@stamp/configure
v1.0.2
Published
Access configuration of your stamps anywhere
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@stamp/configure
Access configuration of your stamps anywhere
Configuration is powerful feature of stamps as it allows you to store additional information with the stamp without interfering with properties or methods. Consider following example.
Usage
import compose from '@stamp/compose'
import jwt from 'jsonwebtoken'
const Jwt = compose({
configuration: {
jwtSecret: process.env.SECRET,
},
initializers: [
initializeJwt(_, { stamp }) {
const { jwtSecret } = stamp.compose.configuration
...
this.createJwtToken = (payload) => jwt.sign(payload, jwtSecret)
this.verifyJwtToken = (token) => jwt.verify(token, jwtSecret)
}
]
})
That approach brings several advantages.
- Clearly specify what makes the stamp tick.
- Configured values are immutable.
- Stamp with a modified configuration can be made.
The last bullet is especially useful for automated testing allowing you to insert different values based on various conditions. Unfortunately, there is apparent boilerplate hidden behind this, and it can get tedious for a larger project.
Now consider next example that is using @stamp/configure
stamp.
import Configure from '@stamp/configure'
import jwt from 'jsonwebtoken'
const Jwt = Configure.compose({
configuration: {
jwtSecret: process.env.SECRET,
},
methods: {
createJwtToken(payload) {
return jwt.sign(payload, this.config.jwtSecret)
},
verifyJwtToken(token) {
return jwt.verify(token, this.config.jwtSecret)
}
}
})
Looks good, doesn't it? But wait, all those advantages of the configuration are suddenly gone, right? Not exactly.
Under the hood, we are using @stamp/privatize
stamp. That allows us to access this.config
within our methods and yet keep them hidden from outside world. Immutability is ensured by using Object.freeze()
.
The deepConfiguration
gets assigned to the same this.config
object as well while the configuration
has a precedence over it. In case of name conflict, the value from configuration
always wins.
No fan of @stamp/privatize ?
By including @stamp/configure
your whole stamp is privatized by default which you may not like that much. For that case, we are offering opt-out option of using Configure.noPrivatize()
instead of plain Configure
.