How to generate basic TypeScript interfaces from Swagger schema?

Question

I'm looking for a way to generate simplistic TypeScript interfaces from a Swagger schema. Most solutions I find are needlessly complicated.

I would like to generate interfaces like this:

export interface IBar {
    a?: string;
    b: number;
    c: Date;
    baz?: IBaz;
}

export interface IBaz {
    d: number;
    color: Color;
}

export enum Color {
    RED = 0,
    GREEN = 1,
    BLUE = 2,
}

From a schema like this:

    {
  "x-generator": "NSwag v11.14.0.0 (NJsonSchema v9.10.24.0 (Newtonsoft.Json v9.0.0.0))",
  "swagger": "2.0",
  "info": {
    "title": "",
    "version": ""
  },
  "schemes": [],
  "consumes": [
    "application/json"
  ],
  "produces": [
    "application/json"
  ],
  "paths": {
    "/api/Foo/GetBarDescriptions": {
      "get": {
        "tags": [
          "Foo"
        ],
        "operationId": "Foo_GetBarDescriptions",
        "parameters": [],
        "responses": {
          "200": {
            "description": "",
            "schema": {
              "type": "array",
              "items": {
                "type": "string"
              }
            },
            "x-nullable": true
          }
        }
      }
    },
    "/api/Foo/GetBar": {
      "get": {
        "tags": [
          "Foo"
        ],
        "operationId": "Foo_GetBar",
        "parameters": [
          {
            "type": "integer",
            "name": "id",
            "in": "query",
            "required": true,
            "x-nullable": false,
            "format": "int32"
          }
        ],
        "responses": {
          "200": {
            "description": "",
            "schema": {
              "$ref": "#/definitions/Bar"
            },
            "x-nullable": true
          }
        }
      }
    },
    "/api/Foo/SetBar": {
      "post": {
        "tags": [
          "Foo"
        ],
        "operationId": "Foo_SetBar",
        "parameters": [
          {
            "name": "value",
            "in": "body",
            "required": true,
            "schema": {
              "$ref": "#/definitions/Bar"
            },
            "x-nullable": true
          }
        ],
        "responses": {
          "204": {
            "description": ""
          }
        }
      }
    }
  },
  "definitions": {
    "Bar": {
      "type": "object",
      "additionalProperties": false,
      "required": [
        "B",
        "C"
      ],
      "properties": {
        "A": {
          "type": "string"
        },
        "B": {
          "type": "integer",
          "format": "int32"
        },
        "C": {
          "type": "string",
          "format": "date-time"
        },
        "Baz": {
          "$ref": "#/definitions/Baz"
        }
      }
    },
    "Baz": {
      "type": "object",
      "additionalProperties": false,
      "required": [
        "D",
        "Color"
      ],
      "properties": {
        "D": {
          "type": "number",
          "format": "decimal"
        },
        "Color": {
          "$ref": "#/definitions/Color"
        }
      }
    },
    "Color": {
      "type": "integer",
      "description": "",
      "x-enumNames": [
        "RED",
        "GREEN",
        "BLUE"
      ],
      "enum": [
        0,
        1,
        2
      ]
    }
  },
  "parameters": {},
  "responses": {},
  "securityDefinitions": {}
}

Answer 1

Not sure if that's a sane way to do this, it's the first time I'm playing around with Swagger.

I bumped into the following link and pasted the schema from the project I integrate with. From the top 'Generate Client' menu I chose one of the TypeScript presets and it generated a minimal project where I could extract the bits I needed, interface and classes, etc.

http://editor.swagger.io/#/

I tried running your schema. Here's a small excerpt of the generated code:

export interface Bar {
    "a"?: string;
    "b": number;
    "c": Date;
    "baz"?: Baz;
}

export interface Baz {
    "d": number;
    "color": Color;
}

/**
 * 
 */
export type Color = "0" | "1" | "2";

Maybe with a bit more tweaking it can make exactly what you're looking for.

Further reading may be about tools like https://github.com/swagger-api/swagger-codegen but the online web editor is a quick and dirty way to do this.

Answer 2

I use dtsgen and it works well in my case.

yarn dtsgen --out ./path/to/generated-types.d.ts ./path/to/input/swagger.json.or.yml

Answer 3

I'm using swagger-typescript-api to generate interfaces from swagger schema

npx swagger-typescript-api -p PATH_TO_YOUR_SCHEMA -o ./

Answer 4

You can also take a look at autorest.typescript client code generator. It provides good interfaces for all the model definitions, accurately defines readonly properties and enums. It supports a bunch of custom extensions that can be useful to improve the user experience of the generated client. You can take a look at some generated sample clients.

Bonus: The generated typescript client works in node.js and also in the browser with the help of webpack.

Answer 5

You can try this tool sw2dts, which generated code like below:

export interface Bar {
    A?: string;
    B: number; // int32
    C: string; // date-time
    Baz?: Baz;
}
export interface Baz {
    D: number; // decimal
    Color: Color;
}
/**
 * 
 */
export type Color = 0 | 1 | 2;

The Color enum seems to need a little tweak, that should contain the names of properties to iterate over, instead of the real number.