redis-json    

Nodejs library to store/retrieve JSON Objects in RedisDB without loosing type information, i.e. WYSIWYG (What You Store Is What You Get)

Description

Every time set is called JSON object is flattened(embeded objects are converted to path keys) and then stored in Redis(just like a normal hashset), on get the hashset is unflattened and converted back to the original JSON object(with the same types as was in the original object).

What's new in v6.0.0?

- In response to issue: #24, we now replace the array in the cache when array is found in set object.

If you are on V5 then please check this Migration Guide to V6

API

Please visit this page for detailed API documentation.

Usage

Simple
``typescript
import Redis from 'ioredis';
import JSONCache from 'redis-json';

const redis = new Redis() as any;

const user = {
name: 'redis-json',
age: 25,
address: {
doorNo: '12B',
locality: 'pentagon',
pincode: 123456
},
cars: ['BMW 520i', 'Audo A8']
}

const jsonCache = new JSONCache(redis, {prefix: 'cache:'});


await jsonCache.set('123', user)

await jsonCache.get('123')
// output
// {
// name: 'redis-json',
// age: 25,
// address: {
// doorNo: '12B',
// locality: 'pentagon',
// pincode: 123456
// },
// cars: ['BMW 520i', 'Audo A8']
// }

await jsonCache.set('123', {gender: 'male'})
await jsonCache.get('123')
// output
// {
// name: 'redis-json',
// age: 25,
// address: {
// doorNo: '12B',
// locality: 'pentagon',
// pincode: 123456
// },
// cars: ['BMW 520i', 'Audo A8']
// gender: 'male'
// }

await jsonCache.get('123', 'name', 'age');
// output
// {
// name: 'redis-json',
// age: 25,
// }

await jsonCache.get('123', 'name', 'address.doorNo');
// {
// name: 'redis-json',
// address: {
// doorNo: '12B'
// }
// }

await jsonCache.clearAll();

await jsonCache.get('123');
// undefined


await jsonCache.incr('123', {age: 1}) // increments age by 1
`

With custom stringifier and parser:
`typescript
const jsonCache = new JSONCache(redis, {
stringifier: {
Date: (val: Date) => val.toISOString()
},
parser: {
Date: (str: string) => new Date(str)
}
})

const date = new Date()
await jsonCache.set('test', {
date: date
})

// Redis hashset
> hgetall jc:test /// data
1) "date"
2) "2020-05-17T14:41:45.861Z"
> hgetall jc:test_t /// type info
1) "date"
2) "Date"


const result = await jsonCache.get('test')
result.date == date /// true
`

With transactions:
`typescript
const transaction = redisClient.multi();

transaction
.set('name', 'foo')
.set('bar', 'baz')

await jsonCache.set('test', {name: 'testing'}, {transaction})
await jsonCache.del('test1', {transaction})
await jsonCache.rewrite('test2', {name: 'testing', age: 25}, {transaction})

transaction
.exec(function(err, replies) => {
/// your logic here after
})
`
Please note that only set(), rewrite(), del() & incr() supports transaction, where as get() & clearAll() do NOT support transaction because we process those results before returning it to the calling function. Moreover there is no real usecase in supporting transaction in get() & clearAll() methods!




Changelogs

Please refer to this page

Coverage Report

> npm run coverage

Contributions

This is open-source, which makes it obvious for any PRs, but I would request you to add necessary test-cases for the same.

$3

Run your redis-server and then point the same client to the same.
An easier way to start redis-server, provided you've already installed docker` (else visit this page) is by running this command:
> docker run --rm -it --name redis -p 6379:6379 redis

We follow TDD approach, so write your test cases first and then run the same paralelly during development by running the following command:
> npm run test:dev

LICENCE

MIT License