Implement the --strict-global-state command-line option and the beStrictAboutChangesToGlobalState configuration setting

sebastianbergmann · sebastianbergmann · commit e2c209dd6618 · 2015-03-16T15:58:05.000+01:00
diff --git a/ChangeLog-4.6.md b/ChangeLog-4.6.md
@@ -2,6 +2,7 @@
 
 ## PHPUnit 4.6.0
 
+* Added the `--strict-global-state` command-line option and the `beStrictAboutChangesToGlobalState` configuration setting for enabling a check that global variabes, super-global variables, and static attributes in user-defined classes are not modified during a test
 * Merged [#1527](https://github.com/sebastianbergmann/phpunit/issues/1527) and [#1529](https://github.com/sebastianbergmann/phpunit/issues/1529): Allow to define options for displaying colors
 * Merged [#1528](https://github.com/sebastianbergmann/phpunit/issues/1528): Improve message when `PHPUnit_Framework_Constraint_Count` is used with logical operators
 * Merged [#1537](https://github.com/sebastianbergmann/phpunit/issues/1537): Fix problem of `--stderr` with `--tap` and `--testdox`
diff --git a/phpunit.xsd b/phpunit.xsd
@@ -208,6 +208,7 @@
     <xs:attribute name="beStrictAboutOutputDuringTests" type="xs:boolean" default="false"/>
     <xs:attribute name="beStrictAboutTestSize" type="xs:boolean" default="false"/>
     <xs:attribute name="beStrictAboutTodoAnnotatedTests" type="xs:boolean" default="false"/>
+    <xs:attribute name="beStrictAboutChangesToGlobalState" type="xs:boolean" default="false"/>
     <xs:attribute name="checkForUnintentionallyCoveredCode" type="xs:boolean" default="false"/>
     <xs:attribute name="strict" type="xs:boolean" default="false"/>
     <xs:attribute name="testSuiteLoaderClass" type="xs:string" default="PHPUnit_Runner_StandardTestSuiteLoader"/>
diff --git a/src/Framework/TestCase.php b/src/Framework/TestCase.php
@@ -11,6 +11,7 @@
 use SebastianBergmann\GlobalState\Snapshot;
 use SebastianBergmann\GlobalState\Restorer;
 use SebastianBergmann\GlobalState\Blacklist;
+use SebastianBergmann\Diff\Differ;
 use SebastianBergmann\Exporter\Exporter;
 use Prophecy\Exception\Prediction\PredictionException;
 use Prophecy\Prophet;
@@ -264,6 +265,11 @@ abstract class PHPUnit_Framework_TestCase extends PHPUnit_Framework_Assert imple
      */
     private $prophet;
 
+    /**
+     * @var boolean
+     */
+    private $disallowChangesToGlobalState = false;
+
     /**
      * Constructs a test case with the given name.
      *
@@ -1010,6 +1016,15 @@ public function setDependencyInput(array $dependencyInput)
         $this->dependencyInput = $dependencyInput;
     }
 
+    /**
+     * @param boolean $disallowChangesToGlobalState
+     * @since Method available since Release 4.6.0
+     */
+    public function setDisallowChangesToGlobalState($disallowChangesToGlobalState)
+    {
+        $this->disallowChangesToGlobalState = $disallowChangesToGlobalState;
+    }
+
     /**
      * Calling this method in setUp() has no effect!
      *
@@ -1908,52 +1923,14 @@ private function stopOutputBuffering()
 
     private function snapshotGlobalState()
     {
-        if ($this->runTestInSeparateProcess || $this->inIsolation) {
-            return;
-        }
-
         $backupGlobals = $this->backupGlobals === null || $this->backupGlobals === true;
 
