How to generate augmented types from V14 metadata generated with subwasm

Question

The common way of generated type augmentation is by fetching the latest metadata from a running node with the following piece of code:

await provider.connect()
await provider.isReady
const result = await provider.send('state_getMetadata')

The return type of the call seems to be an object with the following structure:

{
  "result": <scale_and_hex_encoded_metadata>
}

On the resulting JSON file, some variation of the ts-node --skip-project ../../node_modules/.bin/polkadot-types-from-defs is to be run.

We want to expose the generated metadata for a built WASM using subwasm, with subwasm metadata --json <runtime_wasm>, which generates metadata in the following format:

{
  "V14": {
    "types": {...},
    "pallets": [...],
    "extrinsic": {...},
    "ty": 232
  }
}

What is the way to use this metadata format to generate the augmented types? Do we need to apply some sort of encoding on the data before calling the polkadot-types-from-defs script? If so, what is the process? The RPC node seems to be returning a MagicNumber which the script expects, and I could not find much information about it.

Answer 1

The latest release of subwasm contains a flag --format=json+scale which will return exactly the {"result": "<scale and hex encoded metadata>"} that is needed.