quickcheck_macros/
lib.rs

1use std::mem;
2
3use proc_macro::TokenStream;
4use quote::quote;
5use syn::{
6    parse::{Parse, Parser},
7    parse_quote,
8    spanned::Spanned,
9};
10
11#[proc_macro_attribute]
12pub fn quickcheck(_args: TokenStream, input: TokenStream) -> TokenStream {
13    let output = match syn::Item::parse.parse(input.clone()) {
14        Ok(syn::Item::Fn(mut item_fn)) => {
15            let mut inputs = syn::punctuated::Punctuated::new();
16            let mut errors = Vec::new();
17
18            item_fn.sig.inputs.iter().for_each(|input| match *input {
19                syn::FnArg::Typed(syn::PatType { ref ty, .. }) => {
20                    inputs.push(parse_quote!(_: #ty));
21                }
22                _ => errors.push(syn::parse::Error::new(
23                    input.span(),
24                    "unsupported kind of function argument",
25                )),
26            });
27
28            if errors.is_empty() {
29                let attrs = mem::take(&mut item_fn.attrs);
30                let name = &item_fn.sig.ident;
31                if let Some(variadic) = &item_fn.sig.variadic {
32                    // variadics are just for `extern fn`
33                    errors.push(syn::parse::Error::new(
34                        variadic.span(),
35                        "unsupported variadic",
36                    ));
37                }
38                let fn_type = syn::TypeBareFn {
39                    lifetimes: None,
40                    unsafety: item_fn.sig.unsafety,
41                    abi: item_fn.sig.abi.clone(),
42                    fn_token: <syn::Token![fn]>::default(),
43                    paren_token: syn::token::Paren::default(),
44                    inputs,
45                    variadic: None,
46                    output: item_fn.sig.output.clone(),
47                };
48
49                quote! {
50                    #[test]
51                    #(#attrs)*
52                    fn #name() {
53                        #item_fn
54                       ::quickcheck::quickcheck(#name as #fn_type)
55                    }
56                }
57            } else {
58                errors
59                    .iter()
60                    .map(syn::parse::Error::to_compile_error)
61                    .collect()
62            }
63        }
64        Ok(syn::Item::Static(mut item_static)) => {
65            let attrs = mem::take(&mut item_static.attrs);
66            let name = &item_static.ident;
67
68            quote! {
69                #[test]
70                #(#attrs)*
71                fn #name() {
72                    #item_static
73                    ::quickcheck::quickcheck(#name)
74                }
75            }
76        }
77        _ => {
78            let span = proc_macro2::TokenStream::from(input).span();
79            let msg =
80                "#[quickcheck] is only supported on statics and functions";
81
82            syn::parse::Error::new(span, msg).to_compile_error()
83        }
84    };
85
86    output.into()
87}
quickcheck_macros/lib.rs

quickcheck_macros/
lib.rs
