@sclable/nestjs-es-cqrs-schematics

Schematics try-out and generator for the ES/CQRS library

Usage

Create a JSON file with your configuration. Check the schema: src/es-cqrs/schema.json.

Example: new-command.json

{
  "moduleName": "main",
  "verb": "do",
  "subject": "stuff again",
  "parameters": [
    {
      "name": "param1",
      "type": "string"
    },
    {
      "name": "param2",
      "type": "ImportedParameter",
      "importPath": "imported-params"
    }
  ]
}

Install schematics and this project:

npm i -g @angular-devkit/schematics-cli
npm i @sclable/es-cqrs-schematics

Run schematics in your code to create a command-event chain

schematics @sclable/es-cqrs-schematics:json new-command.json all

There are targets other than all but they may need a different JSON Schema which can be read from the source.

Example: to only create a command, you can use the upper mentioned JSON file with the command target or check src/es-cqrs/command/command.schema.json and run your JSON with the command-standalone target.

Additional features

REST-API generation

Use the collection all-rest to create nestjs controllers as well. For create operation it will generate Post endpoints that returns the new ID, for other modification it will Put endpoint with /:id as parameter and returns nothing

Graphql generation

TBD

Examples and recommendations

Aggregate creation

Usually there is no ID associated with a creation, only a user, so the system can assign and return a new ID. To help with this logic this schematics can generate create component with UUID generation. It will create such components if the verb is one of [add, create, new, insert] and the subject is the same as the moduleName

Aggregate member generation

If needed this schematics can generate member properties for the aggregate and will set their value from the events (otherwise handler contain just /* no-op */ placeholder). To achieve this, set isMember to true for the parameter that needs a member created.

Using object parameters

If the mutation uses a single object parameter and not a list of primitive types, set isExistingObject to true. This will generate proper value assignments.