codama_attributes/codama_directives/
default_value_directive.rs

1use crate::{utils::FromMeta, Attribute, CodamaAttribute, CodamaDirective};
2use codama_errors::CodamaError;
3use codama_nodes::InstructionInputValueNode;
4use codama_syn_helpers::Meta;
5
6#[derive(Debug, PartialEq)]
7pub struct DefaultValueDirective {
8    pub node: InstructionInputValueNode,
9}
10
11impl DefaultValueDirective {
12    pub fn parse(meta: &Meta) -> syn::Result<Self> {
13        let pv = meta.assert_directive("default_value")?.as_path_value()?;
14        let node = InstructionInputValueNode::from_meta(&pv.value)?;
15        Ok(Self { node })
16    }
17}
18
19impl<'a> TryFrom<&'a CodamaAttribute<'a>> for &'a DefaultValueDirective {
20    type Error = CodamaError;
21
22    fn try_from(attribute: &'a CodamaAttribute) -> Result<Self, Self::Error> {
23        match attribute.directive {
24            CodamaDirective::DefaultValue(ref a) => Ok(a),
25            _ => Err(CodamaError::InvalidCodamaDirective {
26                expected: "default_value".to_string(),
27                actual: attribute.directive.name().to_string(),
28            }),
29        }
30    }
31}
32
33impl<'a> TryFrom<&'a Attribute<'a>> for &'a DefaultValueDirective {
34    type Error = CodamaError;
35
36    fn try_from(attribute: &'a Attribute) -> Result<Self, Self::Error> {
37        <&CodamaAttribute>::try_from(attribute)?.try_into()
38    }
39}
40
41#[cfg(test)]
42mod tests {
43    use super::*;
44    use codama_nodes::BooleanValueNode;
45    use syn::parse_quote;
46
47    #[test]
48    fn ok() {
49        let meta: Meta = parse_quote! { default_value = true };
50        let node = DefaultValueDirective::parse(&meta).unwrap().node;
51
52        assert_eq!(node, BooleanValueNode::new(true).into());
53    }
54
55    #[test]
56    fn no_input() {
57        let meta: Meta = parse_quote! { default_value =  };
58        let error = DefaultValueDirective::parse(&meta).unwrap_err();
59        assert_eq!(error.to_string(), "unrecognized value");
60    }
61
62    #[test]
63    fn multiple_inputs() {
64        let meta: Meta = parse_quote! { default_value = (true, false) };
65        let error = DefaultValueDirective::parse(&meta).unwrap_err();
66        assert_eq!(error.to_string(), "expected a single value, found a list");
67    }
68
69    #[test]
70    fn unrecognized_value() {
71        let meta: Meta = parse_quote! { default_value = banana };
72        let error = DefaultValueDirective::parse(&meta).unwrap_err();
73        assert_eq!(error.to_string(), "unrecognized value");
74    }
75}
codama_attributes/codama_directives/default_value_directive.rs

codama_attributes/codama_directives/
default_value_directive.rs