-        if ($backupGlobals || $this->backupStaticAttributes) {
-            $blacklist = new Blacklist;
-
-            if ($backupGlobals) {
-                foreach ($this->backupGlobalsBlacklist as $globalVariable) {
-                    $blacklist->addGlobalVariable($globalVariable);
-                }
-            }
-
-            if ($this->backupStaticAttributes && !defined('PHPUNIT_TESTSUITE')) {
-                $blacklist->addClassNamePrefix('PHPUnit');
-                $blacklist->addClassNamePrefix('File_Iterator');
-                $blacklist->addClassNamePrefix('PHP_CodeCoverage');
-                $blacklist->addClassNamePrefix('PHP_Invoker');
-                $blacklist->addClassNamePrefix('PHP_Timer');
-                $blacklist->addClassNamePrefix('PHP_Token');
-                $blacklist->addClassNamePrefix('Symfony');
-                $blacklist->addClassNamePrefix('Text_Template');
-                $blacklist->addClassNamePrefix('Doctrine\Instantiator');
-
-                foreach ($this->backupStaticAttributesBlacklist as $class => $attributes) {
-                    foreach ($attributes as $attribute) {
-                        $blacklist->addStaticAttribute($class, $attribute);
-                    }
-                }
-            }
-
-            $this->snapshot = new Snapshot(
-                $blacklist,
-                $backupGlobals,
-                $this->backupStaticAttributes,
-                false,
-                false,
-                false,
-                false,
-                false,
-                false,
-                false
-            );
+        if ($this->runTestInSeparateProcess || $this->inIsolation ||
+            (!$backupGlobals && !$this->backupStaticAttributes)) {
+            return;
         }
+
+        $this->snapshot = $this->createGlobalStateSnapshot($backupGlobals);
     }
 
     private function restoreGlobalState()
@@ -1962,9 +1939,18 @@ private function restoreGlobalState()
             return;
         }
 
+        $backupGlobals = $this->backupGlobals === null || $this->backupGlobals === true;
+
+        if ($this->disallowChangesToGlobalState) {
+            $this->compareGlobalStateSnapshots(
+                $this->snapshot,
+                $this->createGlobalStateSnapshot($backupGlobals)
+            );
+        }
+
         $restorer = new Restorer;
 
-        if ($this->backupGlobals === null || $this->backupGlobals === true) {
+        if ($backupGlobals) {
             $restorer->restoreGlobalVariables($this->snapshot);
         }
 
@@ -1975,6 +1961,105 @@ private function restoreGlobalState()
         $this->snapshot = null;
     }
 
+    /**
+     * @param  boolean $backupGlobals
+     * @return Snapshot
+     */
+    private function createGlobalStateSnapshot($backupGlobals)
+    {
+        $blacklist = new Blacklist;
+
+        foreach ($this->backupGlobalsBlacklist as $globalVariable) {
+            $blacklist->addGlobalVariable($globalVariable);
+        }
+
+        if (!defined('PHPUNIT_TESTSUITE')) {
+            $blacklist->addClassNamePrefix('PHPUnit');
+            $blacklist->addClassNamePrefix('File_Iterator');
+            $blacklist->addClassNamePrefix('PHP_CodeCoverage');
+            $blacklist->addClassNamePrefix('PHP_Invoker');
+            $blacklist->addClassNamePrefix('PHP_Timer');
+            $blacklist->addClassNamePrefix('PHP_Token');
+            $blacklist->addClassNamePrefix('Symfony');
+            $blacklist->addClassNamePrefix('Text_Template');
+            $blacklist->addClassNamePrefix('Doctrine\Instantiator');
+
+            foreach ($this->backupStaticAttributesBlacklist as $class => $attributes) {
+                foreach ($attributes as $attribute) {
+                    $blacklist->addStaticAttribute($class, $attribute);
+                }
+            }
+        }
+
+        return new Snapshot(
+            $blacklist,
+            $backupGlobals,
+            $this->backupStaticAttributes,
+            false,
+            false,
+            false,
+            false,
+            false,
+            false,
+            false
+        );
+    }
+
+    /**
+     * @param  Snapshot $before
+     * @param  Snapshot $after
+     * @throws PHPUnit_Framework_RiskyTestError
+     */
+    private function compareGlobalStateSnapshots(Snapshot $before, Snapshot $after)
+    {
+        $backupGlobals = $this->backupGlobals === null || $this->backupGlobals === true;
+
+        if ($backupGlobals) {
+            $this->compareGlobalStateSnapshotPart(
+                $before->globalVariables(),
+                $after->globalVariables(),
+                "--- Global variables before the test\n+++ Global variables after the test\n"
+            );
+
+            $this->compareGlobalStateSnapshotPart(
+                $before->superGlobalVariables(),
+                $after->superGlobalVariables(),
+                "--- Super-global variables before the test\n+++ Super-global variables after the test\n"
+            );
+        }
+
+        if ($this->backupStaticAttributes) {
+            $this->compareGlobalStateSnapshotPart(
+                $before->staticAttributes(),
+                $after->staticAttributes(),
+                "--- Static attributes before the test\n+++ Static attributes after the test\n"
+            );
+        }
+    }
+
+    /**
+     * @param  array  $before
+     * @param  array  $after
+     * @param  string $header
+     * @throws PHPUnit_Framework_RiskyTestError
+     */
+    private function compareGlobalStateSnapshotPart(array $before, array $after, $header)
+    {
+        if ($before != $after) {
+            $differ   = new Differ($header);
+            $exporter = new Exporter;
+
+            $diff = $differ->diff(
+                $exporter->export($before),
+                $exporter->export($after)
+            );
+
+            throw new PHPUnit_Framework_RiskyTestError(
+                $diff
+            );
+        }
+    }
+
     /**
      * @return Prophecy\Prophet
      * @since Method available since Release 4.5.0
diff --git a/src/Framework/TestSuite.php b/src/Framework/TestSuite.php
@@ -60,6 +60,11 @@ class PHPUnit_Framework_TestSuite implements PHPUnit_Framework_Test, PHPUnit_Fra
      */
     protected $backupStaticAttributes = null;
 
