@nomiclabs/buidler/src/builtin-tasks/console.ts

import debug from "debug";
import fsExtra from "fs-extra";
import * as path from "path";
import * as semver from "semver";

import { task } from "../internal/core/config/config-env";
import { runScriptWithBuidler } from "../internal/util/scripts-runner";

import { TASK_CONSOLE } from "./task-names";

export default function () {
  const log = debug("buidler:core:tasks:console");

  task(TASK_CONSOLE, "Opens a buidler console")
    .addFlag("noCompile", "Don't compile before running this task")
    .setAction(
      async (
        { noCompile }: { noCompile: boolean },
        { config, run, buidlerArguments }
      ) => {
        if (!noCompile) {
          await run("compile");
        }

        await fsExtra.ensureDir(config.paths.cache);
        const historyFile = path.join(
          config.paths.cache,
          "console-history.txt"
        );

        const nodeArgs = [];
        if (semver.gte(process.version, "10.0.0")) {
          nodeArgs.push("--experimental-repl-await");
        }

        log(
          `Creating a Node REPL subprocess with Buidler's register so we can set some Node's flags`
        );

        // Running the script "" is like running `node`, so this starts the repl
        await runScriptWithBuidler(buidlerArguments, "", [], nodeArgs, {
          NODE_REPL_HISTORY: historyFile,
        });
      }
    );
}