summaryrefslogtreecommitdiffstats
path: root/tokio-macros/src/lib.rs
blob: 80c838e61881f5ee2afa8a103c308e4f77555b2d (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
#![deny(missing_debug_implementations, unreachable_pub, rust_2018_idioms)]
#![cfg_attr(test, deny(warnings))]
#![doc(test(no_crate_inject, attr(deny(rust_2018_idioms))))]

//! Macros for use with Tokio

extern crate proc_macro;

use proc_macro::TokenStream;
use quote::{quote, quote_spanned};
use syn::spanned::Spanned;

/// Define the program entry point
///
/// # Examples
///
/// ```
/// #[tokio::main]
/// async fn main() {
///     println!("Hello from Tokio!");
/// }
/// ```
#[proc_macro_attribute]
#[cfg(not(test))] // Work around for rust-lang/rust#62127
pub fn main(_attr: TokenStream, item: TokenStream) -> TokenStream {
    let input = syn::parse_macro_input!(item as syn::ItemFn);

    let ret = &input.decl.output;
    let name = &input.ident;
    let body = &input.block;

    if input.asyncness.is_none() {
        let tokens = quote_spanned! { input.span() =>
          compile_error!("the async keyword is missing from the function declaration");
        };

        return TokenStream::from(tokens);
    }

    let result = quote! {
        fn #name() #ret {
            let mut rt = tokio::runtime::Runtime::new().unwrap();
            rt.block_on(async { #body })
        }
    };

    result.into()
}

/// Define a Tokio aware unit test
///
/// # Examples
///
/// ```ignore
/// #[tokio::test]
/// async fn my_test() {
///     assert!(true);
/// }
/// ```
#[proc_macro_attribute]
pub fn test(_attr: TokenStream, item: TokenStream) -> TokenStream {
    let input = syn::parse_macro_input!(item as syn::ItemFn);

    let ret = &input.decl.output;
    let name = &input.ident;
    let body = &input.block;
    let attrs = &input.attrs;

    if input.asyncness.is_none() {
        let tokens = quote_spanned! { input.span() =>
          compile_error!("the async keyword is missing from the function declaration");
        };

        return TokenStream::from(tokens);
    }

    let result = quote! {
        #[test]
        #(#attrs)*
        fn #name() #ret {
            let mut rt = tokio::runtime::current_thread::Runtime::new().unwrap();
            rt.block_on_async(async { #body })
        }
    };

    result.into()
}