What's Changed

• bump version to 8.17.1 by @jasoniangreen in #2472

Full Changelog: v8.17.0...v8.17.1

Plus everything in 8.17.0 which failed to release

The only functional change is to switch from uri-js (which is no longer supported), to fast-uri. This is the second attempt and the team on fast-uri have been really helpful addressing the issues we found last time.

Revert "Revert fast-uri change (#2444)" by @gurgunday in #2448
fix: ignore new eslint error for @typescript-eslint/no-extraneous-class by @jasoniangreen in #2455
docs: clarify behaviour of addVocabulary by @jasoniangreen in #2454
docs: refactor to improve legibility by @blottn in #2432
Fix grammatical typo in managing-schemas.md by @wetneb in #2305
docs: Fix broken strict-mode link by @alexanderjsx in #2459
feat: add test for encoded refs and bump fast-uri by @jasoniangreen in #2449
fix: changes for @typescript-eslint/array-type rule by @jasoniangreen in #2467
fixes #2217 - clarify custom keyword naming by @jasoniangreen in #2457

What's Changed

• Revert fast-uri change by @jasoniangreen in #2444

Full Changelog: v8.15.0...v8.16.0

What's Changed

• Replace uri-js with fast-uri by @vixalien in #2415
• Bump to 8.15.0 by @jasoniangreen in #2442

New Contributors

• @vixalien made their first contribution in #2415

Full Changelog: v8.14.0...v8.15.0

What's Changed

• readme: build badge by @epoberezkin in #2424
• Update workflows by @rotu in #2410
• docs: add warning to maxLength / minLength by @jasoniangreen in #2428
• fix: broken link in docs warning by @jasoniangreen in #2431
• compileAsync a schema with discriminator and $ref, fixes #2427 by @jasoniangreen in #2433
• bump version to 8.14.0 for publishing by @jasoniangreen in #2440

New Contributors

• @rotu made their first contribution in #2410

Full Changelog: v8.13.0...v8.14.0

• add named exports
• update dependencies
• update node.js

• fix JTD serialisation (remove leading comma in objects with only optional properties) (#2190, @piliugin-anton)
• empty JTD "values" schema (#2191)
• empty object to work with JTD utility type (#2158, @erikbrinkman)
• fix JTD "discriminator" schema for objects with more than 8 properties (#2194)
• correctly narrow "number" type to "integer" (#2192, @JacobLey)
• update Node.js versions in CI to 14, 16, 18 and 19

Update dependencies

Export ValidationError and MissingRefError (https://github.com/ajv-validator/ajv/pull/1840, @dannyb648)

Update dependencies

Export ValidationError and MissingRefError (#1840, @dannyb648)

Use root schemaEnv when resolving references in oneOf (#1901, @asprouse)

Only use equal function in generated code when it is used (#1922, @bhvngt)

uriResolver option (@zekth, #1862)

Option code.esm to generate ESM exports for standalone validation functions (@rehanvdm, #1861) Support discriminator keyword with $ref in oneOf subschemas (@dfeufel, #1815)

Use full RegExp string (with flags) as cache key, related to https://github.com/ajv-validator/ajv-keywords/issues/220

Fix browser bundles in cdnjs regExp option allowing to specify alternative RegExp engine, e.g. re2 (@efebarlas)

Publish Ajv bundle for JSON Schema 2020-12 to cdnjs.com

Update JSON Schema Test Suite. Change minContains: 0 now correctly allows empty array.

Fix $ref resolution for schemas without $id (@rbuckton, #1725) Support standalone module import from ESM modules without using .default property (@bhvngt, #1757) Update code for breaking TS change - error in catch has type unknown (#1760)

Fix "not" keyword preventing validation of "allOf" and some other keywords (#1668)

Track evaluated properties with patternProperties that have always valid schemas (e.g., true) (@P0lip, #1626) Option int32range to disable number range checking for int32 and uint32 type in JTD schemas

Optimize validation code for const keyword with scalar values (@SoAsEr, #1561) Add option schemaId to support ajv-draft-04 - Ajv for JSON Schema drat-04.

