refactor: add declare(strict_types=1)

contributing/internals.md

@@ -29,10 +29,9 @@ PHP7 provides [Type declarations](https://www.php.net/manual/en/language.types.d
 for method parameters and return types. Use it where possible. Return type
 declaration is not always practical, but do try to make it work.
 
-At this time, shipped CI4 production code does not use 
-[Strict typing](https://www.php.net/manual/en/language.types.declarations.php#language.types.declarations.strict), 
-and will not be any time soon. However, in the development phase, 
-there are internal classes (in `utils/`) that are strictly typed.
+At this time, shipped CI4 production code does use
+[Strict typing](https://www.php.net/manual/en/language.types.declarations.php#language.types.declarations.strict)
+as much as possible.
 
 ## Abstractions
 

rector.php

@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 /**
  * This file is part of CodeIgniter 4 framework.
  *
@@ -43,6 +45,7 @@
 use Rector\Set\ValueObject\LevelSetList;
 use Rector\Set\ValueObject\SetList;
 use Rector\Strict\Rector\If_\BooleanInIfConditionRuleFixerRector;
+use Rector\TypeDeclaration\Rector\StmtsAwareInterface\DeclareStrictTypesRector;
 use Utils\Rector\PassStrictParameterToFunctionParameterRector;
 use Utils\Rector\RemoveErrorSuppressInTryCatchStmtsRector;
 use Utils\Rector\UnderscoreToCamelCaseVariableNameRector;
@@ -106,6 +109,19 @@
  __DIR__ . '/system/Session/Handlers',
  ],
 
+ DeclareStrictTypesRector::class => [
+ __DIR__ . '/app',
+ __DIR__ . '/system/CodeIgniter.php',
+ __DIR__ . '/system/Config/BaseConfig.php',
+ __DIR__ . '/system/Commands/Generators/Views',
+ __DIR__ . '/system/Pager/Views',
+ __DIR__ . '/system/Test/ControllerTestTrait.php',
+ __DIR__ . '/system/Validation/Views',
+ __DIR__ . '/system/View/Parser.php',
+ __DIR__ . '/tests/system/Debug/ExceptionsTest.php',
+ __DIR__ . '/tests/system/View/Views',
+ ],
+
  // use mt_rand instead of random_int on purpose on non-cryptographically random
  RandomFunctionRector::class,
 
@@ -116,6 +132,7 @@
  $rectorConfig->importNames();
  $rectorConfig->removeUnusedImports();
 
+ $rectorConfig->rule(DeclareStrictTypesRector::class);
  $rectorConfig->rule(UnderscoreToCamelCaseVariableNameRector::class);
  $rectorConfig->rule(SimplifyUselessVariableRector::class);
  $rectorConfig->rule(RemoveAlwaysElseRector::class);

system/API/ResponseTrait.php

@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 /**
  * This file is part of CodeIgniter 4 framework.
  *

system/Autoloader/Autoloader.php

@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 /**
  * This file is part of CodeIgniter 4 framework.
  *

system/Autoloader/FileLocator.php

@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 /**
  * This file is part of CodeIgniter 4 framework.
  *

system/Autoloader/FileLocatorCached.php

@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 /**
  * This file is part of CodeIgniter 4 framework.
  *

system/Autoloader/FileLocatorInterface.php

@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 /**
  * This file is part of CodeIgniter 4 framework.
  *

system/BaseModel.php

@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 /**
  * This file is part of CodeIgniter 4 framework.
  *

system/CLI/BaseCommand.php

@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 /**
  * This file is part of CodeIgniter 4 framework.
  *

system/CLI/CLI.php

@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 /**
  * This file is part of CodeIgniter 4 framework.
  *

system/CLI/Commands.php

@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 /**
  * This file is part of CodeIgniter 4 framework.
  *

system/CLI/Console.php

@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 /**
  * This file is part of CodeIgniter 4 framework.
  *

system/CLI/Exceptions/CLIException.php

@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 /**
  * This file is part of CodeIgniter 4 framework.
  *

system/CLI/GeneratorTrait.php

@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 /**
  * This file is part of CodeIgniter 4 framework.
  *

system/Cache/CacheFactory.php

@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 /**
  * This file is part of CodeIgniter 4 framework.
  *

system/Cache/CacheInterface.php

@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 /**
  * This file is part of CodeIgniter 4 framework.
  *

system/Cache/Exceptions/CacheException.php

@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 /**
  * This file is part of CodeIgniter 4 framework.
  *

system/Cache/Exceptions/ExceptionInterface.php

@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 /**
  * This file is part of CodeIgniter 4 framework.
  *

system/Cache/FactoriesCache.php

@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 /**
  * This file is part of CodeIgniter 4 framework.
  *

system/Cache/FactoriesCache/FileVarExportHandler.php

@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 /**
  * This file is part of CodeIgniter 4 framework.
  *

system/Cache/Handlers/BaseHandler.php

@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 /**
  * This file is part of CodeIgniter 4 framework.
  *

system/Cache/Handlers/DummyHandler.php

@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 /**
  * This file is part of CodeIgniter 4 framework.
  *

system/Cache/Handlers/FileHandler.php

@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 /**
  * This file is part of CodeIgniter 4 framework.
  *

system/Cache/Handlers/MemcachedHandler.php

@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 /**
  * This file is part of CodeIgniter 4 framework.
  *

system/Cache/Handlers/PredisHandler.php

@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 /**
  * This file is part of CodeIgniter 4 framework.
  *

system/Cache/Handlers/RedisHandler.php

@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 /**
  * This file is part of CodeIgniter 4 framework.
  *

system/Cache/Handlers/WincacheHandler.php

@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 /**
  * This file is part of CodeIgniter 4 framework.
  *

system/Cache/ResponseCache.php

@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 /**
  * This file is part of CodeIgniter 4 framework.
  *

system/CodeIgniter.php

@@ -919,6 +919,8 @@ protected function runController($class)
  // This is a Web request or PHP CLI request
  $params = $this->router->params();
 
+ // The controller method param types may not be string.
+ // So cannot set `declare(strict_types=1)` in this file.
  $output = method_exists($class, '_remap')
  ? $class->_remap($this->method, ...$params)
  : $class->{$this->method}(...$params);

system/Commands/Cache/ClearCache.php

@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 /**
  * This file is part of CodeIgniter 4 framework.
  *

system/Commands/Cache/InfoCache.php

@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 /**
  * This file is part of CodeIgniter 4 framework.
  *

system/Commands/Database/CreateDatabase.php

@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 /**
  * This file is part of CodeIgniter 4 framework.
  *

system/Commands/Database/Migrate.php

@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 /**
  * This file is part of CodeIgniter 4 framework.
  *

system/Commands/Database/MigrateRefresh.php

@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 /**
  * This file is part of CodeIgniter 4 framework.
  *

system/Commands/Database/MigrateRollback.php

@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 /**
  * This file is part of CodeIgniter 4 framework.
  *

system/Commands/Database/MigrateStatus.php

@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 /**
  * This file is part of CodeIgniter 4 framework.
  *

system/Commands/Database/Seed.php

@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 /**
  * This file is part of CodeIgniter 4 framework.
  *

system/Commands/Database/ShowTableInfo.php

@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 /**
  * This file is part of CodeIgniter 4 framework.
  *

system/Commands/Encryption/GenerateKey.php

@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 /**
  * This file is part of CodeIgniter 4 framework.
  *

system/Commands/Generators/CellGenerator.php

@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 /**
  * This file is part of CodeIgniter 4 framework.
  *

system/Commands/Generators/CommandGenerator.php

@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 /**
  * This file is part of CodeIgniter 4 framework.
  *

system/Commands/Generators/ConfigGenerator.php

@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 /**
  * This file is part of CodeIgniter 4 framework.
  *

system/Commands/Generators/ControllerGenerator.php

@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 /**
  * This file is part of CodeIgniter 4 framework.
  *

system/Commands/Generators/EntityGenerator.php

@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 /**
  * This file is part of CodeIgniter 4 framework.
  *

contributing/internals.md

@@ -29,10 +29,9 @@ PHP7 provides [Type declarations](https://www.php.net/manual/en/language.types.d
 for method parameters and return types. Use it where possible. Return type
 declaration is not always practical, but do try to make it work.
 
