From b112516f59e2e8be7b84b23368c8343c6a13c49c Mon Sep 17 00:00:00 2001
From: Piotr Figiela <77412592+Draggu@users.noreply.github.com>
Date: Wed, 23 Oct 2024 18:27:39 +0200
Subject: [PATCH] Add `ExpandDerive` handler

commit-id:20ad0a61
---
 .../methods/expand_derive.rs                  | 54 +++++++++++++++++++
 .../src/ops/proc_macro_server/methods/mod.rs  |  1 +
 scarb/src/ops/proc_macro_server/mod.rs        |  3 +-
 3 files changed, 57 insertions(+), 1 deletion(-)
 create mode 100644 scarb/src/ops/proc_macro_server/methods/expand_derive.rs

diff --git a/scarb/src/ops/proc_macro_server/methods/expand_derive.rs b/scarb/src/ops/proc_macro_server/methods/expand_derive.rs
new file mode 100644
index 000000000..73032484d
--- /dev/null
+++ b/scarb/src/ops/proc_macro_server/methods/expand_derive.rs
@@ -0,0 +1,54 @@
+use crate::{
+    compiler::plugin::proc_macro::{Expansion, ExpansionKind, ProcMacroHost},
+    ops::proc_macro_server::json_rpc::Handler,
+};
+use anyhow::Result;
+use cairo_lang_macro::TokenStream;
+use convert_case::{Case, Casing};
+use scarb_proc_macro_server_types::methods::{expand::ExpandDerive, ProcMacroResult};
+use std::sync::Arc;
+
+impl Handler for ExpandDerive {
+    fn handle(proc_macros: Arc<ProcMacroHost>, params: Self::Params) -> Result<Self::Response> {
+        let mut derived_code = String::new();
+        let mut all_diagnostics = vec![];
+
+        for derive in params.derives {
+            let expansion = Expansion::new(derive.to_case(Case::Snake), ExpansionKind::Derive);
+            let package_id = proc_macros
+                .macros()
+                .into_iter()
+                .find(|e| e.get_expansions().contains(&expansion))
+                .map(|m| m.package_id())
+                .unwrap();
+
+            let instance = proc_macros
+                .macros()
+                .iter()
+                .find(|m| m.package_id() == package_id)
+                .unwrap();
+
+            let result = instance.generate_code(
+                expansion.name.clone(),
+                TokenStream::empty(),
+                params.item.clone(),
+            );
+
+            // Register diagnostics.
+            all_diagnostics.extend(result.diagnostics);
+
+            if result.token_stream.is_empty() {
+                // No code has been generated.
+                // We do not need to do anything.
+                continue;
+            }
+
+            derived_code.push_str(result.token_stream.to_string().as_str());
+        }
+
+        Ok(ProcMacroResult {
+            token_stream: TokenStream::new(derived_code),
+            diagnostics: all_diagnostics,
+        })
+    }
+}
diff --git a/scarb/src/ops/proc_macro_server/methods/mod.rs b/scarb/src/ops/proc_macro_server/methods/mod.rs
index d4c1e839e..1a3926524 100644
--- a/scarb/src/ops/proc_macro_server/methods/mod.rs
+++ b/scarb/src/ops/proc_macro_server/methods/mod.rs
@@ -1,2 +1,3 @@
 pub mod defined_macros;
 pub mod expand_attribute;
+pub mod expand_derive;
diff --git a/scarb/src/ops/proc_macro_server/mod.rs b/scarb/src/ops/proc_macro_server/mod.rs
index 614fdc172..dc8ee6603 100644
--- a/scarb/src/ops/proc_macro_server/mod.rs
+++ b/scarb/src/ops/proc_macro_server/mod.rs
@@ -8,7 +8,7 @@ use crossbeam_channel::{Receiver, Sender};
 use json_rpc::Handler;
 use scarb_proc_macro_server_types::jsonrpc::{ResponseError, RpcRequest, RpcResponse};
 use scarb_proc_macro_server_types::methods::defined_macros::DefinedMacros;
-use scarb_proc_macro_server_types::methods::expand::ExpandAttribute;
+use scarb_proc_macro_server_types::methods::expand::{ExpandAttribute, ExpandDerive};
 use scarb_proc_macro_server_types::methods::Method;
 use serde_json::Value;
 
@@ -75,6 +75,7 @@ fn route_request(proc_macros: Arc<ProcMacroHost>, request: RpcRequest) -> Result
         ExpandAttribute::METHOD => {
             run_handler::<ExpandAttribute>(proc_macros.clone(), request.value)
         }
+        ExpandDerive::METHOD => run_handler::<ExpandDerive>(proc_macros.clone(), request.value),
         _ => Err(anyhow!("method not found")),
     }
 }