1use proc_macro::TokenStream;
2use quote::{format_ident, quote};
3use std::mem;
4use syn::{
5 parse_macro_input, parse_quote, spanned::Spanned as _, AttributeArgs, FnArg, ItemFn, Lit, Meta,
6 NestedMeta, Type,
7};
8
9#[proc_macro_attribute]
10pub fn test(args: TokenStream, function: TokenStream) -> TokenStream {
11 let mut namespace = format_ident!("gpui");
12
13 let args = syn::parse_macro_input!(args as AttributeArgs);
14 let mut max_retries = 0;
15 let mut num_iterations = 1;
16 let mut starting_seed = 0;
17
18 for arg in args {
19 match arg {
20 NestedMeta::Meta(Meta::Path(name))
21 if name.get_ident().map_or(false, |n| n == "self") =>
22 {
23 namespace = format_ident!("crate");
24 }
25 NestedMeta::Meta(Meta::NameValue(meta)) => {
26 let key_name = meta.path.get_ident().map(|i| i.to_string());
27 let result = (|| {
28 match key_name.as_deref() {
29 Some("retries") => max_retries = parse_int(&meta.lit)?,
30 Some("iterations") => num_iterations = parse_int(&meta.lit)?,
31 Some("seed") => starting_seed = parse_int(&meta.lit)?,
32 _ => {
33 return Err(TokenStream::from(
34 syn::Error::new(meta.path.span(), "invalid argument")
35 .into_compile_error(),
36 ))
37 }
38 }
39 Ok(())
40 })();
41
42 if let Err(tokens) = result {
43 return tokens;
44 }
45 }
46 other => {
47 return TokenStream::from(
48 syn::Error::new_spanned(other, "invalid argument").into_compile_error(),
49 )
50 }
51 }
52 }
53
54 let mut inner_fn = parse_macro_input!(function as ItemFn);
55 if max_retries > 0 && num_iterations > 1 {
56 return TokenStream::from(
57 syn::Error::new_spanned(inner_fn, "retries and randomized iterations can't be mixed")
58 .into_compile_error(),
59 );
60 }
61 let inner_fn_attributes = mem::take(&mut inner_fn.attrs);
62 let inner_fn_name = format_ident!("_{}", inner_fn.sig.ident);
63 let outer_fn_name = mem::replace(&mut inner_fn.sig.ident, inner_fn_name.clone());
64
65 let mut outer_fn: ItemFn = if inner_fn.sig.asyncness.is_some() {
66 // Pass to the test function the number of app contexts that it needs,
67 // based on its parameter list.
68 let mut cx_vars = proc_macro2::TokenStream::new();
69 let mut cx_teardowns = proc_macro2::TokenStream::new();
70 let mut inner_fn_args = proc_macro2::TokenStream::new();
71 for (ix, arg) in inner_fn.sig.inputs.iter().enumerate() {
72 if let FnArg::Typed(arg) = arg {
73 if let Type::Path(ty) = &*arg.ty {
74 let last_segment = ty.path.segments.last();
75 match last_segment.map(|s| s.ident.to_string()).as_deref() {
76 Some("StdRng") => {
77 inner_fn_args.extend(quote!(rand::SeedableRng::seed_from_u64(seed),));
78 continue;
79 }
80 Some("bool") => {
81 inner_fn_args.extend(quote!(is_last_iteration,));
82 continue;
83 }
84 Some("Arc") => {
85 if let syn::PathArguments::AngleBracketed(args) =
86 &last_segment.unwrap().arguments
87 {
88 if let Some(syn::GenericArgument::Type(syn::Type::Path(ty))) =
89 args.args.last()
90 {
91 let last_segment = ty.path.segments.last();
92 if let Some("Deterministic") =
93 last_segment.map(|s| s.ident.to_string()).as_deref()
94 {
95 inner_fn_args.extend(quote!(deterministic.clone(),));
96 continue;
97 }
98 }
99 }
100 }
101 _ => {}
102 }
103 } else if let Type::Reference(ty) = &*arg.ty {
104 if let Type::Path(ty) = &*ty.elem {
105 let last_segment = ty.path.segments.last();
106 if let Some("TestAppContext") =
107 last_segment.map(|s| s.ident.to_string()).as_deref()
108 {
109 let first_entity_id = ix * 100_000;
110 let cx_varname = format_ident!("cx_{}", ix);
111 cx_vars.extend(quote!(
112 let mut #cx_varname = #namespace::TestAppContext::new(
113 foreground_platform.clone(),
114 cx.platform().clone(),
115 deterministic.build_foreground(#ix),
116 deterministic.build_background(),
117 cx.font_cache().clone(),
118 cx.leak_detector(),
119 #first_entity_id,
120 stringify!(#outer_fn_name).to_string(),
121 );
122 ));
123 cx_teardowns.extend(quote!(
124 #cx_varname.update(|cx| cx.remove_all_windows());
125 deterministic.run_until_parked();
126 #cx_varname.update(|cx| cx.clear_globals());
127 ));
128 inner_fn_args.extend(quote!(&mut #cx_varname,));
129 continue;
130 }
131 }
132 }
133 }
134
135 return TokenStream::from(
136 syn::Error::new_spanned(arg, "invalid argument").into_compile_error(),
137 );
138 }
139
140 parse_quote! {
141 #[test]
142 fn #outer_fn_name() {
143 #inner_fn
144
145 #namespace::test::run_test(
146 #num_iterations as u64,
147 #starting_seed as u64,
148 #max_retries,
149 &mut |cx, foreground_platform, deterministic, seed, is_last_iteration| {
150 #cx_vars
151 cx.foreground().run(#inner_fn_name(#inner_fn_args));
152 #cx_teardowns
153 },
154 stringify!(#outer_fn_name).to_string(),
155 );
156 }
157 }
158 } else {
159 let mut inner_fn_args = proc_macro2::TokenStream::new();
160 for arg in inner_fn.sig.inputs.iter() {
161 if let FnArg::Typed(arg) = arg {
162 if let Type::Path(ty) = &*arg.ty {
163 let last_segment = ty.path.segments.last();
164 match last_segment.map(|s| s.ident.to_string()).as_deref() {
165 Some("StdRng") => {
166 inner_fn_args.extend(quote!(rand::SeedableRng::seed_from_u64(seed),));
167 }
168 Some("bool") => {
169 inner_fn_args.extend(quote!(is_last_iteration,));
170 }
171 _ => {}
172 }
173 } else {
174 inner_fn_args.extend(quote!(cx,));
175 }
176 } else {
177 return TokenStream::from(
178 syn::Error::new_spanned(arg, "invalid argument").into_compile_error(),
179 );
180 }
181 }
182
183 parse_quote! {
184 #[test]
185 fn #outer_fn_name() {
186 #inner_fn
187
188 #namespace::test::run_test(
189 #num_iterations as u64,
190 #starting_seed as u64,
191 #max_retries,
192 &mut |cx, _, _, seed, is_last_iteration| #inner_fn_name(#inner_fn_args),
193 stringify!(#outer_fn_name).to_string(),
194 );
195 }
196 }
197 };
198 outer_fn.attrs.extend(inner_fn_attributes);
199
200 TokenStream::from(quote!(#outer_fn))
201}
202
203fn parse_int(literal: &Lit) -> Result<usize, TokenStream> {
204 let result = if let Lit::Int(int) = &literal {
205 int.base10_parse()
206 } else {
207 Err(syn::Error::new(literal.span(), "must be an integer"))
208 };
209
210 result.map_err(|err| TokenStream::from(err.into_compile_error()))
211}