scraps 2.1.0

Scraps is a portable CLI knowledge hub for managing interconnected Markdown documentation with Wiki-link notation.
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
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181

use chrono::format::StrftimeItems;
use chrono::DateTime;
use chrono_tz::Tz;
use tera::{Error, Kwargs, State, Tera, TeraResult, Value};

/// tera v1 shipped these filters through its default `builtins` feature, which
/// v2 dropped along with its chrono/serde_json dependencies. Both the built-in
/// templates and user-authored ones rely on them, so they are reimplemented
/// here to keep template behaviour unchanged across the upgrade.
pub fn register(tera: &mut Tera) {
    tera.register_filter("date", date);
    tera.register_filter("json_encode", json_encode);
    tera.register_filter("slice", slice);
    tera.register_filter("striptags", striptags);
}

fn date(value: Value, kwargs: Kwargs, _: &State) -> TeraResult<String> {
    let timestamp = value
        .as_i64()
        .ok_or_else(|| Error::message("Filter `date` expects a unix timestamp"))?;
    let datetime = DateTime::from_timestamp(timestamp, 0).ok_or_else(|| {
        Error::message(format!(
            "Filter `date` received an out of range timestamp: {timestamp}"
        ))
    })?;

    let format = kwargs.get::<&str>("format")?.unwrap_or("%Y-%m-%d");
    // Parsing up front keeps an invalid format an error rather than a panic
    // inside chrono's Display impl.
    let items = StrftimeItems::new(format).parse().map_err(|_| {
        Error::message(format!(
            "Filter `date` received an invalid format: {format}"
        ))
    })?;

    match kwargs.get::<&str>("timezone")? {
        Some(name) => {
            let timezone = name.parse::<Tz>().map_err(|_| {
                Error::message(format!(
                    "Filter `date` received an unknown timezone: {name}"
                ))
            })?;
            Ok(datetime
                .with_timezone(&timezone)
                .format_with_items(items.iter())
                .to_string())
        }
        None => Ok(datetime.format_with_items(items.iter()).to_string()),
    }
}

fn json_encode(value: Value, _: Kwargs, _: &State) -> TeraResult<String> {
    serde_json::to_string(&value)
        .map_err(|e| Error::message(format!("Filter `json_encode` failed: {e}")))
}

fn slice(value: &[Value], kwargs: Kwargs, _: &State) -> TeraResult<Vec<Value>> {
    let len = value.len() as i64;
    // Negative bounds count back from the end, as they did in tera v1.
    let resolve = |bound: i64| -> usize {
        if bound < 0 {
            (len + bound).clamp(0, len) as usize
        } else {
            bound.min(len) as usize
        }
    };

    let start = resolve(kwargs.get::<i64>("start")?.unwrap_or(0));
    let end = resolve(kwargs.get::<i64>("end")?.unwrap_or(len));
    if start >= end {
        return Ok(Vec::new());
    }
    let step = kwargs.get::<usize>("step")?.unwrap_or(1).max(1);

    Ok(value[start..end].iter().step_by(step).cloned().collect())
}

fn striptags(value: &str, _: Kwargs, _: &State) -> String {
    let mut stripped = String::with_capacity(value.len());
    let mut rest = value;

    while let Some(open) = rest.find('<') {
        // An unclosed `<` is literal text rather than the start of a tag.
        let Some(close) = rest[open..].find('>') else {
            break;
        };
        stripped.push_str(&rest[..open]);
        rest = &rest[open + close + 1..];
    }
    stripped.push_str(rest);

    stripped
}

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

    fn render(template: &str, context: &tera::Context) -> String {
        let mut tera = Tera::new();
        register(&mut tera);
        tera.add_raw_template("test.txt", template).unwrap();
        tera.render("test.txt", context).unwrap()
    }

    #[rstest]
    #[case("{{ ts | date }}", "2024-05-01")]
    #[case("{{ ts | date(format=\"%Y/%m/%d\") }}", "2024/05/01")]
    #[case("{{ ts | date(format=\"%Y-%m-%d %H:%M\") }}", "2024-05-01 12:30")]
    fn date_formats_a_unix_timestamp(#[case] template: &str, #[case] expected: &str) {
        let mut context = tera::Context::new();
        context.insert("ts", &1714566600i64); // 2024-05-01T12:30:00Z

        assert_eq!(render(template, &context), expected);
    }

    #[test]
    fn date_applies_the_timezone() {
        let mut context = tera::Context::new();
        context.insert("ts", &1714566600i64); // 2024-05-01T12:30:00Z
        context.insert("timezone", "Asia/Tokyo");

        // 12:30 UTC is 21:30 the same day in Tokyo.
        let template = "{{ ts | date(format=\"%Y-%m-%d %H:%M\", timezone=timezone) }}";
        assert_eq!(render(template, &context), "2024-05-01 21:30");
    }

    #[test]
    fn date_errors_on_an_unknown_timezone() {
        let mut tera = Tera::new();
        register(&mut tera);
        tera.add_raw_template("test.txt", "{{ ts | date(timezone=\"Mars/Olympus\") }}")
            .unwrap();

        let mut context = tera::Context::new();
        context.insert("ts", &1714566600i64);

        assert!(tera.render("test.txt", &context).is_err());
    }

    #[test]
    fn json_encode_quotes_and_escapes() {
        let mut context = tera::Context::new();
        context.insert("title", "a \"quoted\" title");

        assert_eq!(
            render("{{ title | json_encode() }}", &context),
            "\"a \\\"quoted\\\" title\""
        );
    }

    #[rstest]
    #[case("{{ items | slice(end=2) | join(sep=\",\") }}", "a,b")]
    #[case("{{ items | slice(start=1) | join(sep=\",\") }}", "b,c,d")]
    #[case("{{ items | slice(start=1, end=3) | join(sep=\",\") }}", "b,c")]
    #[case("{{ items | slice(end=-1) | join(sep=\",\") }}", "a,b,c")]
    #[case("{{ items | slice(step=2) | join(sep=\",\") }}", "a,c")]
    #[case("{{ items | slice(end=99) | join(sep=\",\") }}", "a,b,c,d")]
    #[case("{{ items | slice(start=3, end=1) | join(sep=\",\") }}", "")]
    fn slice_selects_a_sub_range(#[case] template: &str, #[case] expected: &str) {
        let mut context = tera::Context::new();
        context.insert("items", &["a", "b", "c", "d"]);

        assert_eq!(render(template, &context), expected);
    }

    #[rstest]
    #[case("<p>hello <b>world</b></p>", "hello world")]
    #[case("no tags here", "no tags here")]
    #[case("2 < 3, unclosed", "2 < 3, unclosed")]
    // Anything between a `<` and the next `>` goes, matching tera v1's `<[^>]*>`.
    #[case("a < b and c > d", "a  d")]
    #[case("<a href=\"https://example.com\">link</a>", "link")]
    fn striptags_removes_markup(#[case] input: &str, #[case] expected: &str) {
        let mut context = tera::Context::new();
        context.insert("html", input);

        assert_eq!(render("{{ html | striptags }}", &context), expected);
    }
}