fix: guard against undefined MCP tool output causing output.split crash#24618
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leandrosnx wants to merge 2 commits intoanomalyco:devfrom
Open
fix: guard against undefined MCP tool output causing output.split crash#24618leandrosnx wants to merge 2 commits intoanomalyco:devfrom
leandrosnx wants to merge 2 commits intoanomalyco:devfrom
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When an MCP tool returns a result with no text content (e.g., only images or empty content array), part.state.output can be undefined. This flows into truncateToolOutput() and Truncate.output() which call .split() and .length on the undefined value, causing: TypeError: undefined is not an object (evaluating 'output.split') Fix: - Add null guard in truncateToolOutput() returning empty string - Add ?? fallback at call site in toModelMessagesEffect() - Add null guard in Truncate.output() returning safe default
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Issue for this PR
Closes #24402
Type of change
What does this PR do?
Fixes a crash (
TypeError: undefined is not an object (evaluating 'output.split')) that occurs when MCP tools return results with no text content (e.g., only images or empty content arrays).When an MCP tool result has no text content,
part.state.outputbecomesundefined. This propagates totruncateToolOutput()andTruncate.output(), which try to call.lengthand.split("\n")on it respectively, causing the app to crash.I added simple undefined/null guards:
if (!text) return ""intruncateToolOutput()if (text == null)early return inTruncate.output()?? ""fallback at the call site intoModelMessagesEffect()How did you verify your code works?
I tested this locally with an MCP server that returns non-text responses (specifically an image generation tool). After the changes, the crash no longer happens and the output is safely handled as an empty string.
Screenshots / recordings
N/A
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