es-fluent 0.16.0

use super::FluentLocalizer;

/// A trait for types that have a Fluent label key representing the type itself.
///
/// This trait is automatically implemented by `#[derive(EsFluentLabel)]`, or by
/// `#[derive(EsFluentVariants)]` when combined with `#[fluent_label(variants)]`.
pub trait FluentLabel {
    /// Returns the localized label for this type using an explicit localization
    /// context.
    fn localize_label<L: FluentLocalizer + ?Sized>(localizer: &L) -> String;
}

#[doc(hidden)]
pub fn localize_label<L: FluentLocalizer + ?Sized>(
    localizer: &L,
    domain: &str,
    id: &str,
) -> String {
    localizer
        .localize_in_domain(domain, id, None)
        .unwrap_or_else(|| {
            tracing::warn!(domain, message_id = id, "missing Fluent label");
            id.to_string()
        })
}

#[cfg(test)]
mod tests {
    use super::*;
    use crate::FluentValue;
    use std::collections::HashMap;

    struct LabelLocalizer;

    impl FluentLocalizer for LabelLocalizer {
        fn localize<'a>(
            &self,
            id: &str,
            _args: Option<&HashMap<&str, FluentValue<'a>>>,
        ) -> Option<String> {
            (id == "label-id").then(|| "Label".to_string())
        }

        fn localize_in_domain<'a>(
            &self,
            domain: &str,
            id: &str,
            args: Option<&HashMap<&str, FluentValue<'a>>>,
        ) -> Option<String> {
            (domain == "label-domain")
                .then(|| self.localize(id, args))
                .flatten()
        }
    }

    struct TestLabel;

    impl FluentLabel for TestLabel {
        fn localize_label<L: FluentLocalizer + ?Sized>(localizer: &L) -> String {
            localize_label(localizer, "label-domain", "label-id")
        }
    }

    #[test]
    fn localize_label_returns_localized_value_or_id_fallback() {
        let localizer = LabelLocalizer;

        assert_eq!(
            localize_label(&localizer, "label-domain", "label-id"),
            "Label"
        );
        assert_eq!(
            localize_label(&localizer, "label-domain", "missing-id"),
            "missing-id"
        );
        assert_eq!(TestLabel::localize_label(&localizer), "Label");
    }
}