validate repository responses against JSON schemas

* compute_scripts.awk (include_file): don't enforce specific path format on #INCLUDE'd files
* .gitmodules, schemas: add Haketilo JSON schemas subrepo
* html/install.js (InstallView): import schema validator and run it against downloaded mapping and resource definitions
* html/repo_query.js (RepoEntry): import schema validator and run it against obtained query results
* test/haketilo_test/unit/test_install.py (test_install_normal_usage, test_install_dialogs): use underscore instead of hyphen in item identifiers
* test/haketilo_test/unit/test_install.py (test_install_dialogs): adapt error message test cases to new handling method of invalid JSON instanced
* test/haketilo_test/unit/test_repo_query.py (test_repo_query_normal_usage): use underscore instead of hyphen in item identifiers
* test/haketilo_test/unit/test_repo_query.py (test_repo_query_messages): use higher sample unsupported schema version to avoid having to modify the test case soon
* test/haketilo_test/world_wide_library.py: use underscore instead of hyphen in item identifiers
* common/jsonschema.js, common/jsonschema: adapt tdegrunt's jsonschema and include in Haketilo, load schema documents from schemas/

5 files changed, 1964 insertions, 0 deletions

diff --git a/common/jsonschema/attribute.js b/common/jsonschema/attribute.js
new file mode 100644
index 0000000..5f10b7c
--- /dev/null
+++ b/common/jsonschema/attribute.js
@@ -0,0 +1,1002 @@
+/* SPDX-License-Identifier: MIT
+ *
+ * jsonschema is licensed under MIT license.
+ *
+ * Copyright (C) 2012-2015 Tom de Grunt <tom@degrunt.nl>
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy of
+ * this software and associated documentation files (the "Software"), to deal in
+ * the Software without restriction, including without limitation the rights to
+ * use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies
+ * of the Software, and to permit persons to whom the Software is furnished to do
+ * so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in all
+ * copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+ * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+ * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+ * SOFTWARE.
+ */
+
+#IMPORT common/jsonschema/helpers.js
+
+/** @type ValidatorResult */
+var ValidatorResult = helpers.ValidatorResult;
+/** @type SchemaError */
+var SchemaError = helpers.SchemaError;
+
+var attribute = {};
+
+const ignoreProperties = {
+  // informative properties
+  'id': true,
+  'default': true,
+  'description': true,
+  'title': true,
+  // arguments to other properties
+  'additionalItems': true,
+  'then': true,
+  'else': true,
+  // special-handled properties
+  '$schema': true,
+  '$ref': true,
+  'extends': true,
+};
+#EXPORT ignoreProperties
+
+/**
+ * @name validators
+ */
+const validators = {};
+
+/**
+ * Validates whether the instance if of a certain type
+ * @param instance
+ * @param schema
+ * @param options
+ * @param ctx
+ * @return {ValidatorResult|null}
+ */
+validators.type = function validateType (instance, schema, options, ctx) {
+  // Ignore undefined instances
+  if (instance === undefined) {
+    return null;
+  }
+  var result = new ValidatorResult(instance, schema, options, ctx);
+  var types = Array.isArray(schema.type) ? schema.type : [schema.type];
+  if (!types.some(this.testType.bind(this, instance, schema, options, ctx))) {
+    var list = types.map(function (v) {
+      if(!v) return;
+      var id = v.$id || v.id;
+      return id ? ('<' + id + '>') : (v+'');
+    });
+    result.addError({
+      name: 'type',
+      argument: list,
+      message: "is not of a type(s) " + list,
+    });
+  }
+  return result;
+};
+
+function testSchemaNoThrow(instance, options, ctx, callback, schema){
+  var throwError = options.throwError;
+  var throwAll = options.throwAll;
+  options.throwError = false;
+  options.throwAll = false;
+  var res = this.validateSchema(instance, schema, options, ctx);
+  options.throwError = throwError;
+  options.throwAll = throwAll;
+
+  if (!res.valid && callback instanceof Function) {
+    callback(res);
+  }
+  return res.valid;
+}
+
+/**
+ * Validates whether the instance matches some of the given schemas
+ * @param instance
+ * @param schema
+ * @param options
+ * @param ctx
+ * @return {ValidatorResult|null}
+ */
+validators.anyOf = function validateAnyOf (instance, schema, options, ctx) {
+  // Ignore undefined instances
+  if (instance === undefined) {
+    return null;
+  }
+  var result = new ValidatorResult(instance, schema, options, ctx);
+  var inner = new ValidatorResult(instance, schema, options, ctx);
+  if (!Array.isArray(schema.anyOf)){
+    throw new SchemaError("anyOf must be an array");
+  }
+  if (!schema.anyOf.some(
+    testSchemaNoThrow.bind(
+      this, instance, options, ctx, function(res){inner.importErrors(res);}
+    ))) {
+    var list = schema.anyOf.map(function (v, i) {
+      var id = v.$id || v.id;
+      if(id) return '<' + id + '>';
+      return(v.title && JSON.stringify(v.title)) || (v['$ref'] && ('<' + v['$ref'] + '>')) || '[subschema '+i+']';
+    });
+    if (options.nestedErrors) {
+      result.importErrors(inner);
+    }
+    result.addError({
+      name: 'anyOf',
+      argument: list,
+      message: "is not any of " + list.join(','),
+    });
+  }
+  return result;
+};
+
+/**
+ * Validates whether the instance matches every given schema
+ * @param instance
+ * @param schema
+ * @param options
+ * @param ctx
+ * @return {String|null}
+ */
+validators.allOf = function validateAllOf (instance, schema, options, ctx) {
+  // Ignore undefined instances
+  if (instance === undefined) {
+    return null;
+  }
+  if (!Array.isArray(schema.allOf)){
+    throw new SchemaError("allOf must be an array");
+  }
+  var result = new ValidatorResult(instance, schema, options, ctx);
+  var self = this;
+  schema.allOf.forEach(function(v, i){
+    var valid = self.validateSchema(instance, v, options, ctx);
+    if(!valid.valid){
+      var id = v.$id || v.id;
+      var msg = id || (v.title && JSON.stringify(v.title)) || (v['$ref'] && ('<' + v['$ref'] + '>')) || '[subschema '+i+']';
+      result.addError({
+        name: 'allOf',
+        argument: { id: msg, length: valid.errors.length, valid: valid },
+        message: 'does not match allOf schema ' + msg + ' with ' + valid.errors.length + ' error[s]:',
+      });
+      result.importErrors(valid);
+    }
+  });
+  return result;
+};
+
+/**
+ * Validates whether the instance matches exactly one of the given schemas
+ * @param instance
+ * @param schema
+ * @param options
+ * @param ctx
+ * @return {String|null}
+ */
+validators.oneOf = function validateOneOf (instance, schema, options, ctx) {
+  // Ignore undefined instances
+  if (instance === undefined) {
+    return null;
+  }
+  if (!Array.isArray(schema.oneOf)){
+    throw new SchemaError("oneOf must be an array");
+  }
+  var result = new ValidatorResult(instance, schema, options, ctx);
+  var inner = new ValidatorResult(instance, schema, options, ctx);
+  var count = schema.oneOf.filter(
+    testSchemaNoThrow.bind(
+      this, instance, options, ctx, function(res) {inner.importErrors(res);}
+    ) ).length;
+  var list = schema.oneOf.map(function (v, i) {
+    var id = v.$id || v.id;
+    return id || (v.title && JSON.stringify(v.title)) || (v['$ref'] && ('<' + v['$ref'] + '>')) || '[subschema '+i+']';
+  });
+  if (count!==1) {
+    if (options.nestedErrors) {
+      result.importErrors(inner);
+    }
+    result.addError({
+      name: 'oneOf',
+      argument: list,
+      message: "is not exactly one from " + list.join(','),
+    });
+  }
+  return result;
+};
+
+/**
+ * Validates "then" or "else" depending on the result of validating "if"
+ * @param instance
+ * @param schema
+ * @param options
+ * @param ctx
+ * @return {String|null}
+ */
+validators.if = function validateIf (instance, schema, options, ctx) {
+  // Ignore undefined instances
+  if (instance === undefined) return null;
+  if (!helpers.isSchema(schema.if)) throw new Error('Expected "if" keyword to be a schema');
+  var ifValid = testSchemaNoThrow.call(this, instance, options, ctx, null, schema.if);
+  var result = new ValidatorResult(instance, schema, options, ctx);
+  var res;
+  if(ifValid){
+    if (schema.then === undefined) return;
+    if (!helpers.isSchema(schema.then)) throw new Error('Expected "then" keyword to be a schema');
+    res = this.validateSchema(instance, schema.then, options, ctx.makeChild(schema.then));
+    result.importErrors(res);
+  }else{
+    if (schema.else === undefined) return;
+    if (!helpers.isSchema(schema.else)) throw new Error('Expected "else" keyword to be a schema');
+    res = this.validateSchema(instance, schema.else, options, ctx.makeChild(schema.else));
+    result.importErrors(res);
+  }
+  return result;
+};
+
+function getEnumerableProperty(object, key){
+  // Determine if `key` shows up in `for(var key in object)`
+  // First test Object.hasOwnProperty.call as an optimization: that guarantees it does
+  if(Object.hasOwnProperty.call(object, key)) return object[key];
+  // Test `key in object` as an optimization; false means it won't
+  if(!(key in object)) return;
+  while( (object = Object.getPrototypeOf(object)) ){
+    if(Object.propertyIsEnumerable.call(object, key)) return object[key];
+  }
+}
+
+/**
+ * Validates propertyNames
+ * @param instance
+ * @param schema
+ * @param options
+ * @param ctx
+ * @return {String|null|ValidatorResult}
+ */
+validators.propertyNames = function validatePropertyNames (instance, schema, options, ctx) {
+  if(!this.types.object(instance)) return;
+  var result = new ValidatorResult(instance, schema, options, ctx);
+  var subschema = schema.propertyNames!==undefined ? schema.propertyNames : {};
+  if(!helpers.isSchema(subschema)) throw new SchemaError('Expected "propertyNames" to be a schema (object or boolean)');
+
+  for (var property in instance) {
+    if(getEnumerableProperty(instance, property) !== undefined){
+      var res = this.validateSchema(property, subschema, options, ctx.makeChild(subschema));
+      result.importErrors(res);
+    }
+  }
+
+  return result;
+};
+
+/**
+ * Validates properties
+ * @param instance
+ * @param schema
+ * @param options
+ * @param ctx
+ * @return {String|null|ValidatorResult}
+ */
+validators.properties = function validateProperties (instance, schema, options, ctx) {
+  if(!this.types.object(instance)) return;
+  var result = new ValidatorResult(instance, schema, options, ctx);
+  var properties = schema.properties || {};
+  for (var property in properties) {
+    var subschema = properties[property];
+    if(subschema===undefined){
+      continue;
+    }else if(subschema===null){
+      throw new SchemaError('Unexpected null, expected schema in "properties"');
+    }
+    if (typeof options.preValidateProperty == 'function') {
+      options.preValidateProperty(instance, property, subschema, options, ctx);
+    }
+    var prop = getEnumerableProperty(instance, property);
+    var res = this.validateSchema(prop, subschema, options, ctx.makeChild(subschema, property));
+    if(res.instance !== result.instance[property]) result.instance[property] = res.instance;
+    result.importErrors(res);
+  }
+  return result;
+};
+
+/**
+ * Test a specific property within in instance against the additionalProperties schema attribute
+ * This ignores properties with definitions in the properties schema attribute, but no other attributes.