+    /**
+     * @var boolean
+     */
+    private $disallowChangesToGlobalState = null;
+
     /**
      * @var boolean
      */
@@ -708,6 +713,7 @@ class_exists($this->name, false) &&
 
             if ($test instanceof PHPUnit_Framework_TestCase ||
                 $test instanceof PHPUnit_Framework_TestSuite) {
+                $test->setDisallowChangesToGlobalState($this->disallowChangesToGlobalState);
                 $test->setBackupGlobals($this->backupGlobals);
                 $test->setBackupStaticAttributes($this->backupStaticAttributes);
                 $test->setRunTestInSeparateProcess($this->runTestInSeparateProcess);
@@ -905,6 +911,17 @@ protected static function incompleteTest($class, $methodName, $message)
         return new PHPUnit_Framework_IncompleteTestCase($class, $methodName, $message);
     }
 
+    /**
+     * @param boolean $disallowChangesToGlobalState
+     * @since  Method available since Release 4.6.0
+     */
+    public function setDisallowChangesToGlobalState($disallowChangesToGlobalState)
+    {
+        if (is_null($this->disallowChangesToGlobalState) && is_bool($disallowChangesToGlobalState)) {
+            $this->disallowChangesToGlobalState = $disallowChangesToGlobalState;
+        }
+    }
+
     /**
      * @param boolean $backupGlobals
      * @since  Method available since Release 3.3.0
diff --git a/src/TextUI/Command.php b/src/TextUI/Command.php
@@ -75,6 +75,7 @@ class PHPUnit_TextUI_Command
       'disallow-test-output' => null,
       'enforce-time-limit' => null,
       'disallow-todo-tests' => null,
+      'strict-global-state' => null,
       'strict' => null,
       'tap' => null,
       'testdox' => null,
@@ -491,6 +492,11 @@ protected function handleArguments(array $argv)
                     }
                 break;
 
+                case '--strict-global-state': {
+                    $this->arguments['disallowChangesToGlobalState'] = true;
+                }
+                break;
+
                 case '--disallow-test-output': {
                     $this->arguments['disallowTestOutput'] = true;
                     }
@@ -904,6 +910,7 @@ protected function showHelp()
 
   --report-useless-tests    Be strict about tests that do not test anything.
   --strict-coverage         Be strict about unintentionally covered code.
+  --strict-global-state     Be strict about changes to global state
   --disallow-test-output    Be strict about output during tests.
   --enforce-time-limit      Enforce time limit based on test size.
   --disallow-todo-tests     Disallow @todo-annotated tests.
diff --git a/src/TextUI/TestRunner.php b/src/TextUI/TestRunner.php
@@ -166,6 +166,10 @@ public function doRun(PHPUnit_Framework_Test $suite, array $arguments = array())
             $suite->setBackupStaticAttributes(true);
         }
 
+        if ($arguments['disallowChangesToGlobalState'] === true) {
+            $suite->setDisallowChangesToGlobalState(true);
+        }
+
         if (is_integer($arguments['repeat'])) {
             $test = new PHPUnit_Extensions_RepeatedTest(
                 $suite,
@@ -590,6 +594,11 @@ protected function handleConfiguration(array &$arguments)
                 $arguments['backupStaticAttributes'] = $phpunitConfiguration['backupStaticAttributes'];
             }
 