JSON Type Definition schema options:

• parseDate: parse timestamp type as Date objects.
• allowDate: non-standard - allow date without time with timestamp type.

Typescript improvements:

• better error reporting for JSONSchemaType in case strictNullChecks option is disabled (@erikbrinkman, #1583)
• support missed boolean type in JTDDataType (@m00s, #1587) JTD timestamp validation option (@jrr, #1584). Docs corrections.

Add JTDDataType to compile signature (@erikbrinkman, #1547) Improve JSONSchemaType for records (@erikbrinkman, #1564) Use rollup for browser bundles (@realityking, #1533) Docs corrections

unicodeRegExp option to not use RegExp unicode flag that may be incompatible with some environments (@asaid-0, #1530) Fix JSONSchemaType (@erikbrinkman, #1541) Extended error message for invalid keyword values (@pcwiek, #1542)

Fix: add source code back to npm package, 8.0.4 is breaking ajv-cli (and possibly other things)

Improve JSONSchemaType errors (@erikbrinkman, #1525)

Support RegExp formats in standalone code (#1470) Add schema path to strictTuple error message (@asaid-0, #1519)

Typescript: export function getData (for ajv-errors)

This document describes changes from v7.2.4 to v8.0.0.

If you are migrating from v6 you can use this document.

New features

Support JSON Schema draft-2020-12: prefixItems keyword and changed semantics of items keyword, dynamic recursive references. OpenAPI discriminator keyword. Improved JSON Type Definition support:

• errors consistent with JTD specification.
• error objects with additional properties to simplify error handling (see Error objects)
• internationalized error messages with ajv-i18n TypeScript: support type unions in JSONSchemaType

Other changes / improvements

Node.js require works without .default property - see examples in Getting started Reduce runtime dependency for standalone validation code Fix resolution of $ref: "#" when $id is present (#815)

Breaking changes

Option strict controls all strict mode restrictions JSON Schema validation errors changes:

• dataPath property replaced with instancePath
• "should" replaced with "must" in the messages
• property name is removed from "propertyName" keyword error message (it is still available in error.params.propertyName).

Revert the change for strict mode options in v8.0.0-beta.1 to allow overrides to disable some options, not only to enable.

These strict mode options are available: strictSchema - new, equivalent to strict: true in v7, default true strictNumbers - reinstated from v6, but with default true strictTypes - same as in v7, default "log" strictTuples - same as in v7, default "log" strictTuples - same as in v7, default false

Option strict sets all options above to the same value.

JSON Schema draft2012-12 support - prefixItems, new semantics of items, dynamicRef and dynamicAnchor

Fixes:

• #815 - incorrect resolution of $ref: "#" with $id in subschema
• #1493 - incorrect error message for missing property with ownProperties: true option
• #1501 - incorrect compilation of JTD schema with many properties in the schema

Support for union types in JSONSchemaType (#1302, @erikbrinkman). More ergonomic Ajv constructor export - no need to use .default in .js and .mjs files (#1381). Remove circular dependencies (#1399). New syntax for strict option (#1392). It can now be used as boolean/"log" (to set all strict mode restrictions) or as an object with properties schema, number, types, tuples and required, the defaults are:

{
  schema: true,
  number: true,
  types: "log",
  tuples: "log",
  required: false
}

Options strictTypes, strictTuples and strictRequired removed.

JTD error objects:

• schemaPath and instancePath are consistent with JSON Type Definition RFC
• added properties keyword and params, message (can be removed with messages: false option) to error objects JTD error messages can be translated with ajv-i18n v4.0.0-beta.0
• typescript: discriminated union type for JTD errors for type-safe error handling, errors need to be cast to JTDErrorObject type.

JSON Schema errors:

• dataPath property replaced with instancePath (update in your code!)
• "should" replaced with "must" in the messages
• property name is removed from "propertyName" keyword error message (it is still available in error.params.propertyName).

