Load a CJS module config inside another file - javascript

I'm trying to load a config inside a node module but I'm not sure which is a good practice to do it, I have this scenario:
A config my.config.js:
module.exports = {
content: [
'./src/**/*.{tsx,ts}',
],
}
Then I have a module cli.mjs is supposed to load it:
import arg from 'arg'
import { readFile } from 'fs/promises'
import path from 'path'
let configPath = './my.config.js'
const args = arg({
'--config': String,
'-c': '--config',
})
if (args['--config']) {
configPath = args['--config']
}
console.log(readFile(path.resolve(configPath), { encoding: 'utf8' }))
This will just return a simple string with my config inside, not a javascript object:
`
module.exports = {
content: [
'./src/**/*.{tsx,ts}',
],
}
`
How should I load my config in the right way?
I've saw basically everyone use configs like that in TypeScript or CJS projects, but it's hard to me see how and where they parse these configs, probably I'm missing some basic information about this?

Related

Cypress: import modules via alias

in my project i am using cypress with plain javascript. i am facing the challenge of importing the modules (page objects) via aliases instead of spaghetti code like ../../../../folder/page.js.
I don't use typescript or react.js and don't have a src folder/directory.
my tests run locally in the browser or via a docker image (pipeline).
I would like to transform from this:
import { LoginPage } from "../../pages/loginPage.js";
to something like this:
import { LoginPage } from "#Pages/loginPage.js";
but I always get an error:
Error: Webpack Compilation Error
./cypress/e2e/accountOverview/accountOverviewPageTest.spec.js
Module not found: Error: Can't resolve 'Pages/loginPage.js' in 'C:\Users\User\automated_frontend_tests\automated_frontend_tests\cypress\e2e\accountOverview'
resolve 'Pages/loginPage.js' in 'C:\Users\User\automated_frontend_tests\automated_frontend_tests\cypress\e2e\accountOverview'
Parsed request is a module
using description file: C:\Users\User\automated_frontend_tests\automated_frontend_tests\package.json (relative path: ./cypress/e2e/accountOverview)
Field 'browser' doesn't contain a valid alias configuration
Looked for and couldn't find the file at the following paths:
[C:\Users\User\automated_frontend_tests\automated_frontend_tests\cypress\e2e\accountOverview\node_modules]
[C:\Users\User\automated_frontend_tests\automated_frontend_tests\cypress\e2e\node_modules]
[C:\Users\User\automated_frontend_tests\automated_frontend_tests\cypress\node_modules]
[C:\Users\node_modules]
[C:\node_modules]
[C:\Users\User\automated_frontend_tests\automated_frontend_tests\node_modules\Pages\loginPage.js]
[C:\Users\User\automated_frontend_tests\node_modules\Pages\loginPage.js]
[C:\Users\User\node_modules\Pages\loginPage.js]
[C:\Users\User\automated_frontend_tests\automated_frontend_tests\node_modules\Pages\loginPage.js.js]
[C:\Users\User\automated_frontend_tests\node_modules\Pages\loginPage.js.js]
[C:\Users\User\node_modules\Pages\loginPage.js.js]
[C:\Users\User\automated_frontend_tests\automated_frontend_tests\node_modules\Pages\loginPage.js.json]
[C:\Users\User\automated_frontend_tests\node_modules\Pages\loginPage.js.json]
[C:\Users\User\node_modules\Pages\loginPage.js.json]
[C:\Users\User\automated_frontend_tests\automated_frontend_tests\node_modules\Pages\loginPage.js.jsx]
[C:\Users\User\automated_frontend_tests\node_modules\Pages\loginPage.js.jsx]
[C:\Users\User\node_modules\Pages\loginPage.js.jsx]
[C:\Users\User\automated_frontend_tests\automated_frontend_tests\node_modules\Pages\loginPage.js.mjs]
[C:\Users\User\automated_frontend_tests\node_modules\Pages\loginPage.js.mjs]
[C:\Users\User\node_modules\Pages\loginPage.js.mjs]
[C:\Users\User\automated_frontend_tests\automated_frontend_tests\node_modules\Pages\loginPage.js.coffee]
[C:\Users\User\automated_frontend_tests\node_modules\Pages\loginPage.js.coffee]
[C:\Users\User\node_modules\Pages\loginPage.js.coffee]
# ./cypress/e2e/accountOverview/accountOverviewPageTest.spec.js 5:17-46
I have tried several solutions, including:
//webpack.config.js
module.exports = {
resolve: {
alias: {
"#pages": path.resolve(__dirname, "cypress/pages/*"),
},
},
};
//testspec file
import { LoginPage } from "#pages/loginPage.js";
const loginPage = new LoginPage();
#Uzair Khan:
I tried your solution, but it still didn't work. The error message remains the same. It seems that the IDE does not search in the correct folder, but only in ...\node_modules\#page\loginPage.js which makes no sense.
If I enter const loginPage = new LoginPage(), the module LoginPage() cannot be found by the IDE either. Something is wrong with the solution. Do I still have to install any packages via NPM?
In your webpack.config.js file add resolve.alias which you want to make alias. It looks like something this below:
resolve: {
alias: {
'#page': path.resolve(__dirname, '{path you want to make alias}')
}
}
Since you are using cypress, you have to update the resolve path in cypress.config.js. Here is mine cypress.config.js
import { defineConfig } from 'cypress'
import webpack from '#cypress/webpack-preprocessor'
import preprocessor from '#badeball/cypress-cucumber-preprocessor'
import path from 'path'
export async function setupNodeEvents (on, config) {
// This is required for the preprocessor to be able to generate JSON reports after each run, and more,
await preprocessor.addCucumberPreprocessorPlugin(on, config)
on(
'file:preprocessor',
webpack({
webpackOptions: {
resolve: {
extensions: ['.ts', '.js', '.mjs'],
alias: {
'#page': path.resolve('cypress/support/pages/')
}
},
module: {
rules: [
{
test: /\.feature$/,
use: [
{
loader: '#badeball/cypress-cucumber-preprocessor/webpack',
options: config
}
]
}
]
}
}
})
)
// Make sure to return the config object as it might have been modified by the plugin.
return config
}
And import in other file via that alias you set in cypress.config.js. Here is mine for example:
import page from '#page/visit.js'
const visit = new page()
When('I visit duckduckgo.com', () => {
visit.page()
})
I think both answers are nearly there, this is what I have for src files:
const webpack = require('#cypress/webpack-preprocessor')
...
module.exports = defineConfig({
...
e2e: {
setupNodeEvents(on, config) {
...
// #src alias
const options = {
webpackOptions: {
resolve: {
alias: {
'#src': path.resolve(__dirname, './src')
},
},
},
watchOptions: {},
}
on('file:preprocessor', webpack(options))
...
path.resolve() resolves a relative path into an absolute one, so you need to start the 2nd param with ./ or ../.
Also, don't use wildcard * in the path, you just need a single folder that will be substituted for the alias in the import statement.
If in doubt, check the folder returned (in the terminal)
module.exports = defineConfig({
...
e2e: {
setupNodeEvents(on, config) {
const pagesFolder = path.resolve(__dirname, './cypress/pages')
console.log('pagesFolder', pagesFolder)

