genies_derive 1.7.0

A powerful derive macro for configuration management in Rust
Documentation 
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119

/*
 * @Author: tzw
 * @Date: 2021-10-31 01:42:16
 * @LastEditors: tzw
 * @LastEditTime: 2022-01-17 00:05:20
 */
use crate::helpers::find_attribute;
use proc_macro::TokenStream;
use quote::quote;
// use syn::export::ToTokens;
use syn::{DataEnum, DataStruct, DataUnion, DeriveInput, Fields};

pub fn derive_event_type_for_enum(ast: &DeriveInput, enum_data: &DataEnum) -> TokenStream {
    let (impl_generics, ty_generics, where_clause) = ast.generics.split_for_impl();
    let tname = &ast.ident;
    let evversion = find_attribute("event_type_version", &ast.attrs)
        .map(|attr| attr.tokens.clone())
        .unwrap_or_else(|| quote!("V0"));
    let evsource = find_attribute("event_source", &ast.attrs)
        .map(|attr| attr.tokens.clone())
        .unwrap_or_else(|| quote!(""));

    let event_matches = enum_data
        .variants
        .iter()
        .map(|variant| {
            let vname = &variant.ident;
            let default_evtype = &format!("{}::{}", tname, vname);
            let evtype = find_attribute("event_type", &variant.attrs)
                .map(|attr| attr.tokens.clone())
                .unwrap_or_else(|| quote!(#default_evtype));
            match variant.fields {
                Fields::Unit => quote! {
                    #tname::#vname => #evtype,
                },
                Fields::Unnamed(ref fields) => {
                    let field_names = fields
                        .unnamed
                        .pairs()
                        .map(|p| p.value().ident.as_ref())
                        .collect::<Vec<_>>();
                    quote! {
                        #tname::#vname( #(_ #field_names,)* ) => #evtype,
                    }
                }
                Fields::Named(ref fields) => {
                    let field_names = fields
                        .named
                        .pairs()
                        .map(|p| p.value().ident.as_ref())
                        .collect::<Vec<_>>();
                    quote! {
                        #tname::#vname { #(#field_names: _,)* } => #evtype,
                    }
                }
            }
        })
        .collect::<Vec<_>>();

    (quote! {
        #[allow(unused_qualifications, unused_parens)]
        #[automatically_derived]
        impl #impl_generics genies::ddd::event::DomainEvent for #tname #ty_generics #where_clause {
            fn event_type_version(&self) -> String {
                #evversion.to_string()
            }
            fn event_type(&self) -> String {
                match self {
                    #(#event_matches.to_string())*
                }
            }
            fn event_source(&self) -> String {
                #evsource.to_string()
            }
            fn json(&self)->String{
                serde_json::to_string(self).unwrap()
            }            
        }
    })
    .into()
}

pub fn derive_event_type_for_struct(ast: &DeriveInput, _struct_data: &DataStruct) -> TokenStream {
    let (impl_generics, ty_generics, where_clause) = ast.generics.split_for_impl();
    let tname = &ast.ident;
    let evversion = find_attribute("event_type_version", &ast.attrs)
        .map(|attr| attr.tokens.clone())
        .unwrap_or_else(|| quote!("V0"));
    let evsource = find_attribute("event_source", &ast.attrs)
        .map(|attr| attr.tokens.clone())
        .unwrap_or_else(|| quote!(""));
    let evtype = find_attribute("event_type", &ast.attrs)
        .map(|attr| attr.tokens.clone())
        .unwrap_or_else(|| quote!(stringify!(#tname)));

    (quote! {
        #[allow(unused_qualifications, unused_parens)]
        #[automatically_derived]
        impl #impl_generics genies::ddd::event::DomainEvent for #tname #ty_generics #where_clause {
            fn event_type_version(&self) ->String{
                #evversion.to_string()
            }
            fn event_type(&self) ->String{
                #evtype.to_string()
            }
            fn event_source(&self) ->String {
                #evsource.to_string()
            }
            fn json(&self)->String{
                serde_json::to_string(self).unwrap()
            }
        }
    })
    .into()
}

pub fn derive_event_type_for_union(_ast: &DeriveInput, _union_data: &DataUnion) -> TokenStream {
    panic!("#[derive(DomainEvent)] is only defined for struct and enum types, but not union types")
}