+ * If too many more types of property-existence tests pop up they may need their own class of tests (like `type` has)
+ * @private
+ * @return {boolean}
+ */
+function testAdditionalProperty (instance, schema, options, ctx, property, result) {
+  if(!this.types.object(instance)) return;
+  if (schema.properties && schema.properties[property] !== undefined) {
+    return;
+  }
+  if (schema.additionalProperties === false) {
+    result.addError({
+      name: 'additionalProperties',
+      argument: property,
+      message: "is not allowed to have the additional property " + JSON.stringify(property),
+    });
+  } else {
+    var additionalProperties = schema.additionalProperties || {};
+
+    if (typeof options.preValidateProperty == 'function') {
+      options.preValidateProperty(instance, property, additionalProperties, options, ctx);
+    }
+
+    var res = this.validateSchema(instance[property], additionalProperties, options, ctx.makeChild(additionalProperties, property));
+    if(res.instance !== result.instance[property]) result.instance[property] = res.instance;
+    result.importErrors(res);
+  }
+}
+
+/**
+ * Validates patternProperties
+ * @param instance
+ * @param schema
+ * @param options
+ * @param ctx
+ * @return {String|null|ValidatorResult}
+ */
+validators.patternProperties = function validatePatternProperties (instance, schema, options, ctx) {
+  if(!this.types.object(instance)) return;
+  var result = new ValidatorResult(instance, schema, options, ctx);
+  var patternProperties = schema.patternProperties || {};
+
+  for (var property in instance) {
+    var test = true;
+    for (var pattern in patternProperties) {
+      var subschema = patternProperties[pattern];
+      if(subschema===undefined){
+        continue;
+      }else if(subschema===null){
+        throw new SchemaError('Unexpected null, expected schema in "patternProperties"');
+      }
+      try {
+        var regexp = new RegExp(pattern, 'u');
+      } catch(_e) {
+        // In the event the stricter handling causes an error, fall back on the forgiving handling
+        // DEPRECATED
+        regexp = new RegExp(pattern);
+      }
+      if (!regexp.test(property)) {
+        continue;
+      }
+      test = false;
+
+      if (typeof options.preValidateProperty == 'function') {
+        options.preValidateProperty(instance, property, subschema, options, ctx);
+      }
+
+      var res = this.validateSchema(instance[property], subschema, options, ctx.makeChild(subschema, property));
+      if(res.instance !== result.instance[property]) result.instance[property] = res.instance;
+      result.importErrors(res);
+    }
+    if (test) {
+      testAdditionalProperty.call(this, instance, schema, options, ctx, property, result);
+    }
+  }
+
+  return result;
+};
+
+/**
+ * Validates additionalProperties
+ * @param instance
+ * @param schema
+ * @param options
+ * @param ctx
+ * @return {String|null|ValidatorResult}
+ */
+validators.additionalProperties = function validateAdditionalProperties (instance, schema, options, ctx) {
+  if(!this.types.object(instance)) return;
+  // if patternProperties is defined then we'll test when that one is called instead
+  if (schema.patternProperties) {
+    return null;
+  }
+  var result = new ValidatorResult(instance, schema, options, ctx);
+  for (var property in instance) {
+    testAdditionalProperty.call(this, instance, schema, options, ctx, property, result);
+  }
+  return result;
+};
+
+/**
+ * Validates whether the instance value is at least of a certain length, when the instance value is a string.
+ * @param instance
+ * @param schema
+ * @return {String|null}
+ */
+validators.minProperties = function validateMinProperties (instance, schema, options, ctx) {
+  if (!this.types.object(instance)) return;
+  var result = new ValidatorResult(instance, schema, options, ctx);
+  var keys = Object.keys(instance);
+  if (!(keys.length >= schema.minProperties)) {
+    result.addError({
+      name: 'minProperties',
+      argument: schema.minProperties,
+      message: "does not meet minimum property length of " + schema.minProperties,
+    });
+  }
+  return result;
+};
+
+/**
+ * Validates whether the instance value is at most of a certain length, when the instance value is a string.
+ * @param instance
+ * @param schema
+ * @return {String|null}
+ */
+validators.maxProperties = function validateMaxProperties (instance, schema, options, ctx) {
+  if (!this.types.object(instance)) return;
+  var result = new ValidatorResult(instance, schema, options, ctx);
+  var keys = Object.keys(instance);
+  if (!(keys.length <= schema.maxProperties)) {
+    result.addError({
+      name: 'maxProperties',
+      argument: schema.maxProperties,
+      message: "does not meet maximum property length of " + schema.maxProperties,
+    });
+  }
+  return result;
+};
+
+/**
+ * Validates items when instance is an array
+ * @param instance
+ * @param schema
+ * @param options
+ * @param ctx
+ * @return {String|null|ValidatorResult}
+ */
+validators.items = function validateItems (instance, schema, options, ctx) {
+  var self = this;
+  if (!this.types.array(instance)) return;
+  if (schema.items===undefined) return;
+  var result = new ValidatorResult(instance, schema, options, ctx);
+  instance.every(function (value, i) {
+    if(Array.isArray(schema.items)){
+      var items =  schema.items[i]===undefined ? schema.additionalItems : schema.items[i];
+    }else{
+      var items = schema.items;
+    }
+    if (items === undefined) {
+      return true;
+    }
+    if (items === false) {
+      result.addError({
+        name: 'items',
+        message: "additionalItems not permitted",
+      });
+      return false;
+    }
+    var res = self.validateSchema(value, items, options, ctx.makeChild(items, i));
+    if(res.instance !== result.instance[i]) result.instance[i] = res.instance;
+    result.importErrors(res);
+    return true;
+  });
+  return result;
+};
+
+/**
+ * Validates the "contains" keyword
+ * @param instance
+ * @param schema
+ * @param options
+ * @param ctx
+ * @return {String|null|ValidatorResult}
+ */
+validators.contains = function validateContains (instance, schema, options, ctx) {
+  var self = this;
+  if (!this.types.array(instance)) return;
+  if (schema.contains===undefined) return;
+  if (!helpers.isSchema(schema.contains)) throw new Error('Expected "contains" keyword to be a schema');
+  var result = new ValidatorResult(instance, schema, options, ctx);
+  var count = instance.some(function (value, i) {
+    var res = self.validateSchema(value, schema.contains, options, ctx.makeChild(schema.contains, i));
+    return res.errors.length===0;
+  });
+  if(count===false){
+    result.addError({
+      name: 'contains',
+      argument: schema.contains,
+      message: "must contain an item matching given schema",
+    });
+  }
+  return result;
+};
+
+/**
+ * Validates minimum and exclusiveMinimum when the type of the instance value is a number.
+ * @param instance
+ * @param schema
+ * @return {String|null}
+ */
+validators.minimum = function validateMinimum (instance, schema, options, ctx) {
+  if (!this.types.number(instance)) return;
+  var result = new ValidatorResult(instance, schema, options, ctx);
+  if (schema.exclusiveMinimum && schema.exclusiveMinimum === true) {
+    if(!(instance > schema.minimum)){
+      result.addError({
+        name: 'minimum',
+        argument: schema.minimum,
+        message: "must be greater than " + schema.minimum,
+      });
+    }
+  } else {
+    if(!(instance >= schema.minimum)){
+      result.addError({
+        name: 'minimum',
+        argument: schema.minimum,
+        message: "must be greater than or equal to " + schema.minimum,
+      });
+    }
+  }
+  return result;
+};
+
+/**
+ * Validates maximum and exclusiveMaximum when the type of the instance value is a number.
+ * @param instance
+ * @param schema
+ * @return {String|null}
+ */
+validators.maximum = function validateMaximum (instance, schema, options, ctx) {
+  if (!this.types.number(instance)) return;
+  var result = new ValidatorResult(instance, schema, options, ctx);
+  if (schema.exclusiveMaximum && schema.exclusiveMaximum === true) {
+    if(!(instance < schema.maximum)){
+      result.addError({
+        name: 'maximum',
+        argument: schema.maximum,
+        message: "must be less than " + schema.maximum,
+      });
+    }
+  } else {
+    if(!(instance <= schema.maximum)){
+      result.addError({
+        name: 'maximum',
+        argument: schema.maximum,
+        message: "must be less than or equal to " + schema.maximum,
+      });
+    }
+  }
+  return result;
+};
+
+/**
+ * Validates the number form of exclusiveMinimum when the type of the instance value is a number.
+ * @param instance
+ * @param schema
+ * @return {String|null}
+ */
+validators.exclusiveMinimum = function validateExclusiveMinimum (instance, schema, options, ctx) {
+  // Support the boolean form of exclusiveMinimum, which is handled by the "minimum" keyword.
