[Solved] A developer wrote this anti-corruption layer code snippet but it causes errors when legacy data is missing some fields: function translateOrder(legacyOrder) { return { id: legacyOrder.orderId, total:... | Microservices

Microservices - Migration from Monolith

A developer wrote this anti-corruption layer code snippet but it causes errors when legacy data is missing some fields:

function translateOrder(legacyOrder) {
  return {
    id: legacyOrder.orderId,
    total: legacyOrder.amount.value,
    status: legacyOrder.status.toUpperCase()
  }
}

What is the main issue and how to fix it?

AThe function should return legacyOrder directly without changes

BThe code assumes nested fields exist; add checks to handle missing or undefined fields

CUse lowercase for status instead of toUpperCase()

DRemove the id field to avoid errors

Step-by-Step Solution

Solution:

Step 1: Identify the error cause
The code accesses nested fields like legacyOrder.amount.value without checking if amount exists, causing errors if missing.
Step 2: Fix by adding safety checks
Use conditional checks or optional chaining to safely access nested fields and avoid runtime errors.
Final Answer:
The code assumes nested fields exist; add checks to handle missing or undefined fields -> Option B
Quick Check:
Missing field checks cause errors = add safety checks [OK]

Quick Trick: Always check nested fields exist before accessing [OK]

Common Mistakes:

Ignoring null or undefined nested objects
Returning legacy data without translation
Changing case without reason
Removing necessary fields

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More Microservices Quizzes

A developer wrote this anti-corruption layer code snippet but it causes errors when legacy data is missing some fields:

Step 1: Identify the error cause

Step 2: Fix by adding safety checks

Final Answer:

Quick Check:

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