liquid_lib/shopify/
pluralize.rs1use 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#[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}