+  if(typeof schema.exclusiveMinimum === 'boolean') return;
+  if (!this.types.number(instance)) return;
+  var result = new ValidatorResult(instance, schema, options, ctx);
+  var valid = instance > schema.exclusiveMinimum;
+  if (!valid) {
+    result.addError({
+      name: 'exclusiveMinimum',
+      argument: schema.exclusiveMinimum,
+      message: "must be strictly greater than " + schema.exclusiveMinimum,
+    });
+  }
+  return result;
+};
+
+/**
+ * Validates the number form of exclusiveMaximum when the type of the instance value is a number.
+ * @param instance
+ * @param schema
+ * @return {String|null}
+ */
+validators.exclusiveMaximum = function validateExclusiveMaximum (instance, schema, options, ctx) {
+  // Support the boolean form of exclusiveMaximum, which is handled by the "maximum" keyword.
+  if(typeof schema.exclusiveMaximum === 'boolean') return;
+  if (!this.types.number(instance)) return;
+  var result = new ValidatorResult(instance, schema, options, ctx);
+  var valid = instance < schema.exclusiveMaximum;
+  if (!valid) {
+    result.addError({
+      name: 'exclusiveMaximum',
+      argument: schema.exclusiveMaximum,
+      message: "must be strictly less than " + schema.exclusiveMaximum,
+    });
+  }
+  return result;
+};
+
+/**
+ * Perform validation for multipleOf and divisibleBy, which are essentially the same.
+ * @param instance
+ * @param schema
+ * @param validationType
+ * @param errorMessage
+ * @returns {String|null}
+ */
+var validateMultipleOfOrDivisbleBy = function validateMultipleOfOrDivisbleBy (instance, schema, options, ctx, validationType, errorMessage) {
+  if (!this.types.number(instance)) return;
+
+  var validationArgument = schema[validationType];
+  if (validationArgument == 0) {
+    throw new SchemaError(validationType + " cannot be zero");
+  }
+
+  var result = new ValidatorResult(instance, schema, options, ctx);
+
+  var instanceDecimals = helpers.getDecimalPlaces(instance);
+  var divisorDecimals = helpers.getDecimalPlaces(validationArgument);
+
+  var maxDecimals = Math.max(instanceDecimals , divisorDecimals);
+  var multiplier = Math.pow(10, maxDecimals);
+
+  if (Math.round(instance * multiplier) % Math.round(validationArgument * multiplier) !== 0) {
+    result.addError({
+      name: validationType,
+      argument:  validationArgument,
+      message: errorMessage + JSON.stringify(validationArgument),
+    });
+  }
+
+  return result;
+};
+
+/**
+ * Validates divisibleBy when the type of the instance value is a number.
+ * @param instance
+ * @param schema
+ * @return {String|null}
+ */
+validators.multipleOf = function validateMultipleOf (instance, schema, options, ctx) {
+  return validateMultipleOfOrDivisbleBy.call(this, instance, schema, options, ctx, "multipleOf", "is not a multiple of (divisible by) ");
+};
+
+/**
+ * Validates multipleOf when the type of the instance value is a number.
+ * @param instance
+ * @param schema
+ * @return {String|null}
+ */
+validators.divisibleBy = function validateDivisibleBy (instance, schema, options, ctx) {
+  return validateMultipleOfOrDivisbleBy.call(this, instance, schema, options, ctx, "divisibleBy", "is not divisible by (multiple of) ");
+};
+
+/**
+ * Validates whether the instance value is present.
+ * @param instance
+ * @param schema
+ * @return {String|null}
+ */
+validators.required = function validateRequired (instance, schema, options, ctx) {
+  var result = new ValidatorResult(instance, schema, options, ctx);
+  if (instance === undefined && schema.required === true) {
+    // A boolean form is implemented for reverse-compatibility with schemas written against older drafts
+    result.addError({
+      name: 'required',
+      message: "is required",
+    });
+  } else if (this.types.object(instance) && Array.isArray(schema.required)) {
+    schema.required.forEach(function(n){
+      if(getEnumerableProperty(instance, n)===undefined){
+        result.addError({
+          name: 'required',
+          argument: n,
+          message: "requires property " + JSON.stringify(n),
+        });
+      }
+    });
+  }
+  return result;
+};
+
+/**
+ * Validates whether the instance value matches the regular expression, when the instance value is a string.
+ * @param instance
+ * @param schema
+ * @return {String|null}
+ */
+validators.pattern = function validatePattern (instance, schema, options, ctx) {
+  if (!this.types.string(instance)) return;
+  var result = new ValidatorResult(instance, schema, options, ctx);
+  var pattern = schema.pattern;
+  try {
+    var regexp = new RegExp(pattern, 'u');
+  } catch(_e) {
+    // In the event the stricter handling causes an error, fall back on the forgiving handling
+    // DEPRECATED
+    regexp = new RegExp(pattern);
+  }
+  if (!instance.match(regexp)) {
+    result.addError({
+      name: 'pattern',
+      argument: schema.pattern,
+      message: "does not match pattern " + JSON.stringify(schema.pattern.toString()),
+    });
+  }
+  return result;
+};
+
+/**
+ * Validates whether the instance value is of a certain defined format or a custom
+ * format.
+ * The following formats are supported for string types:
+ *   - date-time
+ *   - date
+ *   - time
+ *   - ip-address
+ *   - ipv6
+ *   - uri
+ *   - color
+ *   - host-name
+ *   - alpha
+ *   - alpha-numeric
+ *   - utc-millisec
+ * @param instance
+ * @param schema
+ * @param [options]
+ * @param [ctx]
+ * @return {String|null}
+ */
+validators.format = function validateFormat (instance, schema, options, ctx) {
+  if (instance===undefined) return;
+  var result = new ValidatorResult(instance, schema, options, ctx);
+  if (!result.disableFormat && !helpers.isFormat(instance, schema.format, this)) {
+    result.addError({
+      name: 'format',
+      argument: schema.format,
+      message: "does not conform to the " + JSON.stringify(schema.format) + " format",
+    });
+  }
+  return result;
+};
+
+/**
+ * Validates whether the instance value is at least of a certain length, when the instance value is a string.
+ * @param instance
+ * @param schema
+ * @return {String|null}
+ */
+validators.minLength = function validateMinLength (instance, schema, options, ctx) {
+  if (!this.types.string(instance)) return;
+  var result = new ValidatorResult(instance, schema, options, ctx);
+  var hsp = instance.match(/[\uDC00-\uDFFF]/g);
+  var length = instance.length - (hsp ? hsp.length : 0);
+  if (!(length >= schema.minLength)) {
+    result.addError({
+      name: 'minLength',
+      argument: schema.minLength,
+      message: "does not meet minimum length of " + schema.minLength,
+    });
+  }
+  return result;
+};
+
+/**
+ * Validates whether the instance value is at most of a certain length, when the instance value is a string.
+ * @param instance
+ * @param schema
+ * @return {String|null}
+ */
+validators.maxLength = function validateMaxLength (instance, schema, options, ctx) {
+  if (!this.types.string(instance)) return;
+  var result = new ValidatorResult(instance, schema, options, ctx);
+  // TODO if this was already computed in "minLength", use that value instead of re-computing
+  var hsp = instance.match(/[\uDC00-\uDFFF]/g);
+  var length = instance.length - (hsp ? hsp.length : 0);
+  if (!(length <= schema.maxLength)) {
+    result.addError({
+      name: 'maxLength',
+      argument: schema.maxLength,
+      message: "does not meet maximum length of " + schema.maxLength,
+    });
+  }
+  return result;
+};
+
+/**
+ * Validates whether instance contains at least a minimum number of items, when the instance is an Array.
+ * @param instance
+ * @param schema
+ * @return {String|null}
+ */
+validators.minItems = function validateMinItems (instance, schema, options, ctx) {
+  if (!this.types.array(instance)) return;
+  var result = new ValidatorResult(instance, schema, options, ctx);
+  if (!(instance.length >= schema.minItems)) {
+    result.addError({
+      name: 'minItems',
+      argument: schema.minItems,
+      message: "does not meet minimum length of " + schema.minItems,
+    });
+  }
+  return result;
+};
+
+/**
+ * Validates whether instance contains no more than a maximum number of items, when the instance is an Array.
+ * @param instance
+ * @param schema
+ * @return {String|null}
+ */
+validators.maxItems = function validateMaxItems (instance, schema, options, ctx) {
+  if (!this.types.array(instance)) return;
+  var result = new ValidatorResult(instance, schema, options, ctx);
+  if (!(instance.length <= schema.maxItems)) {
+    result.addError({
+      name: 'maxItems',
+      argument: schema.maxItems,
+      message: "does not meet maximum length of " + schema.maxItems,
+    });
+  }
+  return result;
+};
+
+/**
+ * Deep compares arrays for duplicates
+ * @param v
+ * @param i
+ * @param a
+ * @private
+ * @return {boolean}
+ */
+function testArrays (v, i, a) {
+  var j, len = a.length;
+  for (j = i + 1, len; j < len; j++) {
+    if (helpers.deepCompareStrict(v, a[j])) {
+      return false;
+    }
+  }
+  return true;
+}
+
+/**
+ * Validates whether there are no duplicates, when the instance is an Array.
+ * @param instance
+ * @return {String|null}
+ */
+validators.uniqueItems = function validateUniqueItems (instance, schema, options, ctx) {
+  if (schema.uniqueItems!==true) return;
+  if (!this.types.array(instance)) return;
+  var result = new ValidatorResult(instance, schema, options, ctx);
+  if (!instance.every(testArrays)) {
+    result.addError({
+      name: 'uniqueItems',
+      message: "contains duplicate item",
+    });
+  }
+  return result;
+};
+
+/**
+ * Validate for the presence of dependency properties, if the instance is an object.
