Move bg/js (#1387)

* Move bg/js/anki.js to js/comm/anki.js

* Move bg/js/mecab.js to js/comm/mecab.js

* Move bg/js/search-main.js to js/display/search-main.js

* Move bg/js/template-patcher.js to js/templates/template-patcher.js

* Move bg/js/template-renderer-frame-api.js to js/templates/template-renderer-frame-api.js

* Move bg/js/template-renderer-frame-main.js to js/templates/template-renderer-frame-main.js

* Move bg/js/template-renderer-proxy.js to js/templates/template-renderer-proxy.js

* Move bg/js/template-renderer.js to js/templates/template-renderer.js

* Move bg/js/media-utility.js to js/media/media-utility.js

* Move bg/js/native-simple-dom-parser.js to js/dom/native-simple-dom-parser.js

* Move bg/js/simple-dom-parser.js to js/dom/simple-dom-parser.js

* Move bg/js/audio-downloader.js to js/media/audio-downloader.js

* Move bg/js/deinflector.js to js/language/deinflector.js

* Move bg/js/backend.js to js/background/backend.js

* Move bg/js/translator.js to js/language/translator.js

* Move bg/js/search-display-controller.js to js/display/search-display-controller.js

* Move bg/js/request-builder.js to js/background/request-builder.js

* Move bg/js/text-source-map.js to js/general/text-source-map.js

* Move bg/js/clipboard-reader.js to js/comm/clipboard-reader.js

* Move bg/js/clipboard-monitor.js to js/comm/clipboard-monitor.js

* Move bg/js/query-parser.js to js/display/query-parser.js

* Move bg/js/profile-conditions.js to js/background/profile-conditions.js

* Move bg/js/dictionary-database.js to js/language/dictionary-database.js

* Move bg/js/dictionary-importer.js to js/language/dictionary-importer.js

* Move bg/js/anki-note-builder.js to js/data/anki-note-builder.js

* Move bg/js/anki-note-data.js to js/data/anki-note-data.js

* Move bg/js/database.js to js/data/database.js

* Move bg/js/json-schema.js to js/data/json-schema.js

* Move bg/js/options.js to js/data/options-util.js

* Move bg/js/background-main.js to js/background/background-main.js

* Move bg/js/permissions-util.js to js/data/permissions-util.js

* Move bg/js/context-main.js to js/pages/action-popup-main.js

* Move bg/js/generic-page-main.js to js/pages/generic-page-main.js

* Move bg/js/info-main.js to js/pages/info-main.js

* Move bg/js/permissions-main.js to js/pages/permissions-main.js

* Move bg/js/welcome-main.js to js/pages/welcome-main.js

1 files changed, 757 insertions, 0 deletions

diff --git a/ext/js/data/json-schema.js b/ext/js/data/json-schema.js
new file mode 100644
index 00000000..7b6b9c53
--- /dev/null
+++ b/ext/js/data/json-schema.js
@@ -0,0 +1,757 @@
+/*
+ * Copyright (C) 2019-2021  Yomichan Authors
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <https://www.gnu.org/licenses/>.
+ */
+
+/* global
+ * CacheMap
+ */
+
+class JsonSchemaProxyHandler {
+    constructor(schema, jsonSchemaValidator) {
+        this._schema = schema;
+        this._jsonSchemaValidator = jsonSchemaValidator;
+    }
+
+    getPrototypeOf(target) {
+        return Object.getPrototypeOf(target);
+    }
+
+    setPrototypeOf() {
+        throw new Error('setPrototypeOf not supported');
+    }
+
+    isExtensible(target) {
+        return Object.isExtensible(target);
+    }
+
+    preventExtensions(target) {
+        Object.preventExtensions(target);
+        return true;
+    }
+
+    getOwnPropertyDescriptor(target, property) {
+        return Object.getOwnPropertyDescriptor(target, property);
+    }
+
+    defineProperty() {
+        throw new Error('defineProperty not supported');
+    }
+
+    has(target, property) {
+        return property in target;
+    }
+
+    get(target, property) {
+        if (typeof property === 'symbol') {
+            return target[property];
+        }
+
+        if (Array.isArray(target)) {
+            if (typeof property === 'string' && /^\d+$/.test(property)) {
+                property = parseInt(property, 10);
+            } else if (typeof property === 'string') {
+                return target[property];
+            }
+        }
+
+        const propertySchema = this._jsonSchemaValidator.getPropertySchema(this._schema, property, target);
+        if (propertySchema === null) {
+            return;
+        }
+
+        const value = target[property];
+        return value !== null && typeof value === 'object' ? this._jsonSchemaValidator.createProxy(value, propertySchema) : value;
+    }
+
+    set(target, property, value) {
+        if (Array.isArray(target)) {
+            if (typeof property === 'string' && /^\d+$/.test(property)) {
+                property = parseInt(property, 10);
+                if (property > target.length) {
+                    throw new Error('Array index out of range');
+                }
