true-email-validator
v1.0.0-alpha.5
Published
A fully RFC 5322 and RFC 6531/6532 compliant email address validator.
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Readme
true-email-validator
A fully RFC 5322 and RFC 6531/6532 compliant email address validator.
The current version is well tested and can be used in production. The package is considered beta because there are additional features to be added before the gold release.
Install
npm i true-email-validator
Usage
import { validateEmail } from 'true-email-validator' // ESM
// const { validateEmail } = require('true-email-validator') // CJS
const inputs = [
'john(an embedded comment)@foo.com',
'"weird@email"@foo.com,',
'john@[123.123.123.123]', // domain literal notation not valid by default
'just-not-an-email-address'
]
for (const input of inputs) {
const result = validateEmail(inputs/*, { allowIPV4 : true } <- would allow the IPV4 domain literal */)
if (result.isValid) {
process.stdout.write(`${input} is valid`)
}
else {
process.stdout.write(`${input} is invalid for the following reasons: ${result.issues.join(', ')}`)
}
}
API Reference
API generated with dmd-readme-api.
- Functions:
getLatestTLDs()
: Dynamically retrieves the latest list of valid TLDs from the Internet Assigned Numbers Authority (IANA).validateEmail()
: Validates an email address according to RFC 5322 (email messaging), RFC 6531/6532 (internationalized email), and RFC 5890 (internationalized domain names).
- Typedefs:
EmailData
: Email address parts and validation data.
getLatestTLDs()
⇒ Promise.<object>
Dynamically retrieves the latest list of valid TLDs from the Internet Assigned Numbers Authority (IANA). International domains are decoded and both the decoded (international domain) and encoded ('xn--`) domain will be present in the results object as both represent valid domains from a user's point of view.
Returns: Promise.<object>
- A Promise resolving to an object whose keys are valid domains; the value of each entry is
true
. ASCII characters are always lowercased, but the international domains are not transformed after decoding
and may contain uppercase non-ASCII unicode characters per RFC 4343.
validateEmail(input, options)
⇒ EmailData
Validates an email address according to RFC 5322 (email messaging), RFC 6531/6532 (internationalized email), and RFC
5890 (internationalized domain names). Validation happens in two general steps. First, the input is parsed according
to the relevant RFC specifications. If this is successful, then the result will always contain a username
,
address
, and either domain
or domainLiteral
fields. If these are present, you know that the email was
successfully parsed. The second stage validates the parsed email components against the provided options or option
defaults. Therefore, you can have a situation where an email address is valid according to the specs and can be
parsed without an issue, but is still invalid according to the effective options (or defaults).
By default, the validation restricts possible features in the email address—such as comments and domain literals—which are not normally wanted in basic email address. In particular, the default options:
- disallow embedded comments,
- disallow domain literal (IP addressing),
- disallow the 'localhost' domain,
- restricts possible TLDs to known good TLDs,
- restricts domain names to valid subdomain and TLDs based on DNS and ICANN rules beyond the email address specification, and
- performs extra validation for known provider domains google.com and hotmail.com.
Options can be explicitly defined to allow for a more liberal or restrictive validation.
| Param | Type | Description |
| --- | --- | --- |
| input | string
| The string or user input to validate as an email address. |
| options | object
| The validation options. |
| options.allowComments | boolean
| If true, allows embedded comments in the address like '(comment) [email protected]', which are disallowed by default. Note, the comments, if present, will be extracted regardless of this setting, the result valid
field will just be set false and an issue will be reported. |
| options.allowAnyDomain | boolean
| If true, then overrides all default restrictions and format checks of the domain value and allows any syntactically valid domain value except a localhost name or address (unless allowLocalHost
is also set true). Note that impossible sub-domain labels (e.g., a label more than 63 characters long or a single digit) or TLDs (e.g. '123') will still trigger an invalid result. Otherwise, the domain value is verified as recognizable as a domain name (as opposed to an IP address, for instance). |
| options.allowAnyDomainLiteral | boolean
| If true, then overrides default restrictions and format checks of domain literal values and allows any syntactically valid domain literal value that is not a localhost address ( unless allowLocalhost
is also true). In general, domain literal values point to IPV4/6 addresses and the validation will (when allowIP4
and/orallowIPV6
are true), allow valid IP address values but would reject other domain literal values, unless this value is set true. Note, if this value is true then allowIPV4and
allowIPV6 are essentially ignored. |
| options.allowIPV4 |
boolean| Allows IPV4 domain literal values. Note that any loopback address will still cause a validation error unless
allowLocalHostis also set true. See
allowAnyDomainLiteral,
allowIPV6, and
allowLocahost.
