nest-swagger-checker

nest-swagger-checker is a package that validate some specifications about Swagger/OpenApi in NestJs projects.

It has configurable options like checking endpoint summary and description emptiness also same for parameters of endpoint.

Endpoint Informations Check (@ApiOperation)

nest-swagger-checker can check description and summary of an endpoint by parsing ApiOperation decorator. Also, pattern can be provided in configuration to identify rules to standardize every description and summary of endpoints.

  @Post('')
  /* nest-swagger-checker can check whether summary is empty or not in ApiOperation decorator.
  Also it can check that summary matches or not with given regular expression pattern. */
  @ApiOperation({
    summary: 'Create Order',
    description: 'Creating order endpoint description',
  })
  ...
  public async createOrder(
    @Body() createBody: Order,
  ): Promise<CustomResponseType> {
    .....
  }

Endpoint Payload Check ( (@Body | @Query) -> @ApiProperty)

nest-swagger-checker is also able to check fields in ApiProperty decorators. In nestjs we can use ApiProperty decorator to describe informations about endpoint payloads. Paylaods can be defined with @Body or @Query decorators. This flow has recursive structure.

If some properties of the main payload class has also their own properties, which means they are also classes not primitive types, nsc will check properties of these properties also.

For example there is an custom Order class below that used as above endpoints payload by using with @Body decorator. And you can see properties of that class below;

export class Order {

  /* nsc checks example, description and type properties in @ApiProperty decorator
  according to your config options. For example this basketId property does not have
  description. So, it will log a warning to termianl when we run nest-swagger-checker */
  @ApiProperty({ example: '44c4b0ae-1397-11eb-adc1-0242ac120002' })
  basketId: string;

  @ApiProperty({
    example: [{ date: '1997-07-16T19:20:30.45+01:00', status: 'PAID' }],
  })
  statuses: Status[];

  @ApiProperty({
    example: [
      {
        id: 60485482,
        description: '',
      },
    ],
  })
  productIds?: CustomProductClass[]; // nsc also checks ApiProperty decorator of properties in CustomProductClass.

  @ApiProperty({ example: 'Some Description' })
  description: string;

  @ApiProperty({ example: '2021-04-13T00:00:00.000+03:00' })
  orderDate: string;

Firstly nest-swagger-checker checks properties of Order class. After that it will check every non-primitive property of Order class. In this case, it will check properties of Status and CustomProductClass classes also.

Endpoint Param Check (@Param)

nest-swagger-checker can check param of an endpoint like payload. As you knwo, main difference is that param directly comes from endpoints path. So, it has different defining way in NestJs which means nest-swagger-check also different check mechanism about it.

@Get(':id')
@ApiParam({
  name: 'id',
  description: 'Order Id',
  example: '5xaer533312312-jkmser21',
})
public async get(
  @Param('id') id: string,
  @Seller() merchant: Merchant,
): Promise<Order> {
  return this.service.getOrder(id);
}

According to above case, get endpoint has a param that name with id. nest-swagger-will check, if are there any @ApiParam decorator that has same name value with endpoints id param. After that it will check description, example etc. fields in @ApiParam decorator according to configuration options.

Configuration

Whole configuration and hierarchy can shown below section:

{
  "scopes": {
    "file": {
      "pathPattern": "src/**/*.ts"
    },
    "endpoint": {
      "information": {
        "check": true,
        "summary": {
          "check": true,
          "checkEmpty": true,
          "pattern": null
        },
        "description": {
          "check": true,
          "checkEmpty": true,
          "pattern": null
        }
      },
      "body": {
        "check": true,
        "description": {
          "check": false,
          "pattern": "^[A-Z][a-z]*(?:\\s[a-z]*)*$"
        },
        "example": {
          "check": false
        },
        "type": {
          "check": false
        }
      },
      "query": {
        "check": false,
        "description": {
          "check": true,
          "pattern": "^[A-Z][a-z]*(?:\\s[a-z]*)*$"
        },
        "example": {
          "check": false
        },
        "type": {
          "check": false
        }
      },
      "params": {
        "check": true,
        "description": {
          "check": true,
          "pattern": "^[A-Z][a-z]*(?:\\s[a-z]*)*$"
        },
        "example": {
          "check": true
        }
      }
    }
  }
}

Scopes

• file: It is scope about file related configurations.
• endpoint: It is root scope about endpoint configurations.
• information: Scope to set configurations about endpoint information like summary(title) and description.
• summary: Scope to set configurations about endpoint summary.
• description: Scope to set configurations about description of several places like endpoint, endpoint parameters, properties of endpoint payload and queries etc.
• example: Scope to set configurations about example of several places like parameter of endpoint, properties of endpoint body and queries etc. ApiProperty, ApiParam etc. decorators have example field inside them.
• type: Scope to set configurations about type of several places like parameter of endpoint, properties of endpoint body and queries etc. ApiProperty, ApiParam etc. decorators have type field inside them.

Configuration Options

• pathPattern: It is a regex to identify which files should be checked in a project when package runs.
• check: It identifies whether related scope should checked or not. If it is true, nsc package will check whether related scope exists or not.
• checkEmpty: It identifies whether emptiness of related scope should checked or not. If it is true and related scope exists, nsc package will check whether related scope has empty value or not.
• pattern: Regex to check value of related field matches or not. If it is true, nsc package will check whether value of related scope matches with given pattern or not.

As you see structure of sub-scopes are so similar. Let's explain logic about them with one of them:

        "check": true,
        "summary": {
          "check": true,
          "checkEmpty": true,
          "pattern": null
        },
        "description": {
          "check": true,
          "checkEmpty": true,
          "pattern": null
        }
      }

This sub-scope, information, is about to endpoint summary and description. So it has two sub-scope also summary and description. Check means should nsc check endpoint informations or not. If check for information is true, package will check something about endpoint information by using ApiOperation decorator. Like that, the check config of summary and description identify, should package check 'summary' and 'description' field inside ApiOperation decorator.

Usage

Firstly, you need to install nest-swagger-package with your package manager e.g yarn or npm.

If you create .swautomaterc file in your projects root folder you can override default configuration options with your choices. You don't need to identify every option in that file. Just use same hieararchy with same values.

You can run nest-swagger-checker command in terminal. It will check every file that matched with file pattern if file includes controller class.

You can give filePattern in custom config file or you can run command like nest-swagger-checker src/myCustomPath/myCustomFile. So yes, you can give your pattern with command.

There is the example output of nest-swagger-checker command below for nestjs crud example project.

Usage Idea

You can check every file in pre-commit stage with husky package. I don't tell details of husky package, but after installation of husky, we can call nest-swagger-checker command for every files that will be committed before commit.

files=$(git diff --name-only)
for file in $files; do
        nest-swagger-checker $file
done