Fix »OAuth Client Table Changes« migration snippet in the upgrade guide (#1859)

* Fix owner columns are not added after the `user_id` as intended

* Fix `TypeError` when migrating the `oauth_clients` table

TypeError
Laravel\Passport\Client::{closure:Laravel\Passport\Client::grantTypes():157}(): Return value must be of type array, null returned

This happens because `isset($value) ? $this->fromJson($value) : array_keys(/* … */)` evaluates to `null`.

> After adding a non-nullable `grant_types` column with no default values `isset($value)` is `true` because `$value` is an empty string.
> As a result `$this->fromJson($value)` is called with an empty string which evaluates to `null` …

```php
> $value = ''; isset($value);
= true
```

This then violates the return type `get: fn (?string $value): array` …

Making the field nullable first fixes the issue:

```php
> $value = null; isset($value);
= false
```

Once the data is written I set nullable to false because the original migration creates a non-nullable field as well …

An alternative to this "workaround" would be updating the `Laravel\Passport\Client::grantTypes()` implementation.

* Fix broken polymorphic owner relationship

The `config()` call falls back to `null` when the `$client` has on provider.
The result is a client with an `owner_id` that has no corresponding `owner_type` set.
Adding `\App\Models\User::class` as a fallback seems reasonable.

* Replace hardcoded User class-string

Co-authored-by: Hafez Divandari <[email protected]>

* Leave `grant_types` nullable.

---------

Co-authored-by: Hafez Divandari <[email protected]>

Author: hettiger

UPGRADE.md

@@ -139,20 +139,20 @@ If you prefer to use the new structure, you may create a migration to apply the
 
 ```php
 Schema::table('oauth_clients', function (Blueprint $table) {
-    $table->after('user_id', function (Blueprint $table) {
-        $table->nullableMorphs('owner');
-    });
+    $table->nullableMorphs('owner', after: 'user_id');
 
     $table->after('provider', function (Blueprint $table) {
         $table->text('redirect_uris');
-        $table->text('grant_types');
+        $table->text('grant_types')->nullable();
     });
 });
 
 foreach (Passport::client()->cursor() as $client) {
     Model::withoutTimestamps(fn () => $client->forceFill([
         'owner_id' => $client->user_id,
-        'owner_type' => $client->user_id ? config('auth.providers.'.$client->provider.'.model') : null,
+        'owner_type' => $client->user_id
+            ? config('auth.providers.'.($client->provider ?: config('auth.guards.api.provider')).'.model')
+            : null,
         'redirect_uris' => $client->redirect_uris,
         'grant_types' => $client->grant_types,
     ])->save());