The Jest worker has run into 4 child process errors, surpassing the maximum retry threshold

I am a newcomer to Vue and Jest testing, and I keep encountering this error when running a specific test. While I understand that this is a common issue, I am struggling to pinpoint the exact cause of the problem.

Here is the error message:

 Test suite failed to run

    Jest worker encountered 4 child process exceptions, exceeding retry limit

      at ChildProcessWorker.initialize (node_modules/jest-worker/build/workers/ChildProcessWorker.js:185:21)

Below is the failing test snippet:

test("signupAsUser logs results if email is provided", async () => {
  const consoleSpy = jest.spyOn(console, "log");
  const email = ref("<a href="/cdn-cgi/l/email-protection" class="__cf_email__" data-cfemail="d3a7b6a0a7a6a0b6a193a0b0bca6a7b2a3befdb0bcbe">[email protected]</a>");
  const { signupAsUser } = useSignup(email);

  await signupAsUser();

  expect(consoleSpy).toHaveBeenCalledWith("USER:", mockSignup);
});

Additionally, here are the files being tested. The Vue file:

<!--
  View for user signup operations.
-->
<template lang="pug">
.Signup
    .Signup__focus
        .Signup__title Sign Up
            .Signup__form
                .Signup__field
                    va-input.Signup__emailInput(
                       type="email",
                      name="email",
                      placeholder="Email",
                      v-model="email",
                      @keyup.enter="signupAsUser()"
                    )
                        template(v-slot:prependInner="")
                            va-icon(name="email")
                    .Login__buttonRow
                        va-button.Login__submitButton(@click="signupAsUser") Sign Up
</template>

<script lang="ts">
import { ref, defineComponent } from "vue";
import useSignup from "@/views/Signup/useSignup";

/**
 * Assemble the Signup component
 *
 *  @returns Data for the component to use.
 * - email: of the user to sign up with
 * - signupAsUser: function to call to carry out the login operation.
 */
function setup() {
  const email = ref("");
  const { signupAsUser } = useSignup(email);

  return {
    email,
    signupAsUser,
  };
}

export default defineComponent({
  name: "Signup",
  setup,
});
</script>

<style lang="scss">
//basic scss style taken from Login.vue until button and verification code is added
.Signup {
  position: fixed;
  width: 100%;
  height: 100%;
  display: flex;
  align-items: center;
  justify-content: center;

  &__focus {
    width: 360px;
    max-width: 95vw;
  }

  &__field {
    padding-bottom: 0.5em;
  }

  &__title {
    font-size: 1.2em;
    padding-bottom: 0.5em;
    text-align: center;
  }
}
</style>

and the TypeScript file:

import { Ref } from "vue";
import { useApolloClient } from "@vue/apollo-composable";
import { ValidatedUser } from "@/models";
import { gql } from "graphql-tag";
import router from "@/router";

const query = gql`
  query Signup($input: Signup) {
    signup(input: $input) {
      __typename
      token
      user {
        emailAddress
        id
      }
    }
  }
`;

/**
 * Retrieve apollo client and provide useSignup
 * function to validate input and execute Signup process.
 *
 * @param emailAddress - reactively wrapped email address of the user signing up.
 * @returns useSignup composition functionality.
 */
export default function useSignup(emailAddress: Ref<string>): {
  signupAsUser: () => Promise<void>;
} {
  const { resolveClient } = useApolloClient();
  
  async function signupAsUser(): Promise<void> {
    console.log("emailAddress " + emailAddress.value);
    if (emailAddress.value.length < 5) {
      console.log("here");
      return;
    } else {
      const client = resolveClient();

      const variables = {
        input: { username: emailAddress.value },
      };
      
      console.log("here");
      console.log("emailAddress: ", variables);
    }
    router.push({ path: "/signup/verify" });
  }

  return { signupAsUser };
}

Any guidance on where the timeout issue might be originating from or how to troubleshoot would be greatly appreciated.

