootKernel(['environment' => $environment]);
+
+        self::$container->get('mailer')->send(new Email1());
+
+        $this->mailer()->assertSentEmailCount(1);
+    }
+
     /**
      * @test
      */
@@ -198,7 +225,7 @@ public function bundle_must_be_enabled(): void
         self::bootKernel(['environment' => 'no_bundle']);
 
         $this->expectException(\LogicException::class);
-        $this->expectExceptionMessage(\sprintf('Cannot access collected emails - is %s enabled in your test environment?', ZenstruckMailerTestBundle::class));
+        $this->expectExceptionMessage(\sprintf('Cannot access test mailer - is %s enabled in your test environment?', ZenstruckMailerTestBundle::class));
 
         $this->mailer();
     }

tests/NonInteractsWithMailerTest.php

@@ -24,4 +24,19 @@ public function ensure_emails_are_not_collected(): void
 
         self::$container->get('zenstruck_mailer_test.mailer')->sentEmails();
     }
+
+    /**
+     * @test
+     */
+    public function cannot_reset_if_collection_not_yet_started(): void
+    {
+        self::bootKernel();
+
+        self::$container->get('mailer')->send(new Email1());
+
+        $this->expectException(\LogicException::class);
+        $this->expectExceptionMessage('Cannot access sent emails as email collection has not yet been started.');
+
+        self::$container->get('zenstruck_mailer_test.mailer')->reset();
+    }
 }