Problem with parsing javascript file marked as Shebang

I have a react app where I wanted to import a javascript file from a third-party library but file is mark with shebang #!/usr/bin/env node.
I found (e.g. here How to Configure Webpack with Shebang Loader to Ignore Hashbang Importing Cesium React Component into Typescript React Component) I can load file by overriding webpack configuration and adding a new loader shebang-loader (I also have tried shebang-loader2) but overriding webpack in react app is recommended only with #craco/craco so I added it to package.json and tried add loader to existing webpack-config.js.
I produced this lines of code. File craco.config.js:
const throwError = (message) =>
throwUnexpectedConfigError({
packageName: 'craco',
githubRepo: 'gsoft-inc/craco',
message,
githubIssueQuery: 'webpack',
});
module.exports = {
webpack: {
configure: (webpackConfig, {paths}) => {
const shebangLoader = { test: /node_modules\/npm-groovy-lint\/lib\/groovy-lint.js$/, loader: "shebang-loader" }
const {isAdded: shebangLoaderIsAdded1} = addAfterLoader(webpackConfig, loaderByName('url-loader'), shebangLoader);
if (!shebangLoaderIsAdded1) throwError('failed to add shebang-loader');
return webpackConfig;
},
},
};
It resolves problem with shebang and it ignores #!/usr/bin/env node but now I still get error
Module parse failed: Unexpected token (14:16)
File was processed with these loaders:
* ./node_modules/shebang2-loader/index.js
You may need an additional loader to handle the result of these loaders.
| const { getSourceLines, isErrorInLogLevelScope } = require("./utils");
| class NpmGroovyLint {
> "use strict";
| options = {}; // NpmGroovyLint options
| args = []; // Command line arguments
It looks like it does not recognise "use strict" line.
Can anyone put some suggestions what should be a problem ?
After few hours of investigation, I have finally come to a resolution. Firstly I have to say that there is no option to use NpmGroovyLint in react-like applications that run in browsers because after I resolved mentioned problem up here I figured that NpmGroovyLint uses node libraries as perf_hooks which are not available in a browser enviroment.
But I can post code that resolves the problem described in my question. It was needed to add a plugin to babel-loader named 'plugin-proposal-class-properties'. Here is my snipped of craco config. You can use it as a recipe occasionally.
const {addAfterLoader, getLoaders, loaderByName, removeLoaders, throwUnexpectedConfigError} = require('#craco/craco');
const throwError = (message) =>
throwUnexpectedConfigError({
packageName: 'craco',
githubRepo: 'gsoft-inc/craco',
message,
githubIssueQuery: 'webpack',
});
module.exports = {
webpack: {
configure: (webpackConfig, {paths}) => {
const {hasFoundAny, matches} = getLoaders(webpackConfig, loaderByName('babel-loader'));
if (!hasFoundAny) throwError('failed to find babel-loader');
const {hasRemovedAny, removedCount} = removeLoaders(webpackConfig, loaderByName('babel-loader'));
if (!hasRemovedAny) throwError('no babel-loader to remove');
if (removedCount !== 2) throwError('had expected to remove 2 babel loader instances');
//add plugin proposal class properties to existing babel loader
const propClassOptions = {...matches[1].loader.options, ...{plugins: ["#babel/plugin-proposal-class-properties"]}};
const propClassLoader = {...matches[1].loader, ...{options: propClassOptions}};
const babelLoaderWithPropClassPlugin = {...matches[1], ...{loader: propClassLoader}};
const shebangLoader = {
test: /node_modules\/npm-groovy-lint\/lib\/groovy-lint.js$/,
use: [{loader: 'shebang2-loader'}, {...{loader: require.resolve('babel-loader')}, ...{options: propClassOptions}}]
}
const {isAdded: babelLoaderWithPropClassIsAdded} = addAfterLoader(webpackConfig, loaderByName('url-loader'), matches[0].loader);
if (!babelLoaderWithPropClassIsAdded) throwError('failed to add ts-loader');
const {isAdded: babelLoaderIsAdded} = addAfterLoader(webpackConfig, loaderByName('babel-loader'), babelLoaderWithPropClassPlugin.loader);
if (!babelLoaderIsAdded) throwError('failed to add back babel-loader for non-application JS');
const {isAdded: shebangLoaderIsAdded1} = addAfterLoader(webpackConfig, loaderByName('url-loader'), shebangLoader);
if (!shebangLoaderIsAdded1) throwError('failed to add shebang-loader');
return webpackConfig;
},
},
};

