Allow running under PHP 8 and PHPUnit 9.x

- PHPUnit 9.3 is required to support PHP 8. PHPUnit 8.x will not be
  updated to support PHP 8 and will become unsupported in February 2021.

    - Methods that were removed from 9.x were migrated.

    - Prophecy will no longer be bundled with PHPUnit, but the
      replacement phpspec/prophecy-phpunit required PHP 7.3. To keep
      PHP 7.2 compatibility, weirdan/prophecy-shim is used as a
      "migration layer".

      Note: 2.0.1 was tagged incorrectly, hence it is avoided in the
      version constraint.

- http-factory-tests upgraded to 0.7 (allows installing on PHP 8)

- In PHP 8, fopen throws ValueError instead of triggering an error.
  In PHP 7, that exception does not exist and PHPStan fails. Hence the
  symfony/polyfill-php80 dependency was brought.

- Some dependencies cannot be installed on PHP 8 yet (namely,
  fig/http-message-util and php-http/psr7-integration-tests).
  "--ignore-platform-reqs" was temporarily added to the CI build with
  PHP 'nightly'.

.travis.yml

@@ -7,12 +7,13 @@ matrix:
     - php: 7.4
       env: ANALYSIS='true'
     - php: nightly
+      env: IGNORE_PLATFORM_REQS='--ignore-platform-reqs'
   allow_failures:
     - php: nightly
 
 before_script:
   - if [[ "$ANALYSIS" == 'true' ]]; then composer require php-coveralls/php-coveralls:^2.2.0 ; fi
-  - composer install -n
+  - composer install -n "${IGNORE_PLATFORM_REQS:-}"
 
 script:
   - if [[ "$ANALYSIS" != 'true' ]]; then vendor/bin/phpunit ; fi

composer.json

@@ -28,20 +28,22 @@
     }
   ],
   "require": {
-    "php": "^7.2",
+    "php": "^7.2 || ^8.0",
     "fig/http-message-util": "^1.1.4",
     "psr/http-factory": "^1.0",
     "psr/http-message": "^1.0",
-    "ralouphie/getallheaders": "^3"
+    "ralouphie/getallheaders": "^3",
+    "symfony/polyfill-php80": "^1.18"
   },
   "require-dev": {
     "ext-json": "*",
     "adriansuter/php-autoload-override": "^1.2",
-    "http-interop/http-factory-tests": "^0.6.0",
+    "http-interop/http-factory-tests": "^0.7.0",
     "php-http/psr7-integration-tests": "dev-master",
     "phpstan/phpstan": "^0.12",
-    "phpunit/phpunit": "^8.5",
-    "squizlabs/php_codesniffer": "^3.5"
+    "phpunit/phpunit": "^8.5 || ^9.3",
+    "squizlabs/php_codesniffer": "^3.5",
+    "weirdan/prophecy-shim": "^1.0 || 2.0.0 || >2.0.1"
   },
   "provide": {
     "psr/http-message-implementation": "1.0",

src/Factory/StreamFactory.php

@@ -66,7 +66,16 @@ public function createStreamFromFile(
             ));
         });
 
-        $resource = fopen($filename, $mode);
+        try {
+            $resource = fopen($filename, $mode);
+        } catch (\ValueError $exception) {
+            throw new RuntimeException(sprintf(
+                'Unable to open %s using mode %s: %s',
+                $filename,
+                $mode,
+                $exception->getMessage()
+            ));
+        }
         restore_error_handler();
 
         if ($exc) {

tests/Factory/UploadedFileFactoryTest.php

@@ -12,6 +12,7 @@
 
 use Interop\Http\Factory\UploadedFileFactoryTestCase;
 use InvalidArgumentException;
+use Prophecy\PhpUnit\ProphecyTrait;
 use Psr\Http\Message\StreamInterface;
 use Slim\Psr7\Factory\StreamFactory;
 use Slim\Psr7\Factory\UploadedFileFactory;
@@ -24,6 +25,8 @@
 
 class UploadedFileFactoryTest extends UploadedFileFactoryTestCase
 {
+    use ProphecyTrait;
+
     /**
      * @return UploadedFileFactory
      */

tests/StreamTest.php

@@ -11,6 +11,7 @@
 namespace Slim\Tests\Psr7;
 
 use PHPUnit\Framework\TestCase;
+use Prophecy\PhpUnit\ProphecyTrait;
 use ReflectionException;
 use ReflectionMethod;
 use ReflectionProperty;
@@ -24,6 +25,8 @@
 
 class StreamTest extends TestCase
 {
+    use ProphecyTrait;
+
     /**
      * @var resource pipe stream file handle
      */

tests/UploadedFileTest.php

@@ -12,6 +12,7 @@
 
 use InvalidArgumentException;
 use PHPUnit\Framework\TestCase;
+use Prophecy\PhpUnit\ProphecyTrait;
 use Psr\Http\Message\StreamInterface;
 use Psr\Http\Message\UploadedFileInterface;
 use ReflectionProperty;
@@ -42,6 +43,8 @@
 
 class UploadedFileTest extends TestCase
 {
+    use ProphecyTrait;
+
     private static $filename = './phpUxcOty';
 
     private static $tmpFiles = ['./phpUxcOty'];
@@ -245,7 +248,7 @@ public function testMoveTo(UploadedFile $uploadedFile)
     public function testMoveToRenameFailure()
     {
         $this->expectException(RuntimeException::class);
-        $this->expectExceptionMessageRegExp('/^Error moving uploaded file .* to .*$/');
+        $this->expectExceptionMessageMatches('/^Error moving uploaded file .* to .*$/');
 
         $uploadedFile = $this->generateNewTmpFile();
 
@@ -280,7 +283,7 @@ public function testMoveToSapiNonUploadedFile(UploadedFile $uploadedFile)
     public function testMoveToSapiMoveUploadedFileFails(UploadedFile $uploadedFile)
     {
         $this->expectException(RuntimeException::class);
-        $this->expectExceptionMessageRegExp('~Error moving uploaded file.*~');
+        $this->expectExceptionMessageMatches('~Error moving uploaded file.*~');
 
         $GLOBALS['is_uploaded_file_return'] = true;