+            if (isset($phpunitConfiguration['disallowChangesToGlobalState']) &&
+                !isset($arguments['disallowChangesToGlobalState'])) {
+                $arguments['disallowChangesToGlobalState'] = $phpunitConfiguration['disallowChangesToGlobalState'];
+            }
+
             if (isset($phpunitConfiguration['bootstrap']) &&
                 !isset($arguments['bootstrap'])) {
                 $arguments['bootstrap'] = $phpunitConfiguration['bootstrap'];
@@ -895,6 +904,7 @@ protected function handleConfiguration(array &$arguments)
         $arguments['processUncoveredFilesFromWhitelist'] = isset($arguments['processUncoveredFilesFromWhitelist']) ? $arguments['processUncoveredFilesFromWhitelist'] : false;
         $arguments['backupGlobals']                      = isset($arguments['backupGlobals'])                      ? $arguments['backupGlobals']                      : null;
         $arguments['backupStaticAttributes']             = isset($arguments['backupStaticAttributes'])             ? $arguments['backupStaticAttributes']             : null;
+        $arguments['disallowChangesToGlobalState']       = isset($arguments['disallowChangesToGlobalState'])       ? $arguments['disallowChangesToGlobalState']       : null;
         $arguments['cacheTokens']                        = isset($arguments['cacheTokens'])                        ? $arguments['cacheTokens']                        : false;
         $arguments['columns']                            = isset($arguments['columns'])                            ? $arguments['columns']                            : 80;
         $arguments['colors']                             = isset($arguments['colors'])                             ? $arguments['colors']                             : PHPUnit_TextUI_ResultPrinter::COLOR_DEFAULT;
diff --git a/src/Util/Configuration.php b/src/Util/Configuration.php
@@ -43,6 +43,7 @@
  *          beStrictAboutTestSize="false"
  *          beStrictAboutTodoAnnotatedTests="false"
  *          checkForUnintentionallyCoveredCode="false"
+ *          disallowChangesToGlobalState="false"
  *          verbose="false">
  *   <testsuites>
  *     <testsuite name="My Test Suite">
@@ -739,6 +740,13 @@ public function getPHPUnitConfiguration()
             );
         }
 
+        if ($root->hasAttribute('beStrictAboutChangesToGlobalState')) {
+            $result['disallowChangesToGlobalState'] = $this->getBoolean(
+                (string) $root->getAttribute('beStrictAboutChangesToGlobalState'),
+                false
+            );
+        }
+
         if ($root->hasAttribute('beStrictAboutTestSize')) {
             $result['enforceTimeLimit'] = $this->getBoolean(
                 (string) $root->getAttribute('beStrictAboutTestSize'),
diff --git a/tests/TextUI/help.phpt b/tests/TextUI/help.phpt
@@ -45,6 +45,7 @@ Test Execution Options:
 
   --report-useless-tests    Be strict about tests that do not test anything.
   --strict-coverage         Be strict about unintentionally covered code.
+  --strict-global-state     Be strict about changes to global state
   --disallow-test-output    Be strict about output during tests.
   --enforce-time-limit      Enforce time limit based on test size.
   --disallow-todo-tests     Disallow @todo-annotated tests.
diff --git a/tests/TextUI/help2.phpt b/tests/TextUI/help2.phpt
@@ -46,6 +46,7 @@ Test Execution Options:
 
   --report-useless-tests    Be strict about tests that do not test anything.
   --strict-coverage         Be strict about unintentionally covered code.
+  --strict-global-state     Be strict about changes to global state
   --disallow-test-output    Be strict about output during tests.
   --enforce-time-limit      Enforce time limit based on test size.
   --disallow-todo-tests     Disallow @todo-annotated tests.
diff --git a/tests/Util/ConfigurationTest.php b/tests/Util/ConfigurationTest.php
@@ -353,6 +353,7 @@ public function testPHPUnitConfigurationIsReadCorrectly()
             array(
             'backupGlobals' => true,
             'backupStaticAttributes' => false,
+            'disallowChangesToGlobalState' => false,
             'bootstrap' => '/path/to/bootstrap.php',
             'cacheTokens' => false,
             'columns' => 80,
diff --git a/tests/_files/configuration.xml b/tests/_files/configuration.xml
@@ -23,6 +23,7 @@
          beStrictAboutTestSize="false"
          beStrictAboutTodoAnnotatedTests="false"
          checkForUnintentionallyCoveredCode="false"
+         beStrictAboutChangesToGlobalState="false"
          verbose="false">
   <testsuites>
     <testsuite name="My Test Suite">
diff --git a/tests/_files/configuration_xinclude.xml b/tests/_files/configuration_xinclude.xml
@@ -23,6 +23,7 @@
          beStrictAboutTestSize="false"
          beStrictAboutTodoAnnotatedTests="false"
          checkForUnintentionallyCoveredCode="false"
+         beStrictAboutChangesToGlobalState="false"
          verbose="false">
          <xi:include xmlns:xi="http://www.w3.org/2001/XInclude"
              href="configuration.xml"
