Hyperjump - OAS Schema Validator

OAS Schema Validator is built on JSON Schema Core.

• Supported OAS Schema Versions
  • 3.1
• Schemas can reference other schemas using a different draft
• Load schemas from filesystem (file://), network (http(s)://), or JavaScript

Install

JSV includes support for node.js JavaScript (CommonJS and ES Modules), TypeScript, and browsers.

Node.js

1npm install @hyperjump/oas-schema-validator

Browser

When in a browser context, this package is designed to use the browser's fetch implementation instead of a node.js fetch clone. The Webpack bundler does this properly without any extra configuration, but if you are using the Rollup bundler you will need to include the browser: true option in your Rollup configuration.

1  plugins: [
2    resolve({
3      browser: true
4    }),
5    commonjs()
6  ]

Versioning

This project is in beta and there may be breaking changes at any time. When it's stable enough, I'll publish v1.0.0 and follow semantic versioning from there on out.

Usage

1const OasSchema = require("@hyperjump/oas-schema-validator");
2
3
4// Example: Inline schema
5const schemaJson = {
6  "$schema": "https://spec.openapis.org/oas/3.1/dialect/base",
7  "$id": "http://example.com/schemas/string",
8  "type": "string"
9}
10OasSchema.add(schemaJson);
11const schema = await OasSchema.get("http://example.com/schemas/string");
12
13// Example: Fetch from the web
14const schema = await OasSchema.get("http://example.com/schemas/string");
15
16// Example: Fetch from file
17const schema = await OasSchema.get(`file://${__dirname}/schemas/string.schema.json`);
18
19// Example: Validate instance
20const output = await OasSchema.validate(schema, "foo");
21if (output.valid) {
22  console.log("Instance is valid :-)");
23} else {
24  console.log("Instance is invalid :-(");
25}
26
27// Example: Precompile validator
28const isString = await OasSchema.validate(schema);
29const output = isString("foo");
30
31// Example: Validate OpenAPI document with no schema validation
32const openApiSchema = await OasSchema.get("https://spec.openapis.org/oas/3.1/schema");
33const validateOpenApi = await OasSchema.validate(openApiSchema);
34
35const result = validateOpenApi(openApiDoc);
36console.log("Is Valid:", result.valid);
37
38// Example: Validate OpenAPI document with default dialect
39const openApiSchema = await OasSchema.get("https://spec.openapis.org/oas/3.1/schema-base");
40const validateOpenApi = await OasSchema.validate(openApiSchema);
41
42const result = validateOpenApi(openApiDoc);
43console.log("Is Valid:", result.valid);
44
45// Example: Specify output format
46const output = await OasSchema.validate(schema, "foo", OasSchema.VERBOSE);
47
48// Example: Specify meta-validation output format
49OasSchema.setMetaOutputFormat(OasSchema.FLAG);
50
51// Example: Disable meta-validation
52OasSchema.setShouldMetaValidate(false);

TypeScript

Although the package is written in JavaScript, type definitions are included for TypeScript support. The following example shows the types you might want to know.

1import OasSchema, { InvalidSchemaError } from "@hyperjump/oas-schema-validator";
2import type { SchemaDocument, Validator, Result, Oas31Schema } from "@hyperjump/json-schema";
3
4
5const schemaJson: Oas31Schema = {
6  "$id": "https://json-schema.hyperjump.io/schema",
7  "$schema": "https://spec.openapis.org/oas/3.1/dialect/base",
8
9  "type": "string"
10};
11OasSchema.add(schemaJson);
12
13const schema: SchemaDocument = await OasSchema.get("https://json-schema.hyperjump.io/schema");
14try {
15  const isString: Validator = await OasSchema.validate(schema);
16  const result: Result = isString("foo");
17  console.log("isString:", result.valid);
18} catch (error: unknown) {
19  if (error instanceof InvalidSchemaError) {
20    console.log(error.output);
21  } else {
22    console.log(error);
23  }
24}

API

• add: (schema: object, url?: URI, dialectId?: string) => SDoc

  Load a schema. See JSC - $id and JSC - $schema for more information.

• get: (url: URI, contextDoc?: SDoc, recursive: boolean = false) => Promise

  Fetch a schema. Schemas can come from an HTTP request, a file, or a schema that was added with add.

• validate: (schema: SDoc, instance: any, outputFormat: OutputFormat = FLAG) => Promise

  Validate an instance against a schema. The function is curried to allow compiling the schema once and applying it to multiple instances.

• compile: (schema: SDoc) => Promise

  Compile a schema to be interpreted later. A compiled schema is a JSON serializable structure that can be serialized an restored for later use.

• interpret: (schema: CompiledSchema, instance: any, outputFormat: OutputFormat = FLAG) => OutputUnit

  A curried function for validating an instance against a compiled schema.

• setMetaOutputFormat: (outputFormat: OutputFormat = DETAILED) => undefined

  Set the output format for meta-validation. Meta-validation output is only returned if meta-validation results in an error.

• setShouldMetaValidate: (isEnabled: boolean) => undefined

  Enable or disable meta-validation.

• OutputFormat: [FLAG | BASIC | DETAILED | VERBOSE]

  See JSC - Output for more information on output formats.

Not (yet) Supported

This implementation supports all required features of OAS 3.1 Schema Object. The following optional features are not supported yet.

• The format-assertion vocabulary

Contributing

Tests

Run the tests

1npm test

Run the tests with a continuous test runner

1npm test -- --watch