seriousme
OpenAPI schema validator
A JSON schema validator for OpenAPI specifications, it currently supports:
Tested on over 2,000 real-world APIs from AWS, Microsoft, Google etc.
Install
npm install @seriousme/openapi-schema-validatorUsage
This module is ESM only, if you need to use commonJS please see below.
// ESM
import { Validator } from "@seriousme/openapi-schema-validator";
console.log(Validator.supportedVersions.has("3.1"));
// prints true
const validator = new Validator();
const res = await validator.validate("./petstore.json");
const specification = validator.specification;
// specification now contains a Javascript object containing the specification
if (res.valid) {
console.log("Specification matches schema for version", validator.version);
const schema = validator.resolveRefs();
// schema now contains a Javascript object containing the dereferenced schema
} else {
console.log("Specification does not match Schema");
console.log(res.errors);
}This module can be used in CommonJS code via:
// CommonJS
const { Validator } = await (import("@seriousme/openapi-schema-validator"));See also the upgrading guide if you come from a previous major version.
CLI for API validation
Run with global install:
npm install @seriousme/openapi-schema-validator -g
validate-api <filename>Run without install:
npx -p @seriousme/openapi-schema-validator validate-api <filename>Where <filename> refers to a YAML or JSON file containing the specification.
CLI for API bundling
To make it easier to combine multiple YAML or JSON files into a single specification file there is the bundle-api command.
(see the validateBundle section below)
npm install @seriousme/openapi-schema-validator -g
bundle-api <specFiles> Run without install:
npx -p @seriousme/openapi-schema-validator bundle-api <spec files> The output will be a validated JSON specification. Options: -o --output <filename> the filename to save the output to, default is STDOUT. -t --type [JSON|YAML] the output format, default is JSON.
API
new Validator(ajvOptions)<instance>.validate(specification)<instance>.specification<instance>.version<instance>.resolveRefs(options)<instance>.addSpecRef(subSpecification, uri)<instance>.validateBundle([specification,subspecification, ...])Validator.supportedVersions
new Validator(ajvOptions)
The constructor returns an instance of Validator. By passing an ajv options
object it is possible to influence the behavior of the
AJV schema validator. AJV fails to process the openApi
schemas if you set strict:true therefore this set to false if present. This
is not a bug but a result of the complexity of the openApi JSON schemas.
<instance>.validate(specification)
This function tries to validata a specification against the OpenApi schemas.
specification can be one of:
- a JSON object
- a JSON object encoded as string
- a YAML string
- a filename
External references are not automatically resolved so you need to inline them
yourself if required e.g by using <instance>.addSpecRef() The result is an
object:
{
valid: <boolean>,
errors: <any> // only present if valid is false
}<instance>.specification
If the validator managed to extract data from the specification parameter then the extracted specification is available in this property as javascript object. E.g. if you supplied a filename of a YAML file and the file was sucessfully read and its YAML decoded then the contents is here. Even if validation failed.
<instance>.version
If validation is succesfull this will return the openApi version found e.g. ("2.0","3.0","3.1). The openApi specification only specifies major/minor versions as separate schemas. So "3.0.3" results in "3.0".
<instance>.resolveRefs(options)
This function tries to resolve all internal references. External references are
not automatically resolved so you need to inline them yourself if required e.g
by using <instance>.addSpecRef(). By default it will use the last
specification passed to <instance>.validate() but you can explicity pass a
specification by passing {specification:<object>} as options. The result is an
object where all references have been resolved. Resolution of references is
shallow This should normally not be a problem for this use case.
<instance>.addSpecRef(subSpecification, uri)
subSpecification can be one of:
- a JSON object
- a JSON object encoded as string
- a YAML string
- a filename
uri must be a string (e.g. http://www.example.com/subspec), but
is not required if the subSpecification holds a $id attribute at top level.
If you specify a value for uri it will overwrite the definition in the $id
attribute at top level.
Sometimes a specification is composed of multiple files that each contain parts
of the specification. The specification refers to these sub specifications using
external references. Since references are based on URI's (so Identifier and not
Location as in URL's!) there needs to be a way to tell the validator how to
resolve those references. This is where this function comes in:
E.g.: we have a main specification in main-spec.yaml containing:
...
paths:
/pet:
post:
tags:
- pet
summary: Add a new pet to the store
description: ''
operationId: addPet
responses:
'405':
description: Invalid input
requestBody:
$ref: 'http://www.example.com/subspec#/components/requestBodies/Pet'And the reference is in sub-spec.yaml, containing:
components:
requestBodies:
Pet:
content:
application/json:
schema:
$ref: '#/components/schemas/Pet'
application/xml:
schema:
$ref: '#/components/schemas/Pet'
description: Pet object that needs to be added to the store
required: true
...Then the validation can be performed as follows:
import { Validator } from "@seriousme/openapi-schema-validator";
const validator = new Validator();
await validator.addSpecRef("./sub-spec.yaml", "http://www.example.com/subspec");
const res = await validator.validate("./main-spec.yaml");
// res now contains the results of the validation across main-spec and sub-spec
const specification = validator.specification;
// specification now contains a Javascript object containing the specification
// with the subspec inlined<instance>.validateBundle([specification,subspecification, ...])
This offers an alternative to the combination of addSpecRef and validate.
You can pass an array of (sub)specifications where each can be one of:
- a JSON object
- a JSON object encoded as string
- a YAML string
- a filename
There can only be one main specification present (starting with swagger/openapi) but it does not have to be the first one. If you provide filenames and the files do not have $id attributes, then the $id attribute will be generated from the filename.
If we take the YAML specifications from the previous example then validation can be performed as follows:
import { Validator } from "@seriousme/openapi-schema-validator";
const validator = new Validator();
const res = await validator.validateBundle([ "./sub-spec.yaml", "./main-spec.yaml"]);
// res now contains the results of the validation across main-spec and sub-spec
const specification = validator.specification;
// specification now contains a Javascript object containing the specification
// with the subspec inlinedValidator.supportedVersions
This static property returns the OpenApi versions supported by this package as a
Set. If present, the result of <instance>.version is a member of this Set.
Notes
The JSONschemas are copied from the OpenAPI specification JSONschemas which might differ from the OpenAPI specification HTML pages! If you find a bug in a schema (e.g. because it behaves differently than specified in the HTML) then please raise an issue at https://github.com/OAI/OpenAPI-Specification. Shortly after the specification writers update their schema the automation will pick it up and include the updated version in this module.
License
Licensed under the MIT license