Plugin for AJV that adds support for additional international formats and formats added in draft2019.
Currently, iri
, iri-reference
, idn-email
, idn-hostname
, and duration
formats are supported. duration
was added in draft 2019.
An open question is how thoroughly to validate things like hostnames and IRIs
where the syntax and semantics diverge. Writing a regex for a hostname the
syntax (ie. only contains certain characters, there are multiple segments
separated by .
and the lengths of all segments and the total length). But that
won't catch obviously fake domains like unknown.unknown
. This library goes a
step further than just checking the syntax and also attempts to check the
semantics as well. For example, when validating idn-hostname
, this library
will also check for a valid TLD.
Validating a IRI references is challenging since the syntax is so permissive. Basically, any URL-safe string is a valid IRI syntactically. I struggled to find negative test cases when writing the unit tests for IRI-references. Consider:
google.com
is NOT a valid IRI because it does not include a scheme.file.txt
is a valid IRI-reference/this:that
is a valid IRI-referencethis:that
is a NOT a valid IRI-reference
Regardless, the library is a solid first-pass at implementing the
npm install ajv-formats
The default export is an apply
function that patches an existing instance of
ajv
.
const Ajv = require('ajv');
const apply = require('ajv-formats');
const ajv = new Ajv();
apply(ajv);
let schema = {
type: 'string',
format: 'idn-email',
};
ajv.validate(schema, 'квіточка@пошта.укр'); // returns true
The module also provides an alternate entrypoint ajv-formats/formats
that
works with the ajv
constructor to add the formats to new instances.
const Ajv = require('ajv');
const formats = require('ajv-formats/formats');
const ajv = new Ajv({ formats });
let schema = {
type: 'string',
format: 'idn-email',
};
ajv.validate(schema, 'квіточка@пошта.укр'); // returns true
Using the ajv-formats/formats
entry point also allows cherry picking formats.
Note the approach below only works for formats that don't contain a hypen -
in
the name.
const Ajv = require('ajv');
const { duration, iri } = require('ajv-formats/formats');
const ajv = new Ajv({ formats: { duration, iri } });
The library also provides an idn
export to load only the international formats
(ie. iri
, iri-reference
, idn-hostname
and idn-email
).
const Ajv = require('ajv');
const formats = require('ajv-formats/idn');
const ajv = new Ajv({ formats });
The string is parsed with 'uri-js' and the scheme is checked against the list of
known IANA schemes. If it's a 'mailto' schemes, all of the to:
addresses are
validated, otherwise we check there IRI includes a path and is an absolute
reference.
All valid IRIs are valid. Fragments must have a valid path and of type "relative", "same-document" or "uri". If there is a scheme, it must be valid.
isemail
is used to check the validity
of the email.
The hostname is converted to ascii with punycode and checked for a valid tld.
Note that localhost
is technically not a valid hostname.
The string is checked against a regex.