How can I validate different schemas based on an enumerated property value with AJV? - validation

Question

I need to validate a json document depending the value in one of the properties, specifically an enum property.
This is the JSON document to be validated:
{
"req": {
"user": "",
"company": "",
"dept": "",
"class": "",
"reqType": "account"
}
}
The reqType can take different values like account, dept, and class based on the enumerated values.
I have tried using anyOf for the same but it does not validate correctly.
For example, I have tried the schema below:
{
"$id": "http://example.com/example.json",
"type": "object",
"definitions": {},
"$schema": "http://json-schema.org/draft-07/schema#",
"properties": {
"req": {
"$id": "/properties/req",
"type": "object",
"properties": {
"user": {
"$id": "/properties/req/properties/user",
"type": "string",
"title": "The User Schema ",
"default": "",
"examples": [
"a"
]
},
"company": {
"$id": "/properties/req/properties/company",
"type": "string",
"title": "The Company Schema ",
"default": "",
"examples": [
"b"
]
},
"dept": {
"$id": "/properties/req/properties/dept",
"type": "string",
"title": "The Dept Schema ",
"default": "",
"examples": [
"c"
]
},
"class": {
"$id": "/properties/req/properties/class",
"type": "string",
"title": "The Class Schema ",
"default": "",
"examples": [
"d"
]
},
"reqType": {
"$id": "/properties/req/properties/reqType",
"type": "string",
"title": "The Reqtype Schema ",
"default": "",
"examples": [
"account"
],
"enum": [
"account",
"dept",
"class"
]
}
},
"required": [
"reqType"
],
"anyOf": [
{
"properties": {
"reqType": {
"enum": [
"account"
]
}
},
"required": [
"user",
"company"
]
},
{
"properties": {
"reqType": {
"enum": [
"dept"
]
}
},
"required": [
"dept"
]
}
]
}
},
"required": [
"req"
]
}
This seems to work fine when it meets all of the conditions but when I check the failing case it throws an error for others as follows:
[
{
keyword: 'required',
dataPath: '.req',
schemaPath: '#/properties/req/anyOf/0/required',
params: {
missingProperty: 'user'
},
message: 'should have required property \'user\'',
schema: ['user', 'company'],
parentSchema: {
properties: [Object],
required: [Array]
},
data: {
company: 'b', dept: 'c', class: 'd', reqType: 'account'
}
},
{
keyword: 'enum',
dataPath: '.req.reqType',
schemaPath: '#/properties/req/anyOf/1/properties/reqType/enum',
params: {
allowedValues: [Array]
},
message: 'should be equal to one of the allowed values',
schema: ['dept'],
parentSchema: {
enum: [Array]
},
data: 'account'
},
{
keyword: 'anyOf',
dataPath: '.req',
schemaPath: '#/properties/req/anyOf',
params: {},
message: 'should match some schema in anyOf',
schema: [
[Object],
[Object]
],
parentSchema: {
'$id': '/properties/req',
type: 'object',
properties: [Object],
required: [Array],
anyOf: [Array]
},
data: {
company: 'b', dept: 'c', class: 'd', reqType: 'account'
}
}
]
I expected to get an error for the first and should have validated the 2nd case. Instead it says it did not get the enum value. Am i doing something wrong here?

Answer 1

You're doing it right. The anyOf keyword means that one or more of the given schemas must be valid.
It checks the first and finds that the enum keyword passes, but the required keyword fails. Therefore, this schema fails.
So, it moves on to the next schema and finds that the enum keyword fails and the required keyword passes. Therefore, this schema fails too.
anyOf did not find a valid schema, so it fails and reports that neither schema passes validation.
You see, anyOf doesn't know that enum has a special meaning in this schema. Both schemas have one keyword that passes and one that fails. To anyOf, they are the same.
Here is an alternative that can give you slightly better error messaging. The error messages still end up being quite cryptic, but they are focused where the problem really is.
{
"type": "object",
"properties": {
"req": {
"type": "object",
"properties": {
"reqType": { "enum": ["account", "dept", "class"] }
},
"required": ["reqType"],
"allOf": [
{
"anyOf": [
{
"not": {
"properties": {
"reqType": { "enum": ["account"] }
}
}
},
{ "required": ["user", "company"] }
]
},
{
"anyOf": [
{
"not": {
"properties": {
"reqType": { "enum": ["dept"] }
}
}
},
{ "required": ["dept"] }
]
}
]
}
},
"required": ["req"]
}