+ * @param instance
+ * @param schema
+ * @param options
+ * @param ctx
+ * @return {null|ValidatorResult}
+ */
+validators.dependencies = function validateDependencies (instance, schema, options, ctx) {
+  if (!this.types.object(instance)) return;
+  var result = new ValidatorResult(instance, schema, options, ctx);
+  for (var property in schema.dependencies) {
+    if (instance[property] === undefined) {
+      continue;
+    }
+    var dep = schema.dependencies[property];
+    var childContext = ctx.makeChild(dep, property);
+    if (typeof dep == 'string') {
+      dep = [dep];
+    }
+    if (Array.isArray(dep)) {
+      dep.forEach(function (prop) {
+        if (instance[prop] === undefined) {
+          result.addError({
+            // FIXME there's two different "dependencies" errors here with slightly different outputs
+            // Can we make these the same? Or should we create different error types?
+            name: 'dependencies',
+            argument: childContext.propertyPath,
+            message: "property " + prop + " not found, required by " + childContext.propertyPath,
+          });
+        }
+      });
+    } else {
+      var res = this.validateSchema(instance, dep, options, childContext);
+      if(result.instance !== res.instance) result.instance = res.instance;
+      if (res && res.errors.length) {
+        result.addError({
+          name: 'dependencies',
+          argument: childContext.propertyPath,
+          message: "does not meet dependency required by " + childContext.propertyPath,
+        });
+        result.importErrors(res);
+      }
+    }
+  }
+  return result;
+};
+
+/**
+ * Validates whether the instance value is one of the enumerated values.
+ *
+ * @param instance
+ * @param schema
+ * @return {ValidatorResult|null}
+ */
+validators['enum'] = function validateEnum (instance, schema, options, ctx) {
+  if (instance === undefined) {
+    return null;
+  }
+  if (!Array.isArray(schema['enum'])) {
+    throw new SchemaError("enum expects an array", schema);
+  }
+  var result = new ValidatorResult(instance, schema, options, ctx);
+  if (!schema['enum'].some(helpers.deepCompareStrict.bind(null, instance))) {
+    result.addError({
+      name: 'enum',
+      argument: schema['enum'],
+      message: "is not one of enum values: " + schema['enum'].map(String).join(','),
+    });
+  }
+  return result;
+};
+
+/**
+ * Validates whether the instance exactly matches a given value
+ *
+ * @param instance
+ * @param schema
+ * @return {ValidatorResult|null}
+ */
+validators['const'] = function validateEnum (instance, schema, options, ctx) {
+  if (instance === undefined) {
+    return null;
+  }
+  var result = new ValidatorResult(instance, schema, options, ctx);
+  if (!helpers.deepCompareStrict(schema['const'], instance)) {
+    result.addError({
+      name: 'const',
+      argument: schema['const'],
+      message: "does not exactly match expected constant: " + schema['const'],
+    });
+  }
+  return result;
+};
+
+/**
+ * Validates whether the instance if of a prohibited type.
+ * @param instance
+ * @param schema
+ * @param options
+ * @param ctx
+ * @return {null|ValidatorResult}
+ */
+validators.not = validators.disallow = function validateNot (instance, schema, options, ctx) {
+  var self = this;
+  if(instance===undefined) return null;
+  var result = new ValidatorResult(instance, schema, options, ctx);
+  var notTypes = schema.not || schema.disallow;
+  if(!notTypes) return null;
+  if(!Array.isArray(notTypes)) notTypes=[notTypes];
+  notTypes.forEach(function (type) {
+    if (self.testType(instance, schema, options, ctx, type)) {
+      var id = type && (type.$id || type.id);
+      var schemaId = id || type;
+      result.addError({
+        name: 'not',
+        argument: schemaId,
+        message: "is of prohibited type " + schemaId,
+      });
+    }
+  });
+  return result;
+};
+
+#EXPORT validators
diff --git a/common/jsonschema/helpers.js b/common/jsonschema/helpers.js
new file mode 100644
index 0000000..f6a72a6
--- /dev/null
+++ b/common/jsonschema/helpers.js
@@ -0,0 +1,429 @@
+/* SPDX-License-Identifier: MIT
+ *
+ * jsonschema is licensed under MIT license.
+ *
+ * Copyright (C) 2012-2015 Tom de Grunt <tom@degrunt.nl>
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy of
+ * this software and associated documentation files (the "Software"), to deal in
+ * the Software without restriction, including without limitation the rights to
+ * use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies
+ * of the Software, and to permit persons to whom the Software is furnished to do
+ * so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in all
+ * copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+ * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+ * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+ * SOFTWARE.
+ */
+
+#IMPORT common/jsonschema/urllib_mock.js AS uri
+
+function ValidationError (message, instance, schema, path, name, argument) {
+  if(Array.isArray(path)){
+    this.path = path;
+    this.property = path.reduce(function(sum, item){
+      return sum + makeSuffix(item);
+    }, 'instance');
+  }else if(path !== undefined){
+    this.property = path;
+  }
+  if (message) {
+    this.message = message;
+  }
+  if (schema) {
+    var id = schema.$id || schema.id;
+    this.schema = id || schema;
+  }
+  if (instance !== undefined) {
+    this.instance = instance;
+  }
+  this.name = name;
+  this.argument = argument;
+  this.stack = this.toString();
+};
+#EXPORT ValidationError
+
+ValidationError.prototype.toString = function toString() {
+  return this.property + ' ' + this.message;
+};
+
+function ValidatorResult(instance, schema, options, ctx) {
+  this.instance = instance;
+  this.schema = schema;
+  this.options = options;
+  this.path = ctx.path;
+  this.propertyPath = ctx.propertyPath;
+  this.errors = [];
+  this.throwError = options && options.throwError;
+  this.throwFirst = options && options.throwFirst;
+  this.throwAll = options && options.throwAll;
+  this.disableFormat = options && options.disableFormat === true;
+};
+
+ValidatorResult.prototype.addError = function addError(detail) {
+  var err;
+  if (typeof detail == 'string') {
+    err = new ValidationError(detail, this.instance, this.schema, this.path);
+  } else {
+    if (!detail) throw new Error('Missing error detail');
+    if (!detail.message) throw new Error('Missing error message');
+    if (!detail.name) throw new Error('Missing validator type');
+    err = new ValidationError(detail.message, this.instance, this.schema, this.path, detail.name, detail.argument);
+  }
+
+  this.errors.push(err);
+  if (this.throwFirst) {
+    throw new ValidatorResultError(this);
+  }else if(this.throwError){
+    throw err;
+  }
+  return err;
+};
+
+ValidatorResult.prototype.importErrors = function importErrors(res) {
+  if (typeof res == 'string' || (res && res.validatorType)) {
+    this.addError(res);
+  } else if (res && res.errors) {
+    Array.prototype.push.apply(this.errors, res.errors);
+  }
+};
+
+function stringizer (v,i){
+  return i+': '+v.toString()+'\n';
+}
+ValidatorResult.prototype.toString = function toString(res) {
