Allow opt-in to strict return type checking

vimeo · Nov 5, 2020 · 388e804 · 388e804
1 parent d47d817
commit 388e804
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Showing 4 changed files with 59 additions and 48 deletions.
diff --git a/config.xsd b/config.xsd
@@ -76,6 +76,7 @@
         <xs:attribute name="allowInternalNamedArgumentCalls" type="xs:boolean" default="true" />
         <xs:attribute name="allowNamedArgumentCalls" type="xs:boolean" default="true" />
         <xs:attribute name="reportInfo" type="xs:boolean" default="true" />
+        <xs:attribute name="restrictReturnTypes" type="xs:boolean" default="false" />
     </xs:complexType>
 
     <xs:complexType name="ProjectFilesType">

diff --git a/src/Psalm/Config.php b/src/Psalm/Config.php
@@ -433,6 +433,11 @@ class Config
      */
     public $resolve_from_config_file = true;
 
+    /**
+     * @var bool
+     */
+    public $restrict_return_types = false;
+
     /**
      * @var string[]
      */
@@ -835,6 +840,7 @@ private static function fromXmlAndPaths(string $base_dir, string $file_contents,
             'allowNamedArgumentCalls' => 'allow_named_arg_calls',
             'findUnusedPsalmSuppress' => 'find_unused_psalm_suppress',
             'reportInfo' => 'report_info',
+            'restrictReturnTypes' => 'restrict_return_types',
         ];
 
         foreach ($booleanAttributes as $xmlName => $internalName) {

diff --git a/src/Psalm/Internal/Analyzer/FunctionLike/ReturnTypeAnalyzer.php b/src/Psalm/Internal/Analyzer/FunctionLike/ReturnTypeAnalyzer.php
@@ -525,63 +525,68 @@ public static function verifyReturnType(
                         return false;
                     }
                 }
-            } elseif ($codebase->alter_code
-                && isset($project_analyzer->getIssuesToFix()['LessSpecificReturnType'])
-                && !in_array('LessSpecificReturnType', $suppressed_issues)
-                && !($function_like_storage instanceof MethodStorage && $function_like_storage->inheritdoc)
-            ) {
-                if (!UnionTypeComparator::isContainedBy(
+            } elseif (!$inferred_return_type->hasMixed()
+                && !UnionTypeComparator::isContainedBy(
                     $codebase,
                     $declared_return_type,
                     $inferred_return_type,
                     false,
                     false
-                )) {
-                    self::addOrUpdateReturnType(
-                        $function,
-                        $project_analyzer,
-                        $inferred_return_type,
-                        $source,
-                        $compatible_method_ids
-                            || (($project_analyzer->only_replace_php_types_with_non_docblock_types
-                                    || $unsafe_return_type)
-                                && $inferred_return_type->from_docblock),
-                        $function_like_storage
-                    );
-
-                    return null;
-                }
-            } elseif (!$inferred_return_type->hasMixed()
-                && ((!$inferred_return_type->isNullable() && $declared_return_type->isNullable())
-                    || (!$inferred_return_type->isFalsable() && $declared_return_type->isFalsable()))
+                )
             ) {
-                if ($function instanceof Function_
-                    || $function instanceof Closure
-                    || $function instanceof ArrowFunction
-                    || $function->isPrivate()
-                ) {
-                    $check_for_less_specific_type = true;
-                } elseif ($source instanceof StatementsAnalyzer) {
-                    if ($function_like_storage instanceof MethodStorage) {
-                        $check_for_less_specific_type = !$function_like_storage->overridden_somewhere;
+                if ($codebase->alter_code) {
+                    if (isset($project_analyzer->getIssuesToFix()['LessSpecificReturnType'])
+                        && !in_array('LessSpecificReturnType', $suppressed_issues)
+                        && !($function_like_storage instanceof MethodStorage && $function_like_storage->inheritdoc)
+                    ) {
+                        self::addOrUpdateReturnType(
+                            $function,
+                            $project_analyzer,
+                            $inferred_return_type,
+                            $source,
+                            $compatible_method_ids
+                                || (($project_analyzer->only_replace_php_types_with_non_docblock_types
+                                        || $unsafe_return_type)
+                                    && $inferred_return_type->from_docblock),
+                            $function_like_storage
+                        );
+                    }
+                } else {
+                    if ($function instanceof Function_
+                        || $function instanceof Closure
+                        || $function instanceof ArrowFunction
+                        || $function->isPrivate()
+                    ) {
+                        $check_for_less_specific_type = true;
+                    } elseif ($source instanceof StatementsAnalyzer) {
+                        if ($function_like_storage instanceof MethodStorage) {
+                            $check_for_less_specific_type = !$function_like_storage->overridden_somewhere;
+                        } else {
+                            $check_for_less_specific_type = false;
+                        }
                     } else {
                         $check_for_less_specific_type = false;
                     }
-                } else {
-                    $check_for_less_specific_type = false;
-                }
 
-                if ($check_for_less_specific_type) {
-                    if (IssueBuffer::accepts(
-                        new LessSpecificReturnType(
-                            'The inferred return type \'' . $inferred_return_type . '\' for ' . $cased_method_id .
-                                ' is more specific than the declared return type \'' . $declared_return_type . '\'',
-                            $return_type_location
-                        ),
-                        $suppressed_issues,
-                        !($function_like_storage instanceof MethodStorage && $function_like_storage->inheritdoc)
-                    )) {
-                        return false;
+                    if ($check_for_less_specific_type
+                        && (\Psalm\Config::getInstance()->restrict_return_types
+                            || (!$inferred_return_type->isNullable() && $declared_return_type->isNullable())
+                            || (!$inferred_return_type->isFalsable() && $declared_return_type->isFalsable()))
+                    ) {
+                        if (IssueBuffer::accepts(
+                            new LessSpecificReturnType(
+                                'The inferred return type \''
+                                    . $inferred_return_type->getId()
+                                    . '\' for ' . $cased_method_id
+                                    . ' is more specific than the declared return type \''
+                                    . $declared_return_type->getId() . '\'',
+                                $return_type_location
+                            ),
+                            $suppressed_issues,
+                            !($function_like_storage instanceof MethodStorage && $function_like_storage->inheritdoc)
+                        )) {
+                            return false;
+                        }
                     }
                 }
             }

diff --git a/tests/Template/ConditionalReturnTypeTest.php b/tests/Template/ConditionalReturnTypeTest.php
@@ -597,7 +597,6 @@ public static function ofType(string $type) {
                      * @template T of mixed|false|null
                      * @param T $i
                      * @return (T is false ? no-return : T is null ? no-return : T)
-                     * @psalm-suppress LessSpecificReturnType
                      */
                     function orThrow($i) {
                         if ($i === false || $i === null) {