Link all top-level commands with macro recording/replaying logic

recordable_derive/Cargo.toml

@@ -0,0 +1,11 @@
+[package]
+name = "recordable_derive"
+version = "0.1.0"
+edition = "2021"
+
+[lib]
+proc-macro = true
+
+[dependencies]
+quote = "1.0.35"
+syn = { version = "2.0.49", features = ["full"] }

recordable_derive/src/lib.rs

@@ -0,0 +1,42 @@
+use proc_macro::TokenStream;
+use syn::{spanned::Spanned, Data};
+
+/// Macro to allow Recordable to be implemented on an enum by dispatching over each variant.
+#[proc_macro_derive(Recordable)]
+pub fn extract(input: TokenStream) -> TokenStream {
+    let ast = syn::parse_macro_input!(input);
+
+    impl_recordable(&ast)
+}
+
+fn impl_recordable(ast: &syn::DeriveInput) -> TokenStream {
+    let name = &ast.ident;
+
+    match &ast.data {
+        Data::Enum(en) => {
+            let extracted = en.variants.iter().map(|var| {
+                let ident = &var.ident;
+
+                quote::quote_spanned! {var.span()=>
+                    Self::#ident (opt) => opt.run(ctx).await?
+                }
+            });
+
+            TokenStream::from(quote::quote! {
+                impl Recordable for #name {
+                    async fn run(self, ctx: crate::Context<'_>) -> Result<(), crate::Error> {
+                        match self {
+                            #(#extracted,)*
+                        }
+
+                        Ok(())
+                    }
+                }
+            })
+        }
+
+        _ => {
+            panic!("Only enums can derive Recordable");
+        }
+    }
+}