diff --git a/dictionaries/scripts/update_signaturemap_from_other_tool.php b/dictionaries/scripts/update_signaturemap_from_other_tool.php
index e2547a58757..21fb61166d5 100644
--- a/dictionaries/scripts/update_signaturemap_from_other_tool.php
+++ b/dictionaries/scripts/update_signaturemap_from_other_tool.php
@@ -34,7 +34,7 @@
 
 foreach ($new_local as $name => $data) {
     if (!is_array($data)) {
-        throw new \UnexpectedValueException('bad data for ' . $name);
+        throw new UnexpectedValueException('bad data for ' . $name);
     }
     $return_type = array_shift($data);
     echo '\'' . str_replace("'", "\'", $name) . '\' => [\'' . str_replace("'", "\'", $return_type) . '\'';
diff --git a/examples/TemplateChecker.php b/examples/TemplateChecker.php
index 8e9e0792df8..f048d9b1a49 100644
--- a/examples/TemplateChecker.php
+++ b/examples/TemplateChecker.php
@@ -1,6 +1,7 @@
 <?php
 namespace Psalm\Examples\Template;
 
+use InvalidArgumentException;
 use PhpParser;
 use Psalm;
 use Psalm\CodeLocation;
@@ -12,6 +13,7 @@
 use Psalm\Internal\Analyzer\ClassLikeNameOptions;
 use Psalm\Internal\Analyzer\MethodAnalyzer;
 use Psalm\Internal\Analyzer\StatementsAnalyzer;
+use Psalm\Internal\Provider\NodeDataProvider;
 use Psalm\Node\Stmt\VirtualClass;
 use Psalm\Node\Stmt\VirtualClassMethod;
 use Psalm\Storage\MethodStorage;
@@ -48,7 +50,7 @@ public function analyze(?Context $file_context = null, ?Context $global_context
                 $matches = [];
 
                 if (!preg_match($first_line_regex, $variables_from, $matches)) {
-                    throw new \InvalidArgumentException('Could not interpret doc comment correctly');
+                    throw new InvalidArgumentException('Could not interpret doc comment correctly');
                 }
 
                 /** @psalm-suppress ArgumentTypeCoercion */
@@ -167,7 +169,7 @@ protected function checkWithViewClass(Context $context, array $stmts): void
 
         $statements_source = new StatementsAnalyzer(
             $view_method_analyzer,
-            new \Psalm\Internal\Provider\NodeDataProvider()
+            new NodeDataProvider()
         );
 
         $statements_source->analyze($pseudo_method_stmts, $context);
diff --git a/examples/TemplateScanner.php b/examples/TemplateScanner.php
index 86afa8766a4..f713dfcc8ac 100644
--- a/examples/TemplateScanner.php
+++ b/examples/TemplateScanner.php
@@ -1,6 +1,7 @@
 <?php
 namespace Psalm\Examples\Template;
 
+use InvalidArgumentException;
 use PhpParser;
 use Psalm;
 use Psalm\Checker\CommentChecker;
@@ -45,7 +46,7 @@ public function scan(
                 $matches = [];
 
                 if (!preg_match($first_line_regex, $variables_from, $matches)) {
-                    throw new \InvalidArgumentException('Could not interpret doc comment correctly');
+                    throw new InvalidArgumentException('Could not interpret doc comment correctly');
                 }
 
                 [$fq_class_name] = explode('::', $matches[1]);
diff --git a/examples/plugins/ClassUnqualifier.php b/examples/plugins/ClassUnqualifier.php
index f99a8bc64c9..be5555e82b5 100644
--- a/examples/plugins/ClassUnqualifier.php
+++ b/examples/plugins/ClassUnqualifier.php
@@ -2,8 +2,10 @@
 namespace Psalm\Example\Plugin;
 
 use Psalm\FileManipulation;
+use Psalm\Internal\Type\TypeTokenizer;
 use Psalm\Plugin\EventHandler\AfterClassLikeExistenceCheckInterface;
 use Psalm\Plugin\EventHandler\Event\AfterClassLikeExistenceCheckEvent;
+use function strpos;
 use function strtolower;
 use function implode;
 use function array_map;
@@ -25,8 +27,8 @@ public static function afterClassLikeExistenceCheck(
             return;
         }
 
