added TryFrom<String> and Display for ModelProvider

src/program/atomics.rs

@@ -264,6 +264,38 @@ pub enum Model {
     GPT4oMini,
 }
 
+impl From<Model> for String {
+    fn from(model: Model) -> Self {
+        model.to_string() // via Display
+    }
+}
+
+impl fmt::Display for Model {
+    fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
+        // guaranteed not to fail because this is enum to string serialization
+        let self_str = serde_json::to_string(&self).unwrap_or_default();
+
+        // remove quotes from JSON
+        write!(f, "{}", self_str.trim_matches('"'))
+    }
+}
+
+impl TryFrom<LocalModel> for Model {
+    type Error = String;
+    fn try_from(value: LocalModel) -> Result<Self, Self::Error> {
+        Model::try_from(value.name)
+    }
+}
+
+impl TryFrom<String> for Model {
+    type Error = String;
+    fn try_from(value: String) -> Result<Self, Self::Error> {
+        // serde requires quotes (for JSON)
+        serde_json::from_str::<Self>(&format!("\"{}\"", value))
+            .map_err(|e| format!("Model {} invalid: {}", value, e))
+    }
+}
+
 /// A model provider is a service that hosts the chosen Model.
 /// It can be derived from the model name, e.g. GPT4o is hosted by OpenAI (via API), or Phi3 is hosted by Ollama (locally).
 #[derive(Debug, Clone, PartialEq, Deserialize, Serialize)]
@@ -290,13 +322,16 @@ impl From<Model> for ModelProvider {
     }
 }
 
-impl From<Model> for String {
-    fn from(model: Model) -> Self {
-        model.to_string() // via Display
+impl TryFrom<String> for ModelProvider {
+    type Error = String;
+    fn try_from(value: String) -> Result<Self, Self::Error> {
+        // serde requires quotes (for JSON)
+        serde_json::from_str::<Self>(&format!("\"{}\"", value))
+            .map_err(|e| format!("Model provider {} invalid: {}", value, e))
     }
 }
 
-impl fmt::Display for Model {
+impl fmt::Display for ModelProvider {
     fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
         // guaranteed not to fail because this is enum to string serialization
         let self_str = serde_json::to_string(&self).unwrap_or_default();
@@ -306,27 +341,12 @@ impl fmt::Display for Model {
     }
 }
 
-impl TryFrom<LocalModel> for Model {
-    type Error = String;
-    fn try_from(value: LocalModel) -> Result<Self, Self::Error> {
-        Model::try_from(value.name)
-    }
-}
-
-impl TryFrom<String> for Model {
-    type Error = String;
-    fn try_from(value: String) -> Result<Self, Self::Error> {
-        // serde requires quotes (for JSON)
-        serde_json::from_str::<Self>(&format!("\"{}\"", value))
-            .map_err(|e| format!("Model {} invalid: {}", value, e))
-    }
-}
-
 #[cfg(test)]
 mod tests {
     use super::*;
 
     const MODEL_NAME: &str = "phi3:3.8b";
+    const PROVIDER_NAME: &str = "openai";
     #[test]
     fn test_model_string_conversion() {
         let model = Model::Phi3Mini;
@@ -357,7 +377,26 @@ mod tests {
         assert_eq!(model_from, model);
 
         // (try) deserialize from invalid model
-        let model = serde_json::from_str::<Model>("\"this-model-does-not-will-not-exist\"");
-        assert!(model.is_err());
+        let bad_model = serde_json::from_str::<Model>("\"this-model-does-not-will-not-exist\"");
+        assert!(bad_model.is_err());
+    }
+
+    #[test]
+    fn test_provider_string_serde() {
+        let provider = ModelProvider::OpenAI;
+
+        // serialize to string via serde
+        let provider_str = serde_json::to_string(&provider).expect("should serialize");
+        assert_eq!(provider_str, format!("\"{}\"", PROVIDER_NAME));
+
+        // deserialize from string via serde
+        let provider_from: ModelProvider =
+            serde_json::from_str(&provider_str).expect("should deserialize");
+        assert_eq!(provider_from, provider);
+
+        // (try) deserialize from invalid model
+        let bad_provider =
+            serde_json::from_str::<ModelProvider>("\"this-provider-does-not-will-not-exist\"");
+        assert!(bad_provider.is_err());
     }
 }