cli-testing-library/src/process-helpers.ts

Simple and complete CLI testing utilities that encourage good testing practices.

import treeKill from "tree-kill";
import { getConfig } from "./config";
import type { TestInstance } from "./types";

export const killProc = (instance: TestInstance, signal: string | undefined) =>
  new Promise<void>((resolve, reject) => {
    if (!instance.process.pid || (instance.process.pid && instance.hasExit())) {
      resolve();
      return;
    }

    treeKill(instance.process.pid, signal, async (err) => {
      try {
        if (err) {
          if (
            err.message.includes("The process") &&
            err.message.includes("not found.")
          ) {
            resolve();
            return;
          }
          if (
            err.message.includes("could not be terminated") &&
            err.message.includes("There is no running instance of the task.") &&
            instance.hasExit()
          ) {
            resolve();
            return;
          }
          const isOperationNotSupported = err.message.includes(
            "The operation attempted is not supported.",
          );
          const isAccessDenied = err.message.includes("Access is denied.");
          if (
            err.message.includes("could not be terminated") &&
            (isOperationNotSupported || isAccessDenied)
          ) {
            const sleep = (t: number) => new Promise((r) => setTimeout(r, t));
            await sleep(getConfig().errorDebounceTimeout);
            if (instance.hasExit()) {
              resolve();
              return;
            }
            console.warn("Ran into error while trying to kill process:");
            console.warn(err.toString());
            console.warn(`This is likely due to Window's permissions.
                Because this error is prevalent on CI Windows systems with the tree-kill package, we are attempting
                 an alternative kill method.`);
            console.warn();
            console.warn(
              "Be aware that this alternative kill method is not guaranteed to work with subprocesses, and they may not exit properly as a result.",
            );

            const didKill = instance.process.kill(signal as "SIGKILL");
            if (didKill) {
              resolve();
            } else {
              console.error(
                "Alternative kill method failed. Rejecting with original error.",
              );
              reject(err);
            }
            return;
          }
          reject(err);
        } else resolve();
      } catch (e: unknown) {
        reject(e);
      }
    });
  });