codama_attributes/codama_directives/
default_value_directive.rs

1use crate::{utils::FromMeta, Attribute, CodamaAttribute, CodamaDirective};
2use codama_errors::CodamaError;
3use codama_nodes::{DefaultValueStrategy, InstructionInputValueNode, ValueNode};
4use codama_syn_helpers::{extensions::*, Meta};
5
6#[derive(Debug, PartialEq)]
7pub struct DefaultValueDirective {
8    pub node: InstructionInputValueNode,
9    pub default_value_strategy: Option<DefaultValueStrategy>,
10}
11
12impl DefaultValueDirective {
13    pub fn parse(meta: &Meta) -> syn::Result<Self> {
14        Self::parse_logic(meta, false)
15    }
16
17    pub fn parse_value_nodes_only(meta: &Meta) -> syn::Result<Self> {
18        Self::parse_logic(meta, true)
19    }
20
21    fn parse_logic(meta: &Meta, value_nodes_only: bool) -> syn::Result<Self> {
22        let pv = meta.as_path_value()?;
23        let is_default_value = pv.path.is_strict("default_value");
24        let is_value = pv.path.is_strict("value");
25        if !is_default_value && !is_value {
26            return Err(pv
27                .path
28                .error("expected #[codama(default_value)] or #[codama(value)] attributes"));
29        };
30
31        let node = match value_nodes_only {
32            true => ValueNode::from_meta(&pv.value)?.into(),
33            false => InstructionInputValueNode::from_meta(&pv.value)?,
34        };
35
36        let default_value_strategy = match is_value {
37            true => Some(DefaultValueStrategy::Omitted),
38            false => None,
39        };
40
41        Ok(Self {
42            node,
43            default_value_strategy,
44        })
45    }
46}
47
48impl<'a> TryFrom<&'a CodamaAttribute<'a>> for &'a DefaultValueDirective {
49    type Error = CodamaError;
50
51    fn try_from(attribute: &'a CodamaAttribute) -> Result<Self, Self::Error> {
52        match attribute.directive {
53            CodamaDirective::DefaultValue(ref a) => Ok(a),
54            _ => Err(CodamaError::InvalidCodamaDirective {
55                expected: "default_value".to_string(),
56                actual: attribute.directive.name().to_string(),
57            }),
58        }
59    }
60}
61
62impl<'a> TryFrom<&'a Attribute<'a>> for &'a DefaultValueDirective {
63    type Error = CodamaError;
64
65    fn try_from(attribute: &'a Attribute) -> Result<Self, Self::Error> {
66        <&CodamaAttribute>::try_from(attribute)?.try_into()
67    }
68}
69
70#[cfg(test)]
71mod tests {
72    use super::*;
73    use codama_nodes::{BooleanValueNode, PayerValueNode};
74    use syn::parse_quote;
75
76    #[test]
77    fn default_value_ok() {
78        let meta: Meta = parse_quote! { default_value = payer };
79        let directive = DefaultValueDirective::parse(&meta).unwrap();
80
81        assert_eq!(
82            directive,
83            DefaultValueDirective {
84                node: PayerValueNode::new().into(),
85                default_value_strategy: None,
86            }
87        );
88    }
89
90    #[test]
91    fn value_ok() {
92        let meta: Meta = parse_quote! { value = payer };
93        let directive = DefaultValueDirective::parse(&meta).unwrap();
94
95        assert_eq!(
96            directive,
97            DefaultValueDirective {
98                node: PayerValueNode::new().into(),
99                default_value_strategy: Some(DefaultValueStrategy::Omitted),
100            }
101        );
102    }
103
104    #[test]
105    fn parse_value_nodes_only_ok() {
106        let meta: Meta = parse_quote! { value = true };
107        let directive = DefaultValueDirective::parse_value_nodes_only(&meta).unwrap();
108
109        assert_eq!(
110            directive,
111            DefaultValueDirective {
112                node: BooleanValueNode::new(true).into(),
113                default_value_strategy: Some(DefaultValueStrategy::Omitted),
114            }
115        );
116    }
117
118    #[test]
119    fn parse_value_nodes_only_err() {
120        let meta: Meta = parse_quote! { value = payer };
121        let error = DefaultValueDirective::parse_value_nodes_only(&meta).unwrap_err();
122        assert_eq!(error.to_string(), "unrecognized value");
123    }
124
125    #[test]
126    fn no_input() {
127        let meta: Meta = parse_quote! { default_value =  };
128        let error = DefaultValueDirective::parse(&meta).unwrap_err();
129        assert_eq!(error.to_string(), "unrecognized value");
130    }
131
132    #[test]
133    fn multiple_inputs() {
134        let meta: Meta = parse_quote! { default_value = (true, false) };
135        let error = DefaultValueDirective::parse(&meta).unwrap_err();
136        assert_eq!(error.to_string(), "expected a single value, found a list");
137    }
138
139    #[test]
140    fn unrecognized_value() {
141        let meta: Meta = parse_quote! { default_value = banana };
142        let error = DefaultValueDirective::parse(&meta).unwrap_err();
143        assert_eq!(error.to_string(), "unrecognized value");
144    }
145}