[12.x] assertThrowsNothing (#55100)

* assertThrowsNothing

* formatting

---------

Co-authored-by: Taylor Otwell <[email protected]>

Author: gdebrauwer

src/Illuminate/Foundation/Testing/Concerns/InteractsWithExceptionHandling.php

@@ -213,4 +213,31 @@ protected function assertThrows(Closure $test, string|Closure $expectedClass = T
 
         return $this;
     }
+
+    /**
+     * Assert that the given callback does not throw an exception.
+     *
+     * @param  \Closure  $test
+     * @return $this
+     */
+    protected function assertDoesntThrow(Closure $test)
+    {
+        try {
+            $test();
+
+            $thrown = false;
+        } catch (Throwable $exception) {
+            $thrown = true;
+
+            $exceptionClass = get_class($exception);
+            $exceptionMessage = $exception->getMessage();
+        }
+
+        Assert::assertTrue(
+            ! $thrown,
+            sprintf('Unexpected exception of type %s with message %s was thrown.', $exceptionClass ?? null, $exceptionMessage ?? null)
+        );
+
+        return $this;
+    }
 }

tests/Foundation/FoundationExceptionsHandlerTest.php

@@ -571,6 +571,35 @@ public function testAssertExceptionIsThrown()
         }
     }
 
+    public function testAssertNoExceptionIsThrown()
+    {
+        try {
+            $this->assertDoesntThrow(function () {
+                throw new Exception;
+            });
+
+            $testFailed = true;
+        } catch (AssertionFailedError) {
+            $testFailed = false;
+        }
+
+        if ($testFailed) {
+            Assert::fail('assertDoesntThrow failed: thrown exception was not detected.');
+        }
+
+        try {
+            $this->assertDoesntThrow(function () { });
+
+            $testFailed = false;
+        } catch (AssertionFailedError) {
+            $testFailed = true;
+        }
+
+        if ($testFailed) {
+            Assert::fail('assertDoesntThrow failed: exception was detected while no exception was thrown.');
+        }
+    }
+
     public function testItReportsDuplicateExceptions()
     {
         $reported = [];