Add result type casting for simple column aliases.

When columns in the schema are aliased to other fields we can easily and
correctly infer the result set types. Doing this makes the result sets
consistent when columns are aliased and when they are not.

Refs #9402

src/ORM/Query.php

@@ -1020,6 +1020,9 @@ protected function _addDefaultSelectTypes()
                 $types[$alias] = $typeMap[$alias];
                 continue;
             }
+            if (is_string($value) && isset($typeMap[$value])) {
+                $types[$alias] = $typeMap[$value];
+            }
             if ($value instanceof TypedResultInterface) {
                 $types[$alias] = $value->returnType();
             }

tests/TestCase/ORM/QueryTest.php

@@ -2947,6 +2947,22 @@ public function testSelectWithTableAndAssociationInstance()
         $this->assertEquals($expected, $result);
     }
 
+    /**
+     * Test that simple aliased field have results typecast.
+     *
+     * @return void
+     */
+    public function testSelectTypeInferSimpleAliases()
+    {
+        $table = TableRegistry::get('comments');
+        $result = $table
+            ->find()
+            ->select(['created', 'updated_time' => 'updated'])
+            ->first();
+        $this->assertInstanceOf(Time::class, $result->created);
+        $this->assertInstanceOf(Time::class, $result->updated_time);
+    }
+
     /**
      * Tests that isEmpty() can be called on a query
      *