Implement config type parsing

res/composer-schema.json

@@ -326,7 +326,7 @@
                 },
                 "github-protocols": {
                     "type": "array",
-                    "description": "A list of protocols to use for github.com clones, in priority order, defaults to [\"git\", \"https\", \"http\"].",
+                    "description": "A list of protocols to use for github.com clones, in priority order, defaults to [\"https\", \"ssh\", \"git\"].",
                     "items": {
                         "type": "string"
                     }

src/Composer/PHPStan/ConfigReturnTypeExtension.php

@@ -3,20 +3,39 @@
 namespace Composer\PHPStan;
 
 use Composer\Config;
+use Composer\Json\JsonFile;
 use PhpParser\Node\Expr\MethodCall;
 use PHPStan\Analyser\Scope;
 use PHPStan\Reflection\MethodReflection;
 use PHPStan\Reflection\ParametersAcceptorSelector;
 use PHPStan\Type\ArrayType;
 use PHPStan\Type\BooleanType;
+use PHPStan\Type\Constant\ConstantArrayType;
 use PHPStan\Type\Constant\ConstantStringType;
 use PHPStan\Type\DynamicMethodReturnTypeExtension;
+use PHPStan\Type\IntegerRangeType;
+use PHPStan\Type\IntegerType;
+use PHPStan\Type\MixedType;
 use PHPStan\Type\ObjectType;
 use PHPStan\Type\StringType;
 use PHPStan\Type\Type;
 use PHPStan\Type\TypeCombinator;
+use PHPStan\Type\UnionType;
 
-final class ConfigReturnTypeExtension implements DynamicMethodReturnTypeExtension {
+final class ConfigReturnTypeExtension implements DynamicMethodReturnTypeExtension
+{
+    /** @var array<string, \PHPStan\Type\Type> */
+    private $properties = [];
+
+    public function __construct()
+    {
+        $schema = JsonFile::parseJson(file_get_contents(__DIR__.'/../../../res/composer-schema.json'));
+        foreach ($schema['properties']['config']['properties'] as $prop => $conf) {
+            $type = $this->parseType($conf, $prop);
+
+            $this->properties[$prop] = $type;
+        }
+    }
 
     public function getClass(): string
     {
@@ -38,13 +57,115 @@ final class ConfigReturnTypeExtension implements DynamicMethodReturnTypeExtensio
 
         $keyType = $scope->getType($args[0]->value);
         if ($keyType instanceof ConstantStringType) {
-            if ($keyType->getValue() == 'allow-plugins') {
-                return TypeCombinator::addNull(
-                    new ArrayType(new StringType(), new BooleanType())
-                );
+            if (isset($this->properties[$keyType->getValue()])) {
+                return $this->properties[$keyType->getValue()];
             }
         }
 
         return ParametersAcceptorSelector::selectSingle($methodReflection->getVariants())->getReturnType();
     }
+
+    /**
+     * @param array<mixed> $types
+     */
+    private function parseType(array $def, string $path): Type
+    {
+        if (isset($def['type'])) {
+            $types = [];
+            foreach ((array) $def['type'] as $type) {
+                switch ($type) {
+                    case 'integer':
+                        if (in_array($path, ['process-timeout', 'cache-ttl', 'cache-files-ttl'], true)) {
+                            $types[] = IntegerRangeType::createAllGreaterThan(0);
+                        } else {
+                            $types[] = new IntegerType();
+                        }
+                        break;
+
+                    case 'string':
+                        if ($path === 'discard-changes') {
+                            $types[] = new ConstantStringType('stash');
+                        } elseif ($path === 'use-parent-dir') {
+                            $types[] = new ConstantStringType('prompt');
+                        } elseif ($path === 'store-auths') {
+                            $types[] = new ConstantStringType('prompt');
+                        } elseif ($path === 'platform-check') {
+                            $types[] = new ConstantStringType('php-only');
+                        } elseif ($path === 'github-protocols') {
+                            $types[] = new UnionType([new ConstantStringType('git'), new ConstantStringType('https'), new ConstantStringType('ssh'), new ConstantStringType('http')]);
+                        } elseif (str_starts_with($path, 'preferred-install')) {
+                            $types[] = new UnionType([new ConstantStringType('source'), new ConstantStringType('dist'), new ConstantStringType('auto')]);
+                        } else {
+                            $types[] = new StringType();
+                        }
+                        break;
+
+                    case 'boolean':
+                        $types[] = new BooleanType();
+                        break;
+
+                    case 'object':
+                        $addlPropType = null;
+                        if (isset($def['additionalProperties'])) {
+                            $addlPropType = $this->parseType($def['additionalProperties'], $path.'.additionalProperties');
+                        }
+
+                        if (isset($def['properties'])) {
+                            $keyNames = [];
+                            $valTypes = [];
+                            foreach ($def['properties'] as $propName => $propdef) {
+                                $keyNames[] = new ConstantStringType($propName);
+                                $valType = $this->parseType($propdef, $path.'.'.$propName);
+                                if (!isset($def['required']) || !in_array($propName, $def['required'])) {
+                                    $valType = TypeCombinator::addNull($valType);
+                                }
+                                $valTypes[] = $valType;
+                            }
+
+                            if ($addlPropType !== null) {
+                                $types[] = new ArrayType(TypeCombinator::union(new StringType(), ...$keyNames), TypeCombinator::union($addlPropType, ...$valTypes));
+                            } else {
+                                $types[] = new ConstantArrayType($keyNames, $valTypes);
+                            }
+                        } else {
+                            $types[] = new ArrayType(new StringType(), $addlPropType ?? new MixedType());
+                        }
+                        break;
+
+                    case 'array':
+                        if (isset($def['items'])) {
+                            $valType = $this->parseType($def['items'], $path.'.items');
+                        } else {
+                            $valType = new MixedType();
+                        }
+
+                        $types[] = new ArrayType(new IntegerType(), $valType);
+                        break;
+
+                    default:
+                        $types[] = new MixedType();
+                }
+            }
+        } elseif (isset($def['enum'])) {
+            $types[] = TypeCombinator::union(...array_map(function (string $value): ConstantStringType {
+                return new ConstantStringType($value);
+            }, $def['enum']));
+        } else {
+            $types = [new MixedType()];
+        }
+
+        $type = \count($types) === 1 ? $types[0] : TypeCombinator::union(...$types);
+
+        // allow-plugins defaults to null until July 1st 2022 for some BC hackery, but after that it is not nullable anymore
+        if ($path === 'allow-plugins' && time() < strtotime('2022-07-01')) {
+            $type = TypeCombinator::addNull($type);
+        }
+
+        // default null props
+        if (in_array($path, ['autoloader-suffix', 'gitlab-protocol'], true)) {
+            $type = TypeCombinator::addNull($type);
+        }
+
+        return $type;
+    }
 }