fix: harden API macro expansion hygiene

crates/api-macros/src/lib.rs

@@ -58,6 +58,8 @@
 //! explicit variants for future transport work; accepting one requires a deliberate macro and
 //! adapter change rather than silently treating it as JSON.
 
+extern crate self as api_macros;
+
 pub use api_macros_impl::api;
 
 /// A transport-neutral HTTP method.

crates/api-macros/tests/expansion.rs

@@ -35,6 +35,12 @@ pub trait WrapperApi {
     async fn search(&self) -> SearchResult<Widget>;
 }
 
+#[api]
+pub trait RawIdentifierApi {
+    #[get("/type", operation_id = "raw.type")]
+    async fn r#type(&self) -> Widget;
+}
+
 fn assert_operation_types<O>()
 where
     O: Operation<
@@ -52,6 +58,8 @@ fn expansion_exposes_deterministic_metadata_and_type_connections() {
 
     fn assert_named_wrapper<O: Operation<ResponseBody = SearchResult<Widget>>>() {}
     assert_named_wrapper::<wrapper_api_operations::Search>();
+    let raw = <raw_identifier_api_operations::Type as Operation>::METADATA;
+    assert_eq!(raw.operation_id, "raw.type");
 
     let operations = <WidgetApiMetadata as ApiContract>::OPERATIONS;
     assert_eq!(operations.len(), 3);

crates/api-macros/tests/renamed_dependency.rs

@@ -0,0 +1,66 @@
+use std::{fs, path::PathBuf, process::Command};
+
+#[test]
+fn macro_expansion_resolves_a_renamed_support_dependency() {
+    let fixture = std::env::temp_dir().join(format!(
+        "api-macros-renamed-dependency-{}",
+        std::process::id()
+    ));
+    let _ = fs::remove_dir_all(&fixture);
+    fs::create_dir_all(fixture.join("src")).expect("create fixture source directory");
+
+    let package_path = PathBuf::from(env!("CARGO_MANIFEST_DIR"));
+    let package_path = package_path
+        .to_str()
+        .expect("package path is UTF-8")
+        .replace('\\', "\\\\");
+    fs::write(
+        fixture.join("Cargo.toml"),
+        format!(
+            r#"[package]
+name = "renamed-api-consumer"
+version = "0.0.0"
+edition = "2024"
+
+[workspace]
+
+[dependencies]
+yoi-api = {{ package = "api-macros", path = "{package_path}" }}
+"#,
+        ),
+    )
+    .expect("write fixture manifest");
+    fs::write(
+        fixture.join("src/lib.rs"),
+        r#"use yoi_api::{ApiContract, api};
+
+pub struct Output;
+
+#[api]
+pub trait RenamedApi {
+    #[get("/output", operation_id = "renamed.output")]
+    async fn output(&self) -> Output;
+}
+
+pub fn operation_count() -> usize {
+    <RenamedApiMetadata as ApiContract>::OPERATIONS.len()
+}
+"#,
+    )
+    .expect("write fixture source");
+
+    let output = Command::new(env!("CARGO"))
+        .args(["check", "--quiet", "--offline"])
+        .current_dir(&fixture)
+        .env("CARGO_TARGET_DIR", fixture.join("target"))
+        .output()
+        .expect("run cargo check for renamed dependency fixture");
+    let _ = fs::remove_dir_all(&fixture);
+
+    assert!(
+        output.status.success(),
+        "renamed dependency fixture failed:\nstdout:\n{}\nstderr:\n{}",
+        String::from_utf8_lossy(&output.stdout),
+        String::from_utf8_lossy(&output.stderr),
+    );
+}

crates/api-macros/tests/ui/marker_collision.rs

@@ -0,0 +1,14 @@
+use api_macros::api;
+
+pub struct Response;
+
+#[api]
+pub trait MarkerCollision {
+    #[get("/first")]
+    async fn foo_bar(&self) -> Response;
+
+    #[get("/second")]
+    async fn foo__bar(&self) -> Response;
+}
+
+fn main() {}

crates/api-macros/tests/ui/marker_collision.stderr

@@ -0,0 +1,11 @@
+error: generated operation marker `FooBar` collides with method `foo_bar`
+  --> tests/ui/marker_collision.rs:11:14
+   |
+11 |     async fn foo__bar(&self) -> Response;
+   |              ^^^^^^^^
+
+error: first method generating marker `FooBar`
+ --> tests/ui/marker_collision.rs:8:14
+  |
+8 |     async fn foo_bar(&self) -> Response;
+  |              ^^^^^^^