-        if (\strpos($candidate_type, '\\' . $fq_class_name) !== false) {
-            $type_tokens = \Psalm\Internal\Type\TypeTokenizer::tokenize($candidate_type, false);
+        if (strpos($candidate_type, '\\' . $fq_class_name) !== false) {
+            $type_tokens = TypeTokenizer::tokenize($candidate_type, false);
 
             foreach ($type_tokens as &$type_token) {
                 if ($type_token[0] === ('\\' . $fq_class_name)
diff --git a/examples/plugins/FunctionCasingChecker.php b/examples/plugins/FunctionCasingChecker.php
index 6323251a8c6..ca74d9d4a3a 100644
--- a/examples/plugins/FunctionCasingChecker.php
+++ b/examples/plugins/FunctionCasingChecker.php
@@ -1,6 +1,7 @@
 <?php
 namespace Psalm\Example\Plugin;
 
+use Exception;
 use PhpParser;
 use PhpParser\Node\Expr\MethodCall;
 use PhpParser\Node\Expr\StaticCall;
@@ -8,6 +9,8 @@
 use Psalm\Checker\StatementsChecker;
 use Psalm\CodeLocation;
 use Psalm\FileManipulation;
+use Psalm\Issue\PluginIssue;
+use Psalm\IssueBuffer;
 use Psalm\Plugin\EventHandler\AfterFunctionCallAnalysisInterface;
 use Psalm\Plugin\EventHandler\AfterMethodCallAnalysisInterface;
 use Psalm\Plugin\EventHandler\Event\AfterFunctionCallAnalysisEvent;
@@ -49,7 +52,7 @@ public static function afterMethodCallAnalysis(AfterMethodCallAnalysisEvent $eve
             }
 
             if ($function_storage->cased_name !== (string)$expr->name) {
-                if (\Psalm\IssueBuffer::accepts(
+                if (IssueBuffer::accepts(
                     new IncorrectFunctionCasing(
                         'Function is incorrectly cased, expecting ' . $function_storage->cased_name,
                         new CodeLocation($statements_source, $expr->name)
@@ -59,15 +62,11 @@ public static function afterMethodCallAnalysis(AfterMethodCallAnalysisEvent $eve
                     // fall through
                 }
             }
-        } catch (\Exception $e) {
+        } catch (Exception $e) {
             // can throw if storage is missing
         }
     }
 
-    /**
-     * @param non-empty-string $function_id
-     * @param  FileManipulation[] $file_replacements
-     */
     public static function afterFunctionCallAnalysis(AfterFunctionCallAnalysisEvent $event): void
     {
         $expr = $event->getExpr();
@@ -93,7 +92,7 @@ public static function afterFunctionCallAnalysis(AfterFunctionCallAnalysisEvent
             $function_name_parts = explode('\\', $function_storage->cased_name);
 
             if (end($function_name_parts) !== end($expr->name->parts)) {
-                if (\Psalm\IssueBuffer::accepts(
+                if (IssueBuffer::accepts(
                     new IncorrectFunctionCasing(
                         'Function is incorrectly cased, expecting ' . $function_storage->cased_name,
                         new CodeLocation($statements_source, $expr->name)
@@ -103,12 +102,12 @@ public static function afterFunctionCallAnalysis(AfterFunctionCallAnalysisEvent
                     // fall through
                 }
             }
-        } catch (\Exception $e) {
+        } catch (Exception $e) {
             // can throw if storage is missing
         }
     }
 }
 
-class IncorrectFunctionCasing extends \Psalm\Issue\PluginIssue
+class IncorrectFunctionCasing extends PluginIssue
 {
 }
diff --git a/examples/plugins/PreventFloatAssignmentChecker.php b/examples/plugins/PreventFloatAssignmentChecker.php
index e19d1742fe4..cbd7d23243e 100644
--- a/examples/plugins/PreventFloatAssignmentChecker.php
+++ b/examples/plugins/PreventFloatAssignmentChecker.php
@@ -5,6 +5,8 @@
 use Psalm\Checker;
 use Psalm\CodeLocation;
 use Psalm\FileManipulation;
+use Psalm\Issue\PluginIssue;
+use Psalm\IssueBuffer;
 use Psalm\Plugin\EventHandler\AfterExpressionAnalysisInterface;
 use Psalm\Plugin\EventHandler\Event\AfterExpressionAnalysisEvent;
 
