rwconfig 1.1.0

Read/write config files with get/set and dirty-tracking; save() writes all changes at once
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

//! Config file format detection and parse/stringify.
//!
//! Supports JSON (including JSON5, JSONC), YAML, and TOML.
//! Format is inferred from the file extension.

use crate::error::Error;
use c12_parser::{
    Formatted, parse_json, parse_toml, parse_yaml, stringify_json, stringify_toml, stringify_yaml,
};
use serde_json::Value;
use std::path::Path;

/// Supported config format (detected from file extension).
#[derive(Debug, Clone, Copy, PartialEq, Eq)]
pub enum ConfigFormat {
    /// JSON format (`.json`, `.json5`, `.jsonc`).
    Json,
    /// YAML format (`.yaml`, `.yml`).
    Yaml,
    /// TOML format (`.toml`).
    Toml,
}

impl ConfigFormat {
    /// Infer format from file path extension (case-insensitive).
    pub fn from_path(path: &Path) -> Option<Self> {
        path.extension()
            .and_then(|e| e.to_str())
            .and_then(|e| match e.to_lowercase().as_str() {
                "json" | "json5" | "jsonc" => Some(ConfigFormat::Json),
                "yaml" | "yml" => Some(ConfigFormat::Yaml),
                "toml" => Some(ConfigFormat::Toml),
                _ => None,
            })
    }

    /// Parse text into a formatted value.
    pub fn parse(&self, text: &str) -> Result<Formatted<Value>, Error> {
        match self {
            ConfigFormat::Json => parse_json(text, None).map_err(|e| Error::Parse(e.to_string())),
            ConfigFormat::Yaml => parse_yaml(text, None).map_err(|e| Error::Parse(e.to_string())),
            ConfigFormat::Toml => parse_toml(text, None).map_err(|e| Error::Parse(e.to_string())),
        }
    }

    /// Stringify a formatted value back to text.
    pub fn stringify(&self, formatted: &Formatted<Value>) -> Result<String, Error> {
        match self {
            ConfigFormat::Json => {
                stringify_json(formatted, None).map_err(|e| Error::Parse(e.to_string()))
            }
            ConfigFormat::Yaml => {
                stringify_yaml(formatted, None).map_err(|e| Error::Parse(e.to_string()))
            }
            ConfigFormat::Toml => {
                stringify_toml(formatted, None).map_err(|e| Error::Parse(e.to_string()))
            }
        }
    }
}

#[cfg(test)]
mod tests {
    use super::*;
    use std::path::Path;

    #[test]
    fn from_path_json_extensions() {
        assert_eq!(
            ConfigFormat::from_path(Path::new("x.json")),
            Some(ConfigFormat::Json)
        );
        assert_eq!(
            ConfigFormat::from_path(Path::new("x.json5")),
            Some(ConfigFormat::Json)
        );
        assert_eq!(
            ConfigFormat::from_path(Path::new("x.JSONC")),
            Some(ConfigFormat::Json)
        );
    }

    #[test]
    fn from_path_yaml_extensions() {
        assert_eq!(
            ConfigFormat::from_path(Path::new("x.yaml")),
            Some(ConfigFormat::Yaml)
        );
        assert_eq!(
            ConfigFormat::from_path(Path::new("x.yml")),
            Some(ConfigFormat::Yaml)
        );
    }

    #[test]
    fn from_path_toml() {
        assert_eq!(
            ConfigFormat::from_path(Path::new("x.toml")),
            Some(ConfigFormat::Toml)
        );
    }

    #[test]
    fn from_path_unsupported() {
        assert_eq!(ConfigFormat::from_path(Path::new("x.ini")), None);
        assert_eq!(ConfigFormat::from_path(Path::new("x.txt")), None);
        assert_eq!(ConfigFormat::from_path(Path::new("no_ext")), None);
    }

    #[test]
    fn roundtrip_json() {
        let text = r#"{"a":1,"b":2}"#;
        let formatted = ConfigFormat::Json.parse(text).unwrap();
        let out = ConfigFormat::Json.stringify(&formatted).unwrap();
        let formatted2 = ConfigFormat::Json.parse(&out).unwrap();
        assert_eq!(formatted.value.get("a"), formatted2.value.get("a"));
        assert_eq!(formatted.value.get("b"), formatted2.value.get("b"));
    }

    #[test]
    fn roundtrip_yaml() {
        let text = "info:\n  a: 1\n  b: 2";
        let formatted = ConfigFormat::Yaml.parse(text).unwrap();
        let out = ConfigFormat::Yaml.stringify(&formatted).unwrap();
        let formatted2 = ConfigFormat::Yaml.parse(&out).unwrap();
        assert_eq!(
            formatted.value.get("info").and_then(|o| o.get("a")),
            formatted2.value.get("info").and_then(|o| o.get("a"))
        );
    }

    #[test]
    fn roundtrip_toml() {
        let text = "[info]\na = 1\nb = 2";
        let formatted = ConfigFormat::Toml.parse(text).unwrap();
        let out = ConfigFormat::Toml.stringify(&formatted).unwrap();
        let formatted2 = ConfigFormat::Toml.parse(&out).unwrap();
        assert_eq!(
            formatted.value.get("info").and_then(|o| o.get("a")),
            formatted2.value.get("info").and_then(|o| o.get("a"))
        );
    }
}