-At this time, shipped CI4 production code does not use 
-[Strict typing](https://www.php.net/manual/en/language.types.declarations.php#language.types.declarations.strict), 
-and will not be any time soon. However, in the development phase, 
-there are internal classes (in `utils/`) that are strictly typed.
+At this time, shipped CI4 production code does use
+[Strict typing](https://www.php.net/manual/en/language.types.declarations.php#language.types.declarations.strict)
+as much as possible.
 
 ## Abstractions
 

rector.php

@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 /**
  * This file is part of CodeIgniter 4 framework.
  *
@@ -43,6 +45,7 @@
 use Rector\Set\ValueObject\LevelSetList;
 use Rector\Set\ValueObject\SetList;
 use Rector\Strict\Rector\If_\BooleanInIfConditionRuleFixerRector;
+use Rector\TypeDeclaration\Rector\StmtsAwareInterface\DeclareStrictTypesRector;
 use Utils\Rector\PassStrictParameterToFunctionParameterRector;
 use Utils\Rector\RemoveErrorSuppressInTryCatchStmtsRector;
 use Utils\Rector\UnderscoreToCamelCaseVariableNameRector;
@@ -106,6 +109,19 @@
  __DIR__ . '/system/Session/Handlers',
  ],
 
+ DeclareStrictTypesRector::class => [
+ __DIR__ . '/app',
+ __DIR__ . '/system/CodeIgniter.php',
+ __DIR__ . '/system/Config/BaseConfig.php',
+ __DIR__ . '/system/Commands/Generators/Views',
+ __DIR__ . '/system/Pager/Views',
+ __DIR__ . '/system/Test/ControllerTestTrait.php',
+ __DIR__ . '/system/Validation/Views',
+ __DIR__ . '/system/View/Parser.php',
+ __DIR__ . '/tests/system/Debug/ExceptionsTest.php',
+ __DIR__ . '/tests/system/View/Views',
+ ],
+
  // use mt_rand instead of random_int on purpose on non-cryptographically random
  RandomFunctionRector::class,
 
@@ -116,6 +132,7 @@
  $rectorConfig->importNames();
  $rectorConfig->removeUnusedImports();
 
+ $rectorConfig->rule(DeclareStrictTypesRector::class);
  $rectorConfig->rule(UnderscoreToCamelCaseVariableNameRector::class);
  $rectorConfig->rule(SimplifyUselessVariableRector::class);
  $rectorConfig->rule(RemoveAlwaysElseRector::class);

system/API/ResponseTrait.php

@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 /**
  * This file is part of CodeIgniter 4 framework.
  *

system/Autoloader/Autoloader.php

@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 /**
  * This file is part of CodeIgniter 4 framework.
  *

system/Autoloader/FileLocator.php

@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 /**
  * This file is part of CodeIgniter 4 framework.
  *

system/Autoloader/FileLocatorCached.php

@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 /**
  * This file is part of CodeIgniter 4 framework.
  *

system/Autoloader/FileLocatorInterface.php

@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 /**
  * This file is part of CodeIgniter 4 framework.
  *

system/BaseModel.php

@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 /**
  * This file is part of CodeIgniter 4 framework.
  *

system/CLI/BaseCommand.php

@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 /**
  * This file is part of CodeIgniter 4 framework.
  *

system/CLI/CLI.php

@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 /**
  * This file is part of CodeIgniter 4 framework.
  *

system/CLI/Commands.php

@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 /**
  * This file is part of CodeIgniter 4 framework.
  *

system/CLI/Console.php

@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 /**
  * This file is part of CodeIgniter 4 framework.
  *

system/CLI/Exceptions/CLIException.php

@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 /**
  * This file is part of CodeIgniter 4 framework.
  *

system/CLI/GeneratorTrait.php

@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 /**
  * This file is part of CodeIgniter 4 framework.
  *

system/Cache/CacheFactory.php

@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 /**
  * This file is part of CodeIgniter 4 framework.
  *

system/Cache/CacheInterface.php

@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 /**
  * This file is part of CodeIgniter 4 framework.
  *

system/Cache/Exceptions/CacheException.php

@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 /**
  * This file is part of CodeIgniter 4 framework.
  *

system/Cache/Exceptions/ExceptionInterface.php

@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 /**
  * This file is part of CodeIgniter 4 framework.
  *

system/Cache/FactoriesCache.php

@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 /**
  * This file is part of CodeIgniter 4 framework.
  *

system/Cache/FactoriesCache/FileVarExportHandler.php

@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 /**
  * This file is part of CodeIgniter 4 framework.
  *

system/Cache/Handlers/BaseHandler.php

@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 /**
  * This file is part of CodeIgniter 4 framework.
  *

system/Cache/Handlers/DummyHandler.php

@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 /**
  * This file is part of CodeIgniter 4 framework.
  *

system/Cache/Handlers/FileHandler.php

@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 /**
  * This file is part of CodeIgniter 4 framework.
  *

system/Cache/Handlers/MemcachedHandler.php

@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 /**
  * This file is part of CodeIgniter 4 framework.
  *

system/Cache/Handlers/PredisHandler.php

@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 /**
  * This file is part of CodeIgniter 4 framework.
  *

system/Cache/Handlers/RedisHandler.php

@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 /**
  * This file is part of CodeIgniter 4 framework.
  *

system/Cache/Handlers/WincacheHandler.php

@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 /**
  * This file is part of CodeIgniter 4 framework.
  *

system/Cache/ResponseCache.php

@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 /**
  * This file is part of CodeIgniter 4 framework.
  *

system/CodeIgniter.php

@@ -919,6 +919,8 @@ protected function runController($class)
  // This is a Web request or PHP CLI request
  $params = $this->router->params();
 
+ // The controller method param types may not be string.
+ // So cannot set `declare(strict_types=1)` in this file.
  $output = method_exists($class, '_remap')
  ? $class->_remap($this->method, ...$params)
  : $class->{$this->method}(...$params);

system/Commands/Cache/ClearCache.php

@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 /**
  * This file is part of CodeIgniter 4 framework.
  *

system/Commands/Cache/InfoCache.php

@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 /**
  * This file is part of CodeIgniter 4 framework.
  *

system/Commands/Database/CreateDatabase.php

@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 /**
  * This file is part of CodeIgniter 4 framework.
  *

system/Commands/Database/Migrate.php

@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 /**
  * This file is part of CodeIgniter 4 framework.
  *

system/Commands/Database/MigrateRefresh.php

@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 /**
  * This file is part of CodeIgniter 4 framework.
  *

system/Commands/Database/MigrateRollback.php

@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 /**
  * This file is part of CodeIgniter 4 framework.
  *

system/Commands/Database/MigrateStatus.php

@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 /**
  * This file is part of CodeIgniter 4 framework.
  *

system/Commands/Database/Seed.php

@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 /**
  * This file is part of CodeIgniter 4 framework.
  *

system/Commands/Database/ShowTableInfo.php

@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 /**
  * This file is part of CodeIgniter 4 framework.
  *

system/Commands/Encryption/GenerateKey.php

@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 /**
  * This file is part of CodeIgniter 4 framework.
  *

system/Commands/Generators/CellGenerator.php

@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 /**
  * This file is part of CodeIgniter 4 framework.
  *

system/Commands/Generators/CommandGenerator.php

@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 /**
  * This file is part of CodeIgniter 4 framework.
  *

system/Commands/Generators/ConfigGenerator.php

@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 /**
  * This file is part of CodeIgniter 4 framework.
  *

system/Commands/Generators/ControllerGenerator.php

@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 /**
  * This file is part of CodeIgniter 4 framework.
  *

system/Commands/Generators/EntityGenerator.php

@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 /**
  * This file is part of CodeIgniter 4 framework.
  *

contributing/internals.md

@@ -29,10 +29,9 @@ PHP7 provides [Type declarations](https://www.php.net/manual/en/language.types.d
 for method parameters and return types. Use it where possible. Return type
 declaration is not always practical, but do try to make it work.
 
