liquid_lib/shopify/
pluralize.rs

1use liquid_core::Expression;
2use liquid_core::Result;
3use liquid_core::Runtime;
4use liquid_core::{
5    Display_filter, Filter, FilterParameters, FilterReflection, FromFilterParameters, ParseFilter,
6};
7use liquid_core::{Value, ValueView};
8
9use crate::invalid_input;
10
11// shopify-specific
12
13#[derive(Debug, FilterParameters)]
14struct PluralizeArgs {
15    #[parameter(description = "The singular version of the string.")]
16    singular: Expression,
17    #[parameter(description = "The plural version of the string.")]
18    plural: Expression,
19}
20
21#[derive(Clone, ParseFilter, FilterReflection)]
22#[filter(
23    name = "pluralize",
24    description = "Outputs the singular or plural version of a string based on the value of the input.",
25    parameters(PluralizeArgs),
26    parsed(PluralizeFilter)
27)]
28pub struct Pluralize;
29
30#[derive(Debug, FromFilterParameters, Display_filter)]
31#[name = "pluralize"]
32struct PluralizeFilter {
33    #[parameters]
34    args: PluralizeArgs,
35}
36
37impl Filter for PluralizeFilter {
38    fn evaluate(&self, input: &dyn ValueView, runtime: &dyn Runtime) -> Result<Value> {
39        let args = self.args.evaluate(runtime)?;
40
41        let n = input
42            .as_scalar()
43            .and_then(|s| s.to_integer())
44            .ok_or_else(|| invalid_input("Whole number expected"))?;
45
46        if (n as isize) == 1 {
47            Ok(args.singular.to_value())
48        } else {
49            Ok(args.plural.to_value())
50        }
51    }
52}
53
54#[cfg(test)]
55mod tests {
56    use super::*;
57
58    #[test]
59    fn unit_pluralize() {
60        assert_eq!(
61            liquid_core::call_filter!(Pluralize, 1i64, "one", "many").unwrap(),
62            liquid_core::value!("one")
63        );
64
65        assert_eq!(
66            liquid_core::call_filter!(Pluralize, 0i64, "one", "many").unwrap(),
67            liquid_core::value!("many")
68        );
69
70        assert_eq!(
71            liquid_core::call_filter!(Pluralize, 2i64, "one", "many").unwrap(),
72            liquid_core::value!("many")
73        );
74
75        assert_eq!(
76            liquid_core::call_filter!(Pluralize, 10i64, "one", "many").unwrap(),
77            liquid_core::value!("many")
78        );
79    }
80}