Conditional Relationships in API Resource breaks relationship endpoints

[helmroos]

Using Conditional Relationships in a API Resource class breaks the relationship self/related endpoints.

How to repro

1. Have two related models, e.g. Users and Team
2. In your UserSchema.php add the Team relationship like

use LaravelJsonApi\Eloquent\Fields\Relations\BelongsTo;

class UserSchema extends Schema
{
    public function fields(): array
    {
        return [
            ...
            BelongsTo::make('team'),
            ...
        ];
    }
}

3. Setup routes, the following endpoints should now work:

• /users/:id?include=team
• /users/:id/team
• /users/:id/relationships/team

4. Now define a UserResource.php like so

use Illuminate\Http\Request;
use LaravelJsonApi\Core\Resources\JsonApiResource;

class UserResource extends JsonApiResource
{

    ...
    
    public function relationships($request): iterable
    {
        return [
            $this->relation('team')),
        ];
    }

}

5. Try the three endpoints again, they should still work (3)
6. Now make the relationships in the UserResource conditional:

return [
    $this->when(1===1, $this->relation('team')),
];

7. Try the endpoints again, the relationship ones are now broken:

• /users/:id?include=team => ✅ 200 OK
• /users/:id/team => ☠️ 500 INTERNAL SERVER ERROR
• /users/:id/relationships/team => ☠️500 INTERNAL SERVER ERROR

