glib-macros: add test macro for async-glib-context tests

glib-macros/src/async_test.rs

@@ -0,0 +1,47 @@
+// Take a look at the license at the top of the repository in the LICENSE file.
+
+use proc_macro::TokenStream;
+use quote::ToTokens;
+
+pub(crate) fn async_test(_args: TokenStream, mut item: TokenStream) -> TokenStream {
+    let mut item_fn: syn::ItemFn = match syn::parse(item.clone()) {
+        Ok(it) => it,
+        Err(e) => {
+            item.extend(TokenStream::from(e.into_compile_error()));
+            return item;
+        }
+    };
+
+    if item_fn.sig.asyncness.is_none() {
+        item.extend(TokenStream::from(
+            syn::Error::new_spanned(
+                item_fn.sig.ident,
+                "The 'async' keyword is missing from the test function declaration",
+            )
+            .into_compile_error(),
+        ));
+        return item;
+    }
+
+    item_fn.sig.asyncness = None;
+
+    let gen_attr = quote::quote! {
+        #[::core::prelude::v1::test]
+    };
+
+    let body = &item_fn.block;
+
+    item_fn.block = syn::parse2(quote::quote! {
+        {
+            let main_ctx = glib::MainContext::new();
+            main_ctx.block_on(async #body)
+        }
+    })
+    .expect("Body parsing failure");
+
+    let mut tokens = TokenStream::new();
+    tokens.extend(TokenStream::from(gen_attr.to_token_stream()));
+    tokens.extend(TokenStream::from(item_fn.into_token_stream()));
+
+    tokens
+}

glib-macros/src/lib.rs

@@ -1,5 +1,6 @@
 // Take a look at the license at the top of the repository in the LICENSE file.
 
+mod async_test;
 mod boxed_derive;
 mod clone;
 mod closure;
@@ -1567,3 +1568,22 @@ pub fn derive_value_delegate(input: TokenStream) -> TokenStream {
     let input = parse_macro_input!(input as value_delegate_derive::ValueDelegateInput);
     value_delegate_derive::impl_value_delegate(input).unwrap()
 }
+
+/// An attribute macro for writing asynchronous test functions.
+///
+/// This macro is designed to wrap an asynchronous test function and ensure that
+/// it runs within a `glib::MainContext`. It helps in writing async tests that
+/// require the use of an event loop for the asynchronous execution.
+///
+/// # Example
+///
+/// ```
+/// #[glib::async_test]
+/// async fn my_async_test() {
+///     // Test code that runs asynchronously
+/// }
+/// ```
+#[proc_macro_attribute]
+pub fn async_test(args: TokenStream, item: TokenStream) -> TokenStream {
+    async_test::async_test(args, item)
+}

glib/src/lib.rs

@@ -29,8 +29,9 @@ pub use bitflags;
 #[doc(hidden)]
 pub use glib_macros::cstr_bytes;
 pub use glib_macros::{
-    clone, closure, closure_local, derived_properties, flags, object_interface, object_subclass,
-    Boxed, Downgrade, Enum, ErrorDomain, Properties, SharedBoxed, ValueDelegate, Variant,
+    async_test, clone, closure, closure_local, derived_properties, flags, object_interface,
+    object_subclass, Boxed, Downgrade, Enum, ErrorDomain, Properties, SharedBoxed, ValueDelegate,
+    Variant,
 };
 pub use glib_sys as ffi;
 pub use gobject_sys as gobject_ffi;