+  return this.errors.map(stringizer).join('');
+};
+
+Object.defineProperty(ValidatorResult.prototype, "valid", { get: function() {
+  return !this.errors.length;
+} });
+
+#EXPORT ValidatorResult
+
+function ValidatorResultError(result) {
+  if(Error.captureStackTrace){
+    Error.captureStackTrace(this, ValidatorResultError);
+  }
+  this.instance = result.instance;
+  this.schema = result.schema;
+  this.options = result.options;
+  this.errors = result.errors;
+}
+ValidatorResultError.prototype = new Error();
+ValidatorResultError.prototype.constructor = ValidatorResultError;
+ValidatorResultError.prototype.name = "Validation Error";
+#EXPORT ValidatorResultError
+
+/**
+ * Describes a problem with a Schema which prevents validation of an instance
+ * @name SchemaError
+ * @constructor
+ */
+function SchemaError (msg, schema) {
+  this.message = msg;
+  this.schema = schema;
+  Error.call(this, msg);
+  if(Error.captureStackTrace){
+    Error.captureStackTrace(this, SchemaError);
+  }
+};
+SchemaError.prototype = Object.create(Error.prototype,
+  {
+    constructor: {value: SchemaError, enumerable: false},
+    name: {value: 'SchemaError', enumerable: false},
+  });
+#EXPORT SchemaError
+
+function SchemaContext (schema, options, path, base, schemas) {
+  this.schema = schema;
+  this.options = options;
+  if(Array.isArray(path)){
+    this.path = path;
+    this.propertyPath = path.reduce(function(sum, item){
+      return sum + makeSuffix(item);
+    }, 'instance');
+  }else{
+    this.propertyPath = path;
+  }
+  this.base = base;
+  this.schemas = schemas;
+};
+
+SchemaContext.prototype.resolve = function resolve (target) {
+  return uri.resolve(this.base, target);
+};
+
+SchemaContext.prototype.makeChild = function makeChild(schema, propertyName){
+  var path = (propertyName===undefined) ? this.path : this.path.concat([propertyName]);
+  var id = schema.$id || schema.id;
+  var base = uri.resolve(this.base, id||'');
+  var ctx = new SchemaContext(schema, this.options, path, base, Object.create(this.schemas));
+  if(id && !ctx.schemas[base]){
+    ctx.schemas[base] = schema;
+  }
+  return ctx;
+};
+
+#EXPORT SchemaContext
+
+const FORMAT_REGEXPS = {
+  // 7.3.1. Dates, Times, and Duration
+  'date-time': /^\d{4}-(?:0[0-9]{1}|1[0-2]{1})-(3[01]|0[1-9]|[12][0-9])[tT ](2[0-4]|[01][0-9]):([0-5][0-9]):(60|[0-5][0-9])(\.\d+)?([zZ]|[+-]([0-5][0-9]):(60|[0-5][0-9]))$/,
+  'date': /^\d{4}-(?:0[0-9]{1}|1[0-2]{1})-(3[01]|0[1-9]|[12][0-9])$/,
+  'time': /^(2[0-4]|[01][0-9]):([0-5][0-9]):(60|[0-5][0-9])$/,
+  'duration': /P(T\d+(H(\d+M(\d+S)?)?|M(\d+S)?|S)|\d+(D|M(\d+D)?|Y(\d+M(\d+D)?)?)(T\d+(H(\d+M(\d+S)?)?|M(\d+S)?|S))?|\d+W)/i,
+
+  // 7.3.2. Email Addresses
+  // TODO: fix the email production
+  'email': /^(?:[\w\!\#\$\%\&\'\*\+\-\/\=\?\^\`\{\|\}\~]+\.)*[\w\!\#\$\%\&\'\*\+\-\/\=\?\^\`\{\|\}\~]+@(?:(?:(?:[a-zA-Z0-9](?:[a-zA-Z0-9\-](?!\.)){0,61}[a-zA-Z0-9]?\.)+[a-zA-Z0-9](?:[a-zA-Z0-9\-](?!$)){0,61}[a-zA-Z0-9]?)|(?:\[(?:(?:[01]?\d{1,2}|2[0-4]\d|25[0-5])\.){3}(?:[01]?\d{1,2}|2[0-4]\d|25[0-5])\]))$/,
+  'idn-email': /^("(?:[!#-\[\]-\u{10FFFF}]|\\[\t -\u{10FFFF}])*"|[!#-'*+\-/-9=?A-Z\^-\u{10FFFF}](?:\.?[!#-'*+\-/-9=?A-Z\^-\u{10FFFF}])*)@([!#-'*+\-/-9=?A-Z\^-\u{10FFFF}](?:\.?[!#-'*+\-/-9=?A-Z\^-\u{10FFFF}])*|\[[!-Z\^-\u{10FFFF}]*\])$/u,
+
+  // 7.3.3. Hostnames
+
+  // 7.3.4. IP Addresses
+  'ip-address': /^(?:(?:25[0-5]|2[0-4][0-9]|[01]?[0-9][0-9]?)\.){3}(?:25[0-5]|2[0-4][0-9]|[01]?[0-9][0-9]?)$/,
+  // FIXME whitespace is invalid
+  'ipv6': /^\s*((([0-9A-Fa-f]{1,4}:){7}([0-9A-Fa-f]{1,4}|:))|(([0-9A-Fa-f]{1,4}:){6}(:[0-9A-Fa-f]{1,4}|((25[0-5]|2[0-4]\d|1\d\d|[1-9]?\d)(\.(25[0-5]|2[0-4]\d|1\d\d|[1-9]?\d)){3})|:))|(([0-9A-Fa-f]{1,4}:){5}(((:[0-9A-Fa-f]{1,4}){1,2})|:((25[0-5]|2[0-4]\d|1\d\d|[1-9]?\d)(\.(25[0-5]|2[0-4]\d|1\d\d|[1-9]?\d)){3})|:))|(([0-9A-Fa-f]{1,4}:){4}(((:[0-9A-Fa-f]{1,4}){1,3})|((:[0-9A-Fa-f]{1,4})?:((25[0-5]|2[0-4]\d|1\d\d|[1-9]?\d)(\.(25[0-5]|2[0-4]\d|1\d\d|[1-9]?\d)){3}))|:))|(([0-9A-Fa-f]{1,4}:){3}(((:[0-9A-Fa-f]{1,4}){1,4})|((:[0-9A-Fa-f]{1,4}){0,2}:((25[0-5]|2[0-4]\d|1\d\d|[1-9]?\d)(\.(25[0-5]|2[0-4]\d|1\d\d|[1-9]?\d)){3}))|:))|(([0-9A-Fa-f]{1,4}:){2}(((:[0-9A-Fa-f]{1,4}){1,5})|((:[0-9A-Fa-f]{1,4}){0,3}:((25[0-5]|2[0-4]\d|1\d\d|[1-9]?\d)(\.(25[0-5]|2[0-4]\d|1\d\d|[1-9]?\d)){3}))|:))|(([0-9A-Fa-f]{1,4}:){1}(((:[0-9A-Fa-f]{1,4}){1,6})|((:[0-9A-Fa-f]{1,4}){0,4}:((25[0-5]|2[0-4]\d|1\d\d|[1-9]?\d)(\.(25[0-5]|2[0-4]\d|1\d\d|[1-9]?\d)){3}))|:))|(:(((:[0-9A-Fa-f]{1,4}){1,7})|((:[0-9A-Fa-f]{1,4}){0,5}:((25[0-5]|2[0-4]\d|1\d\d|[1-9]?\d)(\.(25[0-5]|2[0-4]\d|1\d\d|[1-9]?\d)){3}))|:)))(%.+)?\s*$/,
+
+  // 7.3.5. Resource Identifiers
+  // TODO: A more accurate regular expression for "uri" goes:
+  // [A-Za-z][+\-.0-9A-Za-z]*:((/(/((%[0-9A-Fa-f]{2}|[!$&-.0-9;=A-Z_a-z~])+|(\[(([Vv][0-9A-Fa-f]+\.[!$&-.0-;=A-Z_a-z~]+)?|[.0-:A-Fa-f]+)\])?)(:\d*)?)?)?#(%[0-9A-Fa-f]{2}|[!$&-;=?-Z_a-z~])*|(/(/((%[0-9A-Fa-f]{2}|[!$&-.0-9;=A-Z_a-z~])+|(\[(([Vv][0-9A-Fa-f]+\.[!$&-.0-;=A-Z_a-z~]+)?|[.0-:A-Fa-f]+)\])?)(:\d*)?[/?]|[!$&-.0-;=?-Z_a-z~])|/?%[0-9A-Fa-f]{2}|[!$&-.0-;=?-Z_a-z~])(%[0-9A-Fa-f]{2}|[!$&-;=?-Z_a-z~])*(#(%[0-9A-Fa-f]{2}|[!$&-;=?-Z_a-z~])*)?|/(/((%[0-9A-Fa-f]{2}|[!$&-.0-9;=A-Z_a-z~])+(:\d*)?|(\[(([Vv][0-9A-Fa-f]+\.[!$&-.0-;=A-Z_a-z~]+)?|[.0-:A-Fa-f]+)\])?:\d*|\[(([Vv][0-9A-Fa-f]+\.[!$&-.0-;=A-Z_a-z~]+)?|[.0-:A-Fa-f]+)\])?)?)?
+  'uri': /^[a-zA-Z][a-zA-Z0-9+.-]*:[^\s]*$/,
+  'uri-reference': /^(((([A-Za-z][+\-.0-9A-Za-z]*(:%[0-9A-Fa-f]{2}|:[!$&-.0-;=?-Z_a-z~]|[/?])|\?)(%[0-9A-Fa-f]{2}|[!$&-;=?-Z_a-z~])*|([A-Za-z][+\-.0-9A-Za-z]*:?)?)|([A-Za-z][+\-.0-9A-Za-z]*:)?\/((%[0-9A-Fa-f]{2}|\/((%[0-9A-Fa-f]{2}|[!$&-.0-9;=A-Z_a-z~])+|(\[(([Vv][0-9A-Fa-f]+\.[!$&-.0-;=A-Z_a-z~]+)?|[.0-:A-Fa-f]+)\])?)(:\d*)?[/?]|[!$&-.0-;=?-Z_a-z~])(%[0-9A-Fa-f]{2}|[!$&-;=?-Z_a-z~])*|(\/((%[0-9A-Fa-f]{2}|[!$&-.0-9;=A-Z_a-z~])+|(\[(([Vv][0-9A-Fa-f]+\.[!$&-.0-;=A-Z_a-z~]+)?|[.0-:A-Fa-f]+)\])?)(:\d*)?)?))#(%[0-9A-Fa-f]{2}|[!$&-;=?-Z_a-z~])*|(([A-Za-z][+\-.0-9A-Za-z]*)?%[0-9A-Fa-f]{2}|[!$&-.0-9;=@_~]|[A-Za-z][+\-.0-9A-Za-z]*[!$&-*,;=@_~])(%[0-9A-Fa-f]{2}|[!$&-.0-9;=@-Z_a-z~])*((([/?](%[0-9A-Fa-f]{2}|[!$&-;=?-Z_a-z~])*)?#|[/?])(%[0-9A-Fa-f]{2}|[!$&-;=?-Z_a-z~])*)?|([A-Za-z][+\-.0-9A-Za-z]*(:%[0-9A-Fa-f]{2}|:[!$&-.0-;=?-Z_a-z~]|[/?])|\?)(%[0-9A-Fa-f]{2}|[!$&-;=?-Z_a-z~])*|([A-Za-z][+\-.0-9A-Za-z]*:)?\/((%[0-9A-Fa-f]{2}|\/((%[0-9A-Fa-f]{2}|[!$&-.0-9;=A-Z_a-z~])+|(\[(([Vv][0-9A-Fa-f]+\.[!$&-.0-;=A-Z_a-z~]+)?|[.0-:A-Fa-f]+)\])?)(:\d*)?[/?]|[!$&-.0-;=?-Z_a-z~])(%[0-9A-Fa-f]{2}|[!$&-;=?-Z_a-z~])*|\/((%[0-9A-Fa-f]{2}|[!$&-.0-9;=A-Z_a-z~])+(:\d*)?|(\[(([Vv][0-9A-Fa-f]+\.[!$&-.0-;=A-Z_a-z~]+)?|[.0-:A-Fa-f]+)\])?:\d*|\[(([Vv][0-9A-Fa-f]+\.[!$&-.0-;=A-Z_a-z~]+)?|[.0-:A-Fa-f]+)\])?)?|[A-Za-z][+\-.0-9A-Za-z]*:?)?$/,
+  'iri': /^[a-zA-Z][a-zA-Z0-9+.-]*:[^\s]*$/,
