Internal refactoring of watch feature handling

Author: tuguzT

crates/cargo-gpu/src/build.rs

@@ -94,46 +94,52 @@ impl Build {
             std::env::current_dir()?.display()
         );
 
-        self.build_or_watch()
+        #[cfg(feature = "watch")]
+        let watching = self.build.watch;
+        #[cfg(not(feature = "watch"))]
+        let watching = false;
+        if watching {
+            return self.watch();
+        }
+
+        self.build()
     }
 
-    /// Builds shader crate locally or watches it for changes
-    /// depending on presence of `watch` feature and `BuildArgs::watch` flag.
-    fn build_or_watch(&self) -> anyhow::Result<()> {
-        let build = || -> anyhow::Result<()> {
-            crate::user_output!(
-                "Compiling shaders at {}...\n",
-                self.install.shader_crate.display()
-            );
-            let result = self.build.spirv_builder.build()?;
-            self.parse_compilation_result(&result)?;
-            Ok(())
-        };
+    /// Builds shader crate locally using [`SpirvBuilder`].
+    fn build(&self) -> anyhow::Result<()> {
+        crate::user_output!(
+            "Compiling shaders at {}...\n",
+            self.install.shader_crate.display()
+        );
+        let result = self.build.spirv_builder.build()?;
+        self.parse_compilation_result(&result)?;
+        Ok(())
+    }
 
+    /// Watches shader crate for changes using [`SpirvBuilder`]
+    /// or panics depending on presence of `watch` feature.
+    fn watch(&self) -> anyhow::Result<()> {
         #[cfg(feature = "watch")]
-        if self.build.watch {
+        {
             let this = self.clone();
             self.build
                 .spirv_builder
                 .watch(move |result, accept| {
-                    let result1 = this.parse_compilation_result(&result);
+                    let parse_result = this.parse_compilation_result(&result);
                     if let Some(accept) = accept {
-                        accept.submit(result1);
+                        accept.submit(parse_result);
                     }
                 })?
                 .context("unreachable")??;
             std::thread::park();
-        } else {
-            build()?;
+            Ok(())
         }
 
         #[cfg(not(feature = "watch"))]
-        build()?;
-
-        Ok(())
+        unreachable!("cannot watch without the `watch` feature")
     }
 
-    /// Parses compilation result from `SpirvBuilder` and writes it out to a file
+    /// Parses compilation result from [`SpirvBuilder`] and writes it out to a file
     fn parse_compilation_result(&self, result: &CompileResult) -> anyhow::Result<()> {
         let shaders = match &result.module {
             ModuleResult::MultiModule(modules) => {