jsonc-parser 0.17.0

JSONC 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

use super::ast::Value as AstValue;
use super::{errors::ParseError, parse_to_ast, ParseOptions};
use serde_json::Value as SerdeValue;
use std::str::FromStr;

/// Parses a string containing JSONC to a `serde_json::Value.
///
/// # Example
///
/// ```
/// use jsonc_parser::parse_to_serde_value;
///
/// let json_value = parse_to_serde_value(r#"{ "test": 5 } // test"#).expect("Should parse.");
/// ```
pub fn parse_to_serde_value(text: &str) -> Result<Option<SerdeValue>, ParseError> {
    let value = parse_to_ast(
        text,
        &ParseOptions {
            comments: false,
            tokens: false,
        },
    )?
    .value;
    Ok(value.map(to_serde))
}

fn to_serde(value: AstValue) -> SerdeValue {
    // originally from the Deno repo, then shaped to work here
    match value {
        AstValue::Array(arr) => {
            let vec = arr.elements.into_iter().map(to_serde).collect();
            SerdeValue::Array(vec)
        }
        AstValue::BooleanLit(bool) => SerdeValue::Bool(bool.value),
        AstValue::NullKeyword(_) => SerdeValue::Null,
        AstValue::NumberLit(num) => {
            let number = serde_json::Number::from_str(num.value).expect("could not parse number");
            SerdeValue::Number(number)
        }
        AstValue::Object(obj) => {
            let mut map = serde_json::map::Map::new();
            for prop in obj.properties.into_iter() {
                map.insert(prop.name.into_string(), to_serde(prop.value));
            }
            SerdeValue::Object(map)
        }
        AstValue::StringLit(str) => SerdeValue::String(str.value.into_owned()),
    }
}

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

    #[test]
    fn it_should_error_when_has_error() {
        assert_has_error(
            "[][]",
            "Text cannot contain more than one JSON value on line 1 column 3.",
        );
    }

    fn assert_has_error(text: &str, message: &str) {
        let result = parse_to_serde_value(text);
        match result {
            Ok(_) => panic!("Expected error, but did not find one."),
            Err(err) => assert_eq!(err.to_string(), message),
        }
    }

    #[test]
    fn it_should_parse_to_serde_value() {
        let result = parse_to_serde_value(
            r#"{ "a": { "a1": 5 }, "b": [0.3e+025], "c": "c1", "d": true, "e": false, "f": null }"#,
        )
        .unwrap();

        let mut expected_value = serde_json::map::Map::new();
        expected_value.insert("a".to_string(), {
            let mut inner_obj = serde_json::map::Map::new();
            inner_obj.insert(
                "a1".to_string(),
                SerdeValue::Number(serde_json::Number::from_str("5").unwrap()),
            );
            SerdeValue::Object(inner_obj)
        });
        expected_value.insert("b".to_string(), {
            let mut inner_array = Vec::new();
            inner_array.push(SerdeValue::Number(
                serde_json::Number::from_str("0.3e+025").unwrap(),
            ));
            SerdeValue::Array(inner_array)
        });
        expected_value.insert("c".to_string(), SerdeValue::String("c1".to_string()));
        expected_value.insert("d".to_string(), SerdeValue::Bool(true));
        expected_value.insert("e".to_string(), SerdeValue::Bool(false));
        expected_value.insert("f".to_string(), SerdeValue::Null);

        assert_eq!(result, Some(SerdeValue::Object(expected_value)));
    }
}