Answer №1

The issue at hand conceals the underlying problem within your test or code. To uncover the true error, consider executing the test in a serial manner using jest --runInBand

Answer №2

In my own experience, I encountered a similar issue, and I found guidance in this discussion thread. Here are two suggestions to consider:

  1. One potential solution is to include --maxWorkers 2 in your jest test command.

  2. This error appears to stem from various issues, including uncaught promise rejections. You may want to explore using waitFor to see if it helps resolve the problem.

    import { waitFor } from 'test/test-utils'
    
    test("signupAsUser logs results if email is provided", async() => {
      const consoleSpy = jest.spyOn(console, "log");
      const email = ref("<a href="/cdn-cgi/l/email-protection" class="__cf_email__" data-cfemail="1c68796f68696f796e5c6f7f7369687d6c71327f73757126">[email protected]</a>");
      const {
        signupAsUser
      } = useSignup(email);
    
      await waitFor(() => signupAsUser());
    
      expect(consoleSpy).toHaveBeenCalledWith("USER:", mockSignup);
    });
    
  3. Additionally, this explanation provides further insights.

    Further investigation revealed that findBy tests return a promise, requiring an await statement. More information can be found at https://testing-library.com/docs/guide-disappearance/#1-using-findby-queries. It would have been helpful if the library had presented a more descriptive error message.

Answer №3

When running the test suite, Jest worker ran into 4 child process exceptions which went over the retry limit

I encountered this same issue during my CI tests, impacting all of my test cases. This error message was masking the actual problem. By changing maxWorkers to 1 and running it on a single thread, I was able to uncover the root cause of the error, enabling me to resolve the issue successfully.

Answer №4

The reason I encountered this issue was due to the index file incorrectly importing the service from a different path. As a result, the error occurred when running the coverage collection.

Answer №5

If you encounter errors during testing, one approach is to place your test code within a try-catch block to identify the root cause of the issue. Once the error is identified, make necessary adjustments and rerun your tests. The try-catch block can then be removed once all tests pass successfully.

For instance, in a project using Typescript, consider the following example:

describe('my-test', () => {
  it('my test description', async () => {
    try {
      // --> insert your test code here <--
    } catch (error: any) {
      console.log('ERROR MESSAGE:', error.message);
    }
  });
});

If you want to view the complete error log, simply output error as shown below:

console.log('ERROR:', error);

Answer №6

Dealing with a similar problem, I found that my issue stemmed from passing an asynchronous callback to jest's act.

To resolve the problem, I made the callback function synchronous and switched from using act to waitFor.

Here is the updated code snippet:

 waitFor(() => {
     
    expect(result.current.tutorials[0].completed).toEqual(false);
           
    result.current.setTutorialCompleted(result.current.tutorials[0], true);
    expect(result.current.tutorials[0].completed).toEqual(true);
});

Answer №7

In my case, the problem arose from neglecting to include an await in the tested code.

// The error occurred after the test had completed
const data = getData()

// To resolve this issue, we need to wait for the promise to be fulfilled
const data = await getData()

I hope this explanation proves useful to others facing a similar question.

Answer №8

The reason behind my issue was due to a mistake in a few unit tests where I had overlooked including the "return" statement for the promise. When I finally added the return keyword, the actual error surfaced, revealing that it was unique to my code.

Similar questions

If you have not found the answer to your question or you are interested in this topic, then look at other similar questions below or use the search

Error encountered when parsing JSON data in Vue.js due to presence of invalid characters in the

I have been working on a web application that allows me to upload a JSON file, make changes to it, and then download it. However, the resulting JSON is not valid because certain characters seem to change during the process. Even when I simply upload and do ...

Difficulties encountered when trying to load liquid using Javascript

Having trouble loading the Shopify liquid object {{product.price | json}} into JS, as it's displaying NaN with the current code on the front end. Any suggestions on how to properly pass liquid into JS? I've tried two functions but neither seem t ...

Progress Bar Modules

I am currently working on creating a customizable animated progress bar that can be utilized as follows: <bar [type]="'health'" [percentage]="'80'"></bar> It is functional up to the point where I need to adjust different p ...

What is preventing me from merging these two arrays together?

Here is some code for a Vuex mutation: export const CREATE_PANORAMAS = (state, panoramas) => { console.log('building.panoramas:', state.building.panoramas) console.log('panoramas:', panoramas) state.building.panoramas.concat(p ...

What kind of function am I using and passing as props in React when working with TypeScript?

