This plugin for Mutent provides an easy way to declare migration strategies for data versioning.
Returns a new Mutent's Plugin that will monitor all fetched Entites and applies the correct migration strategy when needed.
-
options<Object> -
[options.explicitVersion]<boolean>Do not set the latest version automatically during Entities' creation. -
[options.forceUpdate]<boolean>Force Entity's update any time is handled. -
[options.key]<string>Name of the key that holds the Entity's version number. -
[options.strategies]<Object>Collection of migration functions. -
options.version<number>The wanted Entity's version. - Returns:
<Plugin>
Those are the error codes (MutentError instances) that can be throwed by this plugin.
The current Entity have an invalid version value.
Found an Entity that has a future version.
An upgrade is required, but the required strategy function is missing.
A strategy was applied to an Entity, but the Entity does not contain the expected version.
import { Store } from 'mutent'
import ArrayAdapter from 'mutent-array'
import migration from 'mutent-migration'
const items = [
{ id: 1, oldFieldName: 'Calvin' } // implicit "v: 0"
]
const store = new Store({
adapter: new ArrayAdapter({
items
}),
plugins: [
migration({
// Required version
version: 1,
// Version field name
key: 'v',
// Migration strategies
strategies: {
// Migrate from v0 (no version) to v1
1: ({ oldFieldName, ...data }) => {
return {
...data,
v: 1,
newFieldname: oldFieldName
}
}
}
})
]
})
// Read and upgrade (in memory)
const calvin = await store
.find(item => item.id === 1)
.unwrap()
// { id: 1, v: 1, newFieldname: 'Calvin' }
console.log(calvin)
// Create (set latest version if not defined during creation only)
const hobbes = await store
.create({ id: 2, newFieldname: 'Hobbes' })
.unwrap()
// { id: 2, v: 1, newFieldname: 'Hobbes' }
console.log(hobbes)
// Create from an explicit version
const prof = await store
.create({ id: 3, v: 0, oldFieldName: 'Miss Wormwood' })
.unwrap()
// { id: 3, v: 1, newFieldname: 'Miss Wormwood' }
console.log(prof)