mjs and cjs extensions not detected by default #733
Description
Bug Description
depcheck does not seem to recognize JavaScript files using the file extensions .mjs and .cjs by default. These file extensions are used to allow writing JavaScript with ESModule syntax in CommonJS projects (.mjs) or JavaScript with CommonJS syntax in ESModule projects (.cjs). You can read more about this in the Node.js documentation, see ECMAScript modules.
I would expect depcheck to recognize files using .mjs and .cjs by default, rather then having to configure it along the lines of:
{
// Other configuration...
"parsers": {
"**/*.js": "es6",
"**/*.cjs": "es6",
"**/*.mjs": "es6"
}
}This problem was raised before in #615 and #669, but has not been addressed beyond recommendations to use the configuration.
Code snippets
See https://github.com/ericcornelissen/depcheck-bugs/tree/e29920d7d63b14b3825a9f83301a7726dd312dbc/mjs-and-cjs (the specific folder in the repository) for a minimum project reproducing the problem.
1. .mjs
Where the dependency is used:
// ./index.mjs
import test from 'ava';
test('my passing test', t => {
t.pass();
});Where the dependency is listed in package.json:
{
"name": "depcheck-with-mjs-and-cjs",
"version": "0.0.1",
"description": "Example of depcheck not detecting dependencies used in .mjs and .cjs files",
"private": true,
"main": "index.js",
"scripts": {
"test": "echo \"Error: no test specified\" && exit 1",
"vet": "depcheck"
},
"author": "Eric Cornelissen",
"license": "Unlicense",
"dependencies": {
"ava": "4.3.0", // <--- Here
"dotenv": "16.0.1"
},
"devDependencies": {
"depcheck": "1.4.3"
},
"engine": {
"node": "^14.18.0 || ^16.0.0 || ^18.0.0"
}
}1. .cjs
Where the dependency is used:
// ./index.cjs
require("dotenv").config();
console.log(`Hello ${process.env.name}!`);Where the dependency is listed in package.json:
{
"name": "depcheck-with-mjs-and-cjs",
"version": "0.0.1",
"description": "Example of depcheck not detecting dependencies used in .mjs and .cjs files",
"private": true,
"main": "index.js",
"scripts": {
"test": "echo \"Error: no test specified\" && exit 1",
"vet": "depcheck"
},
"author": "Eric Cornelissen",
"license": "Unlicense",
"dependencies": {
"ava": "4.3.0",
"dotenv": "16.0.1" // <--- Here
},
"devDependencies": {
"depcheck": "1.4.3"
},
"engine": {
"node": "^14.18.0 || ^16.0.0 || ^18.0.0"
}
}Versions
node -v: v14.17.6npm -v: 6.14.15depcheck --version: 1.4.3
Extra info
Output of depcheck --json
{
"dependencies": [
"ava",
"dotenv"
],
"devDependencies": [],
"missing": {},
"using": {
"depcheck": [
"/path/to/mjs-and-cjs/package.json"
]
},
"invalidFiles": {},
"invalidDirs": {}
}