@prisma-utils/prisma-crud-generator

This library automatically creates CRUD (create, read, update, delete) services for all your prisma models.

Installation

Install the package via

npm i -D @prisma-utils/prisma-crud-generator

If you would like to use automatically wrap prisma calls with Exceptions, you need to manually install neverthrow as well.

npm i neverthrow

Usage

Open your prisma.schema file to add a new generator.

# prisma.schema file

generator crud {
  provider = "prisma-crud-generator"
  output = "./generated/#{model}"

  # dryRun = true / false
  # strict = true / false
}

General Information

The generator allows for automatically creating a CRUD Service (Create, Read, Update, Delete) for each model defined in the respective prisma schema. Furthermore, it generates so called Input classes for creating and updating the resource. These Input classes can be enriched with Decorators to validate the input (i.e., MaxLength(), IsString(), IsPositiveInteger(), ...).

General Configuration Parameters

The main parameters for this generator as as follows:

Parameter Name	Type	Default Value	Description
provider	string	-	The name of the generator - must be set to prisma-crud-generator
output	string	-	Path where all the files are generated to. You can use #{model} to insert the lowercase name of the currently processed model (i.e., user), #{Model} for the real model name (written as is, i.e., User), #{MODEL} for the uppercase name (i.e., USER), and #{moDel} for the camelCased version of the model name (i.e., userName; only the first letter is lowercased).
dryRun	boolean	false	don't write any content but output everything to the console instead
strict	boolean	false	Whether the generated code should use strict mode (i.e., for variable initializers)

CRUD Service

Additionally, the prisma-crud-generator also offers specific configuration parameters:

Parameter Name	Type	Default Value	Description
GenerateServices	boolean	true	Whether the CRUD Services should be generated or not.
CRUDServicePath	string	"services"	Path, where the classes should be generated to. It is appended to the output parameter.
CRUDServiceSuffix	string	"CrudService"	Suffix that is appended to the name of the model.
CRUDStubFile	string	undefined	(optional) path to a custom stub-file to read the template from.
CRUDAddExceptions	boolean	true	Whether prisma calls should be wrapped in an exception or not (by default it is wrapped)

Exceptions

Using the CRUDAddExceptions feature (i.e., set to true) will wrap the result (i.e., data returned by prisma or an error) in a Result object from neverthrow. For a basic usage, see the wiki of neverthrow.

CRUD Service Stub File

You can add your own CRUD Service Stub file that contains all custom code. You can use the following variables, that are automatically replaced during the generation process:

Variable Name	Description
#{CrudServiceClassName}	The generated class name for the service (i.e., based on the parameter for the generator)
#{Model}	The original model name (i.e., User)
#{model}	The lowercase version of the model name (i.e., user)
#{MODEL}	The uppercase version of the model name (i.e., USER)
#{moDel}	The camelCased version of the model name (i.e., userName). Note that the first letter is lowercased!

Input Classes

Parameter Name	Type	Default	Description
GenerateInputs	boolean	"true"	Whether the Input classes should be generated or not.
GenerateInputSwagger	boolean	"true"	Whether the Input classes should be annotated with swagger decorators.
InputExportPath	string	"data/inputs"	Path, where the classes should be generated to. Is appended to the output parameter.
InputSuffix	string	"Input"	Suffix that is appended to the Model Name for the generated classes.
InputValidatorPackage	string	"class-validator"	Defines the validator package name that is used for the validation decorators. You can also use "@nestjs/class-validator" or your own custom validator package if required.
InputParentClass	string	undefined	The (optional) parent class of the generated input class. Set to undefined, if you don't want to extend ... another class.
InputParentClassPath	string	undefined	The (optional) ImportPath (or package name) where to find the parent class.
InputCreatePrefix	string	"Create"	The Prefix that is prepended to the Model Name for the generated classes used to create a new model.
InputUpdatePrefix	string	"Update"	The Prefix that is prepended to the Model Name for the generated classes used to update an existing model.

Decorating the PrismaModel with Validators

One goal of this package is to have a "single source of truth". This also implies to have "validator rules" (i.e., the field email should be a valid email address, the username must be at least 5 characters long and unique, ...) right in this prisma model.

Prisma itself allows to add some kind of documentation to a model and fields. This feature is used to add custom decorators that are then used in the generation process as well.

Note that the package automatically adds proper validation decorators based on the datatype (i.e., the username String will automatically have the @IsString() decorator).

Consider this simplified model from a schema.prisma file.

model User {
  ///@Omit()
  id Int @id @default(autoincrement())

  ///IsEmail()
  ///MinLength(5)
  email String

  ///@MinLength(5)
  username String

  ///@IsOptional()
  alias String?

  isAdmin Boolean @default(false)

  /// ... more fields here

  ///@Relation()
  posts Post[]

  ///@Omit()
  createdAt DateTime @default(now())
  ///@Omit()
  updatedAt DateTime @updatedAt

  @@map("users")
}

You see a lot of comments (marked with ///) that contains decorators to validate the fields. These decorators are directly copied to the generated classes. The resulting input class looks like this:

export class UserInput {
  @ApiProperty()
  @IsInt()
  id: number;

  @ApiProperty()
  @IsString()
  @IsEmail()
  @MinLength(5)
  email: string;

  @ApiProperty()
  @IsString()
  @MinLength(5)
  username: string;

  @ApiProperty({ required: false })
  @IsOptional()
  @IsString()
  alias?: string;

  @ApiProperty()
  @IsBoolean()
  isAdmin: boolean;

  // ...

  @ApiProperty()
  posts: unknown;

  @ApiProperty()
  @IsDate()
  createdAt: Date;

  @ApiProperty()
  @IsDate()
  updatedAt: Date;
}

As you can see, the generator automatically creates a UserInput class that contains all defined fields. Furthermore, the decorators are applied automatically. Finally, swagger documentation is also added, if you did not disable this feature.

Furthermore, the generator creates 2 additional classes for creating and updating the model. These classes may be called CreateUserInput or UpdateUserInput respectively.

These classes look like this:

export class CreateUserInput extends OmitType(UserInput, [
  'id',
  'createdAt',
  'updatedAt',
  'posts',
] as const) {}

export class UpdateUserInput extends PartialType(UserInput) {}

These classes extend the OmitType and PartialType known from NestJS Mapped Types (i.e., see documentation here and here).

Every field that is decorated with the @Omit() documentation, is added automatically to the OmitType. Hence, this field is not required / allowed / ... anymore when submitting data to your service. Likewise, the PartialType makes every field optional, so that you can only update the username with a PATCH request. Also, fields decorated with @Relation() and @RelationId() are automatically omitted.

Tips

• You can disable the generation of the crud services or the input types by setting the respective GenerateServices or GenerateInputs to false.
• Note that this package also works in combination with PrisMerge (Docs)[https://github.com/prisma-utils/prisma-utils/tree/main/libs/prismerge]

Contributing

This library was generated with Nx.

Building

Run nx build prisma-crud-generator to build the library.

Running unit tests

Run nx test prisma-crud-generator to execute the unit tests via Jest.