fix: preserve selected enum variants and reject secrets

confik-macros/src/lib.rs

@@ -267,8 +267,13 @@ impl VariantImplementer {
 
         let string = ident.to_string();
 
+        // A selected variant counts as data, even if it has no fields.
         quote_spanned! {var_impl.span() =>
-            Self::#ident #bracketed_extract_us_fields => false #( | #contains_non_secret_data.map_err(|err| err.prepend(#string))? )*
+            Self::#ident #bracketed_extract_us_fields => {
+                #( #contains_non_secret_data.map_err(|err| err.prepend(#string))?; )*
+
+                true
+            }
         }
     }
 }

confik/CHANGELOG.md

@@ -2,6 +2,8 @@
 
 ## Unreleased
 
+- Preserve explicitly selected enum unit variants.
+- Reject explicitly selected enum variants in `#[confik(secret)]` fields when the source does not allow secrets.
 - Upgrade `syn` dependency to `3`.
 - Minimum supported Rust version (MSRV) is now 1.88.
 

confik/tests/defaulting_containers/mod.rs

@@ -69,6 +69,29 @@ mod struct_default_merge {
     }
 }
 
+#[cfg(feature = "toml")]
+mod enum_defaults {
+    use confik::{Configuration, TomlSource};
+
+    use crate::TargetEnum;
+
+    #[test]
+    fn unit_enum_variant_overrides_field_default() {
+        #[derive(Configuration)]
+        struct Config {
+            #[confik(default = TargetEnum::First)]
+            value: TargetEnum,
+        }
+
+        let config = Config::builder()
+            .override_with(TomlSource::new(r#"value = "Second""#))
+            .try_build()
+            .expect("TOML deserialization should succeed");
+
+        assert_eq!(config.value, TargetEnum::Second);
+    }
+}
+
 #[derive(Debug, Configuration, PartialEq, Eq, Default)]
 struct Config {
     #[confik(default = 0)]

confik/tests/secret/mod.rs

@@ -161,6 +161,30 @@ mod toml {
         );
     }
 
+    #[test]
+    fn unit_enum_variant_rejected_from_non_secret_source() {
+        use confik::Error;
+
+        use crate::TargetEnum;
+
+        #[derive(Configuration)]
+        struct Config {
+            #[confik(secret)]
+            value: TargetEnum,
+        }
+
+        let err = Config::builder()
+            .override_with(TomlSource::new(r#"value = "Second""#))
+            .try_build()
+            .map(|config| config.value)
+            .expect_err("TOML must reject a secret unit enum variant");
+
+        assert_matches!(
+            err,
+            Error::UnexpectedSecret(path, _) if path.to_string().contains("`value`")
+        );
+    }
+
     /// This functions and all tests using are to catch the issue in FUT-5298
     /// in which depending on ordering a non-secret `Source` may not be caught
     fn check_secret_error_seq_propagation<T>(expected_path: &str)