Fix #1515: correctly initialize evaluated properties.

Docs correction Simplified JSONSchemaType (@erikbrinkman) Fix #1493 - incorrect reporting of missing required property with option ownProperties: true Fix #1501 - JTD not working correctly with many properties in the schema

Add tests and fix parsers compiled with ajv.compileParser from JTD schemas:

• fail on invalid JSON:
  • trailing comma in arrays/objects
  • invalid JSON numbers
  • control characters in strings
• fix parsing of u-escaped characters
• do not fail on duplicate object keys (consistent with JSON.parse)

Compiled parsers are now:

• consistent with JSON.parse in case of invalid JSON
• only parse data that is valid for JTD schema

It is a breaking change for compiled parsers compared with 7.2.0 that was released earlier on the same day.

strictRequired option (off by default) - to log or fail if properties used in JSON Schema "required" are not defined in "properties" (@PBug90, #1403)

Compiled parsers (as fast as JSON.parse on valid JSON, but replace validation and fail much faster on invalid JSON) and serializers (10x+ faster than JSON.stringify) from JSON Type Definition schemas (#1454) - see examples in javascript and typescript

Please note: there are fixes to compiled parsers in 7.2.1

The website migrated to VuePress and documentation is restructured to make navigating Ajv documentation and learning easier - this is still work in progress, but already some improvement on the information structure. Any feedback/corrections would be very much appreciated!

Improved TypeScript support for JSONSchemaType:

• JTDSchemaType<T> utility type to convert your data type into the type of JTD schema, to simplify its writing and to make sure it is consistent with your data type, with type inference support for ajv methods (@erikbrinkman, #1446, #1456, #1457, #1475) - see example here
• Alternatively, you can use JTDDataType<typeof schema> utility type to convert your JTD schema type into the type of data (@erikbrinkman, #1458) - see this example

Other improvements by @Fdawgs (#1466), @t7yang (#1472, #1473), @koba04 (#1460)

Support readonly arrays with JSONSchemaType (@LinusU, #1447)

Support for JSON Type Definition RFC 8927 - a simple schema language provided as an alternative to JSON Schema.

See these docs:

• an informal document on Ajv site
• RFC8927
• choosing schema language - comparison with JSON Schema

Allow ":" in keyword names (#1421, @teq0)

Fix: duplicate functions in standalone validation code with mutually recursive schemas (#1361) Fix: reference resolution when base URI change was not applied (#1414)

Fixes:

• oneOf error type (#1368, @G-Rath)
• remove multiple imports (rollup/plugins#745)

Docs:

• Using in ES5 (#1364, @aladdin-add)
• Option strictTypes: false has to be used with json-schema-secure schema (#1373)

Remove duplicate functions from standalone validation code (#1361)

Update error message for maxLength/minLength keywords

Please note: this document covers the changes from v6.12.6.

The main changes

• support of JSON Schema draft-2019-09 features: unevaluatedProperties and unevaluatedItems, dynamic recursive references and other additional keywords.
• comprehensive support for standalone validation code - compiling one or multiple schemas to standalone modules with one or multiple exports.
• to reduce the mistakes in JSON schemas and unexpected validation results, strict mode is added - it prohibits ignored or ambiguous JSON Schema elements. See Strict mode and Options for more details
• to make code injection from untrusted schemas impossible, code generation is fully re-written to be type-level safe against code injection.
• to simplify Ajv extensions, the new keyword API that is used by pre-defined keywords is available to user-defined keywords - it is much easier to define any keywords now, especially with subschemas.
• schemas are compiled to ES6 code (ES5 code generation is supported with an option).
• to improve reliability and maintainability the code is migrated to TypeScript.
• separate Ajv classes from draft-07 and draft-2019-09 support with different default imports (see Getting started or v7.0.0-beta.5 for the details).

