Add tests

Signed-off-by: sagudev <[email protected]>

Author: sagudev

examples/standalone/custom_backend/src/custom.rs

@@ -262,7 +262,7 @@ impl DeviceInterface for CustomDevice {
 }
 
 #[derive(Debug)]
-struct CustomShaderModule(Counter);
+pub struct CustomShaderModule(pub Counter);
 
 impl ShaderModuleInterface for CustomShaderModule {
     fn get_compilation_info(&self) -> Pin<Box<dyn wgpu::custom::ShaderCompilationInfoFuture>> {

examples/standalone/custom_backend/src/main.rs

@@ -1,6 +1,6 @@
 use std::marker::PhantomData;
 
-use custom::Counter;
+use custom::{Counter, CustomShaderModule};
 use wgpu::{DeviceDescriptor, RequestAdapterOptions};
 
 mod custom;
@@ -31,11 +31,15 @@ async fn main() {
             .unwrap();
         assert_eq!(counter.count(), 5);
 
-        let _module = device.create_shader_module(wgpu::ShaderModuleDescriptor {
+        let module = device.create_shader_module(wgpu::ShaderModuleDescriptor {
             label: Some("shader"),
             source: wgpu::ShaderSource::Dummy(PhantomData),
         });
 
+        let custom_module = module.as_custom::<CustomShaderModule>().unwrap();
+        assert_eq!(custom_module.0.count(), 6);
+        let _module_clone = module.clone();
+
         assert_eq!(counter.count(), 6);
     }
     assert_eq!(counter.count(), 1);