CODEWITHSUNDEEP
typescriptjsonschema
Rohit Verma
Rohit Verma

Reputation: 33

how to validate JSON schema of return type String| undefined using typescript

The two variants of my JSON response are:

{
  firstName: "abc",
  LastName: "xyz",
  Address: "abc123"
}

and 

{
  firstName: undefined,
  LastName: undefined,
  Address: undefined
}

Even though defined JSON Schema as:

var ResponseSchema = {
  "firstName": {
    "type": [String,undefined],
  },
  "LastName": {
    "type": [String,undefined],
  },
  "Address": {
    "type": [String,undefined],
  },
  "required": [
    "firstName",
    "LastName",
    "Address",
  ],
}

Response Object: 

{
  firstName: undefined,
  LastName: undefined,
  Address: undefined
}

getting an error as:

requires property "firstName"
requires property "LastName"
requires property "Address"

using "jsonschema" Node package.

Upvotes: 3

Views: 6905

Answers (4)

Shantanu Aryan
Shantanu Aryan

Reputation: 166

You can use anyOf to select between two schemas

https://json-schema.org/understanding-json-schema/reference/combining.html#id6

"ResponseSchema": {
    "anyOf": [
        {
            "properties": {},
            "type": "object"
        },
        {
            "additionalProperties": false,
            "properties": {
                "firstName": {
                    "type": "string"
                },
                "LastName": {
                    "type": "string"
                },
                "Address": {
                    "type": "string"
                }
            },
            "required": [
                "firstName",
                "LastName",
                "Address"
            ],
            "type": "object"
        }
    ]
}

equivalent TypeScript type

type ResponseSchema = {
  firstName: string
  LastName: string
  Address: string
} | {}

Also undefined is not a type in JSON, so i have assumed the responses to be

either

{
  firstName: "abc",
  LastName: "xyz",
  Address: "abc123"
}

or

{}

Upvotes: 0

fjc
fjc

Reputation: 5815

First: Use proper type names in your schema (strings)

You want to write a JSON schema. According to the definition, your type can either be a string or an array of strings. What you do is pass a TypeScript type definition in, not a string.

Try

  "firstName": {
    "type": ["string", "null"],
  },
  "LastName": {
    "type": ["string", "null"],
  },
  "Address": {
    "type": ["string","null"],
  },
  "required": [
    "firstName",
    "LastName",
    "Address",
  ]

Second: undefined is not a valid type for a JSON schema

Having a property set to undefined is counted as that property not being set. I'd suggest you move to null for cases like that.

Upvotes: 4

Relequestual
Relequestual

Reputation: 12315

null is a valid type in JSON, and so is in JSON Schema.

I don't know typescript, but here's a JSON Schema as an example.

{
  "$schema": "http://json-schema.org/draft-07/schema#",
  "properties": {
    "a": {
      "type": [
        "string",
        "null"
      ]
    }
  },
  "required": [
    "a"
  ]
}

And as an instance JSON, this would pass validation:

{
  "a": null
}

Upvotes: 0

scipper
scipper

Reputation: 3153

I don't know jsonschema, but your definition and your required fields look some kind of conceptual error to me.

You define 

"required": [
  "firstName", 
  "LastName", 
  "Address"
]

but set the type of every field to String,undefined. If you now set them to undefined the requirement is not met.

With other words: jsonschema seems to work, as it throws that error for your response: 

{
  "firstname": undefined,
  "Lastname": undefined,
  "Address": undefined,
}

Upvotes: 0

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