{"version":3,"file":"block-ref.mjs","sourceRoot":"","sources":["../src/block-ref.ts"],"names":[],"mappings":"AAIA,OAAO,EAAE,KAAK,EAAE,cAAc;AAE9B,OAAO,EAAE,aAAa,EAAE,kBAAkB,EAAE,4BAAwB;AAEpE,OAAO,EAAE,kBAAkB,EAAE,0BAAsB;AAOnD,MAAM,GAAG,GAAG,kBAAkB,CAAC,aAAa,EAAE,WAAW,CAAC,CAAC;AAE3D;;;;;;;;GAQG;AACH,MAAM,UAAU,wBAAwB,CAAC,EACvC,QAAQ,EACR,YAAY,MACiB,EAAE;IAC/B,IAAI,CAAC,QAAQ,EAAE,CAAC;QACd,MAAM,KAAK,CAAC,8DAA8D,CAAC,CAAC;IAC9E,CAAC;IAED,IAAI,CAAC,YAAY,EAAE,CAAC;QAClB,MAAM,KAAK,CACT,kEAAkE,CACnE,CAAC;IACJ,CAAC;IAED,OAAO,KAAK,EAAE,EAAE,OAAO,EAAE,IAAI,EAAE,EAAE,EAAE;QACjC,MAAM,aAAa,GAAG,kBAAkB,CAAC,OAAO,CAAC,MAAM,CAAC,CAAC;QAEzD,2CAA2C;QAC3C,IAAI,aAAa,KAAK,SAAS,EAAE,CAAC;YAChC,OAAO,IAAI,EAAE,CAAC;QAChB,CAAC;QAED,MAAM,QAAQ,GAAG,KAAK,CAAC,OAAO,CAAC,OAAO,CAAC,MAAM,CAAC;YAC5C,CAAC,CAAC,CAAC,OAAO,CAAC,MAAM,CAAC,aAAa,CAAC,IAAI,QAAQ,CAAC;YAC7C,CAAC,CAAC,QAAQ,CAAC;QAEb,uBAAuB;QACvB,IAAI,QAAQ,KAAK,QAAQ,EAAE,CAAC;YAC1B,GAAG,CAAC,oDAAoD,CAAC,CAAC;YAC1D,OAAO,IAAI,EAAE,CAAC;QAChB,CAAC;QAED,sBAAsB;QACtB,MAAM,iBAAiB,GAAG,MAAM,YAAY,CAAC,cAAc,EAAE,CAAC;QAC9D,GAAG,CACD,uCAAuC,aAAa,oBAAoB,iBAAiB,EAAE,CAC5F,CAAC;QAEF,+CAA+C;QAC/C,MAAM,YAAY,GAAG,KAAK,CAAC,OAAO,CAAC,CAAC;QAEpC,IAAI,KAAK,CAAC,OAAO,CAAC,YAAY,CAAC,MAAM,CAAC,EAAE,CAAC;YACvC,YAAY,CAAC,MAAM,CAAC,aAAa,CAAC,GAAG,iBAAiB,CAAC;QACzD,CAAC;QAED,wBAAwB;QACxB,GAAG,CAAC,+BAA+B,EAAE,YAAY,CAAC,CAAC;QACnD,2CAA2C;QAC3C,OAAO,MAAM,QAAQ,CAAC,OAAO,CAAuB,YAAY,CAAC,CAAC;IACpE,CAAC,CAAC;AACJ,CAAC","sourcesContent":["import type { PollingBlockTracker } from '@metamask/eth-block-tracker';\nimport type { InternalProvider } from '@metamask/eth-json-rpc-provider';\nimport type { JsonRpcMiddleware } from '@metamask/json-rpc-engine/v2';\nimport type { Json, JsonRpcParams, JsonRpcRequest } from '@metamask/utils';\nimport { klona } from 'klona';\n\nimport { projectLogger, createModuleLogger } from './logging-utils';\nimport type { Block } from './types';\nimport { blockTagParamIndex } from './utils/cache';\n\ntype BlockRefMiddlewareOptions = {\n  blockTracker?: PollingBlockTracker;\n  provider?: InternalProvider;\n};\n\nconst log = createModuleLogger(projectLogger, 'block-ref');\n\n/**\n * Creates a middleware that rewrites \"latest\" block references to the known\n * latest block number from a block tracker.\n *\n * @param options - The options for the middleware.\n * @param options.provider - The provider to use.\n * @param options.blockTracker - The block tracker to use.\n * @returns The middleware.\n */\nexport function createBlockRefMiddleware({\n  provider,\n  blockTracker,\n}: BlockRefMiddlewareOptions = {}): JsonRpcMiddleware<JsonRpcRequest, Json> {\n  if (!provider) {\n    throw Error('BlockRefMiddleware - mandatory \"provider\" option is missing.');\n  }\n\n  if (!blockTracker) {\n    throw Error(\n      'BlockRefMiddleware - mandatory \"blockTracker\" option is missing.',\n    );\n  }\n\n  return async ({ request, next }) => {\n    const blockRefIndex = blockTagParamIndex(request.method);\n\n    // skip if method does not include blockRef\n    if (blockRefIndex === undefined) {\n      return next();\n    }\n\n    const blockRef = Array.isArray(request.params)\n      ? (request.params[blockRefIndex] ?? 'latest')\n      : 'latest';\n\n    // skip if not \"latest\"\n    if (blockRef !== 'latest') {\n      log('blockRef is not \"latest\", carrying request forward');\n      return next();\n    }\n\n    // lookup latest block\n    const latestBlockNumber = await blockTracker.getLatestBlock();\n    log(\n      `blockRef is \"latest\", setting param ${blockRefIndex} to latest block ${latestBlockNumber}`,\n    );\n\n    // create child request with specific block-ref\n    const childRequest = klona(request);\n\n    if (Array.isArray(childRequest.params)) {\n      childRequest.params[blockRefIndex] = latestBlockNumber;\n    }\n\n    // perform child request\n    log('Performing another request %o', childRequest);\n    // copy child result onto original response\n    return await provider.request<JsonRpcParams, Block>(childRequest);\n  };\n}\n"]}