fairjax 0.1.0

Fair join pattern matching
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
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167

use crate::compile::matchers::SetupCodeGen;
use crate::traits::Definition;
use proc_macro2::{Span, TokenStream};
use quote::quote_spanned;

pub trait SetupSectionCodeGen {
    fn generate<D: SetupCodeGen>(def: &dyn Definition) -> TokenStream;
}

pub struct SetupSection;

impl SetupSectionCodeGen for SetupSection {
    fn generate<S: SetupCodeGen>(def: &dyn Definition) -> TokenStream {
        let mailbox = def.context().mailbox;

        let matcher_factories: Vec<_> = def
            .cases()
            .iter()
            .map(|cb| syn::Ident::new(&format!("matcher{}", cb.case().index()), cb.case().span()))
            .collect();

        let setups = matcher_factories
            .iter()
            .zip(def.cases().iter())
            .map(|(ident, case)| S::generate(*case, def.context(), ident))
            .collect::<Vec<TokenStream>>();

        quote_spanned! { Span::call_site() =>
            #(
                #setups
                #mailbox.add_case(#matcher_factories());
            )*
        }
    }
}

#[cfg(test)]
mod tests {
    use super::*;
    use crate::analyse::groups::SubPatternGroups;
    use crate::analyse::partition::Partitioning;
    use crate::analyse::strategy::Strategy;
    use crate::parse::context::Context;
    use crate::traits::{Case, CaseBundle, Definition, Pattern, SubPattern};
    use proc_macro_utils::assert_tokens;
    use proc_macro2::{Ident, Span, TokenStream};
    use quote::{ToTokens, format_ident};

    struct MockCaseBundle {
        case: MockCase,
    }

    impl CaseBundle for MockCaseBundle {
        fn case(&self) -> &dyn Case {
            &self.case
        }
        fn strategy(&self) -> &Strategy {
            unimplemented!()
        }

        fn sub_pattern_groups(&self) -> &SubPatternGroups {
            unimplemented!()
        }

        fn sub_pattern_at_index(&self, _index: usize) -> &dyn SubPattern {
            unimplemented!()
        }

        fn partitioning(&self) -> &Option<Partitioning> {
            unimplemented!()
        }
    }

    // Mock Case
    struct MockCase {
        id: usize,
    }

    impl Case for MockCase {
        fn index(&self) -> usize {
            self.id
        }
        fn pattern(&self) -> &dyn Pattern {
            unimplemented!()
        }
        fn guard(&self) -> Option<syn::Expr> {
            unimplemented!()
        }
        fn body(&self) -> syn::Expr {
            unimplemented!()
        }
        fn span(&self) -> Span {
            Span::call_site()
        }
        fn ident_with_case_id(&self, _name: &'static str) -> Ident {
            unimplemented!()
        }
    }

    // Mock Definition
    struct MockDefinition {
        cases: Vec<MockCaseBundle>,
        context: Context,
    }
    impl Definition for MockDefinition {
        fn cases(&self) -> Vec<&dyn CaseBundle> {
            self.cases.iter().map(|c| c as &dyn CaseBundle).collect()
        }
        fn context(&self) -> Context {
            self.context.clone()
        }
    }

    // Mock SetupCodeGen
    struct MockSetupCodeGen;
    impl SetupCodeGen for MockSetupCodeGen {
        fn generate(case: &dyn CaseBundle, _context: Context, ident: &syn::Ident) -> TokenStream {
            format_ident!("setup{}_{}", case.case().index(), ident).to_token_stream()
        }
    }

    #[test]
    fn test_single_case() {
        let def = MockDefinition {
            cases: vec![MockCaseBundle {
                case: MockCase { id: 0 },
            }],
            context: Context {
                incoming_message: syn::parse_quote! { msg },
                mailbox: syn::parse_quote! { mailbox },
                message_type: syn::parse_quote! { MyMessage },
            },
        };
        let result = SetupSection::generate::<MockSetupCodeGen>(&def);

        assert_tokens!(result, { setup0_matcher0 mailbox.add_case(matcher0()); });
    }

    #[test]
    fn test_multiple_cases() {
        let def = MockDefinition {
            cases: vec![
                MockCaseBundle {
                    case: MockCase { id: 0 },
                },
                MockCaseBundle {
                    case: MockCase { id: 1 },
                },
                MockCaseBundle {
                    case: MockCase { id: 2 },
                },
            ],
            context: Context {
                incoming_message: syn::parse_quote! { msg },
                mailbox: syn::parse_quote! { mailbox },
                message_type: syn::parse_quote! { MyMessage },
            },
        };
        let result = SetupSection::generate::<MockSetupCodeGen>(&def);

        assert_tokens!(result, {
            setup0_matcher0 mailbox.add_case(matcher0());
            setup1_matcher1 mailbox.add_case(matcher1());
            setup2_matcher2 mailbox.add_case(matcher2());
        });
    }
}