Added component validators

Editor/Validators/Component/ComponentValidatorMeshRenderer.cs

@@ -0,0 +1,19 @@
+using System.Collections.Generic;
+using UnityEngine;
+
+namespace Module.ProjectValidator.Editor
+{
+    internal sealed class ComponentValidatorMeshRenderer : IComponentValidator<MeshRenderer>
+    {
+        public void Validate(MeshRenderer component, List<ValidatorResult> results)
+        {
+            var materials = component.sharedMaterials;
+
+            for (var i = 0; i < materials.Length; i++)
+            {
+                if (materials[i] == null)
+                    results.Add(ValidatorResult.Create(EValidatorSeverity.Error, $"Missing material in slot #{i}"));
+            }
+        }
+    }
+}