Node.js: How to import test files in custom test runner - node.js

Question

I'm trying to create my own custom testing framework for learning purpose. Test files are written in following way
import { somemethod } from './some/module'
test(/I click on a button)/, () => {
browser.get("someSelector").should("have.text",somemethod());
});
I user require(file) to load test files. But it throw error SyntaxError: Unexpected token {
for import statement in test file. I'm using node js version 11.15.
If I switch to node v13.14 and define "type": "module" in my package.json then it doesn't let me use require(file) to load a test file or any module in my package.
How can I import tests files considering the user may be importing the modules using import or require?

Answer 1

This answer is very empirical...
Considering that it works using canonical commonjs approach you can try to debug it with newer version of NODE (currently I would use 14). For it, I would suggest you to use a node version manager like NVM so you can switch between node version easily and test that accordling seeing differences between various node installations.
Make a minimal project with npm init with a single dependency, save your index with the .mjs extension and try an import the above dependency. If you are be able to import that dependency with that minimal environment you can blame either your previous node or your configuration or both of them.
At the moment you should only create a small 2 files project to reproduce the problem. It seems your current node does not consider the "type": "module" configuration and runs everything in its classic way.
Regarding your comments....
As far as I know import can be used even in your code, not just at the beginning:
(async () => {
if (somethingIsTrue) {
// import module for side effects
await import('/modules/my-module.js');
}
})();
from https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Statements/import
Additionally you can try Webpack with a configuration like:
// webpack.config.js
const nodeExternals = require('webpack-node-externals');
module.exports = {
mode: 'production',
target: 'node',
externals: [nodeExternals()],
entry: {
'build/output': './src/index.js'
},
output: {
path: __dirname,
filename: '[name].bundle.js',
libraryTarget: 'commonjs2'
},
module: {
rules: [
{
test: /\.js$/,
use: {
loader: 'babel-loader',
options: {
presets: [
['env', {
'targets': {
'node': 'current'
}
}]
]
}
}
}]
}
};
With NodeExternals you don't put your node dependencies in the bundle but only your own code. You refer to node_modules for the rest. You might not want that.