tor-config: Make ItemOrBool an experimental feature.

crates/arti-client/Cargo.toml

@@ -85,6 +85,7 @@ experimental = [
     "tor-netdoc/experimental",
     "tor-dirmgr/experimental",
     "tor-circmgr/experimental",
+    "tor-config/experimental",
 ]
 
 # Enable experimental APIs that are not yet officially supported.

crates/arti-client/src/config.rs

@@ -15,7 +15,7 @@ pub use tor_config::convert_helper_via_multi_line_list_builder;
 pub use tor_config::impl_standard_builder;
 pub use tor_config::list_builder::{MultilineListBuilder, MultilineListBuilderError};
 pub use tor_config::{define_list_builder_accessors, define_list_builder_helper};
-pub use tor_config::{BoolOrAuto, ConfigError, ItemOrBool};
+pub use tor_config::{BoolOrAuto, ConfigError};
 pub use tor_config::{CfgPath, CfgPathError, ConfigBuildError, ConfigurationSource, Reconfigure};
 
 pub use tor_guardmgr::bridge::BridgeConfigBuilder;
@@ -24,6 +24,9 @@ pub use tor_guardmgr::bridge::BridgeConfigBuilder;
 #[cfg_attr(docsrs, doc(cfg(feature = "bridge-client")))]
 pub use tor_guardmgr::bridge::BridgeParseError;
 
+#[cfg(feature = "experimental-api")]
+pub use tor_config::ItemOrBool;
+
 use tor_guardmgr::bridge::BridgeConfig;
 
 /// Types for configuring how Tor circuits are built.
@@ -190,7 +193,7 @@ impl_standard_builder! { StorageConfig }
 /// Deserialize the `keystore_dir` storage field.
 ///
 /// NOTE: The first option is needed because of the builder, the second is the actual type of the field.
-#[cfg(feature = "keymgr")]
+#[cfg(all(feature = "keymgr", feature = "experimental-api"))]
 #[allow(clippy::option_option)]
 fn deserialize_keystore_dir<'de, D>(deserializer: D) -> Result<Option<Option<CfgPath>>, D::Error>
 where
@@ -210,7 +213,7 @@ where
 /// Deserialize the `keystore_dir` storage field.
 ///
 /// NOTE: The first option is needed because of the builder, the second is the actual type of the field.
-#[cfg(not(feature = "keymgr"))]
+#[cfg(all(not(feature = "keymgr"), feature = "experimental-api"))]
 #[allow(clippy::option_option)]
 fn deserialize_keystore_dir<'de, D>(deserializer: D) -> Result<Option<Option<CfgPath>>, D::Error>
 where
@@ -228,6 +231,22 @@ where
     }
 }
 
+/// Deserialize the `keystore_dir` storage field.
+///
+/// NOTE: The first option is needed because of the builder, the second is the actual type of the field.
+#[cfg(not(feature = "experimental-api"))]
+#[allow(clippy::option_option)]
+fn deserialize_keystore_dir<'de, D>(deserializer: D) -> Result<Option<Option<CfgPath>>, D::Error>
+where
+    D: serde::de::Deserializer<'de>,
+{
+    use serde::de::Error as _;
+
+    Err(D::Error::custom(
+        "keystore not available unless the `experimental` feature is enabled".to_string(),
+    ))
+}
+
 /// Return the default cache directory.
 fn default_cache_dir() -> CfgPath {
     CfgPath::new("${ARTI_CACHE}".to_owned())

crates/tor-config/Cargo.toml

@@ -16,8 +16,16 @@ default = ["expand-paths"]
 
 full = ["expand-paths", "fs-mistrust/full", "tor-basic-utils/full", "tor-error/full"]
 
+experimental = ["experimental-api"]
+# Enable experimental APIs that are not yet officially supported.
+#
+# These APIs are not covered by semantic versioning.  Using this
+# feature voids your "semver warrantee".
+experimental-api = ["__is_experimental"]
 expand-paths = ["shellexpand", "directories"]
 
+__is_experimental = []
+
 [dependencies]
 config = { version = "0.13", default-features = false, features = ["toml"] }
 derive_builder = { version = "0.11.2", package = "derive_builder_fork_arti" }

crates/tor-config/src/misc.rs

@@ -387,6 +387,7 @@ impl TryFrom<ListenItemSerde> for ListenItem {
 #[derive(Serialize, Deserialize, Debug)]
 #[allow(clippy::exhaustive_enums)] // we will add variants very rarely if ever
 #[serde(untagged, bound = "T: Serialize, for<'de2> T: Deserialize<'de2>")]
+#[cfg(feature = "experimental-api")]
 pub enum ItemOrBool<T>
 where
     T: std::fmt::Debug + Serialize,
@@ -398,6 +399,7 @@ where
     Bool(bool),
 }
 
+#[cfg(feature = "experimental-api")]
 impl<T> Default for ItemOrBool<T>
 where
     T: std::fmt::Debug + Serialize,
@@ -433,6 +435,7 @@ mod test {
         #[serde(default)]
         listen: Option<Listen>,
 
+        #[cfg(feature = "experimental-api")]
         #[serde(default)]
         enabled_or_string: ItemOrBool<String>,
     }
@@ -585,6 +588,7 @@ mod test {
     }
 
     #[test]
+    #[cfg(feature = "experimental-api")]
     fn enabled_or_string() {
         use ItemOrBool as IOB;