fronma 0.2.0

Front Matter parser.
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

use crate::engines::{Engine, Yaml};
use crate::error::Error;
use crate::result::Result;

#[cfg(feature = "default")]
pub fn parse<T>(text: &str) -> Result<ParsedData<T>>
where
    T: serde::de::DeserializeOwned,
{
    parse_with_engine::<T, Yaml>(text)
}

pub fn parse_with_engine<T, E>(text: &str) -> Result<ParsedData<T>>
where
    T: serde::de::DeserializeOwned,
    E: Engine<T>,
{
    let line_pattern_lf = "---\n";
    let line_pattern_crlf = "---\r\n";

    if let Some(slice) = text.strip_prefix(line_pattern_lf) {
        let index_of_ending_line = slice
            .find(line_pattern_lf)
            .ok_or(Error::MissingEndingLine)?;
        let headers = E::parse(&slice[..index_of_ending_line])?;
        let body = &slice[(index_of_ending_line + line_pattern_lf.len())..];
        Ok(ParsedData { body, headers })
    } else if let Some(slice) = text.strip_prefix(line_pattern_crlf) {
        let index_of_ending_line = slice
            .find(line_pattern_crlf)
            .ok_or(Error::MissingEndingLine)?;
        let headers = E::parse(&slice[..index_of_ending_line])?;
        let body = &slice[(index_of_ending_line + line_pattern_crlf.len())..];
        Ok(ParsedData { body, headers })
    } else {
        Err(Error::MissingBeginningLine)
    }
}

#[derive(Debug)]
pub struct ParsedData<'a, T: serde::de::DeserializeOwned> {
    pub body: &'a str,
    pub headers: T,
}

#[cfg(feature = "default")]
#[cfg(test)]
mod tests {
    use crate::error::Error;
    use crate::parser::parse;
    use serde::Deserialize;

    #[derive(Debug, Deserialize)]
    struct Headers {
        title: String,
    }

    #[test]
    fn parse_with_missing_beginning_line() {
        let text = "";
        let result = parse::<Headers>(text);
        assert!(matches!(result, Err(Error::MissingBeginningLine)));
    }

    #[test]
    fn parse_with_missing_ending_line() {
        let text = "---\n";
        let result = parse::<Headers>(text);
        assert!(matches!(result, Err(Error::MissingEndingLine)));
    }

    #[test]
    fn parse_with_missing_ending_line_crlf() {
        let text = "---\r\n";
        let result = parse::<Headers>(text);
        assert!(matches!(result, Err(Error::MissingEndingLine)));
    }

    #[test]
    fn parse_with_empty_frontmatter() {
        let text = "---\n---\n";
        let result = parse::<Headers>(text);
        assert!(matches!(result, Err(Error::SerdeYaml(_))));
    }

    #[test]
    fn parse_with_empty_frontmatter_crlf() {
        let text = "---\r\n---\r\n";
        let result = parse::<Headers>(text);
        assert!(matches!(result, Err(Error::SerdeYaml(_))));
    }

    #[test]
    fn parse_with_missing_known_field() {
        let text = "---\ndate: 2000-01-01\n---\n";
        let result = parse::<Headers>(text);
        assert!(matches!(result, Err(Error::SerdeYaml(_))));
    }

    #[test]
    fn parse_with_missing_known_field_crlf() {
        let text = "---\r\ndate: 2000-01-01\r\n---\r\n";
        let result = parse::<Headers>(text);
        assert!(matches!(result, Err(Error::SerdeYaml(_))));
    }

    #[test]
    fn parse_with_unknown_field() {
        let text = "---\ndate: 2000-01-01\ntitle: dummy_title\n---\n";
        let result = parse::<Headers>(text);
        dbg!(&result);
        assert!(matches!(result, Ok(_)));
    }

    #[test]
    fn parse_with_unknown_field_crlf() {
        let text = "---\r\ndate: 2000-01-01\r\ntitle: dummy_title\r\n---\r\n";
        let result = parse::<Headers>(text);
        dbg!(&result);
        assert!(matches!(result, Ok(_)));
    }

    #[test]
    fn parse_with_empty_known_field() {
        let text = "---\ntitle:\n---\n";
        let result = parse::<Headers>(text).unwrap();
        assert_eq!(result.headers.title, "~");
        assert_eq!(result.body, "");
    }

    #[test]
    fn parse_with_empty_known_field_crlf() {
        let text = "---\r\ntitle:\r\n---\r\n";
        let result = parse::<Headers>(text).unwrap();
        assert_eq!(result.headers.title, "~");
        assert_eq!(result.body, "");
    }

    #[test]
    fn parse_with_valid_frontmatter() {
        let text = "---\ntitle: dummy_title---\ndummy_body";
        let result = parse::<Headers>(text).unwrap();
        assert_eq!(result.headers.title, "dummy_title");
        assert_eq!(result.body, "dummy_body");
    }
    #[test]
    fn parse_with_valid_frontmatter_crlf() {
        let text = "---\r\ntitle: dummy_title---\r\ndummy_body";
        let result = parse::<Headers>(text).unwrap();
        assert_eq!(result.headers.title, "dummy_title");
        assert_eq!(result.body, "dummy_body");
    }
}