The child processes used for process isolation now use temporary files to communicate their result to the parent process

As of PHP 8.3, specifically as of php/php-src#11169,
it is no longer possible to capture direct writes to standard output.

Such direct writes to standard output interfere with the previous approach
where the child process would print its result to standard output from where
the parent process would read it.

Co-authored-by: Sebastian Bergmann <[email protected]>
Co-authored-by: Arne Blankerts <[email protected]>

Author: sebastianbergmann

ChangeLog-8.5.md

@@ -2,6 +2,12 @@
 
 All notable changes of the PHPUnit 8.5 release series are documented in this file using the [Keep a CHANGELOG](https://keepachangelog.com/) principles.
 
+## [8.5.34] - 2023-MM-DD
+
+### Changed
+
+* The child processes used for process isolation now use temporary files to communicate their result to the parent process
+
 ## [8.5.33] - 2023-02-27
 
 ### Fixed
@@ -268,6 +274,7 @@ All notable changes of the PHPUnit 8.5 release series are documented in this fil
 * [#3967](https://github.com/sebastianbergmann/phpunit/issues/3967): Cannot double interface that extends interface that extends `\Throwable`
 * [#3968](https://github.com/sebastianbergmann/phpunit/pull/3968): Test class run in a separate PHP process are passing when `exit` called inside
 
+[8.5.34]: https://github.com/sebastianbergmann/phpunit/compare/8.5.33...8.5
 [8.5.33]: https://github.com/sebastianbergmann/phpunit/compare/8.5.32...8.5.33
 [8.5.32]: https://github.com/sebastianbergmann/phpunit/compare/8.5.31...8.5.32
 [8.5.31]: https://github.com/sebastianbergmann/phpunit/compare/8.5.30...8.5.31

src/Framework/TestCase.php

@@ -59,6 +59,8 @@
 use function strlen;
 use function strpos;
 use function substr;
+use function sys_get_temp_dir;
+use function tempnam;
 use function trim;
 use function var_export;
 use DeepCopy\DeepCopy;
@@ -801,6 +803,7 @@ public function run(TestResult $result = null): TestResult
             $codeCoverageFilter = "'." . $codeCoverageFilter . ".'";
 
             $configurationFilePath = $GLOBALS['__PHPUNIT_CONFIGURATION_FILE'] ?? '';
+            $processResultFile     = tempnam(sys_get_temp_dir(), 'phpunit_');
 
             $var = [
                 'composerAutoload'                           => $composerAutoload,
@@ -824,6 +827,7 @@ public function run(TestResult $result = null): TestResult
                 'codeCoverageFilter'                         => $codeCoverageFilter,
                 'configurationFilePath'                      => $configurationFilePath,
                 'name'                                       => $this->getName(false),
+                'processResultFile'                          => $processResultFile,
             ];
 
             if (!$runEntireClass) {
@@ -833,7 +837,7 @@ public function run(TestResult $result = null): TestResult
             $template->setVar($var);
 
             $php = AbstractPhpProcess::factory();
-            $php->runTestJob($template->render(), $this, $result);
+            $php->runTestJob($template->render(), $this, $result, $processResultFile);
         } else {
             $result->run($this);
         }

src/Util/PHP/AbstractPhpProcess.php

@@ -15,6 +15,8 @@
 use function array_merge;
 use function assert;
 use function escapeshellarg;
+use function file_exists;
+use function file_get_contents;
 use function ini_get_all;
 use function restore_error_handler;
 use function set_error_handler;
@@ -24,6 +26,7 @@
 use function strrpos;
 use function substr;
 use function trim;
+use function unlink;
 use function unserialize;
 use __PHP_Incomplete_Class;
 use ErrorException;
@@ -174,16 +177,23 @@ public function getTimeout(): int
      *
      * @throws \SebastianBergmann\RecursionContext\InvalidArgumentException
      */
-    public function runTestJob(string $job, Test $test, TestResult $result): void
+    public function runTestJob(string $job, Test $test, TestResult $result, string $processResultFile): void
     {
         $result->startTest($test);
 
-        $_result = $this->runJob($job);
+        $processResult = '';
+        $_result       = $this->runJob($job);
+
+        if (file_exists($processResultFile)) {
+            $processResult = file_get_contents($processResultFile);
+
+            @unlink($processResultFile);
+        }
 
         $this->processChildResult(
             $test,
             $result,
-            $_result['stdout'],
+            $processResult,
             $_result['stderr']
         );
     }

src/Util/PHP/Template/TestCaseClass.tpl

@@ -70,13 +70,16 @@ function __phpunit_run_isolated_test()
         }
     }
 
-    print serialize(
-      [
-        'testResult'    => $test->getResult(),
-        'numAssertions' => $test->getNumAssertions(),
-        'result'        => $result,
-        'output'        => $output
-      ]
+    file_put_contents(
+        '{processResultFile}',
+        serialize(
+            [
+                'testResult'    => $test->getResult(),
+                'numAssertions' => $test->getNumAssertions(),
+                'result'        => $result,
+                'output'        => $output
+            ]
+        )
     );
 }
 

src/Util/PHP/Template/TestCaseMethod.tpl

@@ -73,13 +73,16 @@ function __phpunit_run_isolated_test()
         }
     }
 
-    print serialize(
-      [
-        'testResult'    => $test->getResult(),
-        'numAssertions' => $test->getNumAssertions(),
-        'result'        => $result,
-        'output'        => $output
-      ]
+    file_put_contents(
+        '{processResultFile}',
+        serialize(
+            [
+                'testResult'    => $test->getResult(),
+                'numAssertions' => $test->getNumAssertions(),
+                'result'        => $result,
+                'output'        => $output
+            ]
+        )
     );
 }