+            } else if (typeof property === 'string') {
+                target[property] = value;
+                return true;
+            }
+        }
+
+        const propertySchema = this._jsonSchemaValidator.getPropertySchema(this._schema, property, target);
+        if (propertySchema === null) {
+            throw new Error(`Property ${property} not supported`);
+        }
+
+        value = clone(value);
+
+        this._jsonSchemaValidator.validate(value, propertySchema);
+
+        target[property] = value;
+        return true;
+    }
+
+    deleteProperty(target, property) {
+        const required = this._schema.required;
+        if (Array.isArray(required) && required.includes(property)) {
+            throw new Error(`${property} cannot be deleted`);
+        }
+        return Reflect.deleteProperty(target, property);
+    }
+
+    ownKeys(target) {
+        return Reflect.ownKeys(target);
+    }
+
+    apply() {
+        throw new Error('apply not supported');
+    }
+
+    construct() {
+        throw new Error('construct not supported');
+    }
+}
+
+class JsonSchemaValidator {
+    constructor() {
+        this._regexCache = new CacheMap(100);
+    }
+
+    createProxy(target, schema) {
+        return new Proxy(target, new JsonSchemaProxyHandler(schema, this));
+    }
+
+    isValid(value, schema) {
+        try {
+            this.validate(value, schema);
+            return true;
+        } catch (e) {
+            return false;
+        }
+    }
+
+    validate(value, schema) {
+        const info = new JsonSchemaTraversalInfo(value, schema);
+        this._validate(value, schema, info);
+    }
+
+    getValidValueOrDefault(schema, value) {
+        const info = new JsonSchemaTraversalInfo(value, schema);
+        return this._getValidValueOrDefault(schema, value, info);
+    }
+
+    getPropertySchema(schema, property, value) {
+        return this._getPropertySchema(schema, property, value, null);
+    }
+
+    clearCache() {
+        this._regexCache.clear();
+    }
+
+    // Private
+
+    _getPropertySchema(schema, property, value, path) {
+        const type = this._getSchemaOrValueType(schema, value);
+        switch (type) {
+            case 'object':
+            {
+                const properties = schema.properties;
+                if (this._isObject(properties)) {
+                    const propertySchema = properties[property];
+                    if (this._isObject(propertySchema)) {
+                        if (path !== null) { path.push(['properties', properties], [property, propertySchema]); }
+                        return propertySchema;
+                    }
+                }
+
+                const additionalProperties = schema.additionalProperties;
+                if (additionalProperties === false) {
+                    return null;
+                } else if (this._isObject(additionalProperties)) {
+                    if (path !== null) { path.push(['additionalProperties', additionalProperties]); }
+                    return additionalProperties;
+                } else {
+                    const result = JsonSchemaValidator.unconstrainedSchema;
+                    if (path !== null) { path.push([null, result]); }
+                    return result;
+                }
+            }
+            case 'array':
+            {
+                const items = schema.items;
+                if (this._isObject(items)) {
+                    return items;
+                }
+                if (Array.isArray(items)) {
+                    if (property >= 0 && property < items.length) {
+                        const propertySchema = items[property];
+                        if (this._isObject(propertySchema)) {
+                            if (path !== null) { path.push(['items', items], [property, propertySchema]); }
+                            return propertySchema;
+                        }
+                    }
+                }
+
+                const additionalItems = schema.additionalItems;
+                if (additionalItems === false) {
+                    return null;
+                } else if (this._isObject(additionalItems)) {
+                    if (path !== null) { path.push(['additionalItems', additionalItems]); }
+                    return additionalItems;
+                } else {
+                    const result = JsonSchemaValidator.unconstrainedSchema;
+                    if (path !== null) { path.push([null, result]); }
+                    return result;
+                }
+            }
+            default:
+                return null;
+        }
+    }
+
+    _getSchemaOrValueType(schema, value) {
+        const type = schema.type;
+
+        if (Array.isArray(type)) {