Stacktrace

[2021-10-07 10:15:21] local.ERROR: Call to undefined method LaravelJsonApi\Core\Resources\ConditionalField::fieldName() {"userId":"2f667dda-026e-4c8a-9acf-9e48523a2059","exception":"[object] (Error(code: 0): Call to undefined method LaravelJsonApi\\Core\\Resources\\ConditionalField::fieldName() at /var/www/html/vendor/laravel-json-api/core/src/Core/Resources/JsonApiResource.php:262)
[stacktrace]
#0 /var/www/html/vendor/laravel-json-api/core/src/Core/Responses/Internal/RelatedResourceResponse.php(108): LaravelJsonApi\\Core\\Resources\\JsonApiResource->relationship()
#1 /var/www/html/vendor/laravel-json-api/core/src/Core/Responses/Internal/RelatedResourceResponse.php(97): LaravelJsonApi\\Core\\Responses\\Internal\\RelatedResourceResponse->metaForRelationship()
#2 /var/www/html/vendor/laravel-json-api/core/src/Core/Responses/Internal/RelatedResourceResponse.php(81): LaravelJsonApi\\Core\\Responses\\Internal\\RelatedResourceResponse->allMeta()
#3 /var/www/html/vendor/laravel-json-api/core/src/Core/Responses/RelatedResponse.php(110): LaravelJsonApi\\Core\\Responses\\Internal\\RelatedResourceResponse->toResponse()
#4 /var/www/html/vendor/laravel/framework/src/Illuminate/Routing/Router.php(776): LaravelJsonApi\\Core\\Responses\\RelatedResponse->toResponse()
#5 /var/www/html/vendor/laravel/framework/src/Illuminate/Routing/Router.php(763): Illuminate\\Routing\\Router::toResponse()
#6 /var/www/html/vendor/laravel/framework/src/Illuminate/Routing/Router.php(695): Illuminate\\Routing\\Router->prepareResponse()
#7 /var/www/html/vendor/laravel/framework/src/Illuminate/Pipeline/Pipeline.php(128): Illuminate\\Routing\\Router->Illuminate\\Routing\\{closure}()
#8 /var/www/html/vendor/laravel-json-api/laravel/src/Http/Middleware/BootJsonApi.php(103): Illuminate\\Pipeline\\Pipeline->Illuminate\\Pipeline\\{closure}()
#9 /var/www/html/vendor/laravel/framework/src/Illuminate/Pipeline/Pipeline.php(167): LaravelJsonApi\\Laravel\\Http\\Middleware\\BootJsonApi->handle()
#10 /var/www/html/vendor/laravel/framework/src/Illuminate/Routing/Middleware/SubstituteBindings.php(50): Illuminate\\Pipeline\\Pipeline->Illuminate\\Pipeline\\{closure}()
#11 /var/www/html/vendor/laravel/framework/src/Illuminate/Pipeline/Pipeline.php(167): Illuminate\\Routing\\Middleware\\SubstituteBindings->handle()
#12 /var/www/html/vendor/laravel/framework/src/Illuminate/Auth/Middleware/Authenticate.php(44): Illuminate\\Pipeline\\Pipeline->Illuminate\\Pipeline\\{closure}()
#13 /var/www/html/vendor/laravel/framework/src/Illuminate/Pipeline/Pipeline.php(167): Illuminate\\Auth\\Middleware\\Authenticate->handle()
#14 /var/www/html/vendor/laravel/framework/src/Illuminate/Foundation/Http/Middleware/VerifyCsrfToken.php(78): Illuminate\\Pipeline\\Pipeline->Illuminate\\Pipeline\\{closure}()
#15 /var/www/html/vendor/laravel/framework/src/Illuminate/Pipeline/Pipeline.php(167): Illuminate\\Foundation\\Http\\Middleware\\VerifyCsrfToken->handle()
#16 /var/www/html/vendor/laravel/framework/src/Illuminate/View/Middleware/ShareErrorsFromSession.php(49): Illuminate\\Pipeline\\Pipeline->Illuminate\\Pipeline\\{closure}()
#17 /var/www/html/vendor/laravel/framework/src/Illuminate/Pipeline/Pipeline.php(167): Illuminate\\View\\Middleware\\ShareErrorsFromSession->handle()
#18 /var/www/html/vendor/laravel/framework/src/Illuminate/Session/Middleware/StartSession.php(121): Illuminate\\Pipeline\\Pipeline->Illuminate\\Pipeline\\{closure}()
#19 /var/www/html/vendor/laravel/framework/src/Illuminate/Session/Middleware/StartSession.php(64): Illuminate\\Session\\Middleware\\StartSession->handleStatefulRequest()
#20 /var/www/html/vendor/laravel/framework/src/Illuminate/Pipeline/Pipeline.php(167): Illuminate\\Session\\Middleware\\StartSession->handle()
#21 /var/www/html/vendor/laravel/framework/src/Illuminate/Cookie/Middleware/AddQueuedCookiesToResponse.php(37): Illuminate\\Pipeline\\Pipeline->Illuminate\\Pipeline\\{closure}()
#22 /var/www/html/vendor/laravel/framework/src/Illuminate/Pipeline/Pipeline.php(167): Illuminate\\Cookie\\Middleware\\AddQueuedCookiesToResponse->handle()
