fix(pallet-benchmarking): split test functions in v2 (#3574)

Closes #376

---------

Co-authored-by: command-bot <>

substrate/frame/support/procedural/src/benchmark.rs

@@ -431,7 +431,7 @@ pub fn benchmarks(
 	let mut benchmarks_by_name_mappings: Vec<TokenStream2> = Vec::new();
 	let test_idents: Vec<Ident> = benchmark_names_str
 		.iter()
-		.map(|n| Ident::new(format!("test_{}", n).as_str(), Span::call_site()))
+		.map(|n| Ident::new(format!("test_benchmark_{}", n).as_str(), Span::call_site()))
 		.collect();
 	for i in 0..benchmark_names.len() {
 		let name_ident = &benchmark_names[i];
@@ -441,6 +441,37 @@ pub fn benchmarks(
 		benchmarks_by_name_mappings.push(quote!(#name_str => Self::#test_ident()))
 	}
 
+	let impl_test_function = content
+		.iter_mut()
+		.find_map(|item| {
+			let Item::Macro(item_macro) = item else {
+				return None;
+			};
+
+			if !item_macro
+				.mac
+				.path
+				.segments
+				.iter()
+				.any(|s| s.ident == "impl_benchmark_test_suite")
+			{
+				return None;
+			}
+
+			let tokens = item_macro.mac.tokens.clone();
+			*item = Item::Verbatim(quote! {});
+
+			Some(quote! {
+				impl_test_function!(
+					(#( {} #benchmark_names )*)
+					(#( #extra_benchmark_names )*)
+					(#( #skip_meta_benchmark_names )*)
+					#tokens
+				);
+			})
+		})
+		.unwrap_or(quote! {});
+
 	// emit final quoted tokens
 	let res = quote! {
 		#(#mod_attrs)
@@ -676,6 +707,8 @@ pub fn benchmarks(
 					}
 				}
 			}
+
+			#impl_test_function
 		}
 		#mod_vis use #mod_name::*;
 	};
@@ -733,7 +766,8 @@ fn expand_benchmark(
 	let setup_stmts = benchmark_def.setup_stmts;
 	let verify_stmts = benchmark_def.verify_stmts;
 	let last_stmt = benchmark_def.last_stmt;
-	let test_ident = Ident::new(format!("test_{}", name.to_string()).as_str(), Span::call_site());
+	let test_ident =
+		Ident::new(format!("test_benchmark_{}", name.to_string()).as_str(), Span::call_site());
 
 	// unroll params (prepare for quoting)
 	let unrolled = UnrolledParams::from(&benchmark_def.params);