Ts-openapi

An openapi json generator using joi API schemas that will help you to maintain your API documentation up to date. Joi is the is one of the most used components to validate data schemas, this can be used to generate and maintain API information up to date, without the need to update manually documentation.

This software has some code extracted from joi-to-swagger to interface with Joi schemas.

Installation

Using npm: npm i --save ts-openapi

Visit the GitHub Repo tutorials, documentation, and support

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OpenApi Supported Types

Type	Query	Path (1)(5)	Header	Cookie	Body
String, String Enum, Email, Password, Uuid, Uri, Hostname, Ipv4, Ipv6	YES	YES	YES	YES	NO (4)
Integer, Integer Enum, Number, Number Enum	YES	YES	YES	YES	NO (4)
Date-time, Date	YES	YES	YES	YES	NO (4)
Byte(3), Binary (string)	YES	YES	YES	YES	NO (4)
Array[]	YES (3)	NO	NO	NO	YES (4)
Object	NO	NO	NO	NO	YES (6)

^{(1) Values included in url parameters are always required because they're part of the url.
(2) this type is a Base64 binary encoded string.
(3) array of scalar values.
(4) for body we support objects and arrays.
(5) the name of route parameters must be made up of “word characters” ([A-Za-z0-9_]).
(6) GET requests don't have a body.}

Type Samples

All samples presented here an in Typescript

String Types
Numeric Types
Date-Time Types
Binary Types
Array Type
Object Type

Advanced Topics

Security

Security Schemes

Parameters and Models

Parameters and Models

Mingle multiple services

Mingle multiple services

Declaring an API

First we need to create an OpenApi object to store information

1    const openApi = new OpenApi(
2        "1.0.0",                // API version
3        "Server API",           // API title
4        "Some test api",        // API description
5        "maintainer@domain.com" // API maintainer email
6    );

Then you need to declare an array with the API servers

In the event your API is based on docker instances you should call setServers when OpenApi class is called to get the json, to update the IPs and port numbers. You can even specify different servers depending if the call is internal or external. Up to you.

1    openApi.setServers([
2        { url: "https://api.domain.com:443" },
3        { url: "https://192.168.1.23:80" }
4    ]);

Optionally you can set your license information

This is used to document the API license type, url of the license and terms of service.

1    openApi.setLicense(
2        "Apache 2.0", // license name
3        "http://www.apache.org/licenses/LICENSE-2.0.html", // url for the api license
4        "http://swagger.io/terms/" // terms of service
5    );

Now you need to declare your endpoints (once per http verb)

1    openApi.addPath(
2        "/hello",
3        {
4            get: {
5                summary: "Server Healthcheck",          // Method title
6                description: "Hello world endpoint",    // Method description
7                operationId: "hello-op",                // unique operation id
8                responses: {                            // response codes and description
9                    200: textPlain("Successful operation."),
10/*                  // or if you prefer:
11                    200: {
12                        description: "Successful operation.",
13                        content: { "text-plain": {} },  // mimetype with empty schema
14                    },*/
15                },
16                tags: ["Test Operations"],              // One or more tags, this will allow API grouping
17            },
18        },
19        true                                            // visible ? If not it gets skipped from declaration
20    );

Finally we export the JSON schema

Note that the paths just need to be added one time, during server init, after this the openApi is basically static.

1    openApi.generateJson();

Declaring a GET request

1
2    const errorSchema = Types.Object({
3        description: "Error description",
4        properties: {
5            message: Types.String({ description: "Error message" }),
6            code: Types.Integer({ description: "Error code" }),
7        },
8        example: { message: "Bad request": code: 400 }
9    });
10
11    // body response schema
12    const responseSchema = Types.Object({
13        description: "Customer details",
14        properties: {
15            id: Types.Uuid({ description: "Customer ID" }),
16            name: Types.String({
17                description: "Customer name",
18                maxLength: 100,
19                required: true,
20            }),
21            type: Types.StringEnum({
22                values: Object.values(CustomerType),
23                description: "Customer Type",
24            }),
25            birthdate: Types.Date({ description: "Birthdate" }),
26        },
27        example: { id: "96efe677-f752-426f-a9b8-b9f33b286cc9", name: "customer model", type: "gold", birthdate: "11-11-1911" },
28    });
29
30    openApi.addPath(
31        "/customer/:id", // path parameter
32        {
33            get: {
34                summary: "Get a customer data",
35                description: "This operation retrieves customer information",
36                operationId: "get-customer-op",
37                requestSchema: {
38                    params: { // path parameter
39                        id: Types.Uuid({
40                            description: "Customer ID",
41                            required: true, // param values MUST be required
42                            example: "37237d6a-bb7e-459a-b75d-d1733210ad5c",
43                        }),
44                    },
45                },
46                tags: ["Customer Operations"],
47                responses: {
48                    200: openApi.declareSchema("Get customer success", responseSchema),
49                    400: openApi.declareSchema("Bad Request", errorSchema),
50                },
51            },
52        },
53        true
54  );

Declaring other HTTP methods

You can declare:

• delete requests
• get requests
• patch requests
• post requests
• put methods

Declaring the inputs of your request

When you declare your request you can use as inputs:

• query parameters '?a=1&b=2'
• param parameter '/:userid/list'
• cookie parameter (a cookie)
• header parameters
• body content

Sample server

GitHub Repo for a demo server

Medium Articles

Maintaining REST API Documentation with Node.js — Part I about documenting a single service
Maintaining REST API Documentation with Node.js — Part II about combining multiple services documentation