@@ -25,7 +27,7 @@ public static function afterExpressionAnalysis(AfterExpressionAnalysisEvent $eve
             && ($expr_type = $statements_source->getNodeTypeProvider()->getType($expr->expr))
             && $expr_type->hasFloat()
         ) {
-            if (\Psalm\IssueBuffer::accepts(
+            if (IssueBuffer::accepts(
                 new NoFloatAssignment(
                     'Don’t assign to floats',
                     new CodeLocation($statements_source, $expr)
@@ -40,5 +42,5 @@ public static function afterExpressionAnalysis(AfterExpressionAnalysisEvent $eve
     }
 }
 
-class NoFloatAssignment extends \Psalm\Issue\PluginIssue {
+class NoFloatAssignment extends PluginIssue {
 }
diff --git a/examples/plugins/StringChecker.php b/examples/plugins/StringChecker.php
index ae7b09aadec..91f0b79c55b 100644
--- a/examples/plugins/StringChecker.php
+++ b/examples/plugins/StringChecker.php
@@ -6,6 +6,9 @@
 use Psalm\Checker\StatementsChecker;
 use Psalm\CodeLocation;
 use Psalm\FileManipulation;
+use Psalm\Issue\InvalidClass;
+use Psalm\Issue\UndefinedMethod;
+use Psalm\IssueBuffer;
 use Psalm\Plugin\EventHandler\AfterExpressionAnalysisInterface;
 use Psalm\Plugin\EventHandler\Event\AfterExpressionAnalysisEvent;
 
@@ -29,8 +32,8 @@ public static function afterExpressionAnalysis(AfterExpressionAnalysisEvent $eve
             ) {
                 $absolute_class = preg_split('/[:]/', $expr->value)[0];
 
-                if (\Psalm\IssueBuffer::accepts(
-                    new \Psalm\Issue\InvalidClass(
+                if (IssueBuffer::accepts(
+                    new InvalidClass(
                         'Use ::class constants when representing class names',
                         new CodeLocation($statements_source, $expr),
                         $absolute_class
@@ -54,8 +57,8 @@ public static function afterExpressionAnalysis(AfterExpressionAnalysisEvent $eve
             $appearing_method_id = $codebase->getAppearingMethodId($method_id);
 
             if (!$appearing_method_id) {
-                if (\Psalm\IssueBuffer::accepts(
-                    new \Psalm\Issue\UndefinedMethod(
+                if (IssueBuffer::accepts(
+                    new UndefinedMethod(
                         'Method ' . $method_id . ' does not exist',
                         new CodeLocation($statements_source, $expr),
                         $method_id
diff --git a/examples/plugins/composer-based/echo-checker/EchoChecker.php b/examples/plugins/composer-based/echo-checker/EchoChecker.php
index 2bb8908d281..c75eac76a56 100644
--- a/examples/plugins/composer-based/echo-checker/EchoChecker.php
+++ b/examples/plugins/composer-based/echo-checker/EchoChecker.php
@@ -17,8 +17,6 @@ class EchoChecker implements AfterStatementAnalysisInterface
     /**
      * Called after a statement has been checked
      *
-     * @param  FileManipulation[]   $file_replacements
-     *
      * @return null|false
      */
     public static function afterStatementAnalysis(AfterStatementAnalysisEvent $event): ?bool {
diff --git a/psalm b/psalm
index 84684e60840..a633cb872ac 100755
--- a/psalm
+++ b/psalm
@@ -1,4 +1,7 @@
 #!/usr/bin/env php
 <?php
+
+use Psalm\Internal\Cli\Psalm;
+
 require_once __DIR__ . '/src/Psalm/Internal/Cli/Psalm.php';
-\Psalm\Internal\Cli\Psalm::run($argv);
+Psalm::run($argv);
diff --git a/psalm-language-server b/psalm-language-server
index edc1a161e85..a1869f329ab 100755
--- a/psalm-language-server
+++ b/psalm-language-server
@@ -1,4 +1,7 @@
 #!/usr/bin/env php
 <?php
+
+use Psalm\Internal\Cli\LanguageServer;
+
 require_once __DIR__ . '/src/Psalm/Internal/Cli/LanguageServer.php';
-\Psalm\Internal\Cli\LanguageServer::run($argv);
+LanguageServer::run($argv);
diff --git a/psalm-plugin b/psalm-plugin
index 7ab717dd7b9..6f7d7c5ece0 100755
--- a/psalm-plugin
+++ b/psalm-plugin
@@ -1,4 +1,7 @@
 #!/usr/bin/env php
 <?php
+
+use Psalm\Internal\Cli\Plugin;
+
 require_once __DIR__ . '/src/Psalm/Internal/Cli/Plugin.php';
-\Psalm\Internal\Cli\Plugin::run();
+Plugin::run();
diff --git a/psalm-refactor b/psalm-refactor
index 8848d6ba905..5bdd7f63b65 100755
--- a/psalm-refactor
+++ b/psalm-refactor
@@ -1,4 +1,7 @@
 #!/usr/bin/env php
 <?php
+
+use Psalm\Internal\Cli\Refactor;
+
 require_once __DIR__ . '/src/Psalm/Internal/Cli/Refactor.php';
-\Psalm\Internal\Cli\Refactor::run($argv);
+Refactor::run($argv);
diff --git a/psalter b/psalter
index 63f9db018c7..c36c93fec99 100755
--- a/psalter
+++ b/psalter
@@ -1,4 +1,7 @@
 #!/usr/bin/env php
 <?php
+
+use Psalm\Internal\Cli\Psalter;
+
 require_once __DIR__ . '/src/Psalm/Internal/Cli/Psalter.php';
-\Psalm\Internal\Cli\Psalter::run($argv);
+Psalter::run($argv);
diff --git a/scoper.inc.php b/scoper.inc.php
index 181c2bd1cf6..6dee3af89c1 100644
--- a/scoper.inc.php
+++ b/scoper.inc.php
@@ -1,5 +1,7 @@
 <?php
 