#23 /var/www/html/vendor/laravel/framework/src/Illuminate/Cookie/Middleware/EncryptCookies.php(67): Illuminate\\Pipeline\\Pipeline->Illuminate\\Pipeline\\{closure}()
#24 /var/www/html/vendor/laravel/framework/src/Illuminate/Pipeline/Pipeline.php(167): Illuminate\\Cookie\\Middleware\\EncryptCookies->handle()
#25 /var/www/html/vendor/laravel/framework/src/Illuminate/Pipeline/Pipeline.php(103): Illuminate\\Pipeline\\Pipeline->Illuminate\\Pipeline\\{closure}()
#26 /var/www/html/vendor/laravel/framework/src/Illuminate/Routing/Router.php(697): Illuminate\\Pipeline\\Pipeline->then()
#27 /var/www/html/vendor/laravel/framework/src/Illuminate/Routing/Router.php(672): Illuminate\\Routing\\Router->runRouteWithinStack()
#28 /var/www/html/vendor/laravel/framework/src/Illuminate/Routing/Router.php(636): Illuminate\\Routing\\Router->runRoute()
#29 /var/www/html/vendor/laravel/framework/src/Illuminate/Routing/Router.php(625): Illuminate\\Routing\\Router->dispatchToRoute()
#30 /var/www/html/vendor/laravel/framework/src/Illuminate/Foundation/Http/Kernel.php(166): Illuminate\\Routing\\Router->dispatch()
#31 /var/www/html/vendor/laravel/framework/src/Illuminate/Pipeline/Pipeline.php(128): Illuminate\\Foundation\\Http\\Kernel->Illuminate\\Foundation\\Http\\{closure}()
#32 /var/www/html/vendor/laravel/framework/src/Illuminate/Foundation/Http/Middleware/TransformsRequest.php(21): Illuminate\\Pipeline\\Pipeline->Illuminate\\Pipeline\\{closure}()
#33 /var/www/html/vendor/laravel/framework/src/Illuminate/Foundation/Http/Middleware/ConvertEmptyStringsToNull.php(31): Illuminate\\Foundation\\Http\\Middleware\\TransformsRequest->handle()
#34 /var/www/html/vendor/laravel/framework/src/Illuminate/Pipeline/Pipeline.php(167): Illuminate\\Foundation\\Http\\Middleware\\ConvertEmptyStringsToNull->handle()
#35 /var/www/html/vendor/laravel/framework/src/Illuminate/Foundation/Http/Middleware/TransformsRequest.php(21): Illuminate\\Pipeline\\Pipeline->Illuminate\\Pipeline\\{closure}()
#36 /var/www/html/vendor/laravel/framework/src/Illuminate/Foundation/Http/Middleware/TrimStrings.php(40): Illuminate\\Foundation\\Http\\Middleware\\TransformsRequest->handle()
#37 /var/www/html/vendor/laravel/framework/src/Illuminate/Pipeline/Pipeline.php(167): Illuminate\\Foundation\\Http\\Middleware\\TrimStrings->handle()
#38 /var/www/html/vendor/laravel/framework/src/Illuminate/Foundation/Http/Middleware/ValidatePostSize.php(27): Illuminate\\Pipeline\\Pipeline->Illuminate\\Pipeline\\{closure}()
#39 /var/www/html/vendor/laravel/framework/src/Illuminate/Pipeline/Pipeline.php(167): Illuminate\\Foundation\\Http\\Middleware\\ValidatePostSize->handle()
#40 /var/www/html/vendor/laravel/framework/src/Illuminate/Foundation/Http/Middleware/PreventRequestsDuringMaintenance.php(86): Illuminate\\Pipeline\\Pipeline->Illuminate\\Pipeline\\{closure}()
#41 /var/www/html/vendor/laravel/framework/src/Illuminate/Pipeline/Pipeline.php(167): Illuminate\\Foundation\\Http\\Middleware\\PreventRequestsDuringMaintenance->handle()
#42 /var/www/html/vendor/fruitcake/laravel-cors/src/HandleCors.php(52): Illuminate\\Pipeline\\Pipeline->Illuminate\\Pipeline\\{closure}()
#43 /var/www/html/vendor/laravel/framework/src/Illuminate/Pipeline/Pipeline.php(167): Fruitcake\\Cors\\HandleCors->handle()
#44 /var/www/html/vendor/fideloper/proxy/src/TrustProxies.php(57): Illuminate\\Pipeline\\Pipeline->Illuminate\\Pipeline\\{closure}()
#45 /var/www/html/vendor/laravel/framework/src/Illuminate/Pipeline/Pipeline.php(167): Fideloper\\Proxy\\TrustProxies->handle()
#46 /var/www/html/vendor/laravel/framework/src/Illuminate/Pipeline/Pipeline.php(103): Illuminate\\Pipeline\\Pipeline->Illuminate\\Pipeline\\{closure}()
#47 /var/www/html/vendor/laravel/framework/src/Illuminate/Foundation/Http/Kernel.php(141): Illuminate\\Pipeline\\Pipeline->then()
#48 /var/www/html/vendor/laravel/framework/src/Illuminate/Foundation/Http/Kernel.php(110): Illuminate\\Foundation\\Http\\Kernel->sendRequestThroughRouter()
#49 /var/www/html/public/index.php(52): Illuminate\\Foundation\\Http\\Kernel->handle()
#50 /var/www/html/server.php(21): require_once('...')
#51 {main}
"} 

