Adding difference in detection between mixed[] and array

src/Rules/TypeHints/AbstractMissingTypeHintRule.php

@@ -4,6 +4,7 @@
 namespace TheCodingMachine\PHPStan\Rules\TypeHints;
 
 
+use phpDocumentor\Reflection\DocBlockFactory;
 use phpDocumentor\Reflection\Type;
 use phpDocumentor\Reflection\Types\Array_;
 use phpDocumentor\Reflection\Types\Boolean;
@@ -24,6 +25,8 @@
 use Roave\BetterReflection\Reflection\ReflectionFunction;
 use Roave\BetterReflection\Reflection\ReflectionMethod;
 use Roave\BetterReflection\Reflection\ReflectionParameter;
+use Roave\BetterReflection\TypesFinder\PhpDocumentor\NamespaceNodeToReflectionTypeContext;
+use Roave\BetterReflection\TypesFinder\ResolveTypes;
 
 abstract class AbstractMissingTypeHintRule implements Rule
 {
@@ -181,10 +184,12 @@ private function analyzeWithTypehint($context, Type $phpTypeHint, array $docBloc
                 }
 
                 if ($docblockTypehint->getValueType() instanceof Mixed_) {
-                    if ($context instanceof ReflectionParameter) {
-                        return sprintf('%s, parameter $%s type is "array". Please provide a more specific @param annotation. For instance: @param int[] $%s', $this->getContext($context), $context->getName(), $context->getName());
-                    } else {
-                        return sprintf('%s, return type is "array". Please provide a more specific @return annotation. For instance: @return int[]', $this->getContext($context));
+                    if (!$this->findExplicitMixedArray($context)) {
+                        if ($context instanceof ReflectionParameter) {
+                            return sprintf('%s, parameter $%s type is "array". Please provide a more specific @param annotation in the docblock. For instance: @param int[] $%s. Use @param mixed[] $%s if this is really an array of mixed values.', $this->getContext($context), $context->getName(), $context->getName(), $context->getName());
+                        } else {
+                            return sprintf('%s, return type is "array". Please provide a more specific @return annotation. For instance: @return int[]. Use @return mixed[] if this is really an array of mixed values.', $this->getContext($context));
+                        }
                     }
                 }
             }
@@ -193,6 +198,23 @@ private function analyzeWithTypehint($context, Type $phpTypeHint, array $docBloc
         return null;
     }
 
+    /**
+     * @param ReflectionParameter|ReflectionMethod|ReflectionFunction $context
+     * @return bool
+     */
+    private function findExplicitMixedArray($context) : bool
+    {
+        if ($context instanceof ReflectionParameter) {
+            $context = $context->getDeclaringFunction();
+        }
+
+        $docComment = $context->getDocComment();
+
+        // Very approximate solution: let's find in the whole docblock whether there is a mixed[] value or not.
+        // TODO: improve this to target precisely the parameter or return type.
+        return strpos($docComment, 'mixed[]') !== false;
+    }
+
     /**
      * @param ReflectionParameter|ReflectionMethod|ReflectionFunction $context
      * @param Type[] $docBlockTypeHints

tests/Rules/TypeHints/MissingTypeHintRuleInFunctionTest.php

@@ -64,6 +64,14 @@ public function testCheckCatchedException()
             [
                 'In function "mismatch", return type is type-hinted to "string" but the @return annotation says it is a "int". Please fix the @return annotation.',
                 52,
+            ],
+            [
+                'In function "test8", parameter $any_array type is "array". Please provide a more specific @param annotation in the docblock. For instance: @param int[] $any_array. Use @param mixed[] $any_array if this is really an array of mixed values.',
+                70,
+            ],
+            [
+                'In function "test8", return type is "array". Please provide a more specific @return annotation. For instance: @return int[]. Use @return mixed[] if this is really an array of mixed values.',
+                70,
             ],
 		]);
 	}

tests/Rules/TypeHints/data/typehints.php

@@ -53,3 +53,21 @@ function mismatch(?string $param): string
 {
 
 }
+
+/**
+ * @param mixed[] $any_array
+ * @return mixed[]
+ */
+function test7(array $any_array): array
+{
+
+}
+
+/**
+ * @param array $any_array
+ * @return array
+ */
+function test8(array $any_array): array
+{
+
+}