From e8650f6ad349196c9711e85b71fe7defa7736faf Mon Sep 17 00:00:00 2001
From: firelight flagboy <firelight.flagboy@gmail.com>
Date: Mon, 4 Sep 2023 12:01:24 +0200
Subject: [PATCH] Add attribute `crate` to proc-macro `wasm_bindgen_test`

This attribute allow to specify a path where `wasm-bindgen-test` can be
accessed.

Closes #3588
---
 crates/test-macro/Cargo.toml            |  2 +-
 crates/test-macro/src/lib.rs            | 16 ++++++++++++++--
 crates/test-macro/ui-tests/crate.rs     | 20 ++++++++++++++++++++
 crates/test-macro/ui-tests/crate.stderr |  5 +++++
 4 files changed, 40 insertions(+), 3 deletions(-)
 create mode 100644 crates/test-macro/ui-tests/crate.rs
 create mode 100644 crates/test-macro/ui-tests/crate.stderr

diff --git a/crates/test-macro/Cargo.toml b/crates/test-macro/Cargo.toml
index 6ffc549f2cc..540fd7f0a7a 100644
--- a/crates/test-macro/Cargo.toml
+++ b/crates/test-macro/Cargo.toml
@@ -14,7 +14,7 @@ proc-macro = true
 [dependencies]
 proc-macro2 = "1.0"
 quote = "1.0"
-syn = { version = "2.0", default-features = false, features = [ "parsing", "proc-macro", "derive" ] }
+syn = { version = "2.0", default-features = false, features = [ "parsing", "proc-macro", "derive", "printing" ] }
 
 [dev-dependencies]
 wasm-bindgen-test = { path = "../test" }
diff --git a/crates/test-macro/src/lib.rs b/crates/test-macro/src/lib.rs
index b68afbef2d0..8215bb3206a 100644
--- a/crates/test-macro/src/lib.rs
+++ b/crates/test-macro/src/lib.rs
@@ -74,10 +74,11 @@ pub fn wasm_bindgen_test(
     // later slurp up all of these functions and pass them as arguments to the
     // main test harness. This is the entry point for all tests.
     let name = format_ident!("__wbgt_{}_{}", ident, CNT.fetch_add(1, Ordering::SeqCst));
+    let wasm_bindgen_path = attributes.wasm_bindgen_path;
     tokens.extend(
         quote! {
             #[no_mangle]
-            pub extern "C" fn #name(cx: &::wasm_bindgen_test::__rt::Context) {
+            pub extern "C" fn #name(cx: &#wasm_bindgen_path::__rt::Context) {
                 let test_name = ::core::concat!(::core::module_path!(), "::", ::core::stringify!(#ident));
                 #test_body
             }
@@ -187,15 +188,26 @@ fn compile_error(span: Span, msg: &str) -> proc_macro::TokenStream {
     quote_spanned! { span => compile_error!(#msg); }.into()
 }
 
-#[derive(Default)]
 struct Attributes {
     r#async: bool,
+    wasm_bindgen_path: syn::Path,
+}
+
+impl Default for Attributes {
+    fn default() -> Self {
+        Self {
+            r#async: false,
+            wasm_bindgen_path: syn::parse_quote!(::wasm_bindgen_test),
+        }
+    }
 }
 
 impl Attributes {
     fn parse(&mut self, meta: syn::meta::ParseNestedMeta) -> syn::parse::Result<()> {
         if meta.path.is_ident("async") {
             self.r#async = true;
+        } else if meta.path.is_ident("crate") {
+            self.wasm_bindgen_path = meta.value()?.parse::<syn::Path>()?;
         } else {
             return Err(meta.error("unknown attribute"));
         }
diff --git a/crates/test-macro/ui-tests/crate.rs b/crates/test-macro/ui-tests/crate.rs
new file mode 100644
index 00000000000..2087f7575b6
--- /dev/null
+++ b/crates/test-macro/ui-tests/crate.rs
@@ -0,0 +1,20 @@
+#![no_implicit_prelude]
+
+extern crate wasm_bindgen_test_macro;
+//
+use wasm_bindgen_test_macro::wasm_bindgen_test;
+
+pub mod wasm {
+    pub extern crate wasm_bindgen_test as test;
+}
+
+#[wasm_bindgen_test(crate = ::wasm_bindgen_test)]
+fn success_1() {}
+
+#[wasm_bindgen_test(crate = crate::wasm::test)]
+fn success_2() {}
+
+#[wasm_bindgen_test(crate = foo)]
+fn failure_1() {}
+
+fn main() {}
diff --git a/crates/test-macro/ui-tests/crate.stderr b/crates/test-macro/ui-tests/crate.stderr
new file mode 100644
index 00000000000..2bace352ee4
--- /dev/null
+++ b/crates/test-macro/ui-tests/crate.stderr
@@ -0,0 +1,5 @@
+error[E0433]: failed to resolve: use of undeclared crate or module `foo`
+  --> ui-tests/crate.rs:17:29
+   |
+17 | #[wasm_bindgen_test(crate = foo)]
+   |                             ^^^ use of undeclared crate or module `foo`