Response

500 INTERNAL SERVER ERROR

{
    "jsonapi": {
        "version": "1.0"
    },
    "errors": [
        {
            "detail": "Call to undefined method LaravelJsonApi\\Core\\Resources\\ConditionalField::fieldName()",
            "meta": {
                "exception": "Error",
                "file": "/var/www/html/vendor/laravel-json-api/core/src/Core/Resources/JsonApiResource.php",
                "line": 262,
                "trace": [
                    {
                        "file": "/var/www/html/vendor/laravel-json-api/core/src/Core/Responses/Internal/RelatedResourceResponse.php",
                        "line": 108,
                        "function": "relationship",
                        "class": "LaravelJsonApi\\Core\\Resources\\JsonApiResource",
                        "type": "->"
                    },
                    {
                        "file": "/var/www/html/vendor/laravel-json-api/core/src/Core/Responses/Internal/RelatedResourceResponse.php",
                        "line": 97,
                        "function": "metaForRelationship",
                        "class": "LaravelJsonApi\\Core\\Responses\\Internal\\RelatedResourceResponse",
                        "type": "->"
                    },
                    {
                        "file": "/var/www/html/vendor/laravel-json-api/core/src/Core/Responses/Internal/RelatedResourceResponse.php",
                        "line": 81,
                        "function": "allMeta",
                        "class": "LaravelJsonApi\\Core\\Responses\\Internal\\RelatedResourceResponse",
                        "type": "->"
                    },
                    {
                        "file": "/var/www/html/vendor/laravel-json-api/core/src/Core/Responses/RelatedResponse.php",
                        "line": 110,
                        "function": "toResponse",
                        "class": "LaravelJsonApi\\Core\\Responses\\Internal\\RelatedResourceResponse",
                        "type": "->"
                    },
                    {
                        "file": "/var/www/html/vendor/laravel/framework/src/Illuminate/Routing/Router.php",
                        "line": 776,
                        "function": "toResponse",
                        "class": "LaravelJsonApi\\Core\\Responses\\RelatedResponse",
                        "type": "->"
                    },
                    {
                        "file": "/var/www/html/vendor/laravel/framework/src/Illuminate/Routing/Router.php",
                        "line": 763,
                        "function": "toResponse",
                        "class": "Illuminate\\Routing\\Router",
                        "type": "::"
                    },
                    {
                        "file": "/var/www/html/vendor/laravel/framework/src/Illuminate/Routing/Router.php",
                        "line": 695,
                        "function": "prepareResponse",
                        "class": "Illuminate\\Routing\\Router",
                        "type": "->"
                    },
                    {
                        "file": "/var/www/html/vendor/laravel/framework/src/Illuminate/Pipeline/Pipeline.php",
                        "line": 128,
                        "function": "Illuminate\\Routing\\{closure}",
                        "class": "Illuminate\\Routing\\Router",
                        "type": "->"
                    },
                    {
                        "file": "/var/www/html/vendor/laravel-json-api/laravel/src/Http/Middleware/BootJsonApi.php",
                        "line": 103,
                        "function": "Illuminate\\Pipeline\\{closure}",
                        "class": "Illuminate\\Pipeline\\Pipeline",
                        "type": "->"
                    },
                    {
                        "file": "/var/www/html/vendor/laravel/framework/src/Illuminate/Pipeline/Pipeline.php",
                        "line": 167,
                        "function": "handle",
                        "class": "LaravelJsonApi\\Laravel\\Http\\Middleware\\BootJsonApi",
                        "type": "->"
                    },
                    {
                        "file": "/var/www/html/vendor/laravel/framework/src/Illuminate/Routing/Middleware/SubstituteBindings.php",
                        "line": 50,
                        "function": "Illuminate\\Pipeline\\{closure}",
                        "class": "Illuminate\\Pipeline\\Pipeline",
                        "type": "->"
                    },
                    {
                        "file": "/var/www/html/vendor/laravel/framework/src/Illuminate/Pipeline/Pipeline.php",
                        "line": 167,
                        "function": "handle",
                        "class": "Illuminate\\Routing\\Middleware\\SubstituteBindings",
                        "type": "->"
                    },
                    {
                        "file": "/var/www/html/vendor/laravel/framework/src/Illuminate/Auth/Middleware/Authenticate.php",
                        "line": 44,
                        "function": "Illuminate\\Pipeline\\{closure}",
                        "class": "Illuminate\\Pipeline\\Pipeline",
                        "type": "->"
                    },
                    {
                        "file": "/var/www/html/vendor/laravel/framework/src/Illuminate/Pipeline/Pipeline.php",
                        "line": 167,
                        "function": "handle",
                        "class": "Illuminate\\Auth\\Middleware\\Authenticate",
                        "type": "->"
                    },
                    {
                        "file": "/var/www/html/vendor/laravel/framework/src/Illuminate/Foundation/Http/Middleware/VerifyCsrfToken.php",
                        "line": 78,
                        "function": "Illuminate\\Pipeline\\{closure}",
                        "class": "Illuminate\\Pipeline\\Pipeline",
                        "type": "->"
                    },
                    {
                        "file": "/var/www/html/vendor/laravel/framework/src/Illuminate/Pipeline/Pipeline.php",
                        "line": 167,
                        "function": "handle",
                        "class": "Illuminate\\Foundation\\Http\\Middleware\\VerifyCsrfToken",
                        "type": "->"