-At this time, shipped CI4 production code does not use 
-[Strict typing](https://www.php.net/manual/en/language.types.declarations.php#language.types.declarations.strict), 
-and will not be any time soon. However, in the development phase, 
-there are internal classes (in `utils/`) that are strictly typed.
+At this time, shipped CI4 production code does use
+[Strict typing](https://www.php.net/manual/en/language.types.declarations.php#language.types.declarations.strict)
+as much as possible.
 
 ## Abstractions
 

rector.php

@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 /**
  * This file is part of CodeIgniter 4 framework.
  *
@@ -43,6 +45,7 @@
 use Rector\Set\ValueObject\LevelSetList;
 use Rector\Set\ValueObject\SetList;
 use Rector\Strict\Rector\If_\BooleanInIfConditionRuleFixerRector;
+use Rector\TypeDeclaration\Rector\StmtsAwareInterface\DeclareStrictTypesRector;
 use Utils\Rector\PassStrictParameterToFunctionParameterRector;
 use Utils\Rector\RemoveErrorSuppressInTryCatchStmtsRector;
 use Utils\Rector\UnderscoreToCamelCaseVariableNameRector;
@@ -106,6 +109,19 @@
  __DIR__ . '/system/Session/Handlers',
  ],
 
+ DeclareStrictTypesRector::class => [
+ __DIR__ . '/app',
+ __DIR__ . '/system/CodeIgniter.php',
+ __DIR__ . '/system/Config/BaseConfig.php',
+ __DIR__ . '/system/Commands/Generators/Views',
+ __DIR__ . '/system/Pager/Views',
+ __DIR__ . '/system/Test/ControllerTestTrait.php',
+ __DIR__ . '/system/Validation/Views',
+ __DIR__ . '/system/View/Parser.php',
+ __DIR__ . '/tests/system/Debug/ExceptionsTest.php',
+ __DIR__ . '/tests/system/View/Views',
+ ],
+
  // use mt_rand instead of random_int on purpose on non-cryptographically random
  RandomFunctionRector::class,
 
@@ -116,6 +132,7 @@
  $rectorConfig->importNames();
  $rectorConfig->removeUnusedImports();
 
+ $rectorConfig->rule(DeclareStrictTypesRector::class);
  $rectorConfig->rule(UnderscoreToCamelCaseVariableNameRector::class);
  $rectorConfig->rule(SimplifyUselessVariableRector::class);
  $rectorConfig->rule(RemoveAlwaysElseRector::class);

system/API/ResponseTrait.php

@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 /**
  * This file is part of CodeIgniter 4 framework.
  *

system/Autoloader/Autoloader.php

@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 /**
  * This file is part of CodeIgniter 4 framework.
  *

system/Autoloader/FileLocator.php

@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 /**
  * This file is part of CodeIgniter 4 framework.
  *

system/Autoloader/FileLocatorCached.php

@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 /**
  * This file is part of CodeIgniter 4 framework.
  *

system/Autoloader/FileLocatorInterface.php

@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 /**
  * This file is part of CodeIgniter 4 framework.
  *

system/BaseModel.php

@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 /**
  * This file is part of CodeIgniter 4 framework.
  *

system/CLI/BaseCommand.php

@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 /**
  * This file is part of CodeIgniter 4 framework.
  *

system/CLI/CLI.php

@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 /**
  * This file is part of CodeIgniter 4 framework.
  *

system/CLI/Commands.php

@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 /**
  * This file is part of CodeIgniter 4 framework.
  *

system/CLI/Console.php

@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 /**
  * This file is part of CodeIgniter 4 framework.
  *

system/CLI/Exceptions/CLIException.php

@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 /**
  * This file is part of CodeIgniter 4 framework.
  *

system/CLI/GeneratorTrait.php

@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 /**
  * This file is part of CodeIgniter 4 framework.
  *

system/Cache/CacheFactory.php

@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 /**
  * This file is part of CodeIgniter 4 framework.
  *

system/Cache/CacheInterface.php

@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 /**
  * This file is part of CodeIgniter 4 framework.
  *

system/Cache/Exceptions/CacheException.php

@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 /**
  * This file is part of CodeIgniter 4 framework.
  *

system/Cache/Exceptions/ExceptionInterface.php

@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 /**
  * This file is part of CodeIgniter 4 framework.
  *

system/Cache/FactoriesCache.php

@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 /**
  * This file is part of CodeIgniter 4 framework.
  *

system/Cache/FactoriesCache/FileVarExportHandler.php

@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 /**
  * This file is part of CodeIgniter 4 framework.
  *

system/Cache/Handlers/BaseHandler.php

@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 /**
  * This file is part of CodeIgniter 4 framework.
  *

system/Cache/Handlers/DummyHandler.php

@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 /**
  * This file is part of CodeIgniter 4 framework.
  *

system/Cache/Handlers/FileHandler.php

@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 /**
  * This file is part of CodeIgniter 4 framework.
  *

system/Cache/Handlers/MemcachedHandler.php

@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 /**
  * This file is part of CodeIgniter 4 framework.
  *

system/Cache/Handlers/PredisHandler.php

@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 /**
  * This file is part of CodeIgniter 4 framework.
  *

system/Cache/Handlers/RedisHandler.php

@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 /**
  * This file is part of CodeIgniter 4 framework.
  *

system/Cache/Handlers/WincacheHandler.php

@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 /**
  * This file is part of CodeIgniter 4 framework.
  *

system/Cache/ResponseCache.php

@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 /**
  * This file is part of CodeIgniter 4 framework.
  *

system/CodeIgniter.php

@@ -919,6 +919,8 @@ protected function runController($class)
  // This is a Web request or PHP CLI request
  $params = $this->router->params();
 
+ // The controller method param types may not be string.
+ // So cannot set `declare(strict_types=1)` in this file.
  $output = method_exists($class, '_remap')
  ? $class->_remap($this->method, ...$params)
  : $class->{$this->method}(...$params);

system/Commands/Cache/ClearCache.php

@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 /**
  * This file is part of CodeIgniter 4 framework.
  *

system/Commands/Cache/InfoCache.php

@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 /**
  * This file is part of CodeIgniter 4 framework.
  *

system/Commands/Database/CreateDatabase.php

@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 /**
  * This file is part of CodeIgniter 4 framework.
  *

system/Commands/Database/Migrate.php

@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 /**
  * This file is part of CodeIgniter 4 framework.
  *

system/Commands/Database/MigrateRefresh.php

@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 /**
  * This file is part of CodeIgniter 4 framework.
  *

system/Commands/Database/MigrateRollback.php

@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 /**
  * This file is part of CodeIgniter 4 framework.
  *

system/Commands/Database/MigrateStatus.php

@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 /**
  * This file is part of CodeIgniter 4 framework.
  *

system/Commands/Database/Seed.php

@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 /**
  * This file is part of CodeIgniter 4 framework.
  *

system/Commands/Database/ShowTableInfo.php

@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 /**
  * This file is part of CodeIgniter 4 framework.
  *

system/Commands/Encryption/GenerateKey.php

@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 /**
  * This file is part of CodeIgniter 4 framework.
  *

system/Commands/Generators/CellGenerator.php

@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 /**
  * This file is part of CodeIgniter 4 framework.
  *

system/Commands/Generators/CommandGenerator.php

@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 /**
  * This file is part of CodeIgniter 4 framework.
  *

system/Commands/Generators/ConfigGenerator.php

@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 /**
  * This file is part of CodeIgniter 4 framework.
  *

system/Commands/Generators/ControllerGenerator.php

@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 /**
  * This file is part of CodeIgniter 4 framework.
  *

system/Commands/Generators/EntityGenerator.php

@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 /**
  * This file is part of CodeIgniter 4 framework.
  *

contributing/internals.md

@@ -29,10 +29,9 @@ PHP7 provides [Type declarations](https://www.php.net/manual/en/language.types.d
 for method parameters and return types. Use it where possible. Return type
 declaration is not always practical, but do try to make it work.
 
