Support deeply nested cache relations for model-cache. (#5641)

CHANGELOG-3.0.md

@@ -4,6 +4,7 @@
 
 - [#5634](https://github.com/hyperf/hyperf/pull/5634) Added `Hyperf\Stringable\str()` helper function.
 - [#5639](https://github.com/hyperf/hyperf/pull/5639) Added `Redis::pipeline()` and `Redis::transaction()` support.
+- [#5641](https://github.com/hyperf/hyperf/pull/5641) Support deeply nested cache relations for `model-cache`.
 
 ## Optimized
 

src/model-cache/src/EagerLoad/EagerLoaderBuilder.php

@@ -14,6 +14,7 @@
 use Closure;
 use Hyperf\Collection\Arr;
 use Hyperf\Database\Model\Builder;
+use Hyperf\Database\Model\Collection;
 use Hyperf\Database\Model\Relations\Relation;
 use Hyperf\ModelCache\CacheableInterface;
 
@@ -47,7 +48,18 @@ protected function getEagerModels(Relation $relation)
         $column = sprintf('%s.%s', $model->getTable(), $model->getKeyName());
 
         if ($model instanceof CacheableInterface && $this->couldUseEagerLoad($wheres, $column)) {
-            return $model::findManyFromCache($wheres[0]['values'] ?? []);
+            $models = $model::findManyFromCache($wheres[0]['values'] ?? []);
+            // If we actually found models we will also eager load any relationships that
+            // have been specified as needing to be eager loaded, which will solve the
+            // n+1 query issue for the developers to avoid running a lot of queries.
+            if ($models->count() > 0 && $with = $relation->getEagerLoads()) {
+                $first = $models->first();
+                $self = (new static($this->query->newQuery()));
+                $builder = $first->registerGlobalScopes($self->setModel($first))->setEagerLoads($with);
+                $models = new Collection($builder->eagerLoadRelations($models->all()));
+            }
+
+            return $models;
         }
 
         return $relation->getEager();