Merge pull request #8693 from weirdan/fix-8267

Fixes https://github.com/vimeo/psalm/issues/8267

docs/running_psalm/issues/InvalidEnumCaseValue.md

@@ -75,3 +75,28 @@ enum Status: string
     case Open = "open";
 }
 ```
+
+## Case with a type that cannot back an enum
+
+Case type should be either `int` or `string`.
+
+```php
+<?php
+
+enum Status: int {
+    case Open = [];
+}
+```
+
+### How to fix
+
+Change the case value so that it's one of the allowed types (and matches the backing type)
+
+```php
+<?php
+
+enum Status: int
+{
+    case Open = 1;
+}
+```

src/Psalm/Internal/PhpVisitor/Reflector/ClassLikeNodeScanner.php

@@ -43,6 +43,7 @@ use Psalm\Issue\DuplicateConstant;
 use Psalm\Issue\DuplicateEnumCase;
 use Psalm\Issue\InvalidDocblock;
 use Psalm\Issue\InvalidEnumBackingType;
+use Psalm\Issue\InvalidEnumCaseValue;
 use Psalm\Issue\InvalidTypeImport;
 use Psalm\Issue\MissingDocblockType;
 use Psalm\Issue\ParseError;
@@ -314,17 +315,6 @@ class ClassLikeNodeScanner
             if ($node->scalarType) {
                 if ($node->scalarType->name === 'string' || $node->scalarType->name === 'int') {
                     $storage->enum_type = $node->scalarType->name;
-                } else {
-                    IssueBuffer::maybeAdd(
-                        new InvalidEnumBackingType(
-                            'Enums cannot be backed by ' . $node->scalarType->name . ', string or int expected',
-                            new CodeLocation($this->file_scanner, $node->scalarType),
-                            $fq_classlike_name
-                        )
-                    );
-                    $this->file_storage->has_visitor_issues = true;
-                    $storage->has_visitor_issues = true;
-                }
                     $storage->class_implements['backedenum'] = 'BackedEnum';
                     $storage->direct_class_interfaces['backedenum'] = 'BackedEnum';
                     $this->file_storage->required_interfaces['backedenum'] = 'BackedEnum';
@@ -336,6 +326,17 @@ class ClassLikeNodeScanner
                         'tryfrom'
                     );
                     $storage->appearing_method_ids['tryfrom'] = $storage->declaring_method_ids['tryfrom'];
+                } else {
+                    IssueBuffer::maybeAdd(
+                        new InvalidEnumBackingType(
+                            'Enums cannot be backed by ' . $node->scalarType->name . ', string or int expected',
+                            new CodeLocation($this->file_scanner, $node->scalarType),
+                            $fq_classlike_name
+                        )
+                    );
+                    $this->file_storage->has_visitor_issues = true;
+                    $storage->has_visitor_issues = true;
+                }
             }
 
             $this->codebase->scanner->queueClassLikeForScanning('UnitEnum');
@@ -710,7 +711,11 @@ class ClassLikeNodeScanner
             } elseif ($node_stmt instanceof PhpParser\Node\Stmt\EnumCase
                 && $node instanceof PhpParser\Node\Stmt\Enum_
             ) {
-                $this->visitEnumDeclaration($node_stmt, $storage, $fq_classlike_name);
+                $this->visitEnumDeclaration(
+                    $node_stmt,
+                    $storage,
+                    $fq_classlike_name
+                );
             }
         }
 
@@ -1364,6 +1369,8 @@ class ClassLikeNodeScanner
 
         $enum_value = null;
 
+        $case_location = new CodeLocation($this->file_scanner, $stmt);
+
         if ($stmt->expr !== null) {
             $case_type = SimpleTypeInferer::infer(
                 $this->codebase,
@@ -1381,8 +1388,12 @@ class ClassLikeNodeScanner
                 } elseif ($case_type->isSingleStringLiteral()) {
                     $enum_value = $case_type->getSingleStringLiteral()->value;
                 } else {
-                    throw new RuntimeException(
+                    IssueBuffer::maybeAdd(
-                        'Unexpected: case value for ' . $stmt->name->name . ' is ' . $case_type->getId()
+                        new InvalidEnumCaseValue(
+                            'Case of a backed enum should have either string or int value',
+                            $case_location,
+                            $fq_classlike_name
+                        )
                     );
                 }
             } else {
@@ -1390,7 +1401,6 @@ class ClassLikeNodeScanner
             }
         }
 
-        $case_location = new CodeLocation($this->file_scanner, $stmt);
 
         if (!isset($storage->enum_cases[$stmt->name->name])) {
             $case = new EnumCaseStorage(

tests/EnumTest.php

@@ -575,6 +575,16 @@ class EnumTest extends TestCase
                 'ignored_issues' => [],
                 'php_version' => '8.1',
             ],
+            'invalidCaseTypeForBackedEnum' => [
+                'code' => '<?php
+                    enum Status: int {
+                        case Open = [];
+                    }
+                ',
+                'error_message' => 'InvalidEnumCaseValue',
+                'ignored_issues' => [],
+                'php_version' => '8.1',
+            ],
             'duplicateValues' => [
                 'code' => '<?php
                     enum Status: string