+            if (typeof value !== 'undefined') {
+                const valueType = this._getValueType(value);
+                if (type.indexOf(valueType) >= 0) {
+                    return valueType;
+                }
+            }
+            return null;
+        }
+
+        if (typeof type === 'undefined') {
+            if (typeof value !== 'undefined') {
+                return this._getValueType(value);
+            }
+            return null;
+        }
+
+        return type;
+    }
+
+    _validate(value, schema, info) {
+        this._validateSingleSchema(value, schema, info);
+        this._validateConditional(value, schema, info);
+        this._validateAllOf(value, schema, info);
+        this._validateAnyOf(value, schema, info);
+        this._validateOneOf(value, schema, info);
+        this._validateNoneOf(value, schema, info);
+    }
+
+    _validateConditional(value, schema, info) {
+        const ifSchema = schema.if;
+        if (!this._isObject(ifSchema)) { return; }
+
+        let okay = true;
+        info.schemaPush('if', ifSchema);
+        try {
+            this._validate(value, ifSchema, info);
+        } catch (e) {
+            okay = false;
+        }
+        info.schemaPop();
+
+        const nextSchema = okay ? schema.then : schema.else;
+        if (this._isObject(nextSchema)) {
+            info.schemaPush(okay ? 'then' : 'else', nextSchema);
+            this._validate(value, nextSchema, info);
+            info.schemaPop();
+        }
+    }
+
+    _validateAllOf(value, schema, info) {
+        const subSchemas = schema.allOf;
+        if (!Array.isArray(subSchemas)) { return; }
+
+        info.schemaPush('allOf', subSchemas);
+        for (let i = 0; i < subSchemas.length; ++i) {
+            const subSchema = subSchemas[i];
+            info.schemaPush(i, subSchema);
+            this._validate(value, subSchema, info);
+            info.schemaPop();
+        }
+        info.schemaPop();
+    }
+
+    _validateAnyOf(value, schema, info) {
+        const subSchemas = schema.anyOf;
+        if (!Array.isArray(subSchemas)) { return; }
+
+        info.schemaPush('anyOf', subSchemas);
+        for (let i = 0; i < subSchemas.length; ++i) {
+            const subSchema = subSchemas[i];
+            info.schemaPush(i, subSchema);
+            try {
+                this._validate(value, subSchema, info);
+                return;
+            } catch (e) {
+                // NOP
+            }
+            info.schemaPop();
+        }
+
+        throw new JsonSchemaValidationError('0 anyOf schemas matched', value, schema, info);
+        // info.schemaPop(); // Unreachable
+    }
+
+    _validateOneOf(value, schema, info) {
+        const subSchemas = schema.oneOf;
+        if (!Array.isArray(subSchemas)) { return; }
+
+        info.schemaPush('oneOf', subSchemas);
+        let count = 0;
+        for (let i = 0; i < subSchemas.length; ++i) {
+            const subSchema = subSchemas[i];
+            info.schemaPush(i, subSchema);
+            try {
+                this._validate(value, subSchema, info);
+                ++count;
+            } catch (e) {
+                // NOP
+            }
+            info.schemaPop();
+        }
+
+        if (count !== 1) {
+            throw new JsonSchemaValidationError(`${count} oneOf schemas matched`, value, schema, info);
+        }
+
+        info.schemaPop();
+    }
+
+    _validateNoneOf(value, schema, info) {
+        const subSchemas = schema.not;
+        if (!Array.isArray(subSchemas)) { return; }
+
+        info.schemaPush('not', subSchemas);
+        for (let i = 0; i < subSchemas.length; ++i) {
+            const subSchema = subSchemas[i];
+            info.schemaPush(i, subSchema);
+            try {
+                this._validate(value, subSchema, info);
+            } catch (e) {
+                info.schemaPop();
+                continue;
+            }
+            throw new JsonSchemaValidationError(`not[${i}] schema matched`, value, schema, info);
+        }
+        info.schemaPop();
+    }
+
+    _validateSingleSchema(value, schema, info) {
+        const type = this._getValueType(value);
+        const schemaType = schema.type;
+        if (!this._isValueTypeAny(value, type, schemaType)) {
+            throw new JsonSchemaValidationError(`Value type ${type} does not match schema type ${schemaType}`, value, schema, info);
+        }
+
+        const schemaConst = schema.const;
+        if (typeof schemaConst !== 'undefined' && !this._valuesAreEqual(value, schemaConst)) {
+            throw new JsonSchemaValidationError('Invalid constant value', value, schema, info);
+        }
+
+        const schemaEnum = schema.enum;
