fix: tool_choice encoding/decoding error

crates/forge_provider/src/open_router/mod.rs

@@ -1,41 +1,6 @@
-use serde::{Deserialize, Serialize};
-
 mod model;
+mod parameters;
 mod provider;
 mod request;
 mod response;
-
-#[derive(Serialize, Deserialize, Debug)]
-pub struct ParameterData {
-    pub model: String,
-    pub supported_parameters: Option<Vec<String>>,
-    pub frequency_penalty_p10: Option<f64>,
-    pub frequency_penalty_p50: Option<f64>,
-    pub frequency_penalty_p90: Option<f64>,
-    pub min_p_p10: Option<f64>,
-    pub min_p_p50: Option<f64>,
-    pub min_p_p90: Option<f64>,
-    pub presence_penalty_p10: Option<f64>,
-    pub presence_penalty_p50: Option<f64>,
-    pub presence_penalty_p90: Option<f64>,
-    pub repetition_penalty_p10: Option<f64>,
-    pub repetition_penalty_p50: Option<f64>,
-    pub repetition_penalty_p90: Option<f64>,
-    pub temperature_p10: Option<f64>,
-    pub temperature_p50: Option<f64>,
-    pub temperature_p90: Option<f64>,
-    pub top_a_p10: Option<f64>,
-    pub top_a_p50: Option<f64>,
-    pub top_a_p90: Option<f64>,
-    pub top_k_p10: Option<f64>,
-    pub top_k_p50: Option<f64>,
-    pub top_k_p90: Option<f64>,
-    pub top_p_p10: Option<f64>,
-    pub top_p_p50: Option<f64>,
-    pub top_p_p90: Option<f64>,
-}
-
-#[derive(Serialize, Deserialize, Debug)]
-pub struct ParameterResponse {
-    pub data: ParameterData,
-}
+mod tool_choice;

crates/forge_provider/src/open_router/parameters.rs

@@ -0,0 +1,36 @@
+use serde::{Deserialize, Serialize};
+
+#[derive(Serialize, Deserialize, Debug)]
+pub struct ParameterData {
+    pub model: String,
+    pub supported_parameters: Option<Vec<String>>,
+    pub frequency_penalty_p10: Option<f64>,
+    pub frequency_penalty_p50: Option<f64>,
+    pub frequency_penalty_p90: Option<f64>,
+    pub min_p_p10: Option<f64>,
+    pub min_p_p50: Option<f64>,
+    pub min_p_p90: Option<f64>,
+    pub presence_penalty_p10: Option<f64>,
+    pub presence_penalty_p50: Option<f64>,
+    pub presence_penalty_p90: Option<f64>,
+    pub repetition_penalty_p10: Option<f64>,
+    pub repetition_penalty_p50: Option<f64>,
+    pub repetition_penalty_p90: Option<f64>,
+    pub temperature_p10: Option<f64>,
+    pub temperature_p50: Option<f64>,
+    pub temperature_p90: Option<f64>,
+    pub top_a_p10: Option<f64>,
+    pub top_a_p50: Option<f64>,
+    pub top_a_p90: Option<f64>,
+    pub top_k_p10: Option<f64>,
+    pub top_k_p50: Option<f64>,
+    pub top_k_p90: Option<f64>,
+    pub top_p_p10: Option<f64>,
+    pub top_p_p50: Option<f64>,
+    pub top_p_p90: Option<f64>,
+}
+
+#[derive(Serialize, Deserialize, Debug)]
+pub struct ParameterResponse {
+    pub data: ParameterData,
+}

crates/forge_provider/src/open_router/provider.rs

@@ -5,9 +5,9 @@ use reqwest_eventsource::{Event, EventSource};
 use tokio_stream::StreamExt;
 
 use super::model::{ListModelResponse, OpenRouterModel};
+use super::parameters::ParameterResponse;
 use super::request::OpenRouterRequest;
 use super::response::OpenRouterResponse;
-use super::ParameterResponse;
 use crate::error::Result;
 use crate::provider::ProviderService;
 use crate::{Error, Live, Service};

crates/forge_provider/src/open_router/request.rs

@@ -3,6 +3,7 @@ use forge_domain::{Context, ContextMessage, ModelId, Role, ToolCallId, ToolDefin
 use serde::{Deserialize, Serialize};
 
 use super::response::{FunctionCall, OpenRouterToolCall};
+use super::tool_choice::{FunctionType, ToolChoice};
 
 #[derive(Debug, Deserialize, Serialize, Clone)]
 pub struct TextContent {
@@ -91,17 +92,10 @@ pub struct FunctionDescription {
 #[derive(Debug, Deserialize, Serialize, Clone)]
 pub struct OpenRouterTool {
     // TODO: should be an enum
-    pub r#type: String,
+    pub r#type: FunctionType,
     pub function: FunctionDescription,
 }
 