Please note:

• the support for JSON-Schema draft-04 is removed - if you have schemas using "id" attributes you have to replace them with "$id" (or continue using version 6 that will be supported until 02/28/2021).
• all formats are separated to ajv-formats package - they have to be explicitly added if you use them.
• Ajv instance can only be created with new keyword, as Ajv is now ES6 class.
• browser bundles are automatically published to ajv-dist package (but still available on cdnjs.com).
• order of schema keyword validation changed - keywords that apply to all types (allOf etc.) are now validated first, before the keywords that apply to specific data types. You can still define custom keywords that apply to all types AND are validated after type-specific keywords using option post: true in keyword definition.
• regular expressions in keywords "pattern" and "patternProperties" are now used as if they had unicode "u" flag, as required by JSON Schema specification - it means that some regular expressions that were valid with Ajv v6 are now invalid (and vice versa).

Better TypeScript support:

• Methods compile and compileAsync now return type-guards - see Getting started.
• Method validate is a type-guard.
• Better separation of asynchronous schemas on type level.
• Type utility JSONSchemaType<T> that generates the type for JSON Schema for type interface in the type parameter - it simplifies writing schemas (no unions support at the moment).

API changes:

• addVocabulary - NEW method that allows to add an array of keyword definitions.
• addKeyword - keyword name should be passed as property in definition object, not as the first parameter (old API works with "deprecated" warning). Also "inline" keywords support is removed, code generation keywords can now be defined with "code" keyword - the same definition format that is used by all pre-defined keywords
• Ajv no longer allows to create the instance without new keyword (it is ES6 class).

Added options (and defaults):

• strict: true - strict mode
• strictTypes: "log" - prevent mistakes related to type keywords and keyword applicability (see Strict Types)
• strictTuples: "log" - prevent incomplete tuple schemas (see Prohibit unconstrained tuples)
• allowUnionTypes: false - allow multiple non-null types in "type" keyword
• allowMatchingProperties: false - allow overlap between "properties" and "patternProperties" keywords
• loopEnum: Infinity - optimise validation of enums, similar to loopRequired
• validateFormats: true - enable format validation
• code: {optimize: number|boolean} - control code optimisation
• code: {es5: true} - generate ES5 code, the default is to generate ES6 code.
• code: {lines: true} - add line breaks to generated code - simplifies debugging of compiled schemas when you need it

Changed options:

• keywords - now expects the array of keyword definitions (old API works with "deprecated" warning)

Removed options:

• errorDataPath - was deprecated, now removed.
• format - validateFormats: false can be used instead, old format mode can be chosen via ajv-formats package.
• nullable: nullable keyword is supported by default.
• jsonPointers: JSONPointers are used to report errors by default, jsPropertySyntax: true (deprecated) can be used if old format is needed.
• extendRefs: $ref siblings are validated by default (consistent with draft 2019-09), ignoreKeywordsWithRef (deprecated) can be used instead to ignore $ref siblings.
• missingRefs: now exception is always thrown. Pass empty schema with $id that should be ignored to ajv.addSchema.
• processCode: replaced with code: {process: (code, schemaEnv: object) => string}.
• sourceCode: replaced with code: {source: true}.
• schemaId: removed, as JSON Schema draft-04 is no longer supported.
• strictDefaults, strictKeywords, strictNumbers: it is default now, controlled with strict.
• uniqueItems: '"uniqueItems" keyword is always validated.
• unknownFormats: the same can be achieved by passing true for formats that need to be ignored via ajv.addFormat or formats option.
• cache and serialize: Map is used as cache, schema object as key.

Publish browser bundles to ajv-dist

Improve standalone code generation. Update JSON Schema tests. Code components doc for contributors.

Better types of error objects Remove esModuleInterop from typescript config

Support code generation options code.es5 and code.lines for standalone validation code.

JSONSchemaType support for the new draft-2019-09 keywords.

Support for generation of standalone validation code

Compatible with ajv-errors v2-beta. Keywords for all data types that are executed after others (with post: true in keyword definition).

Add "latest" meta-schema URI "http://json-schema.org/schema" to draft-2019-09 class to reference default meta-schema (to support ajv-keywords)