Docker-compose exits due to invalid plugin in cypress docker-image

[filipe-costa]

I have the following docker file to which I am extending the current cypress image to be able to install a plugin:

FROM cypress/included:9.4.1
COPY cypress.json .
COPY cypress ./cypress
RUN npm install -g cypress-image-snapshot

and the following docker-compose:

version: '3.2'

services:
 ...other services...
 
  service-e2e:
    image: service-e2e
    container_name: service-e2e
    command:
      - npx cypress run --headless
    depends_on:
      - service_client

I have installed the plugin globally:

/usr/local/lib
+-- cypress-image-snapshot@4.0.1
+-- cypress@4.12.1
+-- npm@7.19.1
`-- yarn@1.22.17

and the plugin file:

/// <reference types="cypress" />
// ***********************************************************
// This example plugins/index.js can be used to load plugins
//
// You can change the location of this file or turn off loading
// the plugins file with the 'pluginsFile' configuration option.
//
// You can read more here:
// https://on.cypress.io/plugins-guide
// ***********************************************************

// This function is called when a project is opened or re-opened (e.g. due to
// the project's config changing)
const { addMatchImageSnapshotPlugin } = require('cypress-image-snapshot/plugin');

/**
 * @type {Cypress.PluginConfig}
 */
// eslint-disable-next-line no-unused-vars
module.exports = (on, config) => {
  // `on` is used to hook into various events Cypress emits
  // `config` is the resolved Cypress config
  addMatchImageSnapshotPlugin(on, config);
}

Which ends up throwing the following error:

The plugins file is missing or invalid.

Your `pluginsFile` is set to `/cypress/plugins/index.js`, but either the file is missing, it contains a syntax error, or threw an error when required. The `pluginsFile` must be a `.js`, `.ts`, or `.coffee` file.

Or you might have renamed the extension of your `pluginsFile`. If that's the case, restart the test runner.

Please fix this, or set `pluginsFile` to `false` if a plugins file is not necessary for your project.

Error: Cannot find module 'cypress-image-snapshot/plugin'

Is there anything else besides cypress and the plugin I need to have to successfully execute this within docker/docker-compose?

[filipe-costa]

It works using the following:

FROM cypress/included:9.4.1
WORKDIR /e2e
COPY cypress.json .
COPY cypress ./cypress
RUN npm install cypress-image-snapshot