hardhat-tracer/src/extend/hre.ts

Hardhat Tracer plugin

import createDebug from "debug";
import { extendEnvironment } from "hardhat/config";
import "hardhat/types/config";
import { HardhatRuntimeEnvironment } from "hardhat/types/runtime";

import { Decoder } from "../decoder";
import { TraceRecorder } from "../trace-recorder";
import { TracerEnv } from "../types";
import {
  applyStateOverrides,
  getHardhatBaseProvider,
  getVMFromBaseProvider,
} from "../utils";
import { Switch } from "../switch";
const debug = createDebug("hardhat-tracer:extend:hre");

declare module "hardhat/types/runtime" {
  interface HardhatRuntimeEnvironment {
    tracer: TracerEnv;
  }
}

extendEnvironment((hre) => {
  debug("extending environment...");
  // copy reference of config.tracer to tracer
  // TODO take this properly, env can contain things that config does not need to.
  hre.tracer = hre.config.tracer;
  hre.tracer.decoder = new Decoder(
    hre.artifacts,
    hre.tracer._internal.cache,
    hre.tracer.use4bytesDirectory
  );

  // @ts-ignore
  global.tracerEnv = hre.tracer;
  // @ts-ignore
  global.hreArtifacts = hre.artifacts;

  debug("getting hardhat base provider");
  getHardhatBaseProvider(hre)
    .then((provider) => {
      hre.tracer.switch = new Switch(provider);
      debug("tracer.switch created");
    })
    .then(() => {
      addRecorder(hre)
        .then(() => {
          debug("trace recorder added");
        })
        .catch(console.error);
    });

  debug("environment extended!");
});

export async function addRecorder(hre: HardhatRuntimeEnvironment) {
  // wait for VM to be initialized
  try {
    const vm = await getVMFromBaseProvider(hre.tracer.switch!.edrProvider);

    if (!hre.tracer.recorder) {
      hre.tracer.recorder = new TraceRecorder(vm, hre.tracer);
    } else {
      hre.tracer.recorder.vm = vm;
    }

    if (hre.tracer.stateOverrides) {
      try {
        await applyStateOverrides(hre.tracer.stateOverrides, vm, hre.artifacts);
      } catch {}
    }
  } catch (e) {
    debug(
      "Could not get VM, hardhat tracer is disabled. Error: " +
        (e as any).message
    );
    // if for some reason we can't get the vm, disable hardhat-tracer
    hre.tracer.enabled = false;
  }
}