+use Composer\Autoload\ClassLoader;
+
 return [
     'patchers' => [
         function ($filePath, $prefix, $contents) {
@@ -79,7 +81,7 @@ function ($filePath, $prefix, $contents) {
         },
     ],
     'whitelist' => [
-        \Composer\Autoload\ClassLoader::class,
+        ClassLoader::class,
         'Psalm\*',
     ],
     'files-whitelist' => [
diff --git a/src/Psalm/Internal/Analyzer/Statements/Expression/Call/ArgumentAnalyzer.php b/src/Psalm/Internal/Analyzer/Statements/Expression/Call/ArgumentAnalyzer.php
index 4c6edd38264..84b777c7e20 100644
--- a/src/Psalm/Internal/Analyzer/Statements/Expression/Call/ArgumentAnalyzer.php
+++ b/src/Psalm/Internal/Analyzer/Statements/Expression/Call/ArgumentAnalyzer.php
@@ -658,7 +658,7 @@ private static function checkFunctionLikeTypeMatches(
     }
 
     /**
-     * @param TKeyedArray|TArray|TList|TClassStringMap $unpacked_atomic_array
+     * @param TKeyedArray|TArray|TList|TClassStringMap|null $unpacked_atomic_array
      * @return  null|false
      * @psalm-suppress ComplexMethod
      */
diff --git a/src/Psalm/Internal/Analyzer/Statements/Expression/Call/Method/AtomicMethodCallAnalyzer.php b/src/Psalm/Internal/Analyzer/Statements/Expression/Call/Method/AtomicMethodCallAnalyzer.php
index cb1b5fbbf01..33d6d173ac6 100644
--- a/src/Psalm/Internal/Analyzer/Statements/Expression/Call/Method/AtomicMethodCallAnalyzer.php
+++ b/src/Psalm/Internal/Analyzer/Statements/Expression/Call/Method/AtomicMethodCallAnalyzer.php
@@ -60,7 +60,7 @@
 class AtomicMethodCallAnalyzer extends CallAnalyzer
 {
     /**
-     * @param  TNamedObject|TTemplateParam $static_type
+     * @param  TNamedObject|TTemplateParam|null $static_type
      *
      * @psalm-suppress ComplexMethod it's really complex, but unavoidably so
      */
diff --git a/src/Psalm/Internal/Analyzer/Statements/Expression/Call/Method/ExistingAtomicMethodCallAnalyzer.php b/src/Psalm/Internal/Analyzer/Statements/Expression/Call/Method/ExistingAtomicMethodCallAnalyzer.php
index 2dc0c0592d5..bfb78e45750 100644
--- a/src/Psalm/Internal/Analyzer/Statements/Expression/Call/Method/ExistingAtomicMethodCallAnalyzer.php
+++ b/src/Psalm/Internal/Analyzer/Statements/Expression/Call/Method/ExistingAtomicMethodCallAnalyzer.php
@@ -48,7 +48,7 @@
 class ExistingAtomicMethodCallAnalyzer extends CallAnalyzer
 {
     /**
-     * @param  TNamedObject|TTemplateParam  $static_type
+     * @param  TNamedObject|TTemplateParam|null  $static_type
      * @param  list<PhpParser\Node\Arg> $args
      */
     public static function analyze(
