[Solved] Why does this FileValidationPipe code fail to reject files larger than 1MB?transform(file) { if (file.size > 1_000_000) { throw new BadRequestException('File too large'); } return file; } | NestJS

NestJS - Pipes

Why does this FileValidationPipe code fail to reject files larger than 1MB?

transform(file) {
  if (file.size > 1_000_000) {
    throw new BadRequestException('File too large');
  }
  return file;
}

AThe file size is checked in bytes, but the file size is in kilobytes

BThe condition should use '>=' instead of '>'

CThe underscore notation is not supported in JavaScript numbers

DThe pipe must be async to work correctly

Step-by-Step Solution

Solution:

Step 1: Understand numeric literals in JavaScript
Underscore separators in numbers are supported only in ES2021+; older environments fail.
Step 2: Identify if underscore usage causes syntax error
If environment does not support it, the code will throw a syntax error and fail.
Final Answer:
The underscore notation is not supported in JavaScript numbers -> Option C
Quick Check:
Underscores in numbers need ES2021+ support [OK]

Quick Trick: Use underscores in numbers only if environment supports ES2021+ [OK]

Common Mistakes:

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Why does this FileValidationPipe code fail to reject files larger than 1MB?