-At this time, shipped CI4 production code does not use 
-[Strict typing](https://www.php.net/manual/en/language.types.declarations.php#language.types.declarations.strict), 
-and will not be any time soon. However, in the development phase, 
-there are internal classes (in `utils/`) that are strictly typed.
+At this time, shipped CI4 production code does use
+[Strict typing](https://www.php.net/manual/en/language.types.declarations.php#language.types.declarations.strict)
+as much as possible.
 
 ## Abstractions
 

rector.php

@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 /**
  * This file is part of CodeIgniter 4 framework.
  *
@@ -43,6 +45,7 @@
 use Rector\Set\ValueObject\LevelSetList;
 use Rector\Set\ValueObject\SetList;
 use Rector\Strict\Rector\If_\BooleanInIfConditionRuleFixerRector;
+use Rector\TypeDeclaration\Rector\StmtsAwareInterface\DeclareStrictTypesRector;
 use Utils\Rector\PassStrictParameterToFunctionParameterRector;
 use Utils\Rector\RemoveErrorSuppressInTryCatchStmtsRector;
 use Utils\Rector\UnderscoreToCamelCaseVariableNameRector;
@@ -106,6 +109,19 @@
  __DIR__ . '/system/Session/Handlers',
  ],
 
+ DeclareStrictTypesRector::class => [
+ __DIR__ . '/app',
+ __DIR__ . '/system/CodeIgniter.php',
+ __DIR__ . '/system/Config/BaseConfig.php',
+ __DIR__ . '/system/Commands/Generators/Views',
+ __DIR__ . '/system/Pager/Views',
+ __DIR__ . '/system/Test/ControllerTestTrait.php',
+ __DIR__ . '/system/Validation/Views',
+ __DIR__ . '/system/View/Parser.php',
+ __DIR__ . '/tests/system/Debug/ExceptionsTest.php',
+ __DIR__ . '/tests/system/View/Views',
+ ],
+
  // use mt_rand instead of random_int on purpose on non-cryptographically random
  RandomFunctionRector::class,
 
@@ -116,6 +132,7 @@
  $rectorConfig->importNames();
  $rectorConfig->removeUnusedImports();
 
+ $rectorConfig->rule(DeclareStrictTypesRector::class);
  $rectorConfig->rule(UnderscoreToCamelCaseVariableNameRector::class);
  $rectorConfig->rule(SimplifyUselessVariableRector::class);
  $rectorConfig->rule(RemoveAlwaysElseRector::class);

system/API/ResponseTrait.php

@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 /**
  * This file is part of CodeIgniter 4 framework.
  *

system/Autoloader/Autoloader.php

@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 /**
  * This file is part of CodeIgniter 4 framework.
  *

system/Autoloader/FileLocator.php

@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 /**
  * This file is part of CodeIgniter 4 framework.
  *

system/Autoloader/FileLocatorCached.php

@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 /**
  * This file is part of CodeIgniter 4 framework.
  *

system/Autoloader/FileLocatorInterface.php

@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 /**
  * This file is part of CodeIgniter 4 framework.
  *

system/BaseModel.php

@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 /**
  * This file is part of CodeIgniter 4 framework.
  *

system/CLI/BaseCommand.php

@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 /**
  * This file is part of CodeIgniter 4 framework.
  *

system/CLI/CLI.php

@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 /**
  * This file is part of CodeIgniter 4 framework.
  *

system/CLI/Commands.php

@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 /**
  * This file is part of CodeIgniter 4 framework.
  *

system/CLI/Console.php

@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 /**
  * This file is part of CodeIgniter 4 framework.
  *

system/CLI/Exceptions/CLIException.php

@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 /**
  * This file is part of CodeIgniter 4 framework.
  *

system/CLI/GeneratorTrait.php

@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 /**
  * This file is part of CodeIgniter 4 framework.
  *

system/Cache/CacheFactory.php

@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 /**
  * This file is part of CodeIgniter 4 framework.
  *

system/Cache/CacheInterface.php

@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 /**
  * This file is part of CodeIgniter 4 framework.
  *

system/Cache/Exceptions/CacheException.php

@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 /**
  * This file is part of CodeIgniter 4 framework.
  *

system/Cache/Exceptions/ExceptionInterface.php

@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 /**
  * This file is part of CodeIgniter 4 framework.
  *

system/Cache/FactoriesCache.php

@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 /**
  * This file is part of CodeIgniter 4 framework.
  *

system/Cache/FactoriesCache/FileVarExportHandler.php

@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 /**
  * This file is part of CodeIgniter 4 framework.
  *

system/Cache/Handlers/BaseHandler.php

@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 /**
  * This file is part of CodeIgniter 4 framework.
  *

system/Cache/Handlers/DummyHandler.php

@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 /**
  * This file is part of CodeIgniter 4 framework.
  *

system/Cache/Handlers/FileHandler.php

@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 /**
  * This file is part of CodeIgniter 4 framework.
  *

system/Cache/Handlers/MemcachedHandler.php

@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 /**
  * This file is part of CodeIgniter 4 framework.
  *

system/Cache/Handlers/PredisHandler.php

@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 /**
  * This file is part of CodeIgniter 4 framework.
  *

system/Cache/Handlers/RedisHandler.php

@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 /**
  * This file is part of CodeIgniter 4 framework.
  *

system/Cache/Handlers/WincacheHandler.php

@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 /**
  * This file is part of CodeIgniter 4 framework.
  *

system/Cache/ResponseCache.php

@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 /**
  * This file is part of CodeIgniter 4 framework.
  *

system/CodeIgniter.php

@@ -919,6 +919,8 @@ protected function runController($class)
  // This is a Web request or PHP CLI request
  $params = $this->router->params();
 
+ // The controller method param types may not be string.
+ // So cannot set `declare(strict_types=1)` in this file.
  $output = method_exists($class, '_remap')
  ? $class->_remap($this->method, ...$params)
  : $class->{$this->method}(...$params);

system/Commands/Cache/ClearCache.php

@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 /**
  * This file is part of CodeIgniter 4 framework.
  *

system/Commands/Cache/InfoCache.php

@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 /**
  * This file is part of CodeIgniter 4 framework.
  *

system/Commands/Database/CreateDatabase.php

@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 /**
  * This file is part of CodeIgniter 4 framework.
  *

system/Commands/Database/Migrate.php

@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 /**
  * This file is part of CodeIgniter 4 framework.
  *

system/Commands/Database/MigrateRefresh.php

@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 /**
  * This file is part of CodeIgniter 4 framework.
  *

system/Commands/Database/MigrateRollback.php

@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 /**
  * This file is part of CodeIgniter 4 framework.
  *

system/Commands/Database/MigrateStatus.php

@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 /**
  * This file is part of CodeIgniter 4 framework.
  *

system/Commands/Database/Seed.php

@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 /**
  * This file is part of CodeIgniter 4 framework.
  *

system/Commands/Database/ShowTableInfo.php

@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 /**
  * This file is part of CodeIgniter 4 framework.
  *

system/Commands/Encryption/GenerateKey.php

@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 /**
  * This file is part of CodeIgniter 4 framework.
  *

system/Commands/Generators/CellGenerator.php

@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 /**
  * This file is part of CodeIgniter 4 framework.
  *

system/Commands/Generators/CommandGenerator.php

@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 /**
  * This file is part of CodeIgniter 4 framework.
  *

system/Commands/Generators/ConfigGenerator.php

@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 /**
  * This file is part of CodeIgniter 4 framework.
  *

system/Commands/Generators/ControllerGenerator.php

@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 /**
  * This file is part of CodeIgniter 4 framework.
  *

system/Commands/Generators/EntityGenerator.php

@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 /**
  * This file is part of CodeIgniter 4 framework.
  *

contributing/internals.md

@@ -29,10 +29,9 @@ PHP7 provides [Type declarations](https://www.php.net/manual/en/language.types.d
 for method parameters and return types. Use it where possible. Return type
 declaration is not always practical, but do try to make it work.
 
