tstring-json 0.2.1

JSON parser-first renderer for t-string structured data backends
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

use tstring_json::{
    JsonKeyValue, JsonStringPart, JsonValueNode, check_template, format_template, parse_template,
    parse_validated_template, validate_template,
};
use tstring_syntax::{TemplateInput, TemplateInterpolation, TemplateSegment};

fn interpolation(index: usize, expression: &str) -> TemplateSegment {
    TemplateSegment::Interpolation(TemplateInterpolation {
        expression: expression.to_owned(),
        conversion: None,
        format_spec: String::new(),
        interpolation_index: index,
        raw_source: None,
    })
}

#[test]
fn parses_json_with_interpolated_key_and_value_segments() {
    let template = TemplateInput::from_segments(vec![
        TemplateSegment::StaticText("{\"name-".to_owned()),
        interpolation(0, "left"),
        TemplateSegment::StaticText("\": ".to_owned()),
        interpolation(1, "right"),
        TemplateSegment::StaticText("}".to_owned()),
    ]);

    let document = parse_template(&template).expect("expected JSON parse success");
    let JsonValueNode::Object(object) = document.value else {
        panic!("expected JSON object");
    };
    assert_eq!(object.members.len(), 1);
    let JsonKeyValue::String(key) = &object.members[0].key.value else {
        panic!("expected promoted JSON string key");
    };
    assert!(matches!(key.chunks[1], JsonStringPart::Interpolation(_)));
    assert!(matches!(
        object.members[0].value,
        JsonValueNode::Interpolation(_)
    ));
}

#[test]
fn json_parse_errors_include_spans() {
    let template = TemplateInput::from_segments(vec![TemplateSegment::StaticText(
        "{\"a\": 1 trailing}".to_owned(),
    )]);

    let error = parse_template(&template).expect_err("expected JSON parse failure");
    assert_eq!(error.diagnostics[0].code, "json.parse");
    assert!(error.diagnostics[0].span.is_some());
}

#[test]
fn checks_valid_json_templates() {
    let template = TemplateInput::from_segments(vec![
        TemplateSegment::StaticText("{\"name\": ".to_owned()),
        interpolation(0, "name"),
        TemplateSegment::StaticText(", \"message\": \"hello ".to_owned()),
        TemplateSegment::Interpolation(TemplateInterpolation {
            expression: "user".to_owned(),
            conversion: Some("r".to_owned()),
            format_spec: ">5".to_owned(),
            interpolation_index: 1,
            raw_source: Some("{user!r:>5}".to_owned()),
        }),
        TemplateSegment::StaticText("\"}".to_owned()),
    ]);

    check_template(&template).expect("expected check success");
}

#[test]
fn validates_json_templates_with_supported_interpolations() {
    let template = TemplateInput::from_segments(vec![
        TemplateSegment::StaticText("{\"name\": ".to_owned()),
        interpolation(0, "name"),
        TemplateSegment::StaticText(", \"active\": true}".to_owned()),
    ]);

    validate_template(&template).expect("expected validate success");
    parse_validated_template(&template).expect("expected validated parse success");
}

#[test]
fn formats_json_templates_with_raw_interpolations() {
    let template = TemplateInput::from_segments(vec![
        TemplateSegment::StaticText("{".to_owned()),
        TemplateSegment::Interpolation(TemplateInterpolation {
            expression: "key".to_owned(),
            conversion: None,
            format_spec: String::new(),
            interpolation_index: 0,
            raw_source: Some("{key}".to_owned()),
        }),
        TemplateSegment::StaticText(": ".to_owned()),
        TemplateSegment::Interpolation(TemplateInterpolation {
            expression: "value".to_owned(),
            conversion: None,
            format_spec: String::new(),
            interpolation_index: 1,
            raw_source: Some("{value}".to_owned()),
        }),
        TemplateSegment::StaticText(", \"greeting\": \"hi ".to_owned()),
        TemplateSegment::Interpolation(TemplateInterpolation {
            expression: "user".to_owned(),
            conversion: Some("r".to_owned()),
            format_spec: ">5".to_owned(),
            interpolation_index: 2,
            raw_source: Some("{user!r:>5}".to_owned()),
        }),
        TemplateSegment::StaticText("\"}".to_owned()),
    ]);

    assert_eq!(
        format_template(&template).expect("expected format success"),
        r#"{{key}: {value}, "greeting": "hi {user!r:>5}"}"#
    );
}

#[test]
fn format_requires_raw_source_for_interpolations() {
    let template = TemplateInput::from_segments(vec![
        TemplateSegment::StaticText("{\"name\": ".to_owned()),
        interpolation(0, "name"),
        TemplateSegment::StaticText("}".to_owned()),
    ]);

    let error = format_template(&template).expect_err("expected format failure");
    assert_eq!(error.kind, tstring_syntax::ErrorKind::Semantic);
    assert_eq!(error.diagnostics[0].code, "json.format");
}