S3 Bucket Name Validator

Follows official latest rules published here. Implementation stolen from Serverless

Install

$ yarn add s3-bucket-name-validator

Usage

const validateS3BucketName = require('s3-bucket-name-validator');
 
// Returns error string with reason if invalid. Empty string otherwise
 
const bucketNameError = validateS3BucketName('-invalid.name'); // 'Bucket name must start with a letter or number. -invalid.name'
if (bucketNameError) {
  // ... some logic
}
 
validateS3BucketName('1.this.is.valid.2'); // ''

Reference

This code was grabbed from AWS S3 front-end

Click to expand obfuscated code 😰

URL: d3v76wtu1o9bby.cloudfront.net/js/s3_console_Prod.gz.js

this.isValidBucketName = function(D) {
    var B = arguments.length <= 1 || arguments[1] === undefined ? [] : arguments[1];
    if (!D) {
        B.push(t.instant("createbucketmodal.validation.invalid.error"));
        return false
    }
    var F = "\0";
    var H = "";
    for (var C = 0; C < D.length; C++) {
        var E = D.charAt(C);
        var G = "";
        if (/[A-Z]/.test(E)) {
            var I = t.instant("createbucketmodal.validation.uppercase.error");
            if (B.indexOf(I) === -1) {
                B.push(I)
            }
        }
        if (E === ".") {
            if (F === "\0") {
                G = t.instant("createbucketmodal.validation.start.error")
            }
            if (F === ".") {
                G = t.instant("createbucketmodal.validation.periods.error")
            }
            if (F === "-") {
                G = t.instant("createbucketmodal.validation.dashperiod.error")
            }
        } else {
            if (E === "-") {
                if (F === "\0") {
                    G = t.instant("createbucketmodal.validation.start.error")
                }
                if (F === ".") {
                    G = t.instant("createbucketmodal.validation.dashperiod.error")
                }
            } else {
                if (!/[a-z0-9]/.test(E) && H.indexOf(E) === -1) {
                    if (!/[A-Z]/.test(E)) {
                        H += E
                    }
                    if (F === "\0") {
                        G = t.instant("createbucketmodal.validation.start.error")
                    }
                }
            }
        }
        if (G && B.indexOf(G) === -1) {
            B.push(G)
        }
        F = E
    }
    if (F === "." || F === "-") {
        B.push(t.instant("createbucketmodal.validation.end.error"))
    }
    if (H.length > 0) {
        B.push(t.instant("createbucketmodal.validation.badchars.error") + " '" + H + "'")
    }
    if (D.length < 3 || D.length > 63) {
        B.push(t.instant("createbucketmodal.validation.length.error"))
    }
    if (/^\d{1,3}\.\d{1,3}\.\d{1,3}\.\d{1,3}$/.test(D)) {
        B.push(t.instant("createbucketmodal.validation.ipaddress.error"))
    }
    return B.length === 0
}