-At this time, shipped CI4 production code does not use 
-[Strict typing](https://www.php.net/manual/en/language.types.declarations.php#language.types.declarations.strict), 
-and will not be any time soon. However, in the development phase, 
-there are internal classes (in `utils/`) that are strictly typed.
+At this time, shipped CI4 production code does use
+[Strict typing](https://www.php.net/manual/en/language.types.declarations.php#language.types.declarations.strict)
+as much as possible.
 
 ## Abstractions
 

rector.php

@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 /**
  * This file is part of CodeIgniter 4 framework.
  *
@@ -43,6 +45,7 @@
 use Rector\Set\ValueObject\LevelSetList;
 use Rector\Set\ValueObject\SetList;
 use Rector\Strict\Rector\If_\BooleanInIfConditionRuleFixerRector;
+use Rector\TypeDeclaration\Rector\StmtsAwareInterface\DeclareStrictTypesRector;
 use Utils\Rector\PassStrictParameterToFunctionParameterRector;
 use Utils\Rector\RemoveErrorSuppressInTryCatchStmtsRector;
 use Utils\Rector\UnderscoreToCamelCaseVariableNameRector;
@@ -106,6 +109,19 @@
  __DIR__ . '/system/Session/Handlers',
  ],
 
+ DeclareStrictTypesRector::class => [
+ __DIR__ . '/app',
+ __DIR__ . '/system/CodeIgniter.php',
+ __DIR__ . '/system/Config/BaseConfig.php',
+ __DIR__ . '/system/Commands/Generators/Views',
+ __DIR__ . '/system/Pager/Views',
+ __DIR__ . '/system/Test/ControllerTestTrait.php',
+ __DIR__ . '/system/Validation/Views',
+ __DIR__ . '/system/View/Parser.php',
+ __DIR__ . '/tests/system/Debug/ExceptionsTest.php',
+ __DIR__ . '/tests/system/View/Views',
+ ],
+
  // use mt_rand instead of random_int on purpose on non-cryptographically random
  RandomFunctionRector::class,
 
@@ -116,6 +132,7 @@
  $rectorConfig->importNames();
  $rectorConfig->removeUnusedImports();
 
+ $rectorConfig->rule(DeclareStrictTypesRector::class);
  $rectorConfig->rule(UnderscoreToCamelCaseVariableNameRector::class);
  $rectorConfig->rule(SimplifyUselessVariableRector::class);
  $rectorConfig->rule(RemoveAlwaysElseRector::class);

system/API/ResponseTrait.php

@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 /**
  * This file is part of CodeIgniter 4 framework.
  *

system/Autoloader/Autoloader.php

@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 /**
  * This file is part of CodeIgniter 4 framework.
  *

system/Autoloader/FileLocator.php

@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 /**
  * This file is part of CodeIgniter 4 framework.
  *

system/Autoloader/FileLocatorCached.php

@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 /**
  * This file is part of CodeIgniter 4 framework.
  *

system/Autoloader/FileLocatorInterface.php

@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 /**
  * This file is part of CodeIgniter 4 framework.
  *

system/BaseModel.php

@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 /**
  * This file is part of CodeIgniter 4 framework.
  *

system/CLI/BaseCommand.php

@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 /**
  * This file is part of CodeIgniter 4 framework.
  *

system/CLI/CLI.php

@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 /**
  * This file is part of CodeIgniter 4 framework.
  *

system/CLI/Commands.php

@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 /**
  * This file is part of CodeIgniter 4 framework.
  *

system/CLI/Console.php

@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 /**
  * This file is part of CodeIgniter 4 framework.
  *

system/CLI/Exceptions/CLIException.php

@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 /**
  * This file is part of CodeIgniter 4 framework.
  *

system/CLI/GeneratorTrait.php

@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 /**
  * This file is part of CodeIgniter 4 framework.
  *

system/Cache/CacheFactory.php

@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 /**
  * This file is part of CodeIgniter 4 framework.
  *

system/Cache/CacheInterface.php

@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 /**
  * This file is part of CodeIgniter 4 framework.
  *

system/Cache/Exceptions/CacheException.php

@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 /**
  * This file is part of CodeIgniter 4 framework.
  *

system/Cache/Exceptions/ExceptionInterface.php

@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 /**
  * This file is part of CodeIgniter 4 framework.
  *

system/Cache/FactoriesCache.php

@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 /**
  * This file is part of CodeIgniter 4 framework.
  *

system/Cache/FactoriesCache/FileVarExportHandler.php

@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 /**
  * This file is part of CodeIgniter 4 framework.
  *

system/Cache/Handlers/BaseHandler.php

@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 /**
  * This file is part of CodeIgniter 4 framework.
  *

system/Cache/Handlers/DummyHandler.php

@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 /**
  * This file is part of CodeIgniter 4 framework.
  *

system/Cache/Handlers/FileHandler.php

@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 /**
  * This file is part of CodeIgniter 4 framework.
  *

system/Cache/Handlers/MemcachedHandler.php

@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 /**
  * This file is part of CodeIgniter 4 framework.
  *

system/Cache/Handlers/PredisHandler.php

@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 /**
  * This file is part of CodeIgniter 4 framework.
  *

system/Cache/Handlers/RedisHandler.php

@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 /**
  * This file is part of CodeIgniter 4 framework.
  *

system/Cache/Handlers/WincacheHandler.php

@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 /**
  * This file is part of CodeIgniter 4 framework.
  *

system/Cache/ResponseCache.php

@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 /**
  * This file is part of CodeIgniter 4 framework.
  *

system/CodeIgniter.php

@@ -919,6 +919,8 @@ protected function runController($class)
  // This is a Web request or PHP CLI request
  $params = $this->router->params();
 
+ // The controller method param types may not be string.
+ // So cannot set `declare(strict_types=1)` in this file.
  $output = method_exists($class, '_remap')
  ? $class->_remap($this->method, ...$params)
  : $class->{$this->method}(...$params);

system/Commands/Cache/ClearCache.php

@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 /**
  * This file is part of CodeIgniter 4 framework.
  *

system/Commands/Cache/InfoCache.php

@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 /**
  * This file is part of CodeIgniter 4 framework.
  *

system/Commands/Database/CreateDatabase.php

@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 /**
  * This file is part of CodeIgniter 4 framework.
  *

system/Commands/Database/Migrate.php

@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 /**
  * This file is part of CodeIgniter 4 framework.
  *

system/Commands/Database/MigrateRefresh.php

@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 /**
  * This file is part of CodeIgniter 4 framework.
  *

system/Commands/Database/MigrateRollback.php

@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 /**
  * This file is part of CodeIgniter 4 framework.
  *

system/Commands/Database/MigrateStatus.php

@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 /**
  * This file is part of CodeIgniter 4 framework.
  *

system/Commands/Database/Seed.php

@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 /**
  * This file is part of CodeIgniter 4 framework.
  *

system/Commands/Database/ShowTableInfo.php

@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 /**
  * This file is part of CodeIgniter 4 framework.
  *

system/Commands/Encryption/GenerateKey.php

@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 /**
  * This file is part of CodeIgniter 4 framework.
  *

system/Commands/Generators/CellGenerator.php

@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 /**
  * This file is part of CodeIgniter 4 framework.
  *

system/Commands/Generators/CommandGenerator.php

@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 /**
  * This file is part of CodeIgniter 4 framework.
  *

system/Commands/Generators/ConfigGenerator.php

@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 /**
  * This file is part of CodeIgniter 4 framework.
  *

system/Commands/Generators/ControllerGenerator.php

@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 /**
  * This file is part of CodeIgniter 4 framework.
  *

system/Commands/Generators/EntityGenerator.php

@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 /**
  * This file is part of CodeIgniter 4 framework.
  *

contributing/internals.md

@@ -29,10 +29,9 @@ PHP7 provides [Type declarations](https://www.php.net/manual/en/language.types.d
 for method parameters and return types. Use it where possible. Return type
 declaration is not always practical, but do try to make it work.
 
