JSON-Schema: Conditional dependency (by value) - json

Question

This is the simplified JSON-Schema:
{
"$schema": "http://json-schema.org/draft-04/schema#",
"id": "user",
"type": "object",
"properties": {
"account": {
"type": "object",
"properties": {
"type": {
"type": "string",
"enum": ["COMPANY", "PERSON"]
}
},
"required": ["type"]
},
"person": {
"type": "object",
"properties": {
"firstName": { "type": "string" },
"lastName": { "type": "string" }
},
"required": ["firstName", "lastName"]
},
"company": {
"type": "object",
"properties": {
"name": { "type": "string" },
"taxNumber": { "type": "string" }
}
}
},
"required": ["account", "person"]
}
What I want to achieve is:
If account.type is set to "COMPANY":
company object and its properties should be required.
If account.type isset to "PERSON":
company object should be optional.
But if company object is present, company.name and company.taxNumber should be required.
This can be achieved by defining two long sub-schemas under a oneOf but that would mean too many duplicates and a complex schema, since account and company has many more properties than this simplified version.
AFAIK, the only way to define a specific value in a schema is by using the enum keyword with a single item. I tried this with the dependencies keyword but didn't help.
Can you think of a way without altering the structure of the data object?

Answer 1

You can express this requirement using switch keyword from JSON-schema v5/6 proposals that is supported in Ajv (I am the author).

Answer 2

Under Draft-07, you can do it by conditionally applying schema requirements:
{
"$schema": "http://json-schema.org/draft-07/schema#",
"id": "user",
"type": "object",
"properties": {
"account": {
"type": "object",
"properties": {
"type": {
"type": "string",
"enum": ["COMPANY", "PERSON"]
}
},
"required": ["type"]
},
"person": {
"type": "object",
"properties": {
"firstName": {
"type": "string"
},
"lastName": {
"type": "string"
}
},
"required": ["firstName", "lastName"]
},
"company": {
"type": "object",
"properties": {
"name": {
"type": "string"
},
"taxNumber": {
"type": "string"
}
}
}
},
"if": {
"properties": {
"account": {
"const": {
"type": "COMPANY"
}
}
}
},
"then": {
"required": ["account", "person", "company"]
},
"else": {
"required": ["account", "person"]
}
}
Here's a working example that validates against it:
{
"account": {
"type": "COMPANY"
},
"person": {
"firstName": "John",
"lastName": "Doe"
},
"company": {
"name": "XYZ Corp"
}
}