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123456789101112131415161718192021222324252627282930313233343536373839404142434445464748495051525354555657585960616263646566676869707172737475767778798081828384858687888990919293949596979899100101102103104105106107108109110111112113114115116117118119120121122123124125126127128129130131132133134135136137138139140141142143144145146147148149150151152153154155156157158159160161162163164165166167168169170171172173174175176177178179180181182183184185186187188189190191192193194195196197198199200201202203204205206207208209210211212213214215216217218219220221222223224225226227228229230import { JsonRpcRequest, JsonRpcResponse, JsonRpcBatchResponse, JsonRpcSuccess, JsonRpcFailure, JsonRpcParams, JsonRpcMethod, JsonRpcId, JsonValue,} from "./jsonRpc2Types.ts";
type Resource = string | URL | Request;type Options = RequestInit & { isNotification?: boolean; id?: JsonRpcId; handleUnsuccessfulResponse?: (res: Response) => unknown;};type Batch = | [string, JsonRpcParams?][] | Record<string, [string, JsonRpcParams?]>;
class BadServerDataError extends Error { name: string; code: number; constructor(message: string, errorCode: number) { super(message); this.name = "BadServerDataError"; this.code = errorCode; }}
function send( resource: Resource, fetchInit: RequestInit, handleUnsuccessfulResponse?: (res: Response) => unknown) { return fetch(resource, fetchInit) .then((res: Response) => { if (res.ok) { // check if rpc was a notification return res.text().then(text => (text ? JSON.parse(text) : undefined)); } else if (handleUnsuccessfulResponse) { return handleUnsuccessfulResponse(res); } else { throw Error(`${res.statusText}: ${res.status}`); } }) .catch(err => Promise.reject( new BadServerDataError("Error in fetch API: " + err.message, -32001) ) );}
function createRpcRequestObj( methodName: string, params?: JsonRpcParams, id?: JsonRpcId): JsonRpcRequest { const rpcRequestObj: JsonRpcRequest = { jsonrpc: "2.0", method: methodName, }; if (params) rpcRequestObj.params = params; if (id !== undefined) rpcRequestObj.id = id; return rpcRequestObj;}
function createRpcBatchObj(batchObj: Batch, isNotification = false) { return Array.isArray(batchObj) ? batchObj.map(el => createRpcRequestObj( el[0], el[1], isNotification ? undefined : generateID() ) ) : Object.entries(batchObj).map(([key, value]) => createRpcRequestObj(value[0], value[1], key) );}
function generateID(size = 7): string { const chars = "0123456789ABCDEFGHIJKLMNOPQRSTUVWXTZabcdefghiklmnopqrstuvwxyz"; for (var str = "", i = 0; i < size; i += 1) str += chars[Math.floor(Math.random() * chars.length)]; return str;}
function createRemote(resource: Resource, options: Options = {}) { const handler = { get(client: Client, name: JsonRpcMethod) { if ((client as any)[name] !== undefined) { return client[name as keyof Client]; } else { return (...args: JsonRpcParams[]) => client.makeRpcCall( JSON.stringify( createRpcRequestObj( name, args, options.isNotification ? undefined : options.id || generateID() ) ) ); } }, }; const client = new Client( resource, options, options.handleUnsuccessfulResponse ); return new Proxy(client, handler);}
class Client { private url: Resource; private fetchInit: RequestInit; private isNotification = false; private handleUnsuccessfulResponse?: (res: Response) => unknown; [key: string]: any; // necessary for es6 proxy constructor( url: Resource, options: Options = {}, handleUnsuccessfulResponse?: (res: Response) => unknown ) { this.url = url; this.isNotification = options.isNotification || false; this.handleUnsuccessfulResponse = handleUnsuccessfulResponse; this.fetchInit = { ...options, method: "POST", headers: { ...options.headers, "Content-Type": "application/json" }, }; }
async makeRpcCall( stringifiedRpcRequestObj: string, shouldReturnBatchResultsAsArray = true ): Promise<JsonValue | undefined> { const rpcResponseObjOrBatchOrUndefined = (await send( this.url, { ...this.fetchInit, body: stringifiedRpcRequestObj, }, this.handleUnsuccessfulResponse )) as JsonRpcResponse | JsonRpcBatchResponse | undefined; return rpcResponseObjOrBatchOrUndefined === undefined ? undefined : this.handleResponseData( rpcResponseObjOrBatchOrUndefined, shouldReturnBatchResultsAsArray ); }
batch(batchObj: Batch) { return this.makeRpcCall( JSON.stringify(createRpcBatchObj(batchObj, this.isNotification)), Array.isArray(batchObj) ); }
// public for tests handleResponseData( rpcResponseObjOrBatch: JsonRpcResponse | JsonRpcBatchResponse, shouldReturnBatchResultsAsArray = true ) { if (Array.isArray(rpcResponseObjOrBatch)) { return shouldReturnBatchResultsAsArray ? this.returnBatchAsArray(rpcResponseObjOrBatch) : this.returnBatchAsObject(rpcResponseObjOrBatch); } else { return this.checkRpcResult(rpcResponseObjOrBatch); } }
private returnBatchAsArray(rpcResponseBatch: JsonRpcBatchResponse) { return rpcResponseBatch.reduce<JsonValue[]>((acc, rpcResponseObj) => { acc.push(this.checkRpcResult(rpcResponseObj)); return acc; }, []); }
private returnBatchAsObject(rpcResponseBatch: JsonRpcBatchResponse) { return rpcResponseBatch.reduce<Record<string, JsonValue>>( (acc, rpcResponseObj) => { if (rpcResponseObj.id !== null) { acc[rpcResponseObj.id] = this.checkRpcResult(rpcResponseObj); return acc; } else { // id might be null if (Array.isArray(acc.null)) acc["null"].push(this.checkRpcResult(rpcResponseObj)); else acc["null"] = [this.checkRpcResult(rpcResponseObj)]; return acc; } }, {} ); } private checkRpcResult(data: JsonRpcSuccess | JsonRpcFailure) { if (typeof data !== "object" || data === null) { throw new BadServerDataError("The sent back data is no object.", -32002); } else if ("result" in data && "id" in data) { return data.result as JsonValue; } else if (data.error) { const error = new BadServerDataError(data.error.message, data.error.code); // if error stack from server side has been transmitted, then use the server data if (data.error.data) Object.assign(error, data.error.data); throw error; } else throw new BadServerDataError( "Received data is no RPC response object.", -32002 ); }}
export { createRemote, send, createRpcRequestObj, createRpcBatchObj, Client, BadServerDataError,};