feat: enhance reasoning handling in tool calls and change the thinking order when stream=false

Author: caozhiyuan

src/routes/messages/non-stream-translation.ts

@@ -287,7 +287,7 @@ export function translateToAnthropic(
     )
     const toolUseBlocks = getAnthropicToolUseBlocks(choice.message.tool_calls)
 
-    assistantContentBlocks.push(...textBlocks, ...thingBlocks, ...toolUseBlocks)
+    assistantContentBlocks.push(...thingBlocks, ...textBlocks, ...toolUseBlocks)
 
     // Use the finish_reason from the first choice, or prioritize tool_calls
     if (choice.finish_reason === "tool_calls" || stopReason === "stop") {
@@ -320,7 +320,7 @@ export function translateToAnthropic(
 function getAnthropicTextBlocks(
   messageContent: Message["content"],
 ): Array<AnthropicTextBlock> {
-  if (typeof messageContent === "string") {
+  if (typeof messageContent === "string" && messageContent.length > 0) {
     return [{ type: "text", text: messageContent }]
   }
 

src/routes/messages/stream-translation.ts

@@ -101,6 +101,8 @@ function handleToolCalls(
   if (delta.tool_calls && delta.tool_calls.length > 0) {
     closeThinkingBlockIfOpen(state, events)
 
+    handleReasoningOpaqueInToolCalls(state, events, delta)
+
     for (const toolCall of delta.tool_calls) {
       if (toolCall.id && toolCall.function?.name) {
         // New tool call starting.
@@ -153,6 +155,22 @@ function handleToolCalls(
   }
 }
 
+function handleReasoningOpaqueInToolCalls(
+  state: AnthropicStreamState,
+  events: Array<AnthropicStreamEventData>,
+  delta: Delta,
+) {
+  if (state.contentBlockOpen) {
+    events.push({
+      type: "content_block_stop",
+      index: state.contentBlockIndex,
+    })
+    state.contentBlockIndex++
+    state.contentBlockOpen = false
+  }
+  handleReasoningOpaque(delta, events, state)
+}
+
 function handleContent(
   delta: Delta,
   state: AnthropicStreamState,
@@ -263,6 +281,7 @@ function handleReasoningOpaque(
         index: state.contentBlockIndex,
       },
     )
+    state.contentBlockIndex++
   }
 }