https://github.com/davidnussio/moleculer-cqrs
CQRS and Event sourcing module for moleculerjs
https://github.com/davidnussio/moleculer-cqrs
cqrs ddd event-sourcing history microservices moleculer moleculerjs
Last synced: about 1 month ago
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CQRS and Event sourcing module for moleculerjs
- Host: GitHub
- URL: https://github.com/davidnussio/moleculer-cqrs
- Owner: davidnussio
- License: mit
- Created: 2019-10-24T06:48:01.000Z (over 5 years ago)
- Default Branch: master
- Last Pushed: 2019-11-21T17:44:08.000Z (over 5 years ago)
- Last Synced: 2025-02-18T08:19:23.980Z (2 months ago)
- Topics: cqrs, ddd, event-sourcing, history, microservices, moleculer, moleculerjs
- Language: JavaScript
- Size: 538 KB
- Stars: 18
- Watchers: 3
- Forks: 4
- Open Issues: 0
-
Metadata Files:
- Readme: README.md
- License: LICENSE
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# moleculer-cqrs [](https://www.npmjs.com/package/moleculer-cqrs)
CQRS and Event sourcing module for moleculerjs
## Getting started
If you want skip next steps and start playing with moleculer & moleculer-cqrs clone [moleculer-cqrs-skeleton](https://github.com/davidnussio/moleculer-cqrs-skeleton) repository
### Create node project
```bash
npx moleculer init project moleculer-cqrs-skeleton
```
### Initialize git repository
```bash
git init
```
### Install dependencies
```bash
npm install --save moleculer-db moleculer-cqrs
```
### Create domain code (aggregate)
```bash
node node_modules/moleculer-cqrs/bin/cqrs-generator.js
local@notebook~$ cqrs generate
Aggregate directory: ./aggregates
Aggregate name: todo
? Do you want generate a view model service? Yes
Services directory: ./services
View model name: todo-list
```
Add aggregate path to jest roots
```diff
diff --git a/package.json b/package.json
index 3b31276..c82b69d 100644
--- a/package.json
+++ b/package.json
@@ -37,7 +37,8 @@
"testEnvironment": "node",
"rootDir": "./services",
"roots": [
- "../test"
+ "../test",
+ "../aggregates"
]
}
}
```
### Run test
```bash
npm run ci
```
### Install Event Sourcing storage adapter
```bash
mkdir event-sourcing-storage
mkdir data
touch event-sourcing-storage/index.js
npm install --save resolve-storage-lite
```
```javascript
// event-sourcing-storage/index.js
const createEsStorage = require("resolve-storage-lite").default;
const eventStore = createEsStorage({
databaseFile: "./data/event-store.sqlite",
});
module.exports = eventStore;
```
### Staring up and playing with moleculer services
```bash
npm run dev
# Moleculer repl
mol $
# Dispatch commands
call todo.command '{"aggregateId":"uuid-todo-1", "type":"createTodo", "payload":{"title": "Buy Milk"}}'
call todo.command '{"aggregateId":"uuid-todo-2", "type":"createTodo", "payload":{"title": "Buy Eggs"}}'
call todo.command '{"aggregateId":"uuid-todo-3", "type":"createTodo", "payload":{"title": "Buy a new Google Pixel 4 XL"}}'
# Query view-model todo-list (MoleculerDb service)
call todo-list.list
# Query read-model materialized aggregate on-the-fly from event-sourcing
call todo.read-model '{"aggregateId":"uuid-todo-2"}'
# Dispatch command
call todo.command '{"aggregateId":"uuid-todo-2", "type":"deleteTodo", "payload":{"message": "Alredy bought"}}'
# Query read-model (state after deleted command)
call todo.read-model '{"aggregateId":"uuid-todo-2"}'
# Query view-model (after delete event dipatched by deleted command)
call todo-list.list
# Call MoleculerDb remove, delete data
call todo-list.remove '{"id":"uuid-todo-1"}'
call todo-list.remove '{"id":"uuid-todo-3"}'
# Query view-model after manually deleted data
call todo-list.list
# Regenerate view-model from saved events
call todo.replay '{"viewModels":["todo-list"]}'
# Query view-model after regeneration from events
call todo-list.list
# Query aggregate event history (with or without payload)
call todo.history '{"aggregateId":"uuid-todo-2"}'
call todo.history '{"aggregateId":"uuid-todo-2", "payload": true}'
# Query read-model (using history events timestamp + 1 millis)
# Note: add 1 millis to history timestamp because finishTime in not included
call todo.read-model '{"aggregateId":"uuid-todo-2", "finishTime":1572097057195}'
```
## Aggregate service source code
CQRSEventSourcing service expose four actions but _command_, _read-model_ and _history_ are avaiable only if the mixin recieved and aggregate as parameter.
