Re: [PATCH 2/2] rust/qemu-api-macros: add unit tests

[Zhao Liu <zhao1.liu@intel.com>]

On Fri, Jul 04, 2025 at 01:26:58PM +0300, Manos Pitsidianakis wrote:
> Date: Fri, 04 Jul 2025 13:26:58 +0300
> From: Manos Pitsidianakis <manos.pitsidianakis@linaro.org>
> Subject: [PATCH 2/2] rust/qemu-api-macros: add unit tests
> X-Mailer: b4 0.14.2
> 
> Add unit tests to check Derive macro output for expected error messages,
> or for expected correct codegen output.
> 
> Signed-off-by: Manos Pitsidianakis <manos.pitsidianakis@linaro.org>
> ---
>  rust/qemu-api-macros/meson.build  |   3 +
>  rust/qemu-api-macros/src/lib.rs   |   3 +
>  rust/qemu-api-macros/src/tests.rs | 135 ++++++++++++++++++++++++++++++++++++++
>  rust/qemu-api-macros/src/utils.rs |   1 +
>  4 files changed, 142 insertions(+)
> 
> diff --git a/rust/qemu-api-macros/meson.build b/rust/qemu-api-macros/meson.build
> index 8610ce1c8440c4b6e38a8462d4975bf76d72fb05..2152bcb99b30e4bdcc1c5b887b7903a37f6181c3 100644
> --- a/rust/qemu-api-macros/meson.build
> +++ b/rust/qemu-api-macros/meson.build
> @@ -17,3 +17,6 @@ _qemu_api_macros_rs = rust.proc_macro(
>  qemu_api_macros = declare_dependency(
>    link_with: _qemu_api_macros_rs,
>  )
> +
> +rust.test('rust-qemu-api-macros-tests', _qemu_api_macros_rs,
> +          suite: ['unit', 'rust'])
> diff --git a/rust/qemu-api-macros/src/lib.rs b/rust/qemu-api-macros/src/lib.rs
> index 4b30bea9eafc7924bf593113c3f42c5b1010c4b9..6c6e9b683f047f79cb377e6d30e23490f66bd711 100644
> --- a/rust/qemu-api-macros/src/lib.rs
> +++ b/rust/qemu-api-macros/src/lib.rs
> @@ -15,6 +15,9 @@
>  mod bits;
>  use bits::BitsConstInternal;
>  
> +#[cfg(test)]
> +mod tests;
> +
>  fn get_fields<'a>(
>      input: &'a DeriveInput,
>      msg: &str,
> diff --git a/rust/qemu-api-macros/src/tests.rs b/rust/qemu-api-macros/src/tests.rs
> new file mode 100644
> index 0000000000000000000000000000000000000000..dfca7d4838f141783472a4e728312aebeb9b5a8b
> --- /dev/null
> +++ b/rust/qemu-api-macros/src/tests.rs
> @@ -0,0 +1,135 @@
> +// Copyright 2025, Linaro Limited
> +// Author(s): Manos Pitsidianakis <manos.pitsidianakis@linaro.org>
> +// SPDX-License-Identifier: GPL-2.0-or-later
> +
> +use super::*;
> +use quote::quote;
> +
> +macro_rules! derive_compile_fail {
> +    ($derive_fn:ident, $input:expr, $error_msg:expr) => {{
> +        let input: proc_macro2::TokenStream = $input;
> +        let error_msg: &str = $error_msg;
> +        let derive_fn: fn(input: syn::DeriveInput) -> Result<proc_macro2::TokenStream, MacroError> =
> +            $derive_fn;
> +
> +        let input: syn::DeriveInput = syn::parse2(input).unwrap();
> +        let result = derive_fn(input);
> +        let MacroError::Message(err, _) = result.unwrap_err() else {
> +            panic!()
> +        };
> +        assert_eq!(err, error_msg);
> +    }};
> +}
> +
> +macro_rules! derive_compile {
> +    ($derive_fn:ident, $input:expr, $($expected:tt)*) => {{
> +        let input: proc_macro2::TokenStream = $input;
> +        let expected: proc_macro2::TokenStream = $($expected)*;
> +        let derive_fn: fn(input: syn::DeriveInput) -> Result<proc_macro2::TokenStream, MacroError> =
> +            $derive_fn;
> +
> +        let input: syn::DeriveInput = syn::parse2(input).unwrap();
> +        let result = derive_fn(input).unwrap();
> +        assert_eq!(result.to_string(), expected.to_string());
> +    }};
> +}

Good examples to test macros. LGTM,

Reviewed-by: Zhao Liu <zhao1.liu@intel.com>