                    },
                    {
                        "file": "/var/www/html/vendor/laravel/framework/src/Illuminate/View/Middleware/ShareErrorsFromSession.php",
                        "line": 49,
                        "function": "Illuminate\\Pipeline\\{closure}",
                        "class": "Illuminate\\Pipeline\\Pipeline",
                        "type": "->"
                    },
                    {
                        "file": "/var/www/html/vendor/laravel/framework/src/Illuminate/Pipeline/Pipeline.php",
                        "line": 167,
                        "function": "handle",
                        "class": "Illuminate\\View\\Middleware\\ShareErrorsFromSession",
                        "type": "->"
                    },
                    {
                        "file": "/var/www/html/vendor/laravel/framework/src/Illuminate/Session/Middleware/StartSession.php",
                        "line": 121,
                        "function": "Illuminate\\Pipeline\\{closure}",
                        "class": "Illuminate\\Pipeline\\Pipeline",
                        "type": "->"
                    },
                    {
                        "file": "/var/www/html/vendor/laravel/framework/src/Illuminate/Session/Middleware/StartSession.php",
                        "line": 64,
                        "function": "handleStatefulRequest",
                        "class": "Illuminate\\Session\\Middleware\\StartSession",
                        "type": "->"
                    },
                    {
                        "file": "/var/www/html/vendor/laravel/framework/src/Illuminate/Pipeline/Pipeline.php",
                        "line": 167,
                        "function": "handle",
                        "class": "Illuminate\\Session\\Middleware\\StartSession",
                        "type": "->"
                    },
                    {
                        "file": "/var/www/html/vendor/laravel/framework/src/Illuminate/Cookie/Middleware/AddQueuedCookiesToResponse.php",
                        "line": 37,
                        "function": "Illuminate\\Pipeline\\{closure}",
                        "class": "Illuminate\\Pipeline\\Pipeline",
                        "type": "->"
                    },
                    {
                        "file": "/var/www/html/vendor/laravel/framework/src/Illuminate/Pipeline/Pipeline.php",
                        "line": 167,
                        "function": "handle",
                        "class": "Illuminate\\Cookie\\Middleware\\AddQueuedCookiesToResponse",
                        "type": "->"
                    },
                    {
                        "file": "/var/www/html/vendor/laravel/framework/src/Illuminate/Cookie/Middleware/EncryptCookies.php",
                        "line": 67,
                        "function": "Illuminate\\Pipeline\\{closure}",
                        "class": "Illuminate\\Pipeline\\Pipeline",
                        "type": "->"
                    },
                    {
                        "file": "/var/www/html/vendor/laravel/framework/src/Illuminate/Pipeline/Pipeline.php",
                        "line": 167,
                        "function": "handle",
                        "class": "Illuminate\\Cookie\\Middleware\\EncryptCookies",
                        "type": "->"
                    },
                    {
                        "file": "/var/www/html/vendor/laravel/framework/src/Illuminate/Pipeline/Pipeline.php",
                        "line": 103,
                        "function": "Illuminate\\Pipeline\\{closure}",
                        "class": "Illuminate\\Pipeline\\Pipeline",
                        "type": "->"
                    },
                    {
                        "file": "/var/www/html/vendor/laravel/framework/src/Illuminate/Routing/Router.php",
                        "line": 697,
                        "function": "then",
                        "class": "Illuminate\\Pipeline\\Pipeline",
                        "type": "->"
                    },
                    {
                        "file": "/var/www/html/vendor/laravel/framework/src/Illuminate/Routing/Router.php",
                        "line": 672,
                        "function": "runRouteWithinStack",
                        "class": "Illuminate\\Routing\\Router",
                        "type": "->"
                    },
                    {
                        "file": "/var/www/html/vendor/laravel/framework/src/Illuminate/Routing/Router.php",
                        "line": 636,
                        "function": "runRoute",
                        "class": "Illuminate\\Routing\\Router",
                        "type": "->"
                    },
                    {
                        "file": "/var/www/html/vendor/laravel/framework/src/Illuminate/Routing/Router.php",
                        "line": 625,
                        "function": "dispatchToRoute",
                        "class": "Illuminate\\Routing\\Router",
                        "type": "->"
                    },
                    {
                        "file": "/var/www/html/vendor/laravel/framework/src/Illuminate/Foundation/Http/Kernel.php",
                        "line": 166,
                        "function": "dispatch",
                        "class": "Illuminate\\Routing\\Router",
                        "type": "->"
                    },
                    {
                        "file": "/var/www/html/vendor/laravel/framework/src/Illuminate/Pipeline/Pipeline.php",
                        "line": 128,
                        "function": "Illuminate\\Foundation\\Http\\{closure}",
                        "class": "Illuminate\\Foundation\\Http\\Kernel",
                        "type": "->"
                    },
                    {
                        "file": "/var/www/html/vendor/laravel/framework/src/Illuminate/Foundation/Http/Middleware/TransformsRequest.php",
                        "line": 21,
                        "function": "Illuminate\\Pipeline\\{closure}",
                        "class": "Illuminate\\Pipeline\\Pipeline",
                        "type": "->"
                    },
                    {
                        "file": "/var/www/html/vendor/laravel/framework/src/Illuminate/Foundation/Http/Middleware/ConvertEmptyStringsToNull.php",