+  'iri-reference': /^(((([A-Za-z][+\-.0-9A-Za-z]*(:%[0-9A-Fa-f]{2}|:[!$&-.0-;=?-Z_a-z~-\u{10FFFF}]|[/?])|\?)(%[0-9A-Fa-f]{2}|[!$&-;=?-Z_a-z~-\u{10FFFF}])*|([A-Za-z][+\-.0-9A-Za-z]*:?)?)|([A-Za-z][+\-.0-9A-Za-z]*:)?\/((%[0-9A-Fa-f]{2}|\/((%[0-9A-Fa-f]{2}|[!$&-.0-9;=A-Z_a-z~-\u{10FFFF}])+|(\[(([Vv][0-9A-Fa-f]+\.[!$&-.0-;=A-Z_a-z~-\u{10FFFF}]+)?|[.0-:A-Fa-f]+)\])?)(:\d*)?[/?]|[!$&-.0-;=?-Z_a-z~-\u{10FFFF}])(%[0-9A-Fa-f]{2}|[!$&-;=?-Z_a-z~-\u{10FFFF}])*|(\/((%[0-9A-Fa-f]{2}|[!$&-.0-9;=A-Z_a-z~-\u{10FFFF}])+|(\[(([Vv][0-9A-Fa-f]+\.[!$&-.0-;=A-Z_a-z~-\u{10FFFF}]+)?|[.0-:A-Fa-f]+)\])?)(:\d*)?)?))#(%[0-9A-Fa-f]{2}|[!$&-;=?-Z_a-z~-\u{10FFFF}])*|(([A-Za-z][+\-.0-9A-Za-z]*)?%[0-9A-Fa-f]{2}|[!$&-.0-9;=@_~-\u{10FFFF}]|[A-Za-z][+\-.0-9A-Za-z]*[!$&-*,;=@_~-\u{10FFFF}])(%[0-9A-Fa-f]{2}|[!$&-.0-9;=@-Z_a-z~-\u{10FFFF}])*((([/?](%[0-9A-Fa-f]{2}|[!$&-;=?-Z_a-z~-\u{10FFFF}])*)?#|[/?])(%[0-9A-Fa-f]{2}|[!$&-;=?-Z_a-z~-\u{10FFFF}])*)?|([A-Za-z][+\-.0-9A-Za-z]*(:%[0-9A-Fa-f]{2}|:[!$&-.0-;=?-Z_a-z~-\u{10FFFF}]|[/?])|\?)(%[0-9A-Fa-f]{2}|[!$&-;=?-Z_a-z~-\u{10FFFF}])*|([A-Za-z][+\-.0-9A-Za-z]*:)?\/((%[0-9A-Fa-f]{2}|\/((%[0-9A-Fa-f]{2}|[!$&-.0-9;=A-Z_a-z~-\u{10FFFF}])+|(\[(([Vv][0-9A-Fa-f]+\.[!$&-.0-;=A-Z_a-z~-\u{10FFFF}]+)?|[.0-:A-Fa-f]+)\])?)(:\d*)?[/?]|[!$&-.0-;=?-Z_a-z~-\u{10FFFF}])(%[0-9A-Fa-f]{2}|[!$&-;=?-Z_a-z~-\u{10FFFF}])*|\/((%[0-9A-Fa-f]{2}|[!$&-.0-9;=A-Z_a-z~-\u{10FFFF}])+(:\d*)?|(\[(([Vv][0-9A-Fa-f]+\.[!$&-.0-;=A-Z_a-z~-\u{10FFFF}]+)?|[.0-:A-Fa-f]+)\])?:\d*|\[(([Vv][0-9A-Fa-f]+\.[!$&-.0-;=A-Z_a-z~-\u{10FFFF}]+)?|[.0-:A-Fa-f]+)\])?)?|[A-Za-z][+\-.0-9A-Za-z]*:?)?$/u,
+  'uuid': /^[0-9A-F]{8}-[0-9A-F]{4}-[0-9A-F]{4}-[0-9A-F]{4}-[0-9A-F]{12}$/i,
+
+  // 7.3.6. uri-template
+  'uri-template': /(%[0-9a-f]{2}|[!#$&(-;=?@\[\]_a-z~]|\{[!#&+,./;=?@|]?(%[0-9a-f]{2}|[0-9_a-z])(\.?(%[0-9a-f]{2}|[0-9_a-z]))*(:[1-9]\d{0,3}|\*)?(,(%[0-9a-f]{2}|[0-9_a-z])(\.?(%[0-9a-f]{2}|[0-9_a-z]))*(:[1-9]\d{0,3}|\*)?)*\})*/iu,
+
+  // 7.3.7. JSON Pointers
+  'json-pointer': /^(\/([\x00-\x2e0-@\[-}\x7f]|~[01])*)*$/iu,
+  'relative-json-pointer': /^\d+(#|(\/([\x00-\x2e0-@\[-}\x7f]|~[01])*)*)$/iu,
+
+  // hostname regex from: http://stackoverflow.com/a/1420225/5628
+  'hostname': /^(?=.{1,255}$)[0-9A-Za-z](?:(?:[0-9A-Za-z]|-){0,61}[0-9A-Za-z])?(?:\.[0-9A-Za-z](?:(?:[0-9A-Za-z]|-){0,61}[0-9A-Za-z])?)*\.?$/,
+  'host-name': /^(?=.{1,255}$)[0-9A-Za-z](?:(?:[0-9A-Za-z]|-){0,61}[0-9A-Za-z])?(?:\.[0-9A-Za-z](?:(?:[0-9A-Za-z]|-){0,61}[0-9A-Za-z])?)*\.?$/,
+
+  'utc-millisec': function (input) {
+    return (typeof input === 'string') && parseFloat(input) === parseInt(input, 10) && !isNaN(input);
+  },
+
+  // 7.3.8. regex
+  'regex': function (input) {
+    var result = true;
+    try {
+      new RegExp(input);
+    } catch (e) {
+      result = false;
+    }
+    return result;
+  },
+
+  // Other definitions
+  // "style" was removed from JSON Schema in draft-4 and is deprecated
+  'style': /[\r\n\t ]*[^\r\n\t ][^:]*:[\r\n\t ]*[^\r\n\t ;]*[\r\n\t ]*;?/,
+  // "color" was removed from JSON Schema in draft-4 and is deprecated
+  'color': /^(#?([0-9A-Fa-f]{3}){1,2}\b|aqua|black|blue|fuchsia|gray|green|lime|maroon|navy|olive|orange|purple|red|silver|teal|white|yellow|(rgb\(\s*\b([0-9]|[1-9][0-9]|1[0-9][0-9]|2[0-4][0-9]|25[0-5])\b\s*,\s*\b([0-9]|[1-9][0-9]|1[0-9][0-9]|2[0-4][0-9]|25[0-5])\b\s*,\s*\b([0-9]|[1-9][0-9]|1[0-9][0-9]|2[0-4][0-9]|25[0-5])\b\s*\))|(rgb\(\s*(\d?\d%|100%)+\s*,\s*(\d?\d%|100%)+\s*,\s*(\d?\d%|100%)+\s*\)))$/,
+  'phone': /^\+(?:[0-9] ?){6,14}[0-9]$/,
+  'alpha': /^[a-zA-Z]+$/,
+  'alphanumeric': /^[a-zA-Z0-9]+$/,
+};
+
+FORMAT_REGEXPS.regexp = FORMAT_REGEXPS.regex;
+FORMAT_REGEXPS.pattern = FORMAT_REGEXPS.regex;
+FORMAT_REGEXPS.ipv4 = FORMAT_REGEXPS['ip-address'];
+
+#EXPORT FORMAT_REGEXPS
+
+function isFormat (input, format, validator) {
+  if (typeof input === 'string' && FORMAT_REGEXPS[format] !== undefined) {
+    if (FORMAT_REGEXPS[format] instanceof RegExp) {
+      return FORMAT_REGEXPS[format].test(input);
+    }
+    if (typeof FORMAT_REGEXPS[format] === 'function') {
+      return FORMAT_REGEXPS[format](input);
+    }
+  } else if (validator && validator.customFormats &&
+      typeof validator.customFormats[format] === 'function') {
+    return validator.customFormats[format](input);
+  }
+  return true;
+};
+
+#EXPORT isFormat
+
+function makeSuffix (key) {
+  key = key.toString();
+  // This function could be capable of outputting valid a ECMAScript string, but the
+  // resulting code for testing which form to use would be tens of thousands of characters long
+  // That means this will use the name form for some illegal forms
+  if (!key.match(/[.\s\[\]]/) && !key.match(/^[\d]/)) {
+    return '.' + key;
+  }
+  if (key.match(/^\d+$/)) {
+    return '[' + key + ']';
+  }
+  return '[' + JSON.stringify(key) + ']';
+};
+#EXPORT makeSuffix
+
+function deepCompareStrict (a, b) {
+  if (typeof a !== typeof b) {
+    return false;
+  }
+  if (Array.isArray(a)) {
+    if (!Array.isArray(b)) {
+      return false;
+    }
+    if (a.length !== b.length) {
+      return false;
+    }
+    return a.every(function (v, i) {
+      return deepCompareStrict(a[i], b[i]);
+    });
+  }
+  if (typeof a === 'object') {
+    if (!a || !b) {
+      return a === b;
+    }
+    var aKeys = Object.keys(a);
+    var bKeys = Object.keys(b);
+    if (aKeys.length !== bKeys.length) {
+      return false;
+    }
+    return aKeys.every(function (v) {
+      return deepCompareStrict(a[v], b[v]);
+    });
+  }
+  return a === b;
+};
+#EXPORT deepCompareStrict
+
+function deepMerger (target, dst, e, i) {
+  if (typeof e === 'object') {
+    dst[i] = deepMerge(target[i], e);
+  } else {
+    if (target.indexOf(e) === -1) {
+      dst.push(e);
+    }
+  }
+}
+
+function copyist (src, dst, key) {
+  dst[key] = src[key];
+}
+
+function copyistWithDeepMerge (target, src, dst, key) {
+  if (typeof src[key] !== 'object' || !src[key]) {
+    dst[key] = src[key];
+  }
+  else {
+    if (!target[key]) {
+      dst[key] = src[key];
+    } else {
+      dst[key] = deepMerge(target[key], src[key]);
+    }
+  }
+}
+
+function deepMerge (target, src) {
+  var array = Array.isArray(src);
+  var dst = array && [] || {};
+
+  if (array) {
+    target = target || [];
+    dst = dst.concat(target);
+    src.forEach(deepMerger.bind(null, target, dst));
+  } else {
+    if (target && typeof target === 'object') {
+      Object.keys(target).forEach(copyist.bind(null, target, dst));
+    }
+    Object.keys(src).forEach(copyistWithDeepMerge.bind(null, target, src, dst));
+  }
+
+  return dst;
+}
+#EXPORT deepMerge
+
+/**
+ * Validates instance against the provided schema
+ * Implements URI+JSON Pointer encoding, e.g. "%7e"="~0"=>"~", "~1"="%2f"=>"/"
+ * @param o
+ * @param s The path to walk o along
+ * @return any
+ */
+function objectGetPath(o, s) {
+  var parts = s.split('/').slice(1);
+  var k;
+  while (typeof (k=parts.shift()) == 'string') {
+    var n = decodeURIComponent(k.replace(/~0/,'~').replace(/~1/g,'/'));
+    if (!(n in o)) return;
+    o = o[n];
+  }
+  return o;
+};
+#EXPORT objectGetPath
+
+function pathEncoder (v) {
+  return '/'+encodeURIComponent(v).replace(/~/g,'%7E');
+}
+/**
+ * Accept an Array of property names and return a JSON Pointer URI fragment
+ * @param Array a
+ * @return {String}
+ */
+function encodePointer(a){
+  // ~ must be encoded explicitly because hacks
+  // the slash is encoded by encodeURIComponent
+  return a.map(pathEncoder).join('');
+};
+#EXPORT  encodePointer  AS encodePath
+
+
+/**
+ * Calculate the number of decimal places a number uses
+ * We need this to get correct results out of multipleOf and divisibleBy
+ * when either figure is has decimal places, due to IEEE-754 float issues.
