codama_syn_helpers/extensions/
type.rs

1use super::{PathExtension, ToTokensExtension};
2use codama_errors::CodamaResult;
3use syn::Type;
4
5pub trait TypeExtension {
6    fn get_self(&self) -> &Type;
7
8    fn as_path(&self) -> CodamaResult<&syn::Path> {
9        let this = self.get_self();
10        match this {
11            Type::Path(path) => Ok(&path.path),
12            _ => Err(this.error("expected a path").into()),
13        }
14    }
15
16    fn single_generic_type_from_path(&self, path: &str) -> CodamaResult<&Type> {
17        let this = self.as_path()?;
18        match this.is(path) {
19            true => this.single_generic_type(),
20            false => Err(this.error(format!("expected path: {path}")).into()),
21        }
22    }
23}
24
25impl TypeExtension for Type {
26    fn get_self(&self) -> &Type {
27        self
28    }
29}
30
31#[cfg(test)]
32mod tests {
33    use super::*;
34
35    #[test]
36    fn as_path_ok() {
37        let r#type: Type = syn::parse_quote! { std::option::Option<String> };
38        assert!(r#type.as_path().is_ok());
39    }
40
41    #[test]
42    fn as_path_err() {
43        let r#type: Type = syn::parse_quote! { [u8; 32] };
44        assert!(r#type.as_path().is_err());
45    }
46
47    #[test]
48    fn single_generic_type_from_path_ok() {
49        let r#type: Type = syn::parse_quote! { std::option::Option<String> };
50        assert!(r#type
51            .single_generic_type_from_path("std::option::Option")
52            .is_ok());
53
54        let r#type: Type = syn::parse_quote! { Option<String> };
55        assert!(r#type
56            .single_generic_type_from_path("std::option::Option")
57            .is_ok());
58        assert!(r#type.single_generic_type_from_path("Option").is_ok());
59    }
60
61    #[test]
62    fn single_generic_type_from_path_err() {
63        let r#type: Type = syn::parse_quote! { [u8; 32] };
64        assert!(r#type.single_generic_type_from_path("Option").is_err());
65
66        let r#type: Type = syn::parse_quote! { std::option::Option<String> };
67        assert!(r#type.single_generic_type_from_path("Option").is_err());
68        assert!(r#type
69            .single_generic_type_from_path("wrong::prefix::Option")
70            .is_err());
71
72        let r#type: Type = syn::parse_quote! { Option<String, u32> };
73        assert!(r#type.single_generic_type_from_path("Option").is_err());
74    }
75}
codama_syn_helpers/extensions/type.rs

codama_syn_helpers/extensions/
type.rs
