Fix breakage in simple IncomingConfig (#2648)

* Fix breakage in simple IncomingConfig

* Add issue specific UT

changelog.d/2647.fixed.md

@@ -0,0 +1 @@
+Fix issue introduced in #2612 that broke configs with one-value definition for IncomingConfig for network feature.

mirrord/config/src/feature/network/incoming.rs

@@ -195,11 +195,26 @@ impl<'de> de::Visitor<'de> for IncomingFileConfigVisitor {
         Ok(IncomingFileConfig::Simple(Some(mode)))
     }
 
+    fn visit_none<E>(self) -> Result<Self::Value, E>
+    where
+        E: de::Error,
+    {
+        Ok(IncomingFileConfig::Simple(None))
+    }
+
+    fn visit_some<D>(self, deserializer: D) -> Result<Self::Value, D::Error>
+    where
+        D: de::Deserializer<'de>,
+    {
+        Option::deserialize(deserializer).map(IncomingFileConfig::Simple)
+    }
+
     fn visit_str<E>(self, value: &str) -> Result<Self::Value, E>
     where
         E: de::Error,
     {
         Deserialize::deserialize(de::value::StrDeserializer::new(value))
+            .map(Some)
             .map(IncomingFileConfig::Simple)
     }
 
@@ -208,6 +223,7 @@ impl<'de> de::Visitor<'de> for IncomingFileConfigVisitor {
         E: de::Error,
     {
         Deserialize::deserialize(de::value::StringDeserializer::new(value))
+            .map(Some)
             .map(IncomingFileConfig::Simple)
     }
 

mirrord/config/src/lib.rs

@@ -596,6 +596,35 @@ mod tests {
             }
         }
 
+        fn issue_2647(&self) -> &'static str {
+            match self {
+                ConfigType::Json => {
+                    r#"
+                    {
+                        "feature": {
+                            "network": {
+                                "incoming": "steal"
+                            }
+                        }
+                    }
+                    "#
+                }
+                ConfigType::Toml => {
+                    r#"
+                    [feature.network]
+                    incoming = "steal"
+                    "#
+                }
+                ConfigType::Yaml => {
+                    r#"
+                    feature:
+                        network:
+                            incoming: steal
+                    "#
+                }
+            }
+        }
+
         fn full(&self) -> &'static str {
             match self {
                 ConfigType::Json => {
@@ -726,6 +755,29 @@ mod tests {
         assert_eq!(config, LayerFileConfig::default());
     }
 
+    #[rstest]
+    fn issue_2647(
+        #[values(ConfigType::Json, ConfigType::Toml, ConfigType::Yaml)] config_type: ConfigType,
+    ) {
+        let input = config_type.issue_2647();
+        let config = config_type.parse(input);
+
+        let expect = LayerFileConfig {
+            feature: Some(FeatureFileConfig {
+                network: Some(ToggleableConfig::Config(NetworkFileConfig {
+                    incoming: Some(ToggleableConfig::Config(IncomingFileConfig::Simple(Some(
+                        IncomingMode::Steal,
+                    )))),
+                    ..Default::default()
+                })),
+                ..Default::default()
+            }),
+            ..Default::default()
+        };
+
+        assert_eq!(config, expect);
+    }
+
     #[rstest]
     fn full(
         #[values(ConfigType::Json, ConfigType::Toml, ConfigType::Yaml)] config_type: ConfigType,