I recently developed a customized Checkbox component. The TypeScript setup in my project doesn't allow the use of any type, so I'm struggling to define the specific type for the handleCheckbox() function (found within the FilterBox component) th ...

Utilizing the Double Mapping Feature in React with Typescript

It seems I might be overlooking something, can someone guide me on how to properly double map in this scenario? I'm encountering an error on the second map: Property 'map' does not exist on type '{ departure: { code: string; name: strin ...

Vue.js is like the modern version of jquery-cron

Is there a similar tool to jquery-cron with an easy-to-use text/select interface that anyone knows of? I've come across vue-cron and point-vue-cron, but they seem too complicated for my needs. ...

Using TypeScript, the fetch function cannot be assigned

Why am I encountering this TS warning? Type 'unknown' is not assignable to type 'PokemonList'.ts(2322) This issue is on line: "return e" Here is the code snippet: export interface PokemonList { count: number; next: stri ...

Tips for passing props in Vue 3 and Vue Router 4 when utilizing router-view exclusively for a particular component

My routing and props are functioning properly, but I am facing an issue where the msg prop is being sent to every component loaded by the router. Is there a workaround for this situation? In App.vue, which serves as my base component, I have: <templat ...

Is there a more efficient approach to displaying a list of elements and sharing state in React with TypeScript?

Check out this code sample I'm attempting to display a list with multiple elements and incorporate a counter on the main element that updates every time one of the buttons is clicked. I'm uncertain if this approach is optimal, as I am transition ...

Exploring the capabilities of nested components within React applications

I am facing some challenges when it comes to testing events for nested components. The structure of my component tree is as follows: - ModalComponent (Stateful with value for Input and update handler) - - ModalType (stateless, passes value and update down ...

Accessing and manipulating a intricate JSON structure within an Ionic 3 framework to seamlessly connect it to the user

I'm currently developing an app using Ionic 3. Within my project, I have a JSON object structured like this: { "player": { "username": "thelegend", "platform": "xbox", "stats": { "normal": { "shots ...

Tips for managing open and closed components within a React accordion and ensuring only the clicked component is opened

Unique Accordion component: const CustomAccordion = (props: AccordionProps) => { const { label, levels, activeId, id } = props const [isExpand, setIsExpand] = useState(false) const onPress = useEvent(() => { setIsExpand( ...

Mismatched data types caused by immutability

I'm having trouble with my object that has a middleware property and the types aren't working as expected. The error message is stating that the two middlewares are incompatible because one of them is set to readonly. Does anyone know how I can r ...

Stop ngOnChanges from being triggered after dispatching event (Angular 2+)

In Angular 2+, a custom two-way binding technique can be achieved by utilizing @Input and @Output parameters. For instance, if there is a need for a child component to communicate with an external plugin, the following approach can be taken: export class ...

When in development mode, opt for the unminified version of the library in Web

My TypeScript project utilizes a forked version of the apexcharts npm package. When building the project with webpack in development mode, I want to use the unminified version of the apex charts library. However, for production, I prefer to stick with the ...

The Vue.js application which utilizes Vue I18n encountered the error message: "Unable to define i18n due to TypeError"

I am currently working on implementing internationalization in my Vue.js project using Vue I18n. Although I've been following the documentation found at , I encountered the following error message: [Vue warn]: Error in render: "TypeError: i18n is un ...

Discovering Route modifications with Nuxt and asyncData: a step-by-step guide

Hey everyone, I’m currently working on tracking route changes in my Nuxt.js app. Here is the middleware I have: export default function ({ route }) { return route; //but I'm not sure what to write here } index.vue File middleware: [route ...

The function mustAsync onSuccess is not present in this type (typescript)

I currently have 2 mutations that are functioning well. However, I encountered an issue when attempting to implement onSuccess and invalidateQueries. The error message displayed is as follows: Property 'mutateAsync' does not exist on type '{ ...

What is the procedure for invoking a function when the edit icon is clicked in an Angular application

My current Angular version: Angular CLI: 9.0.0-rc.7 I am currently using ag-grid in my project and I encountered an issue when trying to edit a record. I have a function assigned to the edit icon, but it is giving me an error. Error message: Uncaught Re ...