-At this time, shipped CI4 production code does not use 
-[Strict typing](https://www.php.net/manual/en/language.types.declarations.php#language.types.declarations.strict), 
-and will not be any time soon. However, in the development phase, 
-there are internal classes (in `utils/`) that are strictly typed.
+At this time, shipped CI4 production code does use
+[Strict typing](https://www.php.net/manual/en/language.types.declarations.php#language.types.declarations.strict)
+as much as possible.
 
 ## Abstractions
 

rector.php

@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 /**
  * This file is part of CodeIgniter 4 framework.
  *
@@ -43,6 +45,7 @@
 use Rector\Set\ValueObject\LevelSetList;
 use Rector\Set\ValueObject\SetList;
 use Rector\Strict\Rector\If_\BooleanInIfConditionRuleFixerRector;
+use Rector\TypeDeclaration\Rector\StmtsAwareInterface\DeclareStrictTypesRector;
 use Utils\Rector\PassStrictParameterToFunctionParameterRector;
 use Utils\Rector\RemoveErrorSuppressInTryCatchStmtsRector;
 use Utils\Rector\UnderscoreToCamelCaseVariableNameRector;
@@ -106,6 +109,19 @@
  __DIR__ . '/system/Session/Handlers',
  ],
 
+ DeclareStrictTypesRector::class => [
+ __DIR__ . '/app',
+ __DIR__ . '/system/CodeIgniter.php',
+ __DIR__ . '/system/Config/BaseConfig.php',
+ __DIR__ . '/system/Commands/Generators/Views',
+ __DIR__ . '/system/Pager/Views',
+ __DIR__ . '/system/Test/ControllerTestTrait.php',
+ __DIR__ . '/system/Validation/Views',
+ __DIR__ . '/system/View/Parser.php',
+ __DIR__ . '/tests/system/Debug/ExceptionsTest.php',
+ __DIR__ . '/tests/system/View/Views',
+ ],
+
  // use mt_rand instead of random_int on purpose on non-cryptographically random
  RandomFunctionRector::class,
 
@@ -116,6 +132,7 @@
  $rectorConfig->importNames();
  $rectorConfig->removeUnusedImports();
 
+ $rectorConfig->rule(DeclareStrictTypesRector::class);
  $rectorConfig->rule(UnderscoreToCamelCaseVariableNameRector::class);
  $rectorConfig->rule(SimplifyUselessVariableRector::class);
  $rectorConfig->rule(RemoveAlwaysElseRector::class);

system/API/ResponseTrait.php

@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 /**
  * This file is part of CodeIgniter 4 framework.
  *

system/Autoloader/Autoloader.php

@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 /**
  * This file is part of CodeIgniter 4 framework.
  *

system/Autoloader/FileLocator.php

@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 /**
  * This file is part of CodeIgniter 4 framework.
  *

system/Autoloader/FileLocatorCached.php

@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 /**
  * This file is part of CodeIgniter 4 framework.
  *

system/Autoloader/FileLocatorInterface.php

@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 /**
  * This file is part of CodeIgniter 4 framework.
  *

system/BaseModel.php

@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 /**
  * This file is part of CodeIgniter 4 framework.
  *

system/CLI/BaseCommand.php

@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 /**
  * This file is part of CodeIgniter 4 framework.
  *

system/CLI/CLI.php

@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 /**
  * This file is part of CodeIgniter 4 framework.
  *

system/CLI/Commands.php

@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 /**
  * This file is part of CodeIgniter 4 framework.
  *

system/CLI/Console.php

@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 /**
  * This file is part of CodeIgniter 4 framework.
  *

system/CLI/Exceptions/CLIException.php

@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 /**
  * This file is part of CodeIgniter 4 framework.
  *

system/CLI/GeneratorTrait.php

@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 /**
  * This file is part of CodeIgniter 4 framework.
  *

system/Cache/CacheFactory.php

@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 /**
  * This file is part of CodeIgniter 4 framework.
  *

system/Cache/CacheInterface.php

@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 /**
  * This file is part of CodeIgniter 4 framework.
  *

system/Cache/Exceptions/CacheException.php

@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 /**
  * This file is part of CodeIgniter 4 framework.
  *

system/Cache/Exceptions/ExceptionInterface.php

@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 /**
  * This file is part of CodeIgniter 4 framework.
  *

system/Cache/FactoriesCache.php

@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 /**
  * This file is part of CodeIgniter 4 framework.
  *

system/Cache/FactoriesCache/FileVarExportHandler.php

@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 /**
  * This file is part of CodeIgniter 4 framework.
  *

system/Cache/Handlers/BaseHandler.php

@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 /**
  * This file is part of CodeIgniter 4 framework.
  *

system/Cache/Handlers/DummyHandler.php

@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 /**
  * This file is part of CodeIgniter 4 framework.
  *

system/Cache/Handlers/FileHandler.php

@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 /**
  * This file is part of CodeIgniter 4 framework.
  *

system/Cache/Handlers/MemcachedHandler.php

@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 /**
  * This file is part of CodeIgniter 4 framework.
  *

system/Cache/Handlers/PredisHandler.php

@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 /**
  * This file is part of CodeIgniter 4 framework.
  *

system/Cache/Handlers/RedisHandler.php

@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 /**
  * This file is part of CodeIgniter 4 framework.
  *

system/Cache/Handlers/WincacheHandler.php

@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 /**
  * This file is part of CodeIgniter 4 framework.
  *

system/Cache/ResponseCache.php

@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 /**
  * This file is part of CodeIgniter 4 framework.
  *

system/CodeIgniter.php

@@ -919,6 +919,8 @@ protected function runController($class)
  // This is a Web request or PHP CLI request
  $params = $this->router->params();
 
+ // The controller method param types may not be string.
+ // So cannot set `declare(strict_types=1)` in this file.
  $output = method_exists($class, '_remap')
  ? $class->_remap($this->method, ...$params)
  : $class->{$this->method}(...$params);

system/Commands/Cache/ClearCache.php

@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 /**
  * This file is part of CodeIgniter 4 framework.
  *

system/Commands/Cache/InfoCache.php

@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 /**
  * This file is part of CodeIgniter 4 framework.
  *

system/Commands/Database/CreateDatabase.php

@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 /**
  * This file is part of CodeIgniter 4 framework.
  *

system/Commands/Database/Migrate.php

@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 /**
  * This file is part of CodeIgniter 4 framework.
  *

system/Commands/Database/MigrateRefresh.php

@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 /**
  * This file is part of CodeIgniter 4 framework.
  *

system/Commands/Database/MigrateRollback.php

@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 /**
  * This file is part of CodeIgniter 4 framework.
  *

system/Commands/Database/MigrateStatus.php

@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 /**
  * This file is part of CodeIgniter 4 framework.
  *

system/Commands/Database/Seed.php

@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 /**
  * This file is part of CodeIgniter 4 framework.
  *

system/Commands/Database/ShowTableInfo.php

@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 /**
  * This file is part of CodeIgniter 4 framework.
  *

system/Commands/Encryption/GenerateKey.php

@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 /**
  * This file is part of CodeIgniter 4 framework.
  *

system/Commands/Generators/CellGenerator.php

@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 /**
  * This file is part of CodeIgniter 4 framework.
  *

system/Commands/Generators/CommandGenerator.php

@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 /**
  * This file is part of CodeIgniter 4 framework.
  *

system/Commands/Generators/ConfigGenerator.php

@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 /**
  * This file is part of CodeIgniter 4 framework.
  *

system/Commands/Generators/ControllerGenerator.php

@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 /**
  * This file is part of CodeIgniter 4 framework.
  *

system/Commands/Generators/EntityGenerator.php

@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 /**
  * This file is part of CodeIgniter 4 framework.
  *

contributing/internals.md

@@ -29,10 +29,9 @@ PHP7 provides [Type declarations](https://www.php.net/manual/en/language.types.d
 for method parameters and return types. Use it where possible. Return type
 declaration is not always practical, but do try to make it work.
 