+        if (Array.isArray(schemaEnum) && !this._valuesAreEqualAny(value, schemaEnum)) {
+            throw new JsonSchemaValidationError('Invalid enum value', value, schema, info);
+        }
+
+        switch (type) {
+            case 'number':
+                this._validateNumber(value, schema, info);
+                break;
+            case 'string':
+                this._validateString(value, schema, info);
+                break;
+            case 'array':
+                this._validateArray(value, schema, info);
+                break;
+            case 'object':
+                this._validateObject(value, schema, info);
+                break;
+        }
+    }
+
+    _validateNumber(value, schema, info) {
+        const multipleOf = schema.multipleOf;
+        if (typeof multipleOf === 'number' && Math.floor(value / multipleOf) * multipleOf !== value) {
+            throw new JsonSchemaValidationError(`Number is not a multiple of ${multipleOf}`, value, schema, info);
+        }
+
+        const minimum = schema.minimum;
+        if (typeof minimum === 'number' && value < minimum) {
+            throw new JsonSchemaValidationError(`Number is less than ${minimum}`, value, schema, info);
+        }
+
+        const exclusiveMinimum = schema.exclusiveMinimum;
+        if (typeof exclusiveMinimum === 'number' && value <= exclusiveMinimum) {
+            throw new JsonSchemaValidationError(`Number is less than or equal to ${exclusiveMinimum}`, value, schema, info);
+        }
+
+        const maximum = schema.maximum;
+        if (typeof maximum === 'number' && value > maximum) {
+            throw new JsonSchemaValidationError(`Number is greater than ${maximum}`, value, schema, info);
+        }
+
+        const exclusiveMaximum = schema.exclusiveMaximum;
+        if (typeof exclusiveMaximum === 'number' && value >= exclusiveMaximum) {
+            throw new JsonSchemaValidationError(`Number is greater than or equal to ${exclusiveMaximum}`, value, schema, info);
+        }
+    }
+
+    _validateString(value, schema, info) {
+        const minLength = schema.minLength;
+        if (typeof minLength === 'number' && value.length < minLength) {
+            throw new JsonSchemaValidationError('String length too short', value, schema, info);
+        }
+
+        const maxLength = schema.maxLength;
+        if (typeof maxLength === 'number' && value.length > maxLength) {
+            throw new JsonSchemaValidationError('String length too long', value, schema, info);
+        }
+
+        const pattern = schema.pattern;
+        if (typeof pattern === 'string') {
+            let patternFlags = schema.patternFlags;
+            if (typeof patternFlags !== 'string') { patternFlags = ''; }
+
+            let regex;
+            try {
+                regex = this._getRegex(pattern, patternFlags);
+            } catch (e) {
+                throw new JsonSchemaValidationError(`Pattern is invalid (${e.message})`, value, schema, info);
+            }
+
+            if (!regex.test(value)) {
+                throw new JsonSchemaValidationError('Pattern match failed', value, schema, info);
+            }
+        }
+    }
+
+    _validateArray(value, schema, info) {
+        const minItems = schema.minItems;
+        if (typeof minItems === 'number' && value.length < minItems) {
+            throw new JsonSchemaValidationError('Array length too short', value, schema, info);
+        }
+
+        const maxItems = schema.maxItems;
+        if (typeof maxItems === 'number' && value.length > maxItems) {
+            throw new JsonSchemaValidationError('Array length too long', value, schema, info);
+        }
+
+        this._validateArrayContains(value, schema, info);
+
+        for (let i = 0, ii = value.length; i < ii; ++i) {
+            const schemaPath = [];
+            const propertySchema = this._getPropertySchema(schema, i, value, schemaPath);
+            if (propertySchema === null) {
+                throw new JsonSchemaValidationError(`No schema found for array[${i}]`, value, schema, info);
+            }
+
+            const propertyValue = value[i];
+
+            for (const [p, s] of schemaPath) { info.schemaPush(p, s); }
+            info.valuePush(i, propertyValue);
+            this._validate(propertyValue, propertySchema, info);
+            info.valuePop();
+            for (let j = 0, jj = schemaPath.length; j < jj; ++j) { info.schemaPop(); }
+        }
+    }
+
+    _validateArrayContains(value, schema, info) {
+        const containsSchema = schema.contains;
+        if (!this._isObject(containsSchema)) { return; }
+
+        info.schemaPush('contains', containsSchema);
+        for (let i = 0, ii = value.length; i < ii; ++i) {
+            const propertyValue = value[i];
