wasm api helps to define wasm function
npm install @vectorizedio/wasm-apiRedpanda coprocessing client library for nodejs
1. Simply include the library and create your own instance of the SimpleTransform class.
```
const wasmJs = const {
SimpleTransform,
} = require("@vectorizedio/wasm-api");
const transform = new SimpleTransform();
2. Specify what topics you want your script to consume from:
``
transform.subscribe(["my-topic", PolicyInjection.Stored]);
3. And write your custom transform logic that may filter or transform records in any way you'd like.
```
transform.processRecord((recordBatch) => {
return Promise.resolve(new Map(....));
});
Use the map returned from the processRecord method to determine what output topics you'd like to produce onto. For example if the recordBatch arrived from 'my-topic' and your Map contains a single key 'Foo', the transformed recordBatch will be produced onto a materialized topic named 'my-topic.$Foo$'. Materialized topics share all topic attributes with its source topic.