|
| options.allowIPV6 | boolean
| Allows IPV6 domain literal values. Note that the localhost address will still cause a validation error unless allowLocaHost
is also set true. See allowAnyDomainLiteral
, allowIPV4
, and allowLocahost
.|
| options.allowLocalhost |
boolean| Allows
localhostdomain value or (when
allowIPV6and/or
allowIPV4 also set true) loopback IP addresses. |
| options.allowedTLDs |
boolean| By default, the TLD portion of a domain name will be validated against known good TLDs. To limit this list or use an updated list, set this value to an array of acceptable TLDs or a map with valid TLD keys (the value is not used). You can use the
getLatestTLDs, also exported by this package, to get an object defining the most current TLDs as registered with ICANN. See
arbitraryTLDs. |
| options.allowQuotedLocalPart |
boolean| Overrides default restriction and allows quoted username/local parts. |
| options.arbitraryTLDs |
boolean| Skips the 'known TLD' check and allows any validly formatted TLD name. This is still restricted by the TLD name restrictions which are tighter than standard domain labels. |
| options.excludeChars |
boolean| Either a string or array of excluded characters. In the array form, it will match the whole string, so you can also use this to exclude specific character sequences. |
| options.excludeDomains |
boolean| An array of domains to exclude. Excluding a domain also excludes all subdomains so eclxuding 'foo.com' would exclude '[email protected]' and '[email protected]'. Initial periods are ignored so
excludeDomains: ['com']', and excludeDomains: ['.com']
are equivalent. |
| options.noDomainSpecificValidation | boolean
| Setting this to true will skip domain specific validations. By default, the validation includes domain specific checks for 'google.com' and 'hotmail.com' domains. These domains are known to have more restrictive policies regarding what is and is not a valid email address. |
| options.noLengthCheck | boolean
| If true, then skips username (local part) and total email address length restrictions. Note that domain name label lengths are still enforced. |
| options.noPlusEmails | boolean
| If true, then '+' is not allowed in the username/local part. This is equivalent to setting excludeChars = '+'.
|
| options.noTLDOnly | boolean
| If true, then disallows TLD only domains in an address like 'john@com'. |
| options.noNonASCIILocalPart | boolean
| If true, then disallows non-ASCII/international characters in the username/local part of the address. |
| options.validateInput | function
| A function to perform additional, arbitrary validation on a syntactically valid input string. This function is provided mainly to support input validation libraries where the input is not recoverable from the processed value. In general, users should prefer validateResult
. The inputs two the function are the input string and the original options to this function. The function must return true
if the validation check passes. Any other result is indicative of failure. If the result is a string, then that is understood to be a description of the problem and it's pushed onto the EmailData
issues
list. Otherwise, a generic 'custom validation failed' message is pushed onto the issues
list. |
| options.validateResult | function
| A function to perform additional, arbitrary validation on a syntactically valid email address result. The function should expect two arguments: EmailData
argument which is the result off all other built in validations and any validateInput
result (validateResult
is the last check performed) and a second argument which is the options originally passed into this func. Note, if the input was not recognized as an email address to begin with, then validateResult
is not invoked. The function may return a modified or replacement EmailData
object (any object defining the required fields is recognized as an EmailData
result object). In this case, the function is responsible for setting EmailData
isValid
and issues
fields as appropriate. Otherwise, a return value of true
is taken to indicate the validation succeeded. Any other value is treated as a value and isValid
will be set to false
. If the result is a string, thin it's understood as a description of the issue and is pushed to the issues
list. Otherwise, a generic 'custom validation failed' message is pushed to the issues
list. |
Returns: EmailData
- The results of the validation.
EmailData
: object
Email address parts and validation data.
Properties
| Name | Type | Description |
| --- | --- | --- |
| isValid | boolean
| True if the input is a valid email address according to the options. |
| address | string
| The normalized email address. The domain portion, if any, will always be in lowercase ( the domain
property will preserve the original case). |
| username | string
| The username or local part of the email address. |
| domain | string
| undefined
| The domain value, if present. Exactly one of domain
and domainLiteral
will always be defined for a syntactically valid email address. The original case of the domain is preserved. |
| domainLiteral | string
| undefined
| The domain literal value, if present. Exactly one of domain
and domainLiteral
will always be defined for a syntactically valid email address. |
| issues | Array.<string>
| Lists the issues, if any, rendering the email invalid according to the effective validation options. At least one issue should be present if isValid
is false and the array should be empty if isValid
is true. This is guaranteed for the built in validation checks, but validateResult
checks can cause a violation of this norm if the validation function is not correctly implemented. |
| commentLocalPartPrefix | string
| undefined
| The embedded comment, if any, immediately before the address username (local part). |
| commentLocalPartSuffix | string
| undefined
| The embedded comment, if any, immediately following the address username (local part). |
| commentDomainPrefix | string
| undefined
| The embedded comment, if any, immediately before the domain or domain literal. |
| commentDomainSuffix | string
| undefined
| The embedded comment, if any, immediately after the domain or domain literal. |
TODOs
There are two major additions we plan to add before the gold release.