From c7fc5036fbf736dce785bcdc73e16ac8ca5b76d2 Mon Sep 17 00:00:00 2001
From: Soares Chen <soares.chen@maybevoid.com>
Date: Mon, 4 May 2026 23:43:00 +0200
Subject: [PATCH] Replace `Self` to `Context` in the trait path for
 `#[cgp_impl]`

---
 crates/cgp-macro-lib/src/cgp_impl/transform.rs     |  6 +++++-
 .../component_tests/abstract_types/generics.rs     | 14 ++++++++++++++
 .../tests/component_tests/abstract_types/mod.rs    |  1 +
 3 files changed, 20 insertions(+), 1 deletion(-)
 create mode 100644 crates/cgp-tests/tests/component_tests/abstract_types/generics.rs

diff --git a/crates/cgp-macro-lib/src/cgp_impl/transform.rs b/crates/cgp-macro-lib/src/cgp_impl/transform.rs
index 7fda1cb8..57d804dc 100644
--- a/crates/cgp-macro-lib/src/cgp_impl/transform.rs
+++ b/crates/cgp-macro-lib/src/cgp_impl/transform.rs
@@ -41,7 +41,11 @@ pub fn transform_impl_trait(
     let mut out_impl: ItemImpl = parse2(raw_out_impl)?;
     out_impl.self_ty = Box::new(provider_type.clone());
 
-    let mut provider_trait_path: SimpleType = consumer_trait_path.clone();
+    let mut provider_trait_path: SimpleType = parse2(replace_self_type(
+        consumer_trait_path.to_token_stream(),
+        context_type.to_token_stream(),
+        &local_assoc_types,
+    ))?;
 
     match &mut provider_trait_path.generics {
         Some(generics) => {
diff --git a/crates/cgp-tests/tests/component_tests/abstract_types/generics.rs b/crates/cgp-tests/tests/component_tests/abstract_types/generics.rs
new file mode 100644
index 00000000..26cb258f
--- /dev/null
+++ b/crates/cgp-tests/tests/component_tests/abstract_types/generics.rs
@@ -0,0 +1,14 @@
+use cgp::prelude::*;
+
+#[cgp_component(FooProvider)]
+pub trait Foo<T> {
+    fn foo(&self, value: &T);
+}
+
+// Test that the `Error` parameter in `FooProvider<Error>`
+// is desugared correctly into `Context::Error` and not `Self::Error`
+#[cgp_impl(new FooError)]
+#[use_type(HasErrorType::Error)]
+impl FooProvider<Error> {
+    fn foo(&self, _value: &Error) {}
+}
diff --git a/crates/cgp-tests/tests/component_tests/abstract_types/mod.rs b/crates/cgp-tests/tests/component_tests/abstract_types/mod.rs
index ba04dea3..01fd4853 100644
--- a/crates/cgp-tests/tests/component_tests/abstract_types/mod.rs
+++ b/crates/cgp-tests/tests/component_tests/abstract_types/mod.rs
@@ -1,4 +1,5 @@
 pub mod basic;
 pub mod extend;
 pub mod foreign;
+pub mod generics;
 pub mod self_referential;