Fix #458 - fully support optional array keys

src/Psalm/Checker/TypeChecker.php

@@ -57,6 +57,10 @@ class TypeChecker
             return true;
         }
 
+        if ($input_type->possibly_undefined && !$container_type->possibly_undefined) {
+            return false;
+        }
+
         foreach ($input_type->getTypes() as $input_type_part) {
             if ($input_type_part instanceof TNull && $ignore_null) {
                 continue;

src/Psalm/FileManipulation/FunctionDocblockManipulator.php

@@ -284,7 +284,7 @@ class FunctionDocblockManipulator
         if ($docblock) {
             $parsed_docblock = CommentChecker::parseDocComment((string)$docblock, null, true);
         } else {
-            $parsed_docblock = ['description' => ''];
+            $parsed_docblock = ['description' => '', 'specials' => []];
         }
 
         foreach ($this->new_phpdoc_param_types as $param_name => $phpdoc_type) {

src/Psalm/FunctionDocblockComment.php

@@ -55,7 +55,7 @@ class FunctionDocblockComment
     public $template_types = [];
 
     /**
-     * @var array<int, array{template_type: string, param_name: string, line_number: int}>
+     * @var array<int, array{template_type: string, param_name: string, line_number?: int}>
      */
     public $template_typeofs = [];
 }

src/Psalm/IssueBuffer.php

@@ -210,7 +210,7 @@ class IssueBuffer
     }
 
     /**
-     * @param array<int, array{severity: string, line_from: int, type: string, message: string,
+     * @param array<int, array{severity: string, line_from: int, line_to: int, type: string, message: string,
      *  file_name: string, file_path: string, snippet: string, from: int, to: int, snippet_from: int,
      *  snippet_to: int, column_from: int, column_to: int}> $issues_data
      *

src/Psalm/Type/Atomic/ObjectLike.php

@@ -154,6 +154,8 @@ class ObjectLike extends \Psalm\Type\Atomic
             throw new \UnexpectedValueException('$value_type should not be null here');
         }
 
+        $value_type->possibly_undefined = false;
+
         return $value_type;
     }
 
@@ -183,6 +185,8 @@ class ObjectLike extends \Psalm\Type\Atomic
             throw new \UnexpectedValueException('$value_type should not be null here');
         }
 
+        $value_type->possibly_undefined = false;
+
         return new TArray([Type::combineTypes($key_types), $value_type]);
     }
 

tests/ReturnTypeTest.php

@@ -464,6 +464,13 @@ class ReturnTypeTest extends TestCase
                 'assertions' => [],
                 'error_levels' => ['MixedAssignment', 'MixedArgument'],
             ],
+            'objectLikeArrayOptionalKeyReturn' => [
+                '<?php
+                    /** @return array{a: int, b?: int} */
+                    function foo() : array {
+                        return rand(0, 1) ? ["a" => 1, "b" => 2] : ["a" => 2];
+                    }',
+            ],
         ];
     }
 
@@ -710,6 +717,14 @@ class ReturnTypeTest extends TestCase
                     }',
                 'error_message' => 'InvalidReturnStatement',
             ],
+            'objectLikeArrayOptionalKeyWithNonOptionalReturn' => [
+                '<?php
+                    /** @return array{a: int, b: int} */
+                    function foo() : array {
+                        return rand(0, 1) ? ["a" => 1, "b" => 2] : ["a" => 2];
+                    }',
+                'error_message' => 'LessSpecificReturnStatement',
+            ],
         ];
     }
 }