                        "line": 31,
                        "function": "handle",
                        "class": "Illuminate\\Foundation\\Http\\Middleware\\TransformsRequest",
                        "type": "->"
                    },
                    {
                        "file": "/var/www/html/vendor/laravel/framework/src/Illuminate/Pipeline/Pipeline.php",
                        "line": 167,
                        "function": "handle",
                        "class": "Illuminate\\Foundation\\Http\\Middleware\\ConvertEmptyStringsToNull",
                        "type": "->"
                    },
                    {
                        "file": "/var/www/html/vendor/laravel/framework/src/Illuminate/Foundation/Http/Middleware/TransformsRequest.php",
                        "line": 21,
                        "function": "Illuminate\\Pipeline\\{closure}",
                        "class": "Illuminate\\Pipeline\\Pipeline",
                        "type": "->"
                    },
                    {
                        "file": "/var/www/html/vendor/laravel/framework/src/Illuminate/Foundation/Http/Middleware/TrimStrings.php",
                        "line": 40,
                        "function": "handle",
                        "class": "Illuminate\\Foundation\\Http\\Middleware\\TransformsRequest",
                        "type": "->"
                    },
                    {
                        "file": "/var/www/html/vendor/laravel/framework/src/Illuminate/Pipeline/Pipeline.php",
                        "line": 167,
                        "function": "handle",
                        "class": "Illuminate\\Foundation\\Http\\Middleware\\TrimStrings",
                        "type": "->"
                    },
                    {
                        "file": "/var/www/html/vendor/laravel/framework/src/Illuminate/Foundation/Http/Middleware/ValidatePostSize.php",
                        "line": 27,
                        "function": "Illuminate\\Pipeline\\{closure}",
                        "class": "Illuminate\\Pipeline\\Pipeline",
                        "type": "->"
                    },
                    {
                        "file": "/var/www/html/vendor/laravel/framework/src/Illuminate/Pipeline/Pipeline.php",
                        "line": 167,
                        "function": "handle",
                        "class": "Illuminate\\Foundation\\Http\\Middleware\\ValidatePostSize",
                        "type": "->"
                    },
                    {
                        "file": "/var/www/html/vendor/laravel/framework/src/Illuminate/Foundation/Http/Middleware/PreventRequestsDuringMaintenance.php",
                        "line": 86,
                        "function": "Illuminate\\Pipeline\\{closure}",
                        "class": "Illuminate\\Pipeline\\Pipeline",
                        "type": "->"
                    },
                    {
                        "file": "/var/www/html/vendor/laravel/framework/src/Illuminate/Pipeline/Pipeline.php",
                        "line": 167,
                        "function": "handle",
                        "class": "Illuminate\\Foundation\\Http\\Middleware\\PreventRequestsDuringMaintenance",
                        "type": "->"
                    },
                    {
                        "file": "/var/www/html/vendor/fruitcake/laravel-cors/src/HandleCors.php",
                        "line": 52,
                        "function": "Illuminate\\Pipeline\\{closure}",
                        "class": "Illuminate\\Pipeline\\Pipeline",
                        "type": "->"
                    },
                    {
                        "file": "/var/www/html/vendor/laravel/framework/src/Illuminate/Pipeline/Pipeline.php",
                        "line": 167,
                        "function": "handle",
                        "class": "Fruitcake\\Cors\\HandleCors",
                        "type": "->"
                    },
                    {
                        "file": "/var/www/html/vendor/fideloper/proxy/src/TrustProxies.php",
                        "line": 57,
                        "function": "Illuminate\\Pipeline\\{closure}",
                        "class": "Illuminate\\Pipeline\\Pipeline",
                        "type": "->"
                    },
                    {
                        "file": "/var/www/html/vendor/laravel/framework/src/Illuminate/Pipeline/Pipeline.php",
                        "line": 167,
                        "function": "handle",
                        "class": "Fideloper\\Proxy\\TrustProxies",
                        "type": "->"
                    },
                    {
                        "file": "/var/www/html/vendor/laravel/framework/src/Illuminate/Pipeline/Pipeline.php",
                        "line": 103,
                        "function": "Illuminate\\Pipeline\\{closure}",
                        "class": "Illuminate\\Pipeline\\Pipeline",
                        "type": "->"
                    },
                    {
                        "file": "/var/www/html/vendor/laravel/framework/src/Illuminate/Foundation/Http/Kernel.php",
                        "line": 141,
                        "function": "then",
                        "class": "Illuminate\\Pipeline\\Pipeline",
                        "type": "->"
                    },
                    {
                        "file": "/var/www/html/vendor/laravel/framework/src/Illuminate/Foundation/Http/Kernel.php",
                        "line": 110,
                        "function": "sendRequestThroughRouter",
                        "class": "Illuminate\\Foundation\\Http\\Kernel",
                        "type": "->"
                    },
                    {
                        "file": "/var/www/html/public/index.php",
                        "line": 52,
                        "function": "handle",
                        "class": "Illuminate\\Foundation\\Http\\Kernel",
                        "type": "->"
                    },
                    {
                        "file": "/var/www/html/server.php",
                        "line": 21,
                        "function": "require_once"
                    }
                ]
            },
            "status": "500",
            "title": "Internal Server Error"
        }
    ]
}