+ * @param number
+ * @returns {number}
+ */
+function getDecimalPlaces(number) {
+
+  var decimalPlaces = 0;
+  if (isNaN(number)) return decimalPlaces;
+
+  if (typeof number !== 'number') {
+    number = Number(number);
+  }
+
+  var parts = number.toString().split('e');
+  if (parts.length === 2) {
+    if (parts[1][0] !== '-') {
+      return decimalPlaces;
+    } else {
+      decimalPlaces = Number(parts[1].slice(1));
+    }
+  }
+
+  var decimalParts = parts[0].split('.');
+  if (decimalParts.length === 2) {
+    decimalPlaces += decimalParts[1].length;
+  }
+
+  return decimalPlaces;
+};
+#EXPORT getDecimalPlaces
+
+function isSchema(val){
+  return (typeof val === 'object' && val) || (typeof val === 'boolean');
+};
+#EXPORT isSchema
diff --git a/common/jsonschema/scan.js b/common/jsonschema/scan.js
new file mode 100644
index 0000000..b5e5760
--- /dev/null
+++ b/common/jsonschema/scan.js
@@ -0,0 +1,99 @@
+/* SPDX-License-Identifier: MIT
+ *
+ * jsonschema is licensed under MIT license.
+ *
+ * Copyright (C) 2012-2015 Tom de Grunt <tom@degrunt.nl>
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy of
+ * this software and associated documentation files (the "Software"), to deal in
+ * the Software without restriction, including without limitation the rights to
+ * use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies
+ * of the Software, and to permit persons to whom the Software is furnished to do
+ * so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in all
+ * copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+ * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+ * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+ * SOFTWARE.
+ */
+
+#IMPORT common/jsonschema/urllib_mock.js AS urilib
+#IMPORT common/jsonschema/helpers.js
+
+function SchemaScanResult(found, ref){
+  this.id = found;
+  this.ref = ref;
+}
+#EXPORT SchemaScanResult
+
+/**
+ * Adds a schema with a certain urn to the Validator instance.
+ * @param string uri
+ * @param object schema
+ * @return {Object}
+ */
+function scan(base, schema){
+  function scanSchema(baseuri, schema){
+    if(!schema || typeof schema!='object') return;
+    // Mark all referenced schemas so we can tell later which schemas are referred to, but never defined
+    if(schema.$ref){
+      var resolvedUri = urilib.resolve(baseuri, schema.$ref);
+      ref[resolvedUri] = ref[resolvedUri] ? ref[resolvedUri]+1 : 0;
+      return;
+    }
+    var id = schema.$id || schema.id;
+    var ourBase = id ? urilib.resolve(baseuri, id) : baseuri;
+    if (ourBase) {
+      // If there's no fragment, append an empty one
+      if(ourBase.indexOf('#')<0) ourBase += '#';
+      if(found[ourBase]){
+        if(!helpers.deepCompareStrict(found[ourBase], schema)){
+          throw new Error('Schema <'+ourBase+'> already exists with different definition');
+        }
+        return found[ourBase];
+      }
+      found[ourBase] = schema;
+      // strip trailing fragment
+      if(ourBase[ourBase.length-1]=='#'){
+        found[ourBase.substring(0, ourBase.length-1)] = schema;
+      }
+    }
+    scanArray(ourBase+'/items', (Array.isArray(schema.items)?schema.items:[schema.items]));
+    scanArray(ourBase+'/extends', (Array.isArray(schema.extends)?schema.extends:[schema.extends]));
+    scanSchema(ourBase+'/additionalItems', schema.additionalItems);
+    scanObject(ourBase+'/properties', schema.properties);
+    scanSchema(ourBase+'/additionalProperties', schema.additionalProperties);
+    scanObject(ourBase+'/definitions', schema.definitions);
+    scanObject(ourBase+'/patternProperties', schema.patternProperties);
+    scanObject(ourBase+'/dependencies', schema.dependencies);
+    scanArray(ourBase+'/disallow', schema.disallow);
+    scanArray(ourBase+'/allOf', schema.allOf);
+    scanArray(ourBase+'/anyOf', schema.anyOf);
+    scanArray(ourBase+'/oneOf', schema.oneOf);
+    scanSchema(ourBase+'/not', schema.not);
+  }
+  function scanArray(baseuri, schemas){
+    if(!Array.isArray(schemas)) return;
+    for(var i=0; i<schemas.length; i++){
+      scanSchema(baseuri+'/'+i, schemas[i]);
+    }
+  }
+  function scanObject(baseuri, schemas){
+    if(!schemas || typeof schemas!='object') return;
+    for(var p in schemas){
+      scanSchema(baseuri+'/'+p, schemas[p]);
+    }
+  }
+
+  var found = {};
+  var ref = {};
+  scanSchema(base, schema);
+  return new SchemaScanResult(found, ref);
+};
+#EXPORT scan
diff --git a/common/jsonschema/urllib_mock.js b/common/jsonschema/urllib_mock.js
new file mode 100644
index 0000000..5fdddb7
--- /dev/null
+++ b/common/jsonschema/urllib_mock.js
@@ -0,0 +1,74 @@
+/* SPDX-License-Identifier: MIT AND CC0-1.0
+ *
+ * This file is part of Haketilo.
+ *
+ * Function: Replacement for require('url') to use with jsonschema library.
+ *
+ * License for the resolve() function:
+ *
+ ***************************************
+ *
+ * Copyright Node.js contributors. All rights reserved.
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy
+ * of this software and associated documentation files (the "Software"), to
+ * deal in the Software without restriction, including without limitation the
+ * rights to use, copy, modify, merge, publish, distribute, sublicense, and/or
+ * sell copies of the Software, and to permit persons to whom the Software is
+ * furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in
+ * all copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+ * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
+ * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS
+ * IN THE SOFTWARE.
+ *
+ *******************************************************************************
+ *
+ * License notice for the rest of the file:
+ *
+ ***************************************
+ *
+ * Copyright (C) 2022 Wojtek Kosior <koszko@koszko.org>
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the CC0 1.0 Universal License as published by
+ * the Creative Commons Corporation.
+ *
+ * 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
+ * CC0 1.0 Universal License for more details.
+ */
+
+/*
+ * The original jsonschema code used legacy resolve() function from
+ * require('url'). Here we define in a replacement for it.
+ */
+
+const dummy_host = 'haketilo.resolve.example.com';
+const dummy_prefix = `http://${dummy_host}/`;
+
+function resolve(from, to) {
+    const resolvedUrl = new URL(to, new URL(from, dummy_prefix));
+    if (resolvedUrl.hostname === dummy_host) {
+	// `from` is a relative URL.
+	const { pathname, search, hash } = resolvedUrl;
+	return pathname + search + hash;
+    }
+    return resolvedUrl.toString();
+}
+#EXPORT resolve
+
+function parse(url_string) {
+    if (arguments.length > 1)
+	throw "error: this is a mocked version of parse() that only accepts one argument";
+
+    return new URL(url_string);
+}
+#EXPORT parse
diff --git a/common/jsonschema/validator.js b/common/jsonschema/validator.js
new file mode 100644
index 0000000..4d8e0cf
--- /dev/null
+++ b/common/jsonschema/validator.js
@@ -0,0 +1,360 @@
+/* SPDX-License-Identifier: MIT
+ *
+ * jsonschema is licensed under MIT license.
+ *
+ * Copyright (C) 2012-2015 Tom de Grunt <tom@degrunt.nl>
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy of
+ * this software and associated documentation files (the "Software"), to deal in
+ * the Software without restriction, including without limitation the rights to
+ * use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies
+ * of the Software, and to permit persons to whom the Software is furnished to do
+ * so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in all
+ * copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+ * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+ * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+ * SOFTWARE.
+ */
+
+#IMPORT common/jsonschema/urllib_mock.js AS urilib
+#IMPORT common/jsonschema/attribute.js
+#IMPORT common/jsonschema/helpers.js
+
+#FROM common/jsonschema/scan.js IMPORT scan AS scanSchema
+
+var ValidatorResult = helpers.ValidatorResult;
+var ValidatorResultError = helpers.ValidatorResultError;
+var SchemaError = helpers.SchemaError;
+var SchemaContext = helpers.SchemaContext;
+//var anonymousBase = 'vnd.jsonschema:///';
+var anonymousBase = '/';
+
+/**
+ * Creates a new Validator object
+ * @name Validator
+ * @constructor
+ */
+var Validator = function Validator () {
+  // Allow a validator instance to override global custom formats or to have their
+  // own custom formats.
+  this.customFormats = Object.create(Validator.prototype.customFormats);
+  this.schemas = {};
+  this.unresolvedRefs = [];
+
+  // Use Object.create to make this extensible without Validator instances stepping on each other's toes.
+  this.types = Object.create(types);
+  this.attributes = Object.create(attribute.validators);
+};
+
+// Allow formats to be registered globally.
