docs/guide/environments.md

@@ -77,7 +77,8 @@ The browser bundles are available on [cdnjs](https://cdnjs.com/libraries/ajv).
 Some frameworks, e.g. Dojo, may redefine global require in a way that is not compatible with CommonJS module format. In this case Ajv bundle has to be loaded before the framework and then you can use global `ajv` (see issue [#234](https://github.com/ajv-validator/ajv/issues/234)).
 :::
 
-::: warning Ajv v8 in Internet Explorer 11 (IE11) will not work straight out of the box. To use it either [recompile it](https://ajv.js.org/standalone.html), or set the options [unicodeRegExp](https://ajv.js.org/options.html#unicoderegexp) to `false` and `code: { es5: true }`, and transpile the Ajv node module (see issue [#1585](https://github.com/ajv-validator/ajv/issues/1585#issuecomment-832486204)).
+::: warning Internet Explorer 11
+Ajv v8 in IE 11 will not work straight out of the box. To use it either [recompile it](../standalone.md), or set the options [unicodeRegExp](../options.md#unicoderegexp) to `false` and `code: { es5: true }`, and transpile the Ajv node module (see issue [#1585](https://github.com/ajv-validator/ajv/issues/1585#issuecomment-832486204)).
 :::
 
 ## ES5 environments

lib/compile/index.ts

@@ -63,6 +63,7 @@ export interface SchemaObjCxt extends SchemaCxt {
 }
 interface SchemaEnvArgs {
   readonly schema: AnySchema
+  readonly schemaId?: "$id" | "id"
   readonly root?: SchemaEnv
   readonly baseId?: string
   readonly schemaPath?: string
@@ -72,6 +73,7 @@ interface SchemaEnvArgs {
 
 export class SchemaEnv implements SchemaEnvArgs {
   readonly schema: AnySchema
+  readonly schemaId?: "$id" | "id"
   readonly root: SchemaEnv
   baseId: string // TODO possibly, it should be readonly
   schemaPath?: string
@@ -91,8 +93,9 @@ export class SchemaEnv implements SchemaEnvArgs {
     let schema: AnySchemaObject | undefined
     if (typeof env.schema == "object") schema = env.schema
     this.schema = env.schema
+    this.schemaId = env.schemaId
     this.root = env.root || this
-    this.baseId = env.baseId ?? normalizeId(schema?.$id)
+    this.baseId = env.baseId ?? normalizeId(schema?.[env.schemaId || "$id"])
     this.schemaPath = env.schemaPath
     this.localRefs = env.localRefs
     this.meta = env.meta
@@ -212,7 +215,8 @@ export function resolveRef(
   let _sch = resolve.call(this, root, ref)
   if (_sch === undefined) {
     const schema = root.localRefs?.[ref] // TODO maybe localRefs should hold SchemaEnv
-    if (schema) _sch = new SchemaEnv({schema, root, baseId})
+    const {schemaId} = this.opts
+    if (schema) _sch = new SchemaEnv({schema, schemaId, root, baseId})
   }
 
   if (_sch === undefined) return
@@ -273,8 +277,10 @@ export function resolveSchema(
   if (!schOrRef.validate) compileSchema.call(this, schOrRef)
   if (id === normalizeId(ref)) {
     const {schema} = schOrRef
-    if (schema.$id) baseId = resolveUrl(baseId, schema.$id)
-    return new SchemaEnv({schema, root, baseId})
+    const {schemaId} = this.opts
+    const schId = schema[schemaId]
+    if (schId) baseId = resolveUrl(baseId, schId)
+    return new SchemaEnv({schema, schemaId, root, baseId})
   }
   return getJsonPointer.call(this, p, schOrRef)
 }
@@ -298,8 +304,9 @@ function getJsonPointer(
     schema = schema[unescapeFragment(part)]
     if (schema === undefined) return
     // TODO PREVENT_SCOPE_CHANGE could be defined in keyword def?
-    if (!PREVENT_SCOPE_CHANGE.has(part) && typeof schema == "object" && schema.$id) {
-      baseId = resolveUrl(baseId, schema.$id)
+    const schId = typeof schema == "object" && schema[this.opts.schemaId]
+    if (!PREVENT_SCOPE_CHANGE.has(part) && schId) {
+      baseId = resolveUrl(baseId, schId)
     }
   }
   let env: SchemaEnv | undefined
@@ -309,7 +316,8 @@ function getJsonPointer(
   }
   // even though resolution failed we need to return SchemaEnv to throw exception
   // so that compileAsync loads missing schema.
-  env = env || new SchemaEnv({schema, root, baseId})
+  const {schemaId} = this.opts
+  env = env || new SchemaEnv({schema, schemaId, root, baseId})
   if (env.schema !== env.root.schema) return env
   return undefined
 }

