packages/rpc-provider/src/coder/index.ts
// Copyright 2017-2024 @polkadot/rpc-provider authors & contributors
// SPDX-License-Identifier: Apache-2.0
import type { JsonRpcRequest, JsonRpcResponse, JsonRpcResponseBaseError } from '../types.js';
import { isNumber, isString, isUndefined, stringify } from '@polkadot/util';
import RpcError from './error.js';
function formatErrorData (data?: string | number): string {
if (isUndefined(data)) {
return '';
}
const formatted = `: ${isString(data)
? data.replace(/Error\("/g, '').replace(/\("/g, '(').replace(/"\)/g, ')').replace(/\(/g, ', ').replace(/\)/g, '')
: stringify(data)}`;
// We need some sort of cut-off here since these can be very large and
// very nested, pick a number and trim the result display to it
return formatted.length <= 256
? formatted
: `${formatted.substring(0, 255)}…`;
}
function checkError (error?: JsonRpcResponseBaseError): void {
if (error) {
const { code, data, message } = error;
throw new RpcError(`${code}: ${message}${formatErrorData(data)}`, code, data);
}
}
/** @internal */
export class RpcCoder {
#id = 0;
public decodeResponse <T> (response?: JsonRpcResponse<T>): T {
if (!response || response.jsonrpc !== '2.0') {
throw new Error('Invalid jsonrpc field in decoded object');
}
const isSubscription = !isUndefined(response.params) && !isUndefined(response.method);
if (
!isNumber(response.id) &&
(
!isSubscription || (
!isNumber(response.params.subscription) &&
!isString(response.params.subscription)
)
)
) {
throw new Error('Invalid id field in decoded object');
}
checkError(response.error);
if (response.result === undefined && !isSubscription) {
throw new Error('No result found in jsonrpc response');
}
if (isSubscription) {
checkError(response.params.error);
return response.params.result;
}
return response.result;
}
public encodeJson (method: string, params: unknown[]): [number, string] {
const [id, data] = this.encodeObject(method, params);
return [id, stringify(data)];
}
public encodeObject (method: string, params: unknown[]): [number, JsonRpcRequest] {
const id = ++this.#id;
return [id, {
id,
jsonrpc: '2.0',
method,
params
}];
}
}