@parana-games/tinymo NPM

tinymo simplifies constructing DynamoDB's JSON-based command inputs.

From this:

const update = {
  TableName: 'users',
  Key: { 
    id: 'bob' 
  },
  UpdateExpression: 'SET #orders :orders',
  ConditionExpression: '#age >= :ageCondition',
  ExpressionAttributeNames: { 
    '#age': 'age', 
    '#orders': 'orders' 
  },
  ExpressionAttributeValues: { 
    ':ageCondition': 18, 
    ':orders': 5
  }
}

To this:

tinymo.update('users', { id: 'bob' }).set('orders', 5).condition('age', '>=', 18)

Installation

npm i @parana-games/tinymo

How to Use

Import:

import { tinymo } from '@parana-games/tinymo';

Create requests:
tinymo supports all of DocumentClient's requests:

const update = tinymo.update('table', { name: 'John' })
const put = tinymo.put('table', someItem)
const deleteRequest = tinymo.delete('table', { id: 1 })
const get = tinymo.get('table', { id: 'id' })
const batchGet = tinymo.batchGet()
const batchWrite = tinymo.batchWrite()
const query = tinymo.query('table')
const scan = tinymo.scan('table')
const transactGet = tinymo.transactGet()
const transaction = tinymo.transaction()

Customize requests:
Request options are accessed through members of the class:

get.attributes('id', 'name')

query.key('sk', '>=', 'order#100').filter('type', '=', 'refund')

scan.consistentRead = true

update.returnValues = 'ALL_NEW'

Execute with .run():
Every request is executable with run()

await transaction.run()

const queryResponse = await query.run()

const batchGetResponse = await batchGet.run()

Promise.all([put, update, deleteRequest].map(request => request.run()));

Transactions

There are two ways of adding writes to a transaction: 1. Using the update, put and delete methods:

These methods add the corresponding write item to the list and return it, so you can manipulate and pass it around with ease.
const update = transaction.update('users', { id: 'dan' })
update.add('balance', 10);

transaction.put('users', { id: 'john', balance: 20 }); transaction.delete('orders', { id: '123' });

2. Using the `push` method, which accepts `Write` objects.
> `Write` is the base class of `Update`, `Put` and `Delete`. 
```typescript
const writes: Write[] = generateWrites(); 

// Sometimes you have just one update to make, so a transaction is overkill.
if (writes.length > 1) {
  await transaction.push(...writes).run();
} else (writes.length === 0) {
  await writes[0].run(); 
}

Testability

Generate pure DynamoDB JSON-based command inputs with build():

const put = tinymo.put('games', { name: 'pool-stars' });
put.build()

↓

{
  'TableName': 'games',
  'Item': {
    'name': 'pool-stars'
  }
}

Useful for tiny unit tests!

Using without the tinymo Client

Send commands using your DynamoDBClient:

import { Delete } from '@parana-games/tinymo';

const tinymoDelete = new Delete('users', { name: 'john' });
const command = new DeleteCommand(tinymoDelete.build());
const dynamoDBClient = new DynamoDBClient({});
await dynamoDBClient.send(command);

️ Don't use run() when creating tinymo objects with new. They won't have an associated client.
import { Scan } from '@parana-games/tinymo';

const scan = new Scan('users'); await scan.run(); // error thrown as this instance is clientless

## Use `TinymoClient.setDocumentClient` to set your own DocumentClient
```typescript
TinymoClient.setDocumentClient(myCustomDocumentClient); // Useful when using X-Ray!