codama_attributes/
codama_attribute.rs

1use crate::{utils::SetOnce, Attribute, AttributeContext, CodamaDirective};
2use codama_errors::CodamaError;
3use codama_syn_helpers::extensions::*;
4
5#[derive(Debug, PartialEq)]
6pub struct CodamaAttribute<'a> {
7    pub ast: &'a syn::Attribute,
8    pub directive: Box<CodamaDirective>,
9}
10
11impl<'a> CodamaAttribute<'a> {
12    pub fn parse(ast: &'a syn::Attribute, ctx: &AttributeContext) -> syn::Result<Self> {
13        // Check if the attribute is feature-gated.
14        let unfeatured = ast.unfeatured();
15        let attr = unfeatured.as_ref().unwrap_or(ast);
16
17        // Check if the attribute is a #[codama(...)] attribute.
18        let list = attr.meta.require_list()?;
19        if !list.path.is_strict("codama") {
20            return Err(list.path.error("expected #[codama(...)]"));
21        };
22
23        let mut directive = SetOnce::<CodamaDirective>::new("codama");
24        list.each(|ref meta| directive.set(CodamaDirective::parse(meta, ctx)?, meta))?;
25        Ok(Self {
26            ast,
27            directive: Box::new(directive.take(attr)?),
28        })
29    }
30}
31
32impl<'a> TryFrom<&'a Attribute<'a>> for &'a CodamaAttribute<'a> {
33    type Error = CodamaError;
34
35    fn try_from(attribute: &'a Attribute) -> Result<Self, Self::Error> {
36        match attribute {
37            Attribute::Codama(a) => Ok(a),
38            _ => Err(CodamaError::InvalidAttribute {
39                expected: "codama".to_string(),
40                actual: attribute.name(),
41            }),
42        }
43    }
44}
45
46#[cfg(test)]
47mod tests {
48    use super::*;
49    use syn::parse_quote;
50
51    #[test]
52    fn test_codama_attribute() {
53        let ast = parse_quote! { #[codama(type = boolean)] };
54        let file = syn::File::empty();
55        let ctx = AttributeContext::File(&file);
56        let attribute = CodamaAttribute::parse(&ast, &ctx).unwrap();
57
58        assert_eq!(attribute.ast, &ast);
59        assert!(matches!(
60            attribute.directive.as_ref(),
61            CodamaDirective::Type(_)
62        ));
63    }
64
65    #[test]
66    fn test_feature_gated_codama_attribute() {
67        let ast = parse_quote! { #[cfg_attr(feature = "some_feature", codama(type = boolean))] };
68        let file = syn::File::empty();
69        let ctx = AttributeContext::File(&file);
70        let attribute = CodamaAttribute::parse(&ast, &ctx).unwrap();
71
72        assert_eq!(attribute.ast, &ast);
73        assert!(matches!(
74            attribute.directive.as_ref(),
75            CodamaDirective::Type(_)
76        ));
77    }
78}
codama_attributes/codama_attribute.rs

codama_attributes/
codama_attribute.rs
