[11.x] Add withWhereRelation method to builder (#54668)

* Add `withWhereRelation` method to builder

* formatting

---------

Co-authored-by: Taylor Otwell <[email protected]>

Author: utsavsomaiya

src/Illuminate/Database/Eloquent/Concerns/QueriesRelationships.php

@@ -437,6 +437,25 @@ public function whereRelation($relation, $column, $operator = null, $value = nul
         });
     }
 
+    /**
+     * Add a basic where clause to a relationship query and eager-load the relationship with the same conditions.
+     *
+     * @param  \Illuminate\Database\Eloquent\Relations\Relation<*, *, *>|string  $relation
+     * @param  \Closure|string|array|\Illuminate\Contracts\Database\Query\Expression  $column
+     * @param  mixed  $operator
+     * @param  mixed  $value
+     * @return $this
+     */
+    public function withWhereRelation($relation, $column, $operator = null, $value = null)
+    {
+        return $this->whereRelation($relation, $column, $operator, $value)
+            ->with([
+                $relation => fn ($query) => $column instanceof Closure
+                    ? $column($query)
+                    : $query->where($column, $operator, $value)
+            ]);
+    }
+
     /**
      * Add an "or where" clause to a relationship query.
      *

tests/Database/DatabaseEloquentMorphOneOfManyTest.php

@@ -150,6 +150,23 @@ public function testWithWhereHas()
         $this->assertSame($exists->first()->current_state->state, $currentState->state);
     }
 
+    public function testWithWhereRelation()
+    {
+        $product = MorphOneOfManyTestProduct::create();
+        $currentState = $product->states()->create([
+            'state' => 'active',
+        ]);
+
+        $exists = MorphOneOfManyTestProduct::withWhereRelation('current_state', 'state', 'active')->exists();
+        $this->assertTrue($exists);
+
+        $exists = MorphOneOfManyTestProduct::withWhereRelation('current_state', 'state', 'active')->get();
+
+        $this->assertCount(1, $exists);
+        $this->assertTrue($exists->first()->relationLoaded('current_state'));
+        $this->assertSame($exists->first()->current_state->state, $currentState->state);
+    }
+
     public function testWithExists()
     {
         $product = MorphOneOfManyTestProduct::create();