+            info.valuePush(i, propertyValue);
+            try {
+                this._validate(propertyValue, containsSchema, info);
+                info.schemaPop();
+                return;
+            } catch (e) {
+                // NOP
+            }
+            info.valuePop();
+        }
+        throw new JsonSchemaValidationError('contains schema didn\'t match', value, schema, info);
+    }
+
+    _validateObject(value, schema, info) {
+        const properties = new Set(Object.getOwnPropertyNames(value));
+
+        const required = schema.required;
+        if (Array.isArray(required)) {
+            for (const property of required) {
+                if (!properties.has(property)) {
+                    throw new JsonSchemaValidationError(`Missing property ${property}`, value, schema, info);
+                }
+            }
+        }
+
+        const minProperties = schema.minProperties;
+        if (typeof minProperties === 'number' && properties.length < minProperties) {
+            throw new JsonSchemaValidationError('Not enough object properties', value, schema, info);
+        }
+
+        const maxProperties = schema.maxProperties;
+        if (typeof maxProperties === 'number' && properties.length > maxProperties) {
+            throw new JsonSchemaValidationError('Too many object properties', value, schema, info);
+        }
+
+        for (const property of properties) {
+            const schemaPath = [];
+            const propertySchema = this._getPropertySchema(schema, property, value, schemaPath);
+            if (propertySchema === null) {
+                throw new JsonSchemaValidationError(`No schema found for ${property}`, value, schema, info);
+            }
+
+            const propertyValue = value[property];
+
+            for (const [p, s] of schemaPath) { info.schemaPush(p, s); }
+            info.valuePush(property, propertyValue);
+            this._validate(propertyValue, propertySchema, info);
+            info.valuePop();
+            for (let i = 0; i < schemaPath.length; ++i) { info.schemaPop(); }
+        }
+    }
+
+    _isValueTypeAny(value, type, schemaTypes) {
+        if (typeof schemaTypes === 'string') {
+            return this._isValueType(value, type, schemaTypes);
+        } else if (Array.isArray(schemaTypes)) {
+            for (const schemaType of schemaTypes) {
+                if (this._isValueType(value, type, schemaType)) {
+                    return true;
+                }
+            }
+            return false;
+        }
+        return true;
+    }
+
+    _isValueType(value, type, schemaType) {
+        return (
+            type === schemaType ||
+            (schemaType === 'integer' && Math.floor(value) === value)
+        );
+    }
+
+    _getValueType(value) {
+        const type = typeof value;
+        if (type === 'object') {
+            if (value === null) { return 'null'; }
+            if (Array.isArray(value)) { return 'array'; }
+        }
+        return type;
+    }
+
+    _valuesAreEqualAny(value1, valueList) {
+        for (const value2 of valueList) {
+            if (this._valuesAreEqual(value1, value2)) {
+                return true;
+            }
+        }
+        return false;
+    }
+
+    _valuesAreEqual(value1, value2) {
+        return value1 === value2;
+    }
+
+    _getDefaultTypeValue(type) {
+        if (typeof type === 'string') {
+            switch (type) {
+                case 'null':
+                    return null;
+                case 'boolean':
+                    return false;
+                case 'number':
+                case 'integer':
+                    return 0;
+                case 'string':
+                    return '';
+                case 'array':
+                    return [];
+                case 'object':
+                    return {};
+            }
+        }
+        return null;
+    }
+
+    _getDefaultSchemaValue(schema) {
+        const schemaType = schema.type;
+        const schemaDefault = schema.default;
+        return (
+            typeof schemaDefault !== 'undefined' &&
+            this._isValueTypeAny(schemaDefault, this._getValueType(schemaDefault), schemaType) ?
+            clone(schemaDefault) :
+            this._getDefaultTypeValue(schemaType)
+        );
+    }
+
+    _getValidValueOrDefault(schema, value, info) {
+        let type = this._getValueType(value);
+        if (typeof value === 'undefined' || !this._isValueTypeAny(value, type, schema.type)) {
+            value = this._getDefaultSchemaValue(schema);
+            type = this._getValueType(value);
+        }
+
+        switch (type) {
+            case 'object':
+                value = this._populateObjectDefaults(value, schema, info);
