Support free-form objects

[kshramt]

A free-form object (arbitrary property/value pairs) is defined as:

type: object

This is equivalent to

type: object
additionalProperties: true

and

type: object
additionalProperties: {}

https://swagger.io/docs/specification/data-models/data-types/

[rvadim]

Hi! Why are you using Record type?
AFAU Record used to fix fields in a object. https://www.typescriptlang.org/docs/handbook/utility-types.html#recordkeys-type

But additionalProperties are about free keys in object.

Thank you!

[kshramt]

Thank you for the comment.

Hi! Why are you using Record type?

IIUC, the use case for Record is not limited to restricting keys to the union type of literals. According to https://stackoverflow.com/a/54104476, Record<string, any> is equivalent to {[key: string]: any}. Also,

openapi-typescript-codegen/test/spec/v3.json

Lines 1831 to 1837 in 2721045

	"dictionaryWithEnumFromDescription": {
	"type": "object",
	"additionalProperties": {
	"type": "integer",
	"description": "Success=1,Warning=2,Error=3"
	}
	},

is converted to a Record (

openapi-typescript-codegen/test/__snapshots__/index.spec.ts.snap

Line 1220 in 2721045

dictionaryWithEnumFromDescription?: Record<string, number>;

).

[kshramt]

#1154 might be resolved by the PR.

[ajenkinski]

#1154 might be resolved by the PR.

This PR partially resolves #1154. It resolves the case where the object is completely free-form, but doesn't resolve the case where an object schema explicitly defines some properties, and also adds additionalProperties: true. For example, the following is a valid schema:

Person:
  type: object
  properties:
    name:
      type: string
  additionalProperties: true

This means the name property must be of type string, but other properties with arbitrary types are also allowed. This is equivalent to a Typescript type like:

export type Person = {
  name?: string,
  [key: string]: any
}

However the code in this PR will emit just:

export type Person = Record<string, any>;

This incorrectly allows the name property to have any type.