lib-ruby-parser-nodes 0.37.0

Ruby parser nodes data
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

use crate::template::fns::BucketKey;
use crate::template::{render::Render, shards::FnName, Buffer, Dispatch, Parse, TemplateFns, F};

#[derive(Debug, PartialEq)]
pub struct Condition<Branch> {
    predicate_name: String,
    if_true: Option<Branch>,
    if_false: Option<Branch>,
}

impl<Branch> Condition<Branch> {
    pub(crate) fn new<S>(
        predicate_name: S,
        if_true: Option<Branch>,
        if_false: Option<Branch>,
    ) -> Self
    where
        S: Into<String>,
    {
        Self {
            predicate_name: predicate_name.into(),
            if_true,
            if_false,
        }
    }
}

impl<Branch> Parse for Condition<Branch>
where
    Branch: Parse,
{
    fn parse(buffer: &mut Buffer) -> Option<Self> {
        // consume "{{ if "
        if !buffer.is("{{ if ") {
            return None;
        }
        buffer.consume("{{ if ");

        // capture predicate
        let start = buffer.pos();
        let predicate_name = FnName::parse(buffer)
            .unwrap_or_else(|| panic!("predicate name is empty at pos {}", start))
            .unwrap();

        // consume " }}"
        if !buffer.is(" }}") {
            panic!("{{ if }} is not closed at {}", buffer.pos());
        }
        buffer.consume(" }}");

        // capture if-true body
        let if_true = Branch::parse(buffer);

        // consume "{{ else }}"
        if !buffer.is("{{ else }}") {
            panic!("expected to get {{ else }} at {}", buffer.pos())
        }
        buffer.consume("{{ else }}");

        // capture if-false body
        let if_false = Branch::parse(buffer);

        // consume "{{ end }}"
        if !buffer.is("{{ end }}") {
            panic!("expected to get {{ end }} at {}", buffer.pos())
        }
        buffer.consume("{{ end }}");

        Some(Self::new(predicate_name, if_true, if_false))
    }
}

impl<Context, Branch> Render<Context> for Condition<Branch>
where
    Branch: Render<Context>,
    Context: BucketKey,
    TemplateFns: Dispatch<Context, F::Predicate>,
{
    fn render(&self, ctx: &Context, fns: &TemplateFns) -> String {
        let predicate_value = fns
            .dispatch(&self.predicate_name, ctx)
            .unwrap_or_else(|| panic!("Can't find node predicate {}", self.predicate_name));

        let branch = if predicate_value {
            &self.if_true
        } else {
            &self.if_false
        };

        if let Some(branch) = branch.as_ref() {
            branch.render(ctx, fns)
        } else {
            String::from("")
        }
    }
}

#[cfg(test)]
mod tests {
    use crate::template::{
        global_context::NO_DATA,
        shards::StringPart,
        structs::{Template, TemplatePart},
        GlobalContext, F,
    };

    use super::*;

    #[test]
    fn test_parse() {
        let mut buffer = Buffer::new("{{ if foo }}1{{ else }}2{{ end }}".as_bytes().to_vec());
        let parsed = Condition::<Template>::parse(&mut buffer).unwrap();

        assert_eq!(
            parsed,
            Condition::new(
                "foo",
                Some(Template::new([TemplatePart::StringPart(StringPart::new(
                    "1"
                ))])),
                Some(Template::new([TemplatePart::StringPart(StringPart::new(
                    "2"
                ))]))
            )
        )
    }

    #[test]
    fn test_render() {
        let condition = Condition::new(
            "foo",
            Some(Template::new([TemplatePart::StringPart(StringPart::new(
                "1",
            ))])),
            Some(Template::new([TemplatePart::StringPart(StringPart::new(
                "2",
            ))])),
        );

        let mut fns = TemplateFns::new();
        fn always_true(_: &GlobalContext) -> bool {
            true
        }
        fns.register::<GlobalContext, F::Predicate>("foo", always_true);
        assert_eq!("1", condition.render(NO_DATA, &fns));

        let mut fns = TemplateFns::new();
        fn always_false(_: &GlobalContext) -> bool {
            false
        }
        fns.register::<GlobalContext, F::Predicate>("foo", always_false);
        assert_eq!("2", condition.render(NO_DATA, &fns));
    }
}