+Validator.prototype.customFormats = {};
+
+// Hint at the presence of a property
+Validator.prototype.schemas = null;
+Validator.prototype.types = null;
+Validator.prototype.attributes = null;
+Validator.prototype.unresolvedRefs = null;
+
+/**
+ * Adds a schema with a certain urn to the Validator instance.
+ * @param schema
+ * @param urn
+ * @return {Object}
+ */
+Validator.prototype.addSchema = function addSchema (schema, base) {
+  var self = this;
+  if (!schema) {
+    return null;
+  }
+  var scan = scanSchema(base||anonymousBase, schema);
+  var ourUri = base || schema.$id || schema.id;
+  for(var uri in scan.id){
+    this.schemas[uri] = scan.id[uri];
+  }
+  for(var uri in scan.ref){
+    // If this schema is already defined, it will be filtered out by the next step
+    this.unresolvedRefs.push(uri);
+  }
+  // Remove newly defined schemas from unresolvedRefs
+  this.unresolvedRefs = this.unresolvedRefs.filter(function(uri){
+    return typeof self.schemas[uri]==='undefined';
+  });
+  return this.schemas[ourUri];
+};
+
+Validator.prototype.addSubSchemaArray = function addSubSchemaArray(baseuri, schemas) {
+  if(!Array.isArray(schemas)) return;
+  for(var i=0; i<schemas.length; i++){
+    this.addSubSchema(baseuri, schemas[i]);
+  }
+};
+
+Validator.prototype.addSubSchemaObject = function addSubSchemaArray(baseuri, schemas) {
+  if(!schemas || typeof schemas!='object') return;
+  for(var p in schemas){
+    this.addSubSchema(baseuri, schemas[p]);
+  }
+};
+
+
+
+/**
+ * Sets all the schemas of the Validator instance.
+ * @param schemas
+ */
+Validator.prototype.setSchemas = function setSchemas (schemas) {
+  this.schemas = schemas;
+};
+
+/**
+ * Returns the schema of a certain urn
+ * @param urn
+ */
+Validator.prototype.getSchema = function getSchema (urn) {
+  return this.schemas[urn];
+};
+
+/**
+ * Validates instance against the provided schema
+ * @param instance
+ * @param schema
+ * @param [options]
+ * @param [ctx]
+ * @return {Array}
+ */
+Validator.prototype.validate = function validate (instance, schema, options, ctx) {
+  if((typeof schema !== 'boolean' && typeof schema !== 'object') || schema === null){
+    throw new SchemaError('Expected `schema` to be an object or boolean');
+  }
+  if (!options) {
+    options = {};
+  }
+  // This section indexes subschemas in the provided schema, so they don't need to be added with Validator#addSchema
+  // This will work so long as the function at uri.resolve() will resolve a relative URI to a relative URI
+  var id = schema.$id || schema.id;
+  var base = urilib.resolve(options.base||anonymousBase, id||'');
+  if(!ctx){
+    ctx = new SchemaContext(schema, options, [], base, Object.create(this.schemas));
+    if (!ctx.schemas[base]) {
+      ctx.schemas[base] = schema;
+    }
+    var found = scanSchema(base, schema);
+    for(var n in found.id){
+      var sch = found.id[n];
+      ctx.schemas[n] = sch;
+    }
+  }
+  if(options.required && instance===undefined){
+    var result = new ValidatorResult(instance, schema, options, ctx);
+    result.addError('is required, but is undefined');
+    return result;
+  }
+  var result = this.validateSchema(instance, schema, options, ctx);
+  if (!result) {
+    throw new Error('Result undefined');
+  }else if(options.throwAll && result.errors.length){
+    throw new ValidatorResultError(result);
+  }
+  return result;
+};
+
+/**
+* @param Object schema
+* @return mixed schema uri or false
+*/
+function shouldResolve(schema) {
+  var ref = (typeof schema === 'string') ? schema : schema.$ref;
+  if (typeof ref=='string') return ref;
+  return false;
+}
+
+/**
+ * Validates an instance against the schema (the actual work horse)
+ * @param instance
+ * @param schema
+ * @param options
+ * @param ctx
+ * @private
+ * @return {ValidatorResult}
+ */
+Validator.prototype.validateSchema = function validateSchema (instance, schema, options, ctx) {
+  var result = new ValidatorResult(instance, schema, options, ctx);
+
+  // Support for the true/false schemas
+  if(typeof schema==='boolean') {
+    if(schema===true){
+      // `true` is always valid
+      schema = {};
+    }else if(schema===false){
+      // `false` is always invalid
+      schema = {type: []};
+    }
+  }else if(!schema){
+    // This might be a string
+    throw new Error("schema is undefined");
+  }
+
+  if (schema['extends']) {
+    if (Array.isArray(schema['extends'])) {
+      var schemaobj = {schema: schema, ctx: ctx};
+      schema['extends'].forEach(this.schemaTraverser.bind(this, schemaobj));
+      schema = schemaobj.schema;
+      schemaobj.schema = null;
+      schemaobj.ctx = null;
+      schemaobj = null;
+    } else {
+      schema = helpers.deepMerge(schema, this.superResolve(schema['extends'], ctx));
+    }
+  }
+
+  // If passed a string argument, load that schema URI
+  var switchSchema = shouldResolve(schema);
+  if (switchSchema) {
+    var resolved = this.resolve(schema, switchSchema, ctx);
+    var subctx = new SchemaContext(resolved.subschema, options, ctx.path, resolved.switchSchema, ctx.schemas);
+    return this.validateSchema(instance, resolved.subschema, options, subctx);
+  }
+
+  var skipAttributes = options && options.skipAttributes || [];
+  // Validate each schema attribute against the instance
+  for (var key in schema) {
+    if (!attribute.ignoreProperties[key] && skipAttributes.indexOf(key) < 0) {
+      var validatorErr = null;
+      var validator = this.attributes[key];
+      if (validator) {
+        validatorErr = validator.call(this, instance, schema, options, ctx);
+      } else if (options.allowUnknownAttributes === false) {
+        // This represents an error with the schema itself, not an invalid instance
+        throw new SchemaError("Unsupported attribute: " + key, schema);
+      }
+      if (validatorErr) {
+        result.importErrors(validatorErr);
+      }
+    }
+  }
+
+  if (typeof options.rewrite == 'function') {
+    var value = options.rewrite.call(this, instance, schema, options, ctx);
+    result.instance = value;
+  }
+  return result;
+};
+
+/**
+* @private
+* @param Object schema
+* @param SchemaContext ctx
+* @returns Object schema or resolved schema
+*/
+Validator.prototype.schemaTraverser = function schemaTraverser (schemaobj, s) {
+  schemaobj.schema = helpers.deepMerge(schemaobj.schema, this.superResolve(s, schemaobj.ctx));
+};
+
+/**
+* @private
+* @param Object schema
+* @param SchemaContext ctx
+* @returns Object schema or resolved schema
+*/
+Validator.prototype.superResolve = function superResolve (schema, ctx) {
+  var ref = shouldResolve(schema);
+  if(ref) {
+    return this.resolve(schema, ref, ctx).subschema;
+  }
+  return schema;
+};
+
+/**
+* @private
+* @param Object schema
+* @param Object switchSchema
+* @param SchemaContext ctx
+* @return Object resolved schemas {subschema:String, switchSchema: String}
+* @throws SchemaError
+*/
+Validator.prototype.resolve = function resolve (schema, switchSchema, ctx) {
+  switchSchema = ctx.resolve(switchSchema);
+  // First see if the schema exists under the provided URI
+  if (ctx.schemas[switchSchema]) {
+    return {subschema: ctx.schemas[switchSchema], switchSchema: switchSchema};
+  }
+  // Else try walking the property pointer
+  var parsed = urilib.parse(switchSchema);
+  var fragment = parsed && parsed.hash;
+  var document = fragment && fragment.length && switchSchema.substr(0, switchSchema.length - fragment.length);
+  if (!document || !ctx.schemas[document]) {
+    throw new SchemaError("no such schema <" + switchSchema + ">", schema);
+  }
+  var subschema = helpers.objectGetPath(ctx.schemas[document], fragment.substr(1));
+  if(subschema===undefined){
+      throw new SchemaError("no such schema " + fragment + " located in <" + document + ">", schema);
+  }
+  return {subschema: subschema, switchSchema: switchSchema};
+};
+
+/**
+ * Tests whether the instance if of a certain type.
+ * @private
+ * @param instance
+ * @param schema
+ * @param options
+ * @param ctx
+ * @param type
+ * @return {boolean}
+ */
+Validator.prototype.testType = function validateType (instance, schema, options, ctx, type) {
+  if(type===undefined){
+    return;
+  }else if(type===null){
+    throw new SchemaError('Unexpected null in "type" keyword');
+  }
+  if (typeof this.types[type] == 'function') {
+    return this.types[type].call(this, instance);
+  }
+  if (type && typeof type == 'object') {
+    var res = this.validateSchema(instance, type, options, ctx);
+    return res === undefined || !(res && res.errors.length);
+  }
+  // Undefined or properties not on the list are acceptable, same as not being defined
+  return true;
+};
+
+var types = Validator.prototype.types = {};
+types.string = function testString (instance) {
+  return typeof instance == 'string';
+};
+types.number = function testNumber (instance) {
+  // isFinite returns false for NaN, Infinity, and -Infinity
+  return typeof instance == 'number' && isFinite(instance);
+};
+types.integer = function testInteger (instance) {
+  return (typeof instance == 'number') && instance % 1 === 0;
+};
+types.boolean = function testBoolean (instance) {
+  return typeof instance == 'boolean';
+};
+types.array = function testArray (instance) {
+  return Array.isArray(instance);
+};
+types['null'] = function testNull (instance) {
+  return instance === null;
+};
+types.date = function testDate (instance) {
+  return instance instanceof Date;
+};
+types.any = function testAny (instance) {
+  return true;
+};
+types.object = function testObject (instance) {
+  // TODO: fix this - see #15
+  return instance && (typeof instance === 'object') && !(Array.isArray(instance)) && !(instance instanceof Date);
+};
+
+#EXPORT Validator