ruma_macros/
api.rs

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1//! Methods and types for generating API endpoints.
2
3use std::{env, fs, path::Path, sync::OnceLock};
4
5use proc_macro2::Span;
6use serde::{de::IgnoredAny, Deserialize};
7
8mod attribute;
9mod auth_scheme;
10pub mod request;
11pub mod response;
12
13mod kw {
14    syn::custom_keyword!(error);
15}
16
17// Returns an error with a helpful error if the crate the request or response macro is used from
18// doesn't declare both a `client` and a `server` feature.
19fn ensure_feature_presence() -> Option<&'static syn::Error> {
20    #[derive(Deserialize)]
21    struct CargoToml {
22        features: Features,
23    }
24
25    #[derive(Deserialize)]
26    struct Features {
27        client: Option<IgnoredAny>,
28        server: Option<IgnoredAny>,
29    }
30
31    static RESULT: OnceLock<Result<(), syn::Error>> = OnceLock::new();
32
33    RESULT
34        .get_or_init(|| {
35            let manifest_dir = env::var("CARGO_MANIFEST_DIR").map_err(|_| {
36                syn::Error::new(Span::call_site(), "Failed to read CARGO_MANIFEST_DIR")
37            })?;
38
39            let manifest_file = Path::new(&manifest_dir).join("Cargo.toml");
40            let manifest_bytes = fs::read_to_string(manifest_file)
41                .map_err(|_| syn::Error::new(Span::call_site(), "Failed to read Cargo.toml"))?;
42
43            let manifest_parsed: CargoToml = toml::from_str(&manifest_bytes)
44                .map_err(|_| syn::Error::new(Span::call_site(), "Failed to parse Cargo.toml"))?;
45
46            if manifest_parsed.features.client.is_none() {
47                return Err(syn::Error::new(
48                    Span::call_site(),
49                    "This crate doesn't define a `client` feature in its `Cargo.toml`.\n\
50                 Please add a `client` feature such that generated `OutgoingRequest` and \
51                 `IncomingResponse` implementations can be enabled.",
52                ));
53            }
54
55            if manifest_parsed.features.server.is_none() {
56                return Err(syn::Error::new(
57                    Span::call_site(),
58                    "This crate doesn't define a `server` feature in its `Cargo.toml`.\n\
59                 Please add a `server` feature such that generated `IncomingRequest` and \
60                 `OutgoingResponse` implementations can be enabled.",
61                ));
62            }
63
64            Ok(())
65        })
66        .as_ref()
67        .err()
68}
ruma_macros/api.rs

ruma_macros/
api.rs