+                break;
+            case 'array':
+                value = this._populateArrayDefaults(value, schema, info);
+                break;
+            default:
+                if (!this.isValid(value, schema)) {
+                    const schemaDefault = this._getDefaultSchemaValue(schema);
+                    if (this.isValid(schemaDefault, schema)) {
+                        value = schemaDefault;
+                    }
+                }
+                break;
+        }
+
+        return value;
+    }
+
+    _populateObjectDefaults(value, schema, info) {
+        const properties = new Set(Object.getOwnPropertyNames(value));
+
+        const required = schema.required;
+        if (Array.isArray(required)) {
+            for (const property of required) {
+                properties.delete(property);
+
+                const propertySchema = this._getPropertySchema(schema, property, value, null);
+                if (propertySchema === null) { continue; }
+                info.valuePush(property, value);
+                info.schemaPush(property, propertySchema);
+                const hasValue = Object.prototype.hasOwnProperty.call(value, property);
+                value[property] = this._getValidValueOrDefault(propertySchema, hasValue ? value[property] : void 0, info);
+                info.schemaPop();
+                info.valuePop();
+            }
+        }
+
+        for (const property of properties) {
+            const propertySchema = this._getPropertySchema(schema, property, value, null);
+            if (propertySchema === null) {
+                Reflect.deleteProperty(value, property);
+            } else {
+                info.valuePush(property, value);
+                info.schemaPush(property, propertySchema);
+                value[property] = this._getValidValueOrDefault(propertySchema, value[property], info);
+                info.schemaPop();
+                info.valuePop();
+            }
+        }
+
+        return value;
+    }
+
+    _populateArrayDefaults(value, schema, info) {
+        for (let i = 0, ii = value.length; i < ii; ++i) {
+            const propertySchema = this._getPropertySchema(schema, i, value, null);
+            if (propertySchema === null) { continue; }
+            info.valuePush(i, value);
+            info.schemaPush(i, propertySchema);
+            value[i] = this._getValidValueOrDefault(propertySchema, value[i], info);
+            info.schemaPop();
+            info.valuePop();
+        }
+
+        const minItems = schema.minItems;
+        if (typeof minItems === 'number' && value.length < minItems) {
+            for (let i = value.length; i < minItems; ++i) {
+                const propertySchema = this._getPropertySchema(schema, i, value, null);
+                if (propertySchema === null) { break; }
+                info.valuePush(i, value);
+                info.schemaPush(i, propertySchema);
+                const item = this._getValidValueOrDefault(propertySchema, void 0, info);
+                info.schemaPop();
+                info.valuePop();
+                value.push(item);
+            }
+        }
+
+        const maxItems = schema.maxItems;
+        if (typeof maxItems === 'number' && value.length > maxItems) {
+            value.splice(maxItems, value.length - maxItems);
+        }
+
+        return value;
+    }
+
+    _isObject(value) {
+        return typeof value === 'object' && value !== null && !Array.isArray(value);
+    }
+
+    _getRegex(pattern, flags) {
+        const key = `${flags}:${pattern}`;
+        let regex = this._regexCache.get(key);
+        if (typeof regex === 'undefined') {
+            regex = new RegExp(pattern, flags);
+            this._regexCache.set(key, regex);
+        }
+        return regex;
+    }
+}
+
+Object.defineProperty(JsonSchemaValidator, 'unconstrainedSchema', {
+    value: Object.freeze({}),
+    configurable: false,
+    enumerable: true,
+    writable: false
+});
+
+class JsonSchemaTraversalInfo {
+    constructor(value, schema) {
+        this.valuePath = [];
+        this.schemaPath = [];
+        this.valuePush(null, value);
+        this.schemaPush(null, schema);
+    }
+
+    valuePush(path, value) {
+        this.valuePath.push([path, value]);
+    }
+
+    valuePop() {
+        this.valuePath.pop();
+    }
+
+    schemaPush(path, schema) {
+        this.schemaPath.push([path, schema]);
+    }
+
+    schemaPop() {
+        this.schemaPath.pop();
+    }
+}
+
+class JsonSchemaValidationError extends Error {
+    constructor(message, value, schema, info) {
+        super(message);
+        this.value = value;
+        this.schema = schema;
+        this.info = info;
+    }
+}