diff --git a/src/Psalm/Internal/Analyzer/Statements/Expression/Call/Method/MethodCallReturnTypeFetcher.php b/src/Psalm/Internal/Analyzer/Statements/Expression/Call/Method/MethodCallReturnTypeFetcher.php
index 8f09b222b08..b94dc918d63 100644
--- a/src/Psalm/Internal/Analyzer/Statements/Expression/Call/Method/MethodCallReturnTypeFetcher.php
+++ b/src/Psalm/Internal/Analyzer/Statements/Expression/Call/Method/MethodCallReturnTypeFetcher.php
@@ -37,7 +37,7 @@
 class MethodCallReturnTypeFetcher
 {
     /**
-     * @param  TNamedObject|TTemplateParam  $static_type
+     * @param  TNamedObject|TTemplateParam|null  $static_type
      * @param list<PhpParser\Node\Arg> $args
      */
     public static function fetch(
diff --git a/src/Psalm/Internal/Cli/LanguageServer.php b/src/Psalm/Internal/Cli/LanguageServer.php
index 5d44a9a06b5..e8689ee968c 100644
--- a/src/Psalm/Internal/Cli/LanguageServer.php
+++ b/src/Psalm/Internal/Cli/LanguageServer.php
@@ -219,6 +219,7 @@ function (string $arg) use ($valid_long_options): void {
         $include_collector = new IncludeCollector();
 
         $first_autoloader = $include_collector->runAndCollect(
+            // we ignore the FQN because of a hack in scoper.inc that needs full path
             // phpcs:ignore SlevomatCodingStandard.Namespaces.ReferenceUsedNamesOnly.ReferenceViaFullyQualifiedName
             function () use ($current_dir, $options, $vendor_dir): ?\Composer\Autoload\ClassLoader {
                 return CliUtils::requireAutoloaders($current_dir, isset($options['r']), $vendor_dir);
diff --git a/src/Psalm/Internal/Cli/Psalm.php b/src/Psalm/Internal/Cli/Psalm.php
index f87b17bef17..36043f4cf89 100644
--- a/src/Psalm/Internal/Cli/Psalm.php
+++ b/src/Psalm/Internal/Cli/Psalm.php
@@ -211,6 +211,7 @@ public static function run(array $argv): void
 
         $include_collector = new IncludeCollector();
         $first_autoloader = $include_collector->runAndCollect(
+            // we ignore the FQN because of a hack in scoper.inc that needs full path
             // phpcs:ignore SlevomatCodingStandard.Namespaces.ReferenceUsedNamesOnly.ReferenceViaFullyQualifiedName
             function () use ($current_dir, $options, $vendor_dir): ?\Composer\Autoload\ClassLoader {
                 return CliUtils::requireAutoloaders($current_dir, isset($options['r']), $vendor_dir);
diff --git a/src/Psalm/Internal/Cli/Psalter.php b/src/Psalm/Internal/Cli/Psalter.php
index b04190e66a6..a29491475cf 100644
--- a/src/Psalm/Internal/Cli/Psalter.php
+++ b/src/Psalm/Internal/Cli/Psalter.php
@@ -202,6 +202,7 @@ public static function run(array $argv): void
 
