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use darling::{Error, FromMeta};
use syn::parse_quote;
#[derive(Debug, FromMeta)]
struct Meta {
#[darling(default)]
meta1: Option<String>,
#[darling(default)]
meta2: bool,
}
#[test]
fn nested_meta_meta_value() {
let meta = Meta::from_list(&[parse_quote! {
meta1 = "thefeature"
}])
.unwrap();
assert_eq!(meta.meta1, Some("thefeature".to_string()));
assert!(!meta.meta2);
}
#[test]
fn nested_meta_meta_bool() {
let meta = Meta::from_list(&[parse_quote! {
meta2
}])
.unwrap();
assert_eq!(meta.meta1, None);
assert!(meta.meta2);
}
#[test]
fn nested_meta_lit_string_errors() {
let err = Meta::from_list(&[parse_quote! {
"meta2"
}])
.unwrap_err();
assert_eq!(
err.to_string(),
Error::unsupported_format("literal").to_string()
);
}
#[test]
fn nested_meta_lit_integer_errors() {
let err = Meta::from_list(&[parse_quote! {
2
}])
.unwrap_err();
assert_eq!(
err.to_string(),
Error::unsupported_format("literal").to_string()
);
}
#[test]
fn nested_meta_lit_bool_errors() {
let err = Meta::from_list(&[parse_quote! {
true
}])
.unwrap_err();
assert_eq!(
err.to_string(),
Error::unsupported_format("literal").to_string()
);
}
/// Tests behavior of FromMeta implementation for enums.
mod enum_impl {
use darling::{Error, FromMeta};
use syn::parse_quote;
/// A playback volume.
#[derive(Debug, Clone, Copy, PartialEq, Eq, FromMeta)]
enum Volume {
Normal,
Low,
High,
#[darling(rename = "dB")]
Decibels(u8),
}
#[test]
fn string_for_unit_variant() {
let volume = Volume::from_string("low").unwrap();
assert_eq!(volume, Volume::Low);
}
#[test]
fn single_value_list() {
let unit_variant = Volume::from_list(&[parse_quote!(high)]).unwrap();
assert_eq!(unit_variant, Volume::High);
let newtype_variant = Volume::from_list(&[parse_quote!(dB = 100)]).unwrap();
assert_eq!(newtype_variant, Volume::Decibels(100));
}
#[test]
fn empty_list_errors() {
let err = Volume::from_list(&[]).unwrap_err();
assert_eq!(err.to_string(), Error::too_few_items(1).to_string());
}
#[test]
fn multiple_values_list_errors() {
let err = Volume::from_list(&[parse_quote!(low), parse_quote!(dB = 20)]).unwrap_err();
assert_eq!(err.to_string(), Error::too_many_items(1).to_string());
}
}