Other details

I can repro both in PHPUnit and manually, using either a Web (Laravel Sanctum) or API (Laravel Passport) guard with the folllowing in composer.json:

• "laravel-json-api/laravel": "^1.0"
• "laravel-json-api/non-eloquent": "^1.0"
• "laravel/framework": "^8.40"
• "laravel/passport": "^10.1"
• "laravel/sanctum": "^2.11"

php -v:

PHP 8.0.11 (cli) (built: Sep 23 2021 21:26:42) ( NTS )
Copyright (c) The PHP Group
Zend Engine v4.0.11, Copyright (c) Zend Technologies
    with Zend OPcache v8.0.11, Copyright (c), by Zend Technologies
    with Xdebug v3.0.4, Copyright (c) 2002-2021, by Derick Rethans

[lindyhopchris]

Thanks for reporting.

[estuardoquan]

@helmroos any solution?

[lindyhopchris]

There's probably no work around for this - it needs me to have time to implement a fix, or for someone else to submit a PR fixing it.

[estuardoquan]

@lindyhopchris so I noticed that within the relationship method in theJsonApiResource Class, conditional relationships are given as a ConditionalField object and not as Relation Object... Barely fiddling with the code because I don't understand sh*t of what is going on (pardon my french) I managed to pass all the test (relationship endpoints) by re-writing the relationship method to...

/**
* Get a resource relation by name.
*
* @param string $name
* @return JsonApiRelation
*/
public function relationship(string $name): JsonApiRelation
{
   /** @var JsonApiRelation $relation */
   foreach ($this->relationships(null) as $relation) {
      $relation instanceof JsonApiRelation ?: $relation = ($relation)(); // Invoke (I think) ConditionalField class to return value
      if ($relation->fieldName() === $name) {
           return $relation;
      }
   }

    throw new LogicException(sprintf(
        'Unexpected relationship %s on resource %s.',
        $name,
        $this->type()
   ));
}

This works but I do not understand neither why, nor how... I would've thought that instead of calling ($relation)() I could've just called $relation->get() but this throws a serialization error... does this work around seem logical?

[lindyhopchris]

I think it should actually be checking whether $relation is conditional, and if its - resolve it. I think this is probably one I'm going to have to look at.

[estuardoquan]

how would one "resolve it"?

[estuardoquan]

leaving a note that my solution of

$relation instanceof JsonApiRelation ?: $relation = ($relation)();

only works with when and not mergeWhen, for ConditionalFields is not callable, as is ConditionalField...

[lindyhopchris]

Will be in the 1.1 release.