-At this time, shipped CI4 production code does not use 
-[Strict typing](https://www.php.net/manual/en/language.types.declarations.php#language.types.declarations.strict), 
-and will not be any time soon. However, in the development phase, 
-there are internal classes (in `utils/`) that are strictly typed.
+At this time, shipped CI4 production code does use
+[Strict typing](https://www.php.net/manual/en/language.types.declarations.php#language.types.declarations.strict)
+as much as possible.
 
 ## Abstractions
 

rector.php

@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 /**
  * This file is part of CodeIgniter 4 framework.
  *
@@ -43,6 +45,7 @@
 use Rector\Set\ValueObject\LevelSetList;
 use Rector\Set\ValueObject\SetList;
 use Rector\Strict\Rector\If_\BooleanInIfConditionRuleFixerRector;
+use Rector\TypeDeclaration\Rector\StmtsAwareInterface\DeclareStrictTypesRector;
 use Utils\Rector\PassStrictParameterToFunctionParameterRector;
 use Utils\Rector\RemoveErrorSuppressInTryCatchStmtsRector;
 use Utils\Rector\UnderscoreToCamelCaseVariableNameRector;
@@ -106,6 +109,19 @@
  __DIR__ . '/system/Session/Handlers',
  ],
 
+ DeclareStrictTypesRector::class => [
+ __DIR__ . '/app',
+ __DIR__ . '/system/CodeIgniter.php',
+ __DIR__ . '/system/Config/BaseConfig.php',
+ __DIR__ . '/system/Commands/Generators/Views',
+ __DIR__ . '/system/Pager/Views',
+ __DIR__ . '/system/Test/ControllerTestTrait.php',
+ __DIR__ . '/system/Validation/Views',
+ __DIR__ . '/system/View/Parser.php',
+ __DIR__ . '/tests/system/Debug/ExceptionsTest.php',
+ __DIR__ . '/tests/system/View/Views',
+ ],
+
  // use mt_rand instead of random_int on purpose on non-cryptographically random
  RandomFunctionRector::class,
 
@@ -116,6 +132,7 @@
  $rectorConfig->importNames();
  $rectorConfig->removeUnusedImports();
 
+ $rectorConfig->rule(DeclareStrictTypesRector::class);
  $rectorConfig->rule(UnderscoreToCamelCaseVariableNameRector::class);
  $rectorConfig->rule(SimplifyUselessVariableRector::class);
  $rectorConfig->rule(RemoveAlwaysElseRector::class);

system/API/ResponseTrait.php

@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 /**
  * This file is part of CodeIgniter 4 framework.
  *

system/Autoloader/Autoloader.php

@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 /**
  * This file is part of CodeIgniter 4 framework.
  *

system/Autoloader/FileLocator.php

@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 /**
  * This file is part of CodeIgniter 4 framework.
  *

system/Autoloader/FileLocatorCached.php

@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 /**
  * This file is part of CodeIgniter 4 framework.
  *

system/Autoloader/FileLocatorInterface.php

@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 /**
  * This file is part of CodeIgniter 4 framework.
  *

system/BaseModel.php

@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 /**
  * This file is part of CodeIgniter 4 framework.
  *

system/CLI/BaseCommand.php

@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 /**
  * This file is part of CodeIgniter 4 framework.
  *

system/CLI/CLI.php

@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 /**
  * This file is part of CodeIgniter 4 framework.
  *

system/CLI/Commands.php

@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 /**
  * This file is part of CodeIgniter 4 framework.
  *

system/CLI/Console.php

@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 /**
  * This file is part of CodeIgniter 4 framework.
  *

system/CLI/Exceptions/CLIException.php

@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 /**
  * This file is part of CodeIgniter 4 framework.
  *

system/CLI/GeneratorTrait.php

@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 /**
  * This file is part of CodeIgniter 4 framework.
  *

system/Cache/CacheFactory.php

@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 /**
  * This file is part of CodeIgniter 4 framework.
  *

system/Cache/CacheInterface.php

@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 /**
  * This file is part of CodeIgniter 4 framework.
  *

system/Cache/Exceptions/CacheException.php

@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 /**
  * This file is part of CodeIgniter 4 framework.
  *

system/Cache/Exceptions/ExceptionInterface.php

@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 /**
  * This file is part of CodeIgniter 4 framework.
  *

system/Cache/FactoriesCache.php

@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 /**
  * This file is part of CodeIgniter 4 framework.
  *

system/Cache/FactoriesCache/FileVarExportHandler.php

@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 /**
  * This file is part of CodeIgniter 4 framework.
  *

system/Cache/Handlers/BaseHandler.php

@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 /**
  * This file is part of CodeIgniter 4 framework.
  *

system/Cache/Handlers/DummyHandler.php

@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 /**
  * This file is part of CodeIgniter 4 framework.
  *

system/Cache/Handlers/FileHandler.php

@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 /**
  * This file is part of CodeIgniter 4 framework.
  *

system/Cache/Handlers/MemcachedHandler.php

@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 /**
  * This file is part of CodeIgniter 4 framework.
  *

system/Cache/Handlers/PredisHandler.php

@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 /**
  * This file is part of CodeIgniter 4 framework.
  *

system/Cache/Handlers/RedisHandler.php

@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 /**
  * This file is part of CodeIgniter 4 framework.
  *

system/Cache/Handlers/WincacheHandler.php

@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 /**
  * This file is part of CodeIgniter 4 framework.
  *

system/Cache/ResponseCache.php

@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 /**
  * This file is part of CodeIgniter 4 framework.
  *

system/CodeIgniter.php

@@ -919,6 +919,8 @@ protected function runController($class)
  // This is a Web request or PHP CLI request
  $params = $this->router->params();
 
+ // The controller method param types may not be string.
+ // So cannot set `declare(strict_types=1)` in this file.
  $output = method_exists($class, '_remap')
  ? $class->_remap($this->method, ...$params)
  : $class->{$this->method}(...$params);

system/Commands/Cache/ClearCache.php

@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 /**
  * This file is part of CodeIgniter 4 framework.
  *

system/Commands/Cache/InfoCache.php

@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 /**
  * This file is part of CodeIgniter 4 framework.
  *

system/Commands/Database/CreateDatabase.php

@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 /**
  * This file is part of CodeIgniter 4 framework.
  *

system/Commands/Database/Migrate.php

@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 /**
  * This file is part of CodeIgniter 4 framework.
  *

system/Commands/Database/MigrateRefresh.php

@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 /**
  * This file is part of CodeIgniter 4 framework.
  *

system/Commands/Database/MigrateRollback.php

@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 /**
  * This file is part of CodeIgniter 4 framework.
  *

system/Commands/Database/MigrateStatus.php

@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 /**
  * This file is part of CodeIgniter 4 framework.
  *

system/Commands/Database/Seed.php

@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 /**
  * This file is part of CodeIgniter 4 framework.
  *

system/Commands/Database/ShowTableInfo.php

@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 /**
  * This file is part of CodeIgniter 4 framework.
  *

system/Commands/Encryption/GenerateKey.php

@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 /**
  * This file is part of CodeIgniter 4 framework.
  *

system/Commands/Generators/CellGenerator.php

@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 /**
  * This file is part of CodeIgniter 4 framework.
  *

system/Commands/Generators/CommandGenerator.php

@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 /**
  * This file is part of CodeIgniter 4 framework.
  *

system/Commands/Generators/ConfigGenerator.php

@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 /**
  * This file is part of CodeIgniter 4 framework.
  *

system/Commands/Generators/ControllerGenerator.php

@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 /**
  * This file is part of CodeIgniter 4 framework.
  *

system/Commands/Generators/EntityGenerator.php

@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 /**
  * This file is part of CodeIgniter 4 framework.
  *

contributing/internals.md

@@ -29,10 +29,9 @@ PHP7 provides [Type declarations](https://www.php.net/manual/en/language.types.d
 for method parameters and return types. Use it where possible. Return type
 declaration is not always practical, but do try to make it work.
 
