nest-openapi-gen

Generate openapi document from nest controller

Problem 😕

You already defined your controllers with typescript, and you don't want to write it again in the open API document, or add @ApiProperty() decorator anywhere

Solution 😄

This package can generate the openapi document without adding any code or decorators.

Usage

#### Install
``npm i -D nest-openapi-gen`

#### Generate
`typescript
import { generate } from 'nest-openapi-gen';
generate({ prefix:'/api' });
`
This will generate openapi.schema.json file in the root folder.

#### Options
- prefix - global prefix
- filePath - The path to the generated file
- tsConfigFilePath - tsconfig.json file path. default - [root].tsconfig.json

$3

#### Validation decorators
- Min
- Max
- Pattern
- Date
- Time
- DateTime
- Duration
- Uri
- UriReference
- UriTemplate
- Email
- Hostname
- Ipv4
- Ipv6
- Regex
- Uuid
- JsonPointer
- RelativeJsonPointer
- NumberString
examples
`typescript
class FormatClass {
@Uuid uuid: string;
}

class MinMaxClass {
@Min(1) from: number;
@Max(5) to: number;

@Min(1) array: string[];

@Min(1) object: { a: number };
}

@Controller("")
export class App3Controller {
@Post("format/:mail")
format(@Param("mail") @Email mail: string, @Query() query: FormatClass, @Body() body: FormatClass) {}

@Post("minmax/:mail")
minmax(@Param("mail") @Min(5) @Email mail: string, @Query() query: MinMaxClass, @Body() body: MinMaxClass) {}
}
`

#### Schema decorator
you can set openapi schema by using Schema decorator.
`typescript
@Post("schema/:mail")
schema(
@Param("mail") @Schema({ description: "User email" }) @Email mail: string,
@Query() @Schema({ properties: { someInt: { type: "integer" } } }) query: SomeInterfaceWithInt
) {}
`


Big advantage


Now that we have openapi doc, we can use express-openapi-validator instead of class-validator.
This ugly code:
`typescript
export class GetEventsTimelineParams {
// eslint-disable-next-line no-restricted-syntax
@IsString() projectName!: string;
// eslint-disable-next-line no-restricted-syntax
@IsNumber() storeId!: number;
}

export class GetEventsTimelineQuery {
// eslint-disable-next-line no-restricted-syntax
@IsString() uuid!: string;
// eslint-disable-next-line no-restricted-syntax
@IsNumber() startTime!: number;
@IsNumber() @IsOptional() endTime?: number;
}
@Controller(':projectName/event-timeline')
export class EventTimelineController {
@Get(":storeId")
getEventTimeline(@Param() params: GetEventsTimelineParams,
@Query() query: GetEventsTimelineQuery): Promise {
}
}
`

Became to :
`typescript
export interface GetEventsTimelineQuery {
uuid: string;
startTime: number;
endTime?: number;
}

@Controller(':projectName/event-timeline')
export class EventTimelineController {
@Get(":storeId")
getEventTimeline(@Param('projectName') projectName: string,
@Param('storeId') storeId: number,
@Query() query: GetEventsTimelineQuery): Promise {
}
}
``

TODO

- ci/cd
- cli commands
- Multiple responses
- support files in response and request body

Dependencies

- ts-morph - TypeScript Compiler API wrapper to parse your types to openapi schemas.