Error on conversation request

Feedback source

None

GitHub Copilot plugin version

0.16.0.202604020254

Eclipse IDE and version

Version: 2026-03 (4.39.0) Build id: 20260305-0817

Platform

Microsoft Windows NT 10.0.26100.0 x64

Steps to reproduce

Just encounter the following error while working with Eclipse:

[LS:GitHub Copilot Language Server][Error]	[chat] Error on conversation request: Error: Failed to parse JSON for tool call 'create_file': SyntaxError: Expected ',' or '}' after property value in JSON at position 97 (line 1 column 98)
    at JSON.parse (<anonymous>)
    at parseCallArguments (C:\snapshot\copilot-intellij\lib\src\openai\stream.ts:836:21)
    at extractToolCalls (C:\snapshot\copilot-intellij\lib\src\openai\stream.ts:852:26)
    at convertToAPIJsonData (C:\snapshot\copilot-intellij\lib\src\openai\stream.ts:781:23)
    at prepareChatCompletionForReturn (C:\snapshot\copilot-intellij\lib\src\conversation\openai\stream.ts:29:35)
    at selector (C:\snapshot\copilot-intellij\lib\src\conversation\endpoint\ChatCompletionsEndpointStrategy.ts:207:13)
    at asyncIterableMap (C:\snapshot\copilot-intellij\lib\src\common\iterableHelpers.ts:6:15)
    at process.item (node:internal/process/task_queues:105:5)
    at chatCompletion (C:\snapshot\copilot-intellij\lib\src\common\iterableHelpers.ts:25:22)
    at As.processSuccessfulResponse (C:\snapshot\copilot-intellij\lib\src\conversation\chatMLFetcher.ts:531:26). Input: '{"filePath": "..."'
    at parseCallArguments (C:\snapshot\copilot-intellij\lib\src\openai\stream.ts:841:15)
    at extractToolCalls (C:\snapshot\copilot-intellij\lib\src\openai\stream.ts:852:26)
    at convertToAPIJsonData (C:\snapshot\copilot-intellij\lib\src\openai\stream.ts:781:23)
    at prepareChatCompletionForReturn (C:\snapshot\copilot-intellij\lib\src\conversation\openai\stream.ts:29:35)
    at selector (C:\snapshot\copilot-intellij\lib\src\conversation\endpoint\ChatCompletionsEndpointStrategy.ts:207:13)
    at asyncIterableMap (C:\snapshot\copilot-intellij\lib\src\common\iterableHelpers.ts:6:15)
    at process.item (node:internal/process/task_queues:105:5)
    at chatCompletion (C:\snapshot\copilot-intellij\lib\src\common\iterableHelpers.ts:25:22)
    at As.processSuccessfulResponse (C:\snapshot\copilot-intellij\lib\src\conversation\chatMLFetcher.ts:531:26)
    at As.fetch (C:\snapshot\copilot-intellij\lib\src\conversation\chatMLFetcher.ts:488:28)

Logs (optional)

No response

Expected behavior

No error should occur.

Actual behavior

Error occurs.

Additional information

No response

Start by examining the lib/src/openai/stream.ts entry points parseCallArguments, extractToolCalls, and convertToAPIJsonData named in the stack trace. Reproduce a conversation request that invokes the create_file tool and trace how its arguments are handled; done means the reported malformed tool-call case is handled without the conversation request error.