-At this time, shipped CI4 production code does not use 
-[Strict typing](https://www.php.net/manual/en/language.types.declarations.php#language.types.declarations.strict), 
-and will not be any time soon. However, in the development phase, 
-there are internal classes (in `utils/`) that are strictly typed.
+At this time, shipped CI4 production code does use
+[Strict typing](https://www.php.net/manual/en/language.types.declarations.php#language.types.declarations.strict)
+as much as possible.
 
 ## Abstractions
 

rector.php

@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 /**
  * This file is part of CodeIgniter 4 framework.
  *
@@ -43,6 +45,7 @@
 use Rector\Set\ValueObject\LevelSetList;
 use Rector\Set\ValueObject\SetList;
 use Rector\Strict\Rector\If_\BooleanInIfConditionRuleFixerRector;
+use Rector\TypeDeclaration\Rector\StmtsAwareInterface\DeclareStrictTypesRector;
 use Utils\Rector\PassStrictParameterToFunctionParameterRector;
 use Utils\Rector\RemoveErrorSuppressInTryCatchStmtsRector;
 use Utils\Rector\UnderscoreToCamelCaseVariableNameRector;
@@ -106,6 +109,19 @@
  __DIR__ . '/system/Session/Handlers',
  ],
 
+ DeclareStrictTypesRector::class => [
+ __DIR__ . '/app',
+ __DIR__ . '/system/CodeIgniter.php',
+ __DIR__ . '/system/Config/BaseConfig.php',
+ __DIR__ . '/system/Commands/Generators/Views',
+ __DIR__ . '/system/Pager/Views',
+ __DIR__ . '/system/Test/ControllerTestTrait.php',
+ __DIR__ . '/system/Validation/Views',
+ __DIR__ . '/system/View/Parser.php',
+ __DIR__ . '/tests/system/Debug/ExceptionsTest.php',
+ __DIR__ . '/tests/system/View/Views',
+ ],
+
  // use mt_rand instead of random_int on purpose on non-cryptographically random
  RandomFunctionRector::class,
 
@@ -116,6 +132,7 @@
  $rectorConfig->importNames();
  $rectorConfig->removeUnusedImports();
 
+ $rectorConfig->rule(DeclareStrictTypesRector::class);
  $rectorConfig->rule(UnderscoreToCamelCaseVariableNameRector::class);
  $rectorConfig->rule(SimplifyUselessVariableRector::class);
  $rectorConfig->rule(RemoveAlwaysElseRector::class);

system/API/ResponseTrait.php

@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 /**
  * This file is part of CodeIgniter 4 framework.
  *

system/Autoloader/Autoloader.php

@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 /**
  * This file is part of CodeIgniter 4 framework.
  *

system/Autoloader/FileLocator.php

@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 /**
  * This file is part of CodeIgniter 4 framework.
  *

system/Autoloader/FileLocatorCached.php

@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 /**
  * This file is part of CodeIgniter 4 framework.
  *

system/Autoloader/FileLocatorInterface.php

@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 /**
  * This file is part of CodeIgniter 4 framework.
  *

system/BaseModel.php

@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 /**
  * This file is part of CodeIgniter 4 framework.
  *

system/CLI/BaseCommand.php

@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 /**
  * This file is part of CodeIgniter 4 framework.
  *

system/CLI/CLI.php

@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 /**
  * This file is part of CodeIgniter 4 framework.
  *

system/CLI/Commands.php

@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 /**
  * This file is part of CodeIgniter 4 framework.
  *

system/CLI/Console.php

@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 /**
  * This file is part of CodeIgniter 4 framework.
  *

system/CLI/Exceptions/CLIException.php

@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 /**
  * This file is part of CodeIgniter 4 framework.
  *

system/CLI/GeneratorTrait.php

@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 /**
  * This file is part of CodeIgniter 4 framework.
  *

system/Cache/CacheFactory.php

@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 /**
  * This file is part of CodeIgniter 4 framework.
  *

system/Cache/CacheInterface.php

@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 /**
  * This file is part of CodeIgniter 4 framework.
  *

system/Cache/Exceptions/CacheException.php

@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 /**
  * This file is part of CodeIgniter 4 framework.
  *

system/Cache/Exceptions/ExceptionInterface.php

@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 /**
  * This file is part of CodeIgniter 4 framework.
  *

system/Cache/FactoriesCache.php

@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 /**
  * This file is part of CodeIgniter 4 framework.
  *

system/Cache/FactoriesCache/FileVarExportHandler.php

@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 /**
  * This file is part of CodeIgniter 4 framework.
  *

system/Cache/Handlers/BaseHandler.php

@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 /**
  * This file is part of CodeIgniter 4 framework.
  *

system/Cache/Handlers/DummyHandler.php

@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 /**
  * This file is part of CodeIgniter 4 framework.
  *

system/Cache/Handlers/FileHandler.php

@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 /**
  * This file is part of CodeIgniter 4 framework.
  *

system/Cache/Handlers/MemcachedHandler.php

@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 /**
  * This file is part of CodeIgniter 4 framework.
  *

system/Cache/Handlers/PredisHandler.php

@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 /**
  * This file is part of CodeIgniter 4 framework.
  *

system/Cache/Handlers/RedisHandler.php

@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 /**
  * This file is part of CodeIgniter 4 framework.
  *

system/Cache/Handlers/WincacheHandler.php

@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 /**
  * This file is part of CodeIgniter 4 framework.
  *

system/Cache/ResponseCache.php

@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 /**
  * This file is part of CodeIgniter 4 framework.
  *

system/CodeIgniter.php

@@ -919,6 +919,8 @@ protected function runController($class)
  // This is a Web request or PHP CLI request
  $params = $this->router->params();
 
+ // The controller method param types may not be string.
+ // So cannot set `declare(strict_types=1)` in this file.
  $output = method_exists($class, '_remap')
  ? $class->_remap($this->method, ...$params)
  : $class->{$this->method}(...$params);

system/Commands/Cache/ClearCache.php

@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 /**
  * This file is part of CodeIgniter 4 framework.
  *

system/Commands/Cache/InfoCache.php

@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 /**
  * This file is part of CodeIgniter 4 framework.
  *

system/Commands/Database/CreateDatabase.php

@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 /**
  * This file is part of CodeIgniter 4 framework.
  *

system/Commands/Database/Migrate.php

@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 /**
  * This file is part of CodeIgniter 4 framework.
  *

system/Commands/Database/MigrateRefresh.php

@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 /**
  * This file is part of CodeIgniter 4 framework.
  *

system/Commands/Database/MigrateRollback.php

@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 /**
  * This file is part of CodeIgniter 4 framework.
  *

system/Commands/Database/MigrateStatus.php

@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 /**
  * This file is part of CodeIgniter 4 framework.
  *

system/Commands/Database/Seed.php

@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 /**
  * This file is part of CodeIgniter 4 framework.
  *

system/Commands/Database/ShowTableInfo.php

@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 /**
  * This file is part of CodeIgniter 4 framework.
  *

system/Commands/Encryption/GenerateKey.php

@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 /**
  * This file is part of CodeIgniter 4 framework.
  *

system/Commands/Generators/CellGenerator.php

@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 /**
  * This file is part of CodeIgniter 4 framework.
  *

system/Commands/Generators/CommandGenerator.php

@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 /**
  * This file is part of CodeIgniter 4 framework.
  *

system/Commands/Generators/ConfigGenerator.php

@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 /**
  * This file is part of CodeIgniter 4 framework.
  *

system/Commands/Generators/ControllerGenerator.php

@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 /**
  * This file is part of CodeIgniter 4 framework.
  *

system/Commands/Generators/EntityGenerator.php

@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 /**
  * This file is part of CodeIgniter 4 framework.
  *