lib/compile/resolve.ts

@@ -91,17 +91,18 @@ const ANCHOR = /^[a-z_][-a-z0-9._]*$/i
 
 export function getSchemaRefs(this: Ajv, schema: AnySchema): LocalRefs {
   if (typeof schema == "boolean") return {}
-  const schemaId = normalizeId(schema.$id)
-  const baseIds: {[JsonPtr in string]?: string} = {"": schemaId}
-  const pathPrefix = getFullPath(schemaId, false)
+  const {schemaId} = this.opts
+  const schId = normalizeId(schema[schemaId])
+  const baseIds: {[JsonPtr in string]?: string} = {"": schId}
+  const pathPrefix = getFullPath(schId, false)
   const localRefs: LocalRefs = {}
   const schemaRefs: Set<string> = new Set()
 
   traverse(schema, {allKeys: true}, (sch, jsonPtr, _, parentJsonPtr) => {
     if (parentJsonPtr === undefined) return
     const fullPath = pathPrefix + jsonPtr
     let baseId = baseIds[parentJsonPtr]
-    if (typeof sch.$id == "string") baseId = addRef.call(this, sch.$id)
+    if (typeof sch[schemaId] == "string") baseId = addRef.call(this, sch[schemaId])
     addAnchor.call(this, sch.$anchor)
     addAnchor.call(this, sch.$dynamicAnchor)
     baseIds[jsonPtr] = baseId

lib/compile/validate/index.ts

@@ -112,9 +112,8 @@ function resetEvaluated(it: SchemaObjCxt): void {
 }
 
 function funcSourceUrl(schema: AnySchema, opts: InstanceOptions): Code {
-  return typeof schema == "object" && schema.$id && (opts.code.source || opts.code.process)
-    ? _`/*# sourceURL=${schema.$id} */`
-    : nil
+  const schId = typeof schema == "object" && schema[opts.schemaId]
+  return schId && (opts.code.source || opts.code.process) ? _`/*# sourceURL=${schId} */` : nil
 }
 
 // schema compilation - this function is used recursively to generate code for sub-schemas
@@ -177,7 +176,8 @@ function checkNoDefault(it: SchemaObjCxt): void {
 }
 
 function updateContext(it: SchemaObjCxt): void {
-  if (it.schema.$id) it.baseId = resolveUrl(it.baseId, it.schema.$id)
+  const schId = it.schema[it.opts.schemaId]
+  if (schId) it.baseId = resolveUrl(it.baseId, schId)
 }
 
 function checkAsyncSchema(it: SchemaObjCxt): void {

lib/core.ts

@@ -117,6 +117,7 @@ export interface CurrentOptions {
   next?: boolean // NEW
   unevaluated?: boolean // NEW
   dynamicRef?: boolean // NEW
+  schemaId?: "id" | "$id"
   jtd?: boolean // NEW
   meta?: SchemaObject | boolean
   defaultMeta?: string | AnySchemaObject
@@ -163,7 +164,6 @@ interface RemovedOptions {
   missingRefs?: true | "ignore" | "fail"
   processCode?: (code: string, schema?: SchemaEnv) => string
   sourceCode?: boolean
-  schemaId?: string
   strictDefaults?: boolean
   strictKeywords?: boolean
   uniqueItems?: boolean
@@ -186,7 +186,6 @@ const removedOptions: OptionsInfo<RemovedOptions> = {
   missingRefs: "Pass empty schema with $id that should be ignored to ajv.addSchema.",
   processCode: "Use option `code: {process: (code, schemaEnv: object) => string}`",
   sourceCode: "Use option `code: {source: true}`",
-  schemaId: "JSON Schema draft-04 is not supported in Ajv v7/8.",
   strictDefaults: "It is default now, see option `strict`.",
   strictKeywords: "It is default now, see option `strict`.",
   uniqueItems: '"uniqueItems" keyword is always validated.',
@@ -214,6 +213,7 @@ type RequiredInstanceOptions = {
     | "loopEnum"
     | "meta"
     | "messages"
+    | "schemaId"
     | "addUsedSchema"
     | "validateSchema"
     | "validateFormats"
@@ -241,6 +241,7 @@ function requiredOptions(o: Options): RequiredInstanceOptions {
     meta: o.meta ?? true,
     messages: o.messages ?? true,
     inlineRefs: o.inlineRefs ?? true,
+    schemaId: o.schemaId ?? "$id",
     addUsedSchema: o.addUsedSchema ?? true,
     validateSchema: o.validateSchema ?? true,
     validateFormats: o.validateFormats ?? true,
@@ -299,13 +300,19 @@ export default class Ajv {
   }
 
   _addDefaultMetaSchema(): void {
-    const {$data, meta} = this.opts
-    if (meta && $data) this.addMetaSchema($dataRefSchema, $dataRefSchema.$id, false)
+    const {$data, meta, schemaId} = this.opts
+    let _dataRefSchema: SchemaObject = $dataRefSchema
+    if (schemaId === "id") {
+      _dataRefSchema = {...$dataRefSchema}
+      _dataRefSchema.id = _dataRefSchema.$id
+      delete _dataRefSchema.$id
+    }
+    if (meta && $data) this.addMetaSchema(_dataRefSchema, _dataRefSchema[schemaId], false)
   }
 
   defaultMeta(): string | AnySchemaObject | undefined {
-    const {meta} = this.opts
-    return (this.opts.defaultMeta = typeof meta == "object" ? meta.$id || meta : undefined)
+    const {meta, schemaId} = this.opts
+    return (this.opts.defaultMeta = typeof meta == "object" ? meta[schemaId] || meta : undefined)
   }
 