         $include_collector = new IncludeCollector();
         $first_autoloader = $include_collector->runAndCollect(
+            // we ignore the FQN because of a hack in scoper.inc that needs full path
             // phpcs:ignore SlevomatCodingStandard.Namespaces.ReferenceUsedNamesOnly.ReferenceViaFullyQualifiedName
             function () use ($current_dir, $options, $vendor_dir): ?\Composer\Autoload\ClassLoader {
                 return CliUtils::requireAutoloaders($current_dir, isset($options['r']), $vendor_dir);
diff --git a/src/Psalm/Internal/Cli/Refactor.php b/src/Psalm/Internal/Cli/Refactor.php
index 8f0bd1f4223..1c87f4e84a2 100644
--- a/src/Psalm/Internal/Cli/Refactor.php
+++ b/src/Psalm/Internal/Cli/Refactor.php
@@ -177,6 +177,7 @@ function (string $arg) use ($valid_long_options): void {
 
         $include_collector = new IncludeCollector();
         $first_autoloader = $include_collector->runAndCollect(
+            // we ignore the FQN because of a hack in scoper.inc that needs full path
             // phpcs:ignore SlevomatCodingStandard.Namespaces.ReferenceUsedNamesOnly.ReferenceViaFullyQualifiedName
             function () use ($current_dir, $options, $vendor_dir): ?\Composer\Autoload\ClassLoader {
                 return CliUtils::requireAutoloaders($current_dir, isset($options['r']), $vendor_dir);
diff --git a/src/Psalm/Internal/Stubs/Generator/ClassLikeStubGenerator.php b/src/Psalm/Internal/Stubs/Generator/ClassLikeStubGenerator.php
index 20a7f4bb8a4..6bc81302b96 100644
--- a/src/Psalm/Internal/Stubs/Generator/ClassLikeStubGenerator.php
+++ b/src/Psalm/Internal/Stubs/Generator/ClassLikeStubGenerator.php
@@ -3,6 +3,8 @@
 namespace Psalm\Internal\Stubs\Generator;
 
 use PhpParser;
+use Psalm\Codebase;
+use Psalm\Internal\Codebase\ConstantTypeResolver;
 use Psalm\Node\Name\VirtualFullyQualified;
 use Psalm\Node\Stmt\VirtualClass;
 use Psalm\Node\Stmt\VirtualClassConst;
@@ -18,7 +20,10 @@
 use Psalm\Type;
 use Psalm\Type\Union;
 
+use ReflectionProperty;
+use UnexpectedValueException;
 use function array_slice;
+use function rtrim;
 
 class ClassLikeStubGenerator
 {
@@ -26,7 +31,7 @@ class ClassLikeStubGenerator
      * @return PhpParser\Node\Stmt\Class_|PhpParser\Node\Stmt\Interface_|PhpParser\Node\Stmt\Trait_
      */
     public static function getClassLikeNode(
-        \Psalm\Codebase $codebase,
+        Codebase $codebase,
         ClassLikeStorage $storage,
         string $classlike_name
     ) : PhpParser\Node\Stmt\ClassLike {
@@ -61,7 +66,7 @@ public static function getClassLikeNode(
             'comments' => $docblock->tags
                 ? [
                     new PhpParser\Comment\Doc(
-                        \rtrim($docblock->render('        '))
+                        rtrim($docblock->render('        '))
                     )
                 ]
                 : []
@@ -112,14 +117,14 @@ public static function getClassLikeNode(
     /**
      * @return list<PhpParser\Node\Stmt\ClassConst>
      */
-    private static function getConstantNodes(\Psalm\Codebase $codebase, ClassLikeStorage $storage): array
+    private static function getConstantNodes(Codebase $codebase, ClassLikeStorage $storage): array
     {
         $constant_nodes = [];
 
         foreach ($storage->constants as $constant_name => $constant_storage) {
             if ($constant_storage->unresolved_node) {
                 $type = new Union([
-                    \Psalm\Internal\Codebase\ConstantTypeResolver::resolve(
+                    ConstantTypeResolver::resolve(
                         $codebase->classlikes,
                         $constant_storage->unresolved_node
                     )
@@ -127,7 +132,7 @@ private static function getConstantNodes(\Psalm\Codebase $codebase, ClassLikeSto
             } elseif ($constant_storage->type) {
                 $type = $constant_storage->type;
             } else {
-                throw new \UnexpectedValueException('bad');
+                throw new UnexpectedValueException('bad');
             }
 