Importing custom CommonJS module fails

I created a CommonJS module in project A in the following way:
const { WebElement } = require('selenium-webdriver');
const { By } = require('selenium-webdriver');
class VlElement extends WebElement {
constructor(driver, selector) {
...
}
async getClassList() {
...
}
}
module.exports = VlElement;
In project B I use the following code:
const VlElement = require('projectA');
class VlButton extends VlElement {
constructor(driver, selector) {
super(driver, selector);
}
...
}
module.exports = VlButton;
When running the code, VLElemlent cannot be found.
It is in my package.json and I can see VLElement under projectB > node_modules > projectA.
What am I doing wrong with my exports?
Thanks in advance.
Regards
Make sure you have a projectB/mode_modules/package.json with a main which points to the file that defines/exports VlElement, like this:
"main": "path/to/file/with/VlElement.js",
When you call require('projectA'); this has to be resolved to a file inside projectA so that it can be evaluated to (and return) the exports from that file. The main entry in the package.json allows this (but defaults to index.js, so if you are using that you don't need package.json, probably, but you should have it anyway).
You can have multiple files with various exports, but remember require('projectA'); can still only return one thing, so the way to do that is usually to have an index.js which looks something like:
module.exports = {
'something': require('./something.js'),
'otherthing': require('./otherthing.js'),
'etc': require('./etc.js'),
};

How to access DOM from webpack loader

I'm writing a webpack loader for a specific file extension, and I would like to append a custom import to the DOM
module.exports = function(source) {
...
document.appendChild(myImport)
return `export default 'hello'`;
}
but the DOM is not accessible
ReferenceError: document is not defined
Is there a way to access the DOM from my loader?
My webpack configuration is:
const path = require('path')
module.exports = {
...
module: {
rules: [{
test: /\.myextension$/,
use: {
loader: 'my-loader'
}
}]
}
};
No, the code from loader is going to be ran on a node.js env, which has no power over the dom (browser env). To be able to manipulate the dom, you would have to output a code though loader which would be inserted on that type of file and then when executed on the browser it would do the modifications.
Something like:
module.exports = function(source) {
return `export default function(){
document.appendChild(myImport)
}`;
}

Importing external .js file to nuxt.config.js

I want to import config.js which includes project's API keys. But It returns undefined.
//config.js
var config = {
fbAPI: "key"
}
-
//nuxt.config.js
const cfg = require('./config')
env: {
fbAPI: cfg.apiKey
}
Is this problem about run-time or am I missing something?
You missed modules.export at the end of config.js. The file should look following:
var config = {
fbAPI: "key"
}
module.exports = config;

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