Endpoints with scalar return values have invalid return types

[discordier]

Jane version(s) affected: 7.6.1 (probably all)

Description

How to reproduce

consider openapi3.json with the following endpoint (irrelevant parts have been omitted):

{
  "paths": {
    "/api/create": {
      "post": {
        "responses": {
          "200": {
            "description": "Success",
            "content": {
              "application/json": {
                "schema": {
                  "type": "integer"
                }
              }
            }
          }
        }
      }
    }
  }
}

When running jane on this, the client will get generated with phpdoc like:

<?php

namespace Generated;

class Client extends \Generated\Runtime\Client\Client
{
    /**
     * @return null|\Psr\Http\Message\ResponseInterface
     */
    public function postCreate(/*...*/)
    {
        // ... deserialize code here will return something like 1.
    }
}

Note the missing int in the return types.

When now we run some tool like rector or the code style fixer on this, the return types will get propagated to native return types

<?php

namespace Generated;

class Client extends \Generated\Runtime\Client\Client
{
    public function postCreate(/*...*/): null|\Psr\Http\Message\ResponseInterface
    {
        // BUG: ... deserialize code here will return something like 1 and therefore throw an type error here.
    }
}

Possible Solution

I gave it a quick shot an implemented the following solution, I do not know however if the list of handled types is exhaustive:

--- src/Component/OpenApi3/Generator/Endpoint/GetTransformResponseBodyTrait.php	2024-04-11 18:03:41.526549347 +0200
+++ src/Component/OpenApi3/Generator/Endpoint/GetTransformResponseBodyTrait.php	2024-04-11 18:07:32.957080766 +0200
@@ -278,6 +278,7 @@
             $serializeStmt = new Expr\FuncCall(new Name('json_decode'), [
                 new Node\Arg(new Expr\Variable('body')),
             ]);
+            $returnType = $this->convertResponseType($schema);
         }
 
         $contentStatement = new Stmt\Return_($serializeStmt);
@@ -302,4 +303,30 @@
 
         return [$returnType, $throwType, $contentStatement];
     }
+
+    private function convertResponseType(Schema $schema): ?string
+    {
+        $type = $schema->getType();
+        $additionalProperties = $schema->getAdditionalProperties();
+
+        if (null === $type && null !== $schema->getEnum() && \count($schema->getEnum()) > 0) {
+            $type = 'string';
+        }
+
+        if ($additionalProperties instanceof Schema
+            && 'object' === $type
+            && 'string' === $additionalProperties->getType()) {
+            return 'string';
+        }
+
+        $convertArray = [
+            'string' => 'string',
+            'number' => 'float',
+            'boolean' => 'bool',
+            'integer' => 'int',
+            'array' => 'array',
+        ];
+
+        return $convertArray[$type] ?? null;
+    }
 }

The base code is derived from the parameter handling in the non body parameter generator:

janephp/src/Component/OpenApi3/Generator/Parameter/NonBodyParameterGenerator.php

Lines 173 to 198 in 5ff401d

	private function convertParameterType(Schema $schema): array
	{
	$type = $schema->getType();
	$additionalProperties = $schema->getAdditionalProperties();
	if (null === $type && null !== $schema->getEnum() && \count($schema->getEnum()) > 0) {
	$type = 'string';
	}
	if ($additionalProperties instanceof Schema
	&& 'object' === $type
	&& 'string' === $additionalProperties->getType()) {
	return ['string'];
	}
	$convertArray = [
	'string' => ['string'],
	'number' => ['float'],
	'boolean' => ['bool'],
	'integer' => ['int'],
	'array' => ['array'],
	'file' => ['string', 'resource', '\\' . StreamInterface::class],
	];
	return $convertArray[$type];
	}