             $constant_nodes[] = new VirtualClassConst(
@@ -197,7 +202,7 @@ private static function getPropertyNodes(ClassLikeStorage $storage): array
                     'comments' => $docblock->tags
                         ? [
                             new PhpParser\Comment\Doc(
-                                \rtrim($docblock->render('        '))
+                                rtrim($docblock->render('        '))
                             )
                         ]
                         : []
@@ -220,14 +225,14 @@ private static function getMethodNodes(ClassLikeStorage $storage): array {
 
         foreach ($storage->methods as $method_storage) {
             if (!$method_storage->cased_name) {
-                throw new \UnexpectedValueException('very bad');
+                throw new UnexpectedValueException('very bad');
             }
 
             switch ($method_storage->visibility) {
-                case \ReflectionProperty::IS_PRIVATE:
+                case ReflectionProperty::IS_PRIVATE:
                     $flag = PhpParser\Node\Stmt\Class_::MODIFIER_PRIVATE;
                     break;
-                case \ReflectionProperty::IS_PROTECTED:
+                case ReflectionProperty::IS_PROTECTED:
                     $flag = PhpParser\Node\Stmt\Class_::MODIFIER_PROTECTED;
                     break;
                 default:
@@ -296,7 +301,7 @@ private static function getMethodNodes(ClassLikeStorage $storage): array {
                     'comments' => $docblock->tags
                         ? [
                             new PhpParser\Comment\Doc(
-                                \rtrim($docblock->render('        '))
+                                rtrim($docblock->render('        '))
                             )
                         ]
                         : []
diff --git a/src/Psalm/Internal/Stubs/Generator/StubsGenerator.php b/src/Psalm/Internal/Stubs/Generator/StubsGenerator.php
index d17b843d1c3..23b1ca16ef0 100644
--- a/src/Psalm/Internal/Stubs/Generator/StubsGenerator.php
+++ b/src/Psalm/Internal/Stubs/Generator/StubsGenerator.php
@@ -2,6 +2,10 @@
 
 namespace Psalm\Internal\Stubs\Generator;
 
+use Psalm\Codebase;
+use Psalm\Internal\Provider\ClassLikeStorageProvider;
+use Psalm\Internal\Provider\FileStorageProvider;
+use Psalm\Storage\FunctionLikeStorage;
 use Psalm\Type\Atomic\TAnonymousClassInstance;
 use Psalm\Type\Atomic\TArray;
 use Psalm\Type\Atomic\TArrayKey;
@@ -98,21 +102,25 @@
 use Psalm\Type;
 use Psalm\Type\Union;
 
+use UnexpectedValueException;
 use function dirname;
+use function is_int;
+use function rtrim;
+use function strpos;
 
 class StubsGenerator
 {
     public static function getAll(
-        \Psalm\Codebase $codebase,
-        \Psalm\Internal\Provider\ClassLikeStorageProvider $class_provider,
-        \Psalm\Internal\Provider\FileStorageProvider $file_provider
+        Codebase $codebase,
+        ClassLikeStorageProvider $class_provider,
+        FileStorageProvider $file_provider
     ): string {
         $namespaced_nodes = [];
 
         $psalm_base = dirname(__DIR__, 5);
 
         foreach ($class_provider->getAll() as $storage) {
-            if (\strpos($storage->name, 'Psalm\\') === 0) {
+            if (strpos($storage->name, 'Psalm\\') === 0) {
                 continue;
             }
 
@@ -146,13 +154,13 @@ public static function getAll(
 
         foreach ($codebase->functions->getAllStubbedFunctions() as $function_storage) {
             if ($function_storage->location
-                && \strpos($function_storage->location->file_path, $psalm_base) === 0
+                && strpos($function_storage->location->file_path, $psalm_base) === 0
             ) {
                 continue;
             }
 
             if (!$function_storage->cased_name) {
-                throw new \UnexpectedValueException('very bad');
+                throw new UnexpectedValueException('very bad');
             }
 
             $fq_name = $function_storage->cased_name;
@@ -192,7 +200,7 @@ public static function getAll(
         }
 
         foreach ($file_provider->getAll() as $file_storage) {
-            if (\strpos($file_storage->file_path, $psalm_base) === 0) {
+            if (strpos($file_storage->file_path, $psalm_base) === 0) {
                 continue;
             }
 