-#[derive(Debug, Deserialize, Serialize, Clone)]
-pub enum ToolChoice {
-    None,
-    Auto,
-    Function { name: String },
-}
-
 #[derive(Debug, Deserialize, Serialize, Clone)]
 pub struct ResponseFormat {
     pub r#type: String,
@@ -174,7 +168,7 @@ pub struct OpenRouterRequest {
 impl From<ToolDefinition> for OpenRouterTool {
     fn from(value: ToolDefinition) -> Self {
         OpenRouterTool {
-            r#type: "function".to_string(),
+            r#type: FunctionType,
             function: FunctionDescription {
                 description: Some(value.description),
                 name: value.name.into_string(),
@@ -247,7 +241,7 @@ impl From<ContextMessage> for OpenRouterMessage {
                     // FIXME: All the tool_calls should be added, instead of just one of them
                     vec![OpenRouterToolCall {
                         id: tool_call.call_id,
-                        r#type: "function".to_string(),
+                        r#type: FunctionType,
                         function: FunctionCall {
                             arguments: serde_json::to_string(&tool_call.arguments).unwrap(),
                             name: Some(tool_call.name),
@@ -297,18 +291,6 @@ pub enum OpenRouterRole {
     Tool,
 }
 
-impl From<forge_domain::ToolChoice> for ToolChoice {
-    fn from(value: forge_domain::ToolChoice) -> Self {
-        match value {
-            forge_domain::ToolChoice::None => ToolChoice::None,
-            forge_domain::ToolChoice::Auto => ToolChoice::Auto,
-            forge_domain::ToolChoice::Call(tool_name) => {
-                ToolChoice::Function { name: tool_name.into_string() }
-            }
-        }
-    }
-}
-
 #[cfg(test)]
 mod tests {
     use forge_domain::{

crates/forge_provider/src/open_router/response.rs

@@ -7,6 +7,7 @@ use forge_domain::{
 };
 use serde::{Deserialize, Serialize};
 
+use super::tool_choice::FunctionType;
 use crate::error::Error;
 
 #[derive(Debug, Deserialize, Serialize, Clone)]
@@ -80,7 +81,7 @@ pub struct ResponseMessage {
 #[derive(Debug, Deserialize, Serialize, Clone)]
 pub struct OpenRouterToolCall {
     pub id: Option<ToolCallId>,
-    pub r#type: String,
+    pub r#type: FunctionType,
     pub function: FunctionCall,
 }
 

crates/forge_provider/src/open_router/tool_choice.rs

@@ -0,0 +1,79 @@
+use serde::{Deserialize, Serialize};
+
+#[derive(Debug, Serialize, Deserialize, Clone)]
+#[serde(rename_all = "snake_case")]
+pub enum ToolChoice {
+    None,
+    Auto,
+    #[serde(untagged)]
+    Function {
+        r#type: FunctionType,
+        function: FunctionName,
+    },
+}
+
+#[derive(Debug, Serialize, Deserialize, Clone)]
+#[serde(rename_all = "snake_case")]
+pub struct FunctionName {
+    pub name: String,
+}
+
+#[derive(Default, Debug, Clone)]
+pub struct FunctionType;
+
+impl Serialize for FunctionType {
+    fn serialize<S>(&self, serializer: S) -> Result<S::Ok, S::Error>
+    where
+        S: serde::Serializer,
+    {
+        serializer.serialize_str("function")
+    }
+}
+
+impl<'de> Deserialize<'de> for FunctionType {
+    fn deserialize<D>(_deserializer: D) -> Result<FunctionType, D::Error>
+    where
+        D: serde::Deserializer<'de>,
+    {
+        Ok(FunctionType)
+    }
+}
+
+impl From<forge_domain::ToolChoice> for ToolChoice {
+    fn from(value: forge_domain::ToolChoice) -> Self {
+        match value {
+            forge_domain::ToolChoice::None => ToolChoice::None,
+            forge_domain::ToolChoice::Auto => ToolChoice::Auto,
+            forge_domain::ToolChoice::Call(tool_name) => ToolChoice::Function {
+                function: FunctionName { name: tool_name.into_string() },
+                r#type: FunctionType,
+            },
+        }
+    }
+}
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+
+    #[test]
+    fn test_tool_choice_serialization() {
+        // Test None variant
+        let choice_none = ToolChoice::None;
+        assert_eq!(serde_json::to_string(&choice_none).unwrap(), r#""none""#);
+
+        // Test Auto variant
+        let choice_auto = ToolChoice::Auto;
+        assert_eq!(serde_json::to_string(&choice_auto).unwrap(), r#""auto""#);
+
+        // Test Function variant
+        let choice_function = ToolChoice::Function {
+            function: FunctionName { name: "test_tool".to_string() },
+            r#type: FunctionType,
+        };
+        assert_eq!(
+            serde_json::to_string(&choice_function).unwrap(),
+            r#"{"type":"function","function":{"name":"test_tool"}}"#
+        );
+    }
+}