Methods

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Methods
You can add methods (aka functions) to the objects created from your stamps.
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const Logger = stampit({
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  methods: {
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    debug(str) {
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      console.log(str)
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    }
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  }
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})
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​
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const logger = Logger()
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​
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logger.debug('Server started')
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All the methods are attached to object's prototype.
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logger.__proto__.debug === Logger.compose.methods.debug
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Moreover, the entire methods descriptor metadata becomes the prototype.
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logger.__proto__ === Logger.compose.methods
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If you compose the stamp above with any other stamp, then object instances created from it will also have the .debug method.
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const Server = Logger.compose({
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  methods: {
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    async start() {
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      this.debug('Server started')
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    }
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  }
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})
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​
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const server = Server()
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​
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server.debug('Starting server')
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server.start()
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Descriptor merging algorithm
The methods are copied by assignment. In other words - by reference using Object.assign.
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Logger().debug === Server().debug
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In case of conflicts the last composed method wins. To avoid method collision use the @stamp/collision stamp. To make sure a method is implemented use the @stamp/required stamp.
NOTE
When using the @stamp/required stamp it creates a proxy object and returns from the factory. This means that logger.__proto__ === Logger.compose.methods or logger.__proto__.debug === Logger.compose.methods.debug will no longer be true.
Other ways to add methods
Exactly the same stamp can be created in few ways. Here they all are.
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function myDebug(str) {
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  console.log(str)
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}
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​
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const Logger = stampit({
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  methods: {
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    debug: myDebug
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  }
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})
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​
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const Logger = stampit.methods({
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  debug: myDebug
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})
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​
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const Logger = stampit().methods({
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  debug: myDebug
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})
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Last modified 4yr ago
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Contents
Descriptor merging algorithm
Other ways to add methods