### Actions:
- command
- command action needs aggregateId, type and payload parameters
- read-model
- read-model action needs aggregateId parameter and accept finishTime (timestamp) parameter to load only events untill the specificated datetime
- history
- history action needs aggregateId parameter and accept payload (boolean) parameter to load payload data as well
- replay
- replay action needs viewModels (array of view-model name) parameter
### EventSourcingStorage
- `$ npm install --save resolve-storage-lite` - Adapter info: [SQLite](https://github.com/reimagined/resolve/tree/master/packages/adapters/storage-adapters/resolve-storage-lite)
- `$ npm install --save resolve-storage-mongo` - Adapter info: [Mongo DB](https://github.com/reimagined/resolve/tree/master/packages/adapters/storage-adapters/resolve-storage-mongo)
- `$ npm install --save resolve-storage-mysql` - Adapter info: [MySQL](https://github.com/reimagined/resolve/tree/master/packages/adapters/storage-adapters/resolve-storage-mysql)
- `$ npm install --save resolve-storage-postgresql-serverless` - Adapter info: [Postgresql serverless](https://github.com/reimagined/resolve/tree/master/packages/adapters/storage-adapters/resolve-storage-postgresql-serverless)
```javascript
const CQRSEventSourcing = require("moleculer-cqrs");
const EventSourcingStorage = require("../event-sourcing-storage");
const aggregate = require("../aggregates/todo");
module.exports = {
name: "todo",
mixins: [CQRSEventSourcing({ aggregate })],
storage: EventSourcingStorage,
settings: {},
dependencies: [],
actions: {},
events: {},
methods: {},
created() {},
started() {},
stopped() {},
};
```
## Generate aggregate source code
Getting started with aggregate and service skeleton generated by command line.
`$ node node_modules/moleculer-cqrs/bin/mol-cqrs-gen.js`
## Testing
moleculer-cqrs provide a simple CQRSFixture module that let to test domain logic without any type of service.
CQRSFixture accept an aggregate and provide some methods:
- `givenEvents([...])` initialize aggregate state
- `when(command, payload)` execute command
- `expectEvent(event)` expect event dispatched from command
- `inspectState(state => expectCode)` inspectState where state could be verify
- `whenThrow(command, payload)` execute command that throw errors
```javascript
const { CQRSFixture } = require("moleculer-cqrs");
const aggregate = require("..");
const {
commands: { createNews, deleteNews, addComment },
events: { NewsCreatedEvent, NewsDeletedEvent, AddCommentEvent },
} = aggregate;
jest
.spyOn(global.Date, "now")
.mockImplementation(() => new Date("2019-10-01T11:01:58.135Z").valueOf());
const payload = {
title: "Test document title",
userId: "user-id-1",
text: "Asperiores nam tempora qui et provident temporibus illo et fugit.",
};
describe("Testing aggregate commands in isolation", () => {
test("should commands with empty payload throw error", () => {
expect(() => createNews({}, {})).toThrow("Aggregate validation error");
});
test("should createNews command return an NewsCreatedEvent", () => {
expect(createNews({}, { payload })).toMatchSnapshot();
});
});
describe("Testing aggregate with cqrs fixture", () => {
let fixture;
beforeEach(() => {
fixture = new CQRSFixture(aggregate);
});
test("should call raw command", () => {
fixture
.givenEvents([])
.when({
aggregateId: "aggregate-uuid-1",
aggregateName: "news",
type: "createNews",
payload,
})
.expectEvent(NewsCreatedEvent({ ...payload, createdAt: Date.now() }));
});
test("should createNews return an NewsCreatedEvent event", () => {
fixture
.givenEvents()
.when(createNews, payload)
.expectEvent(NewsCreatedEvent({ ...payload, createdAt: Date.now() }));
});
test("should reject all next commands when aggregate is already deleted", () => {
const initialEventStream = [
NewsCreatedEvent({ ...payload, createdAt: Date.now() }),
NewsDeletedEvent({ deletedAt: Date.now() }),
];
fixture
.givenEvents(initialEventStream)
.whenThrow(deleteNews, {})
.toThrow("Aggregate is already deleted");
fixture
.givenEvents(initialEventStream)
.whenThrow(addComment, {})
.toThrow("Aggregate is already deleted");
});
test("should add comments to news", () => {
const initialEventStream = [
NewsCreatedEvent({ ...payload, createdAt: Date.now() }),
AddCommentEvent({
commentId: "uuid-comment-1",
text: "Comment text 1",
author: "author 1",
createdAt: Date.now(),
}),
];
fixture
.givenEvents(initialEventStream)
.when(addComment, {
commentId: "uuid-comment-2",
text: "Comment text 2",
author: "author 2",
})
.expectEvent(
AddCommentEvent({
commentId: "uuid-comment-2",
text: "Comment text 2",
author: "author 2",
createdAt: Date.now(),
})
)
.inspectState(state =>
expect(Object.keys(state.comments).length).toEqual(2)
);
});
});
```