Files
oak-gpui/gpui_macros/src/lib.rs
T

130 lines
4.4 KiB
Rust

use proc_macro::TokenStream;
use quote::{format_ident, quote};
use std::mem;
use syn::{
parse_macro_input, parse_quote, AttributeArgs, ItemFn, Lit, Meta, MetaNameValue, NestedMeta,
};
#[proc_macro_attribute]
pub fn test(args: TokenStream, function: TokenStream) -> TokenStream {
let mut namespace = format_ident!("gpui");
let args = syn::parse_macro_input!(args as AttributeArgs);
let mut max_retries = 0;
for arg in args {
match arg {
NestedMeta::Meta(Meta::Path(name))
if name.get_ident().map_or(false, |n| n == "self") =>
{
namespace = format_ident!("crate");
}
NestedMeta::Meta(Meta::NameValue(meta)) => {
if let Some(result) = parse_retries(&meta) {
match result {
Ok(retries) => max_retries = retries,
Err(error) => return TokenStream::from(error.into_compile_error()),
}
}
}
other => {
return TokenStream::from(
syn::Error::new_spanned(other, "invalid argument").into_compile_error(),
)
}
}
}
let mut inner_fn = parse_macro_input!(function as ItemFn);
let inner_fn_attributes = mem::take(&mut inner_fn.attrs);
let inner_fn_name = format_ident!("_{}", inner_fn.sig.ident);
let outer_fn_name = mem::replace(&mut inner_fn.sig.ident, inner_fn_name.clone());
let mut outer_fn: ItemFn = if inner_fn.sig.asyncness.is_some() {
parse_quote! {
#[test]
fn #outer_fn_name() {
#inner_fn
if #max_retries > 0 {
let mut retries = 0;
loop {
let result = std::panic::catch_unwind(|| {
#namespace::App::test_async(move |cx| async {
#inner_fn_name(cx).await;
});
});
match result {
Ok(result) => return result,
Err(error) => {
if retries < #max_retries {
retries += 1;
println!("retrying: attempt {}", retries);
} else {
std::panic::resume_unwind(error);
}
}
}
}
} else {
#namespace::App::test_async(move |cx| async {
#inner_fn_name(cx).await;
});
}
}
}
} else {
parse_quote! {
#[test]
fn #outer_fn_name() {
#inner_fn
if #max_retries > 0 {
let mut retries = 0;
loop {
let result = std::panic::catch_unwind(|| {
#namespace::App::test(|cx| {
#inner_fn_name(cx);
});
});
match result {
Ok(result) => return result,
Err(error) => {
if retries < #max_retries {
retries += 1;
println!("retrying: attempt {}", retries);
} else {
std::panic::resume_unwind(error);
}
}
}
}
} else {
#namespace::App::test(|cx| {
#inner_fn_name(cx);
});
}
}
}
};
outer_fn.attrs.extend(inner_fn_attributes);
TokenStream::from(quote!(#outer_fn))
}
fn parse_retries(meta: &MetaNameValue) -> Option<syn::Result<usize>> {
let ident = meta.path.get_ident();
if ident.map_or(false, |n| n == "retries") {
if let Lit::Int(int) = &meta.lit {
Some(int.base10_parse())
} else {
Some(Err(syn::Error::new(
meta.lit.span(),
"retries mut be an integer",
)))
}
} else {
None
}
}