Enqueues a JSON-RPC request that the client will process as soon as possible.

The response will be sent back using the callback passed when adding the chain.

See https://www.jsonrpc.org/specification for a specification of the JSON-RPC format. Only version 2 is supported. Be aware that some requests will cause notifications to be sent back using the same callback as the responses.

If the request is not a valid JSON-RPC request, then a JSON-RPC error response is later generated with an id equal to null, in accordance with the JSON-RPC 2.0 specification.

If, however, the request is a valid JSON-RPC request but that concerns an unknown method, or if for example some parameters are missing, an error response is properly generated and yielded through the JSON-RPC callback.

Two JSON-RPC APIs are supported by smoldot:

• The "legacy" one, documented here: https://polkadot.js.org/docs/substrate/rpc
• The more recent one: https://github.com/paritytech/json-rpc-interface-spec

Waits for a JSON-RPC response or notification to be generated.

Each chain contains a buffer of the responses waiting to be sent out. Calling this function pulls one element from the buffer. If this function is called at a slower rate than responses are generated, then the buffer will eventually become full, at which point calling Chain.sendJsonRpc will throw an exception.

If this function is called multiple times "simultaneously" (generating multiple different Promises), each Promise will return a different JSON-RPC response or notification. In that situation, there is no guarantee in the ordering in which the responses or notifications are yielded. Calling this function multiple times "simultaneously" is in general a niche corner case that you are encouraged to avoid.

Disconnects from the blockchain.

The JSON-RPC callback will no longer be called. This is the case immediately after this function is called. Any on-going JSON-RPC request is instantaneously aborted.

Trying to use the chain again will lead to a AlreadyDestroyedError exception being thrown.

While the chain instantaneously disappears from the public API as soon as this function is called, its shutdown process actually happens asynchronously in the background. This means for example that networking connections to the chain will remain open for a little bit even after this function returns.

If the chain is a relay chain, and that there exists Chain instances corresponding to parachains that are using this relay chain, then these parachains will continue to work and the relay chain will actually remain connected in the background. Smoldot automatically keeps alive all relay chains that have an active parachains. There is no need to track parachains and relay chains, or to destroy them in the correct order, as this is handled automatically internally.