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Zenflow c22ebbe45c New task (zenflow 738246ea)

In the Pairing Simulator page, I am getting the error:

**Error:**Unexpected token '<', "<!DOCTYPE "... is not valid JSON

Fid and fix the bug

2026-03-11 13:02:24 -05:00

1.8 KiB

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Bug Investigation & Implementation Report - Task 7382

Bug Summary

The Pairing Simulator was failing with the error: Unexpected token '<', "<!DOCTYPE "... is not valid JSON. This was caused by a mismatch between the frontend's expected API endpoint and the server's actual routes, leading to a 404 HTML response instead of JSON.

Root Cause Analysis

Endpoint Mismatch: The frontend called POST /api/pedigree/coi, but the server only implemented POST /api/pedigree/trial-pairing.
Property Naming: The frontend expected common_ancestors (snake_case), while the server returned commonAncestors (camelCase).
Data Structure: The frontend expected common_ancestors to be an array of strings, while the server returned an array of objects.
COI Scaling: The server returned COI as a percentage (e.g., 25.00), while the frontend functions (coiColor, coiLabel) expected decimals (e.g., 0.25).

Affected Components

client/src/pages/PairingSimulator.jsx
server/routes/pedigree.js

Proposed & Implemented Solution

Server Fix: Modified calculateCOI in server/routes/pedigree.js to return the raw decimal value for coefficient.
Frontend Fix: Updated PairingSimulator.jsx to:
- Use the documented /api/pedigree/trial-pairing endpoint.
- Use the commonAncestors property from the response.
- Access the .name property when mapping over the common ancestors list.
- The COI display logic (result.coi * 100).toFixed(2) now works correctly with the decimal value from the server.

Verification Results

Manual code analysis confirms that the frontend and backend now share a consistent API contract.
The COI thresholds and color coding in the frontend now correctly interpret the values provided by the server.

1.8 KiB Raw Blame History