@@ -265,7 +273,7 @@ public static function getAll(
     }
 
     private static function getFunctionNode(
-        \Psalm\Storage\FunctionLikeStorage $function_storage,
+        FunctionLikeStorage $function_storage,
         string $function_name,
         string $namespace_name
     ) : PhpParser\Node\Stmt\Function_ {
@@ -327,7 +335,7 @@ private static function getFunctionNode(
                 'comments' => $docblock->tags
                     ? [
                         new PhpParser\Comment\Doc(
-                            \rtrim($docblock->render('        '))
+                            rtrim($docblock->render('        '))
                         )
                     ]
                     : []
@@ -338,7 +346,7 @@ private static function getFunctionNode(
     /**
      * @return list<PhpParser\Node\Param>
      */
-    public static function getFunctionParamNodes(\Psalm\Storage\FunctionLikeStorage $method_storage): array
+    public static function getFunctionParamNodes(FunctionLikeStorage $method_storage): array
     {
         $param_nodes = [];
 
@@ -379,7 +387,7 @@ public static function getParserTypeFromPsalmType(Union $type): ?PhpParser\NodeA
                 $identifier_string = $atomic_type->toPhpString(null, [], null, 8, 0);
 
                 if ($identifier_string === null) {
-                    throw new \UnexpectedValueException(
+                    throw new UnexpectedValueException(
                         $atomic_type->getId() . ' could not be converted to an identifier'
                     );
                 }
@@ -447,7 +455,7 @@ public static function getExpressionFromType(Union $type) : PhpParser\Node\Expr
                 foreach ($atomic_type->properties as $property_name => $property_type) {
                     if ($atomic_type->is_list) {
                         $key_type = null;
-                    } elseif (\is_int($property_name)) {
+                    } elseif (is_int($property_name)) {
                         $key_type = new VirtualLNumber($property_name);
                     } else {
                         $key_type = new VirtualString($property_name);
diff --git a/src/Psalm/Internal/Type/Comparator/UnionTypeComparator.php b/src/Psalm/Internal/Type/Comparator/UnionTypeComparator.php
index b60483522c1..bee00cdb7b1 100644
--- a/src/Psalm/Internal/Type/Comparator/UnionTypeComparator.php
+++ b/src/Psalm/Internal/Type/Comparator/UnionTypeComparator.php
@@ -486,7 +486,7 @@ private static function getTypeParts(
         $atomic_types = [];
         foreach ($union_type->getAtomicTypes() as $atomic_type) {
             if (!$atomic_type instanceof TTypeAlias) {
-                array_push($atomic_types, $atomic_type);
+                $atomic_types[] = $atomic_type;
                 continue;
             }
             $expanded = TypeExpander::expandAtomic(
@@ -499,7 +499,7 @@ private static function getTypeParts(
                 true
             );
             if ($expanded instanceof Atomic) {
-                array_push($atomic_types, $expanded);
+                $atomic_types[] = $expanded;
                 continue;
             }
 
diff --git a/src/Psalm/Internal/Type/TemplateStandinTypeReplacer.php b/src/Psalm/Internal/Type/TemplateStandinTypeReplacer.php
index e29f9d68fae..1dc6033b60e 100644
--- a/src/Psalm/Internal/Type/TemplateStandinTypeReplacer.php
+++ b/src/Psalm/Internal/Type/TemplateStandinTypeReplacer.php
@@ -657,7 +657,7 @@ private static function handleTemplateParamStandin(
                             if ($keyed_template instanceof TKeyedArray) {
                                 $key_type = $keyed_template->getGenericKeyType();
                             } elseif ($keyed_template instanceof TList) {
-                                $key_type = \Psalm\Type::getInt();
+                                $key_type = Type::getInt();
                             } else {
                                 $key_type = $keyed_template->type_params[0];
                             }
diff --git a/src/Psalm/Issue/IfThisIsMismatch.php b/src/Psalm/Issue/IfThisIsMismatch.php
index 9437a5b643e..c9bcba5dc45 100644
--- a/src/Psalm/Issue/IfThisIsMismatch.php
+++ b/src/Psalm/Issue/IfThisIsMismatch.php
@@ -4,6 +4,6 @@
 
 class IfThisIsMismatch extends CodeIssue
 {
-    const ERROR_LEVEL = 4;
-    const SHORTCODE = 300;
+    public const ERROR_LEVEL = 4;
+    public const SHORTCODE = 300;
 }