"allOf" + "additionalProperties false" with interface extensions

[arvind]

export interface A {a: string;}
export interface B extends A {b?: string;}

generates

{
  "$schema": "http://json-schema.org/draft-04/schema#",
  "definitions": {
    "B": {
      "allOf": [
        {
          "type": "object",
          "properties": {
            "b": {
              "type": "string"
            }
          },
          "required": [],
          "additionalProperties": false
        },
        {
          "$ref": "#/definitions/A"
        }
      ]
    },
    "A": {
      "type": "object",
      "properties": {
        "a": {
          "type": "string"
        }
      },
      "required": [
        "a"
      ],
      "additionalProperties": false
    }
  },
  "$ref": "#/definitions/B"
}

The following object type checks correctly with TypeScript. However, it does not validate against the JSON schema. This is because B uses an allOf where each branch has additionalProperties: false (i.e., it fails the first branch).

const foobar:B = {a: 'foo'};

I believe ts2json should be consolidating these definitions together. Note: Switching allOf to anyOf doesn't yield a correct schema either ({b: 'foo'} correctly validates for instance).

[arvind]

This issue also occurs with intersection types. An identical schema is generated with:

export type A = {a: string}
export type B = A & {b?: string}

[domoritz]

The output above is from the version on NPM.

{
  "$ref": "#/definitions/MyAlias",
  "$schema": "http://json-schema.org/draft-04/schema#",
  "definitions": {
    "A": {
      "additionalProperties": false,
      "properties": {
        "a": {
          "type": "string"
        }
      },
      "required": [
        "a"
      ],
      "type": "object"
    },
    "B": {
      "additionalProperties": false,
      "properties": {
        "a": {
          "type": "string"
        },
        "b": {
          "type": "string"
        }
      },
      "required": [
        "a"
      ],
      "type": "object"
    },
    "MyAlias": {
      "anyOf": [
        {
          "$ref": "#/definitions/A"
        },
        {
          "$ref": "#/definitions/B"
        }
      ]
    }
  }
}

Use npm install vega/typescript-to-json-schema#VERSION.