fix(provider/openai-compatible): duplicated tool-input-start in certain cases (vercel#8108)

Author: robinWongM

.changeset/pretty-candles-unite.md

@@ -0,0 +1,5 @@
+---
+'@ai-sdk/openai-compatible': patch
+---
+
+fix duplicated tool-input-start in certain cases

packages/openai-compatible/src/openai-compatible-chat-language-model.test.ts

@@ -1523,9 +1523,9 @@ describe('doStream', () => {
           "type": "tool-input-start",
         },
         {
+          "delta": "{"",
           "id": "call_O17Uplv4lJvD6DVdIvFFeRMw",
-          "toolName": "test-tool",
-          "type": "tool-input-start",
+          "type": "tool-input-delta",
         },
         {
           "delta": "va",
@@ -1773,9 +1773,9 @@ describe('doStream', () => {
           "type": "tool-input-start",
         },
         {
+          "delta": "{"value":"Sparkle Day"}",
           "id": "call_O17Uplv4lJvD6DVdIvFFeRMw",
-          "toolName": "test-tool",
-          "type": "tool-input-start",
+          "type": "tool-input-delta",
         },
         {
           "id": "call_O17Uplv4lJvD6DVdIvFFeRMw",

packages/openai-compatible/src/openai-compatible-chat-language-model.ts

@@ -538,9 +538,9 @@ export class OpenAICompatibleChatLanguageModel implements LanguageModelV2 {
                     // send delta if the argument text has already started:
                     if (toolCall.function.arguments.length > 0) {
                       controller.enqueue({
-                        type: 'tool-input-start',
+                        type: 'tool-input-delta',
                         id: toolCall.id,
-                        toolName: toolCall.function.name,
+                        delta: toolCall.function.arguments,
                       });
                     }