How to use timerGame method in Jest

You can use a regexp with toMatch

like :

expect(str).toMatch(/(abc|cde)/i)

Here are the steps I took to run Jest with a test using ESM. The source files under test were also written using ESM.

1. Set my node version to 14.16.0

2. Install Jest:

   npm i jest -D
   

3. Add "type": "module" to package.json

4. Update test script in package.json:

   "scripts": {
     "test": "node --experimental-vm-modules ./node_modules/.bin/jest"
   }
   

5. Create a jest.config.js file with the following content:

   export default { transform: {} }
   

6. Have at least one test that could be found using the default testMatch (mine was inside __tests__ dir)

7. Run tests:

   npm test
   

There is a more complete example in the magic-comments-loader repository on GitHub.

From the documentation you need to add modulePathIgnorePatterns which is an array of string values which will be matched against

modulePathIgnorePatterns [array<string>] #

(default: []) An array of regexp pattern strings that are matched against all module paths before those paths are to be considered 'visible' to the module loader. If a given module's path matches any of the patterns, it will not be require()-able in the test environment. These pattern strings match against the full path. Use the <rootDir> string token to include the path to your project's root directory to prevent it from accidentally ignoring all of your files in different environments that may have different root directories. Example: ['<rootDir>/build/'].

https://facebook.github.io/jest/docs/configuration.html#modulepathignorepatterns-array-string

Add this to your configuration...

modulePathIgnorePatterns: ["directoryNameToIgnore"]

or:

modulePathIgnorePatterns: ["<rootDir>/dist/"]

You can set console.log to by a spy like this:

global.console = {
  warn: jest.fn(),
  log: jest.fn()
}

// run your code

expect(global.console.log).toHaveBeenCalledWith('test')

As your test file runs in a separate thread you don't need to reset console to the original methods

You try this lib that extends jest: https://github.com/mattphillips/jest-expect-message

test('returns 2 when adding 1 and 1', () => {
  expect(1 + 1, 'Woah this should be 2!').toBe(3);
});

you can update the snapshots in two ways:

1. run npm test and then in the interactive shell press u

2. run npm test -u, the -u flag tells jest to update snapshots.

You could change npm by yarn if you are using yarn

Looking at the webpack config, I could see that, UI kit is getting bundled with react included which might be causing the issue.

To avoid this you could use webpack externals.

https://webpack.js.org/configuration/externals/

The externals configuration option provides a way of excluding dependencies from the output bundles. Instead, the created bundle relies on that dependency to be present in the consumer's environment. This feature is typically most useful to library developers, however there are a variety of applications for it.

So you could update UI Kit webpack config to not include react and the peerDependencies should take care of the dependency handling for any consumers of the library.

Updated webpack.config

const path = require("path");
module.exports = {
  mode: "production",
  entry: "./src/index.js",
  output: {
    path: path.resolve("dist"),
    filename: "index.js",
    libraryTarget: "commonjs2"
  },
  module: {
    rules: [
      {
        test: /\.jsx?$/,
        exclude: /(node_modules)/,
        use: "babel-loader"
      },
      {
        test: /\.(eot|svg|ttf|woff|woff2|otf)$/,
        use: [
          {
            loader: "file-loader",
            options: {
              name: "[name].[ext]",
              limit: 10000,
              mimetype: "application/font-woff"
            }
          }
        ]
      }
    ]
  },
  resolve: {
    alias: {
      components: path.resolve(__dirname, "src/components/"),
      utils: path.resolve(__dirname, "src/utils/"),
      themes: path.resolve(__dirname, "src/themes/")
    },
    extensions: [".js", ".jsx"]
  },
  externals: {
        // Use external version of React
        react: "react"
 },
  devtool: false
};

I have published a test package to confirm this (react-ui-kit-dontuse).

Demo links

v0.0.21(Without webpack externals) 

https://stackblitz.com/edit/react-xyjgep

v0.0.23(With webpack externals) 

https://stackblitz.com/edit/react-ihnmrl

Source code of test package: https://github.com/nithinthampi/react-ui-lib-test

Hope this helps!

Actually, you don't need to use Sinon to test debounces. Jest can mock all timers in JavaScript code.

Check out following code (it's TypeScript, but you can easily translate it to JavaScript):

import * as _ from 'lodash';

// Tell Jest to mock all timeout functions
jest.useFakeTimers();

describe('debounce', () => {

    let func: jest.Mock;
    let debouncedFunc: Function;

    beforeEach(() => {
        func = jest.fn();
        debouncedFunc = _.debounce(func, 1000);
    });

    test('execute just once', () => {
        for (let i = 0; i < 100; i++) {
            debouncedFunc();
        }

        // Fast-forward time
        jest.runAllTimers();

        expect(func).toBeCalledTimes(1);
    });
});

More information: Timer Mocks

As with any other database, the connection should be closed in afterAll.

As the reference states, it's either pgp.end() or db.$pool.end():

afterAll(db.$pool.end);

UPDATE

From pg-promise v10.11.0, you no longer need to shut down the pool explicitely. Instead, you can just set connection option allowExitOnIdle: true, to let process exit when pool is idle.