eth-json-rpc-middleware/dist/block-ref.js

Ethereum-related json-rpc-engine middleware.

"use strict";
var __importDefault = (this && this.__importDefault) || function (mod) {
    return (mod && mod.__esModule) ? mod : { "default": mod };
};
Object.defineProperty(exports, "__esModule", { value: true });
exports.createBlockRefMiddleware = void 0;
const json_rpc_engine_1 = require("json-rpc-engine");
const clone_1 = __importDefault(require("clone"));
const pify_1 = __importDefault(require("pify"));
const logging_utils_1 = require("./logging-utils");
const cache_1 = require("./utils/cache");
const log = logging_utils_1.createModuleLogger(logging_utils_1.projectLogger, 'block-ref');
function createBlockRefMiddleware({ provider, blockTracker, } = {}) {
    if (!provider) {
        throw Error('BlockRefMiddleware - mandatory "provider" option is missing.');
    }
    if (!blockTracker) {
        throw Error('BlockRefMiddleware - mandatory "blockTracker" option is missing.');
    }
    return json_rpc_engine_1.createAsyncMiddleware(async (req, res, next) => {
        var _a, _b;
        const blockRefIndex = cache_1.blockTagParamIndex(req);
        // skip if method does not include blockRef
        if (blockRefIndex === undefined) {
            return next();
        }
        const blockRef = (_b = (_a = req.params) === null || _a === void 0 ? void 0 : _a[blockRefIndex]) !== null && _b !== void 0 ? _b : 'latest';
        // skip if not "latest"
        if (blockRef !== 'latest') {
            log('blockRef is not "latest", carrying request forward');
            return next();
        }
        // lookup latest block
        const latestBlockNumber = await blockTracker.getLatestBlock();
        log(`blockRef is "latest", setting param ${blockRefIndex} to latest block ${latestBlockNumber}`);
        // create child request with specific block-ref
        const childRequest = clone_1.default(req);
        if (childRequest.params) {
            childRequest.params[blockRefIndex] = latestBlockNumber;
        }
        // perform child request
        log('Performing another request %o', childRequest);
        const childRes = await pify_1.default(provider.sendAsync).call(provider, childRequest);
        // copy child response onto original response
        res.result = childRes.result;
        res.error = childRes.error;
        return undefined;
    });
}
exports.createBlockRefMiddleware = createBlockRefMiddleware;
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