Type inconsistency: replyToList accepts EmailJSON | EmailJSON[] in types but requires EmailJSON[] at runtime

[NumanAnees]

Problem

There's a type inconsistency in the Mail class regarding replyToList:

Type Definition suggests both formats are valid:

sendgrid-nodejs/packages/helpers/classes/mail.d.ts

Line 168 in 2bac868

replyToList?: EmailJSON | EmailJSON[],

But, Runtime Validation enforces array-only:

sendgrid-nodejs/packages/helpers/classes/mail.d.ts

Line 372 in 2bac868

setReplyToList(replyToList: EmailJSON[]): void;

sendgrid-nodejs/packages/helpers/classes/mail.js

Line 679 in 2bac868

if (this._doArrayCheck('replyToList', replyToList) && replyToList.length) {

Impact

This inconsistency causes runtime errors

Error: Array expected for replyToList