[tests] Add a proc macro to generate tests for OnlineBlockchain types

macros/Cargo.toml

@@ -11,5 +11,8 @@ syn = { version = "1.0", features = ["parsing"] }
 proc-macro2 = "1.0"
 quote = "1.0"
 
+[features]
+debug = ["syn/extra-traits"]
+
 [lib]
 proc-macro = true

macros/src/lib.rs

@@ -85,7 +85,8 @@ pub fn maybe_async(_attr: TokenStream, item: TokenStream) -> TokenStream {
     } else {
         (quote! {
             compile_error!("#[maybe_async] can only be used on methods, trait or trait impl blocks")
-        }).into()
+        })
+        .into()
     }
 }