   // Validate data using schema
@@ -450,8 +457,11 @@ export default class Ajv {
     }
     let id: string | undefined
     if (typeof schema === "object") {
-      id = schema.$id
-      if (id !== undefined && typeof id != "string") throw new Error("schema $id must be string")
+      const {schemaId} = this.opts
+      id = schema[schemaId]
+      if (id !== undefined && typeof id != "string") {
+        throw new Error(`schema ${schemaId} must be string`)
+      }
     }
     key = normalizeId(key || id)
     this._checkUnique(key)
@@ -499,7 +509,8 @@ export default class Ajv {
     let sch
     while (typeof (sch = getSchEnv.call(this, keyRef)) == "string") keyRef = sch
     if (sch === undefined) {
-      const root = new SchemaEnv({schema: {}})
+      const {schemaId} = this.opts
+      const root = new SchemaEnv({schema: {}, schemaId})
       sch = resolveSchema.call(this, root, keyRef)
       if (!sch) return
       this.refs[keyRef] = sch
@@ -533,7 +544,7 @@ export default class Ajv {
       case "object": {
         const cacheKey = schemaKeyRef
         this._cache.delete(cacheKey)
-        let id = schemaKeyRef.$id
+        let id = schemaKeyRef[this.opts.schemaId]
         if (id) {
           id = normalizeId(id)
           delete this.schemas[id]
@@ -670,8 +681,9 @@ export default class Ajv {
     addSchema = this.opts.addUsedSchema
   ): SchemaEnv {
     let id: string | undefined
+    const {schemaId} = this.opts
     if (typeof schema == "object") {
-      id = schema.$id
+      id = schema[schemaId]
     } else {
       if (this.opts.jtd) throw new Error("schema must be object")
       else if (typeof schema != "boolean") throw new Error("schema must be object or boolean")
@@ -681,7 +693,7 @@ export default class Ajv {
 
     const localRefs = getSchemaRefs.call(this, schema)
     baseId = normalizeId(id || baseId)
-    sch = new SchemaEnv({schema, meta, baseId, localRefs})
+    sch = new SchemaEnv({schema, schemaId, meta, baseId, localRefs})
     this._cache.set(sch.schema, sch)
     if (addSchema && !baseId.startsWith("#")) {
       // TODO atm it is allowed to overwrite schemas without id (instead of not adding them)

lib/types/index.ts

@@ -5,12 +5,14 @@ import type {KeywordCxt} from "../compile/validate"
 import type Ajv from "../core"
 
 interface _SchemaObject {
+  id?: string
   $id?: string
   $schema?: string
   [x: string]: any // TODO
 }
 
 export interface SchemaObject extends _SchemaObject {
+  id?: string
   $id?: string
   $schema?: string
   $async?: false

lib/vocabularies/dynamic/dynamicAnchor.ts

@@ -22,7 +22,8 @@ export function dynamicAnchor(cxt: KeywordCxt, anchor: string): void {
 function _getValidate(cxt: KeywordCxt): Code {
   const {schemaEnv, schema, self} = cxt.it
   const {root, baseId, localRefs, meta} = schemaEnv.root
-  const sch = new SchemaEnv({schema, root, baseId, localRefs, meta})
+  const {schemaId} = self.opts
+  const sch = new SchemaEnv({schema, schemaId, root, baseId, localRefs, meta})
   compileSchema.call(self, sch)
   return getValidate(cxt, sch)
 }

lib/vocabularies/validation/const.ts

@@ -16,9 +16,12 @@ const def: CodeKeywordDefinition = {
   $data: true,
   error,
   code(cxt: KeywordCxt) {
-    const {gen, data, schemaCode} = cxt
-    // TODO optimize for scalar values in schema
-    cxt.fail$data(_`!${useFunc(gen, equal)}(${data}, ${schemaCode})`)
+    const {gen, data, $data, schemaCode, schema} = cxt
+    if ($data || (schema && typeof schema == "object")) {
+      cxt.fail$data(_`!${useFunc(gen, equal)}(${data}, ${schemaCode})`)
+    } else {
+      cxt.fail(_`${schema} !== ${data}`)
+    }
   },
 }
 

lib/vocabularies/validation/enum.ts

@@ -42,7 +42,7 @@ const def: CodeKeywordDefinition = {
 
     function equalCode(vSchema: Name, i: number): Code {
       const sch = schema[i]
-      return sch && typeof sch === "object"
+      return typeof sch === "object" && sch !== null
         ? _`${eql}(${data}, ${vSchema}[${i}])`
         : _`${data} === ${sch}`
     }

package.json

@@ -1,6 +1,6 @@
 {
   "name": "ajv",
-  "version": "8.4.0",
+  "version": "8.5.0",
   "description": "Another JSON Schema Validator",
   "main": "dist/ajv.js",
   "types": "dist/ajv.d.ts",