rollup equivalent of "browserify -r" - browserify

Question

I need to force some modules into my bundle, as they are required dynamically through some code like below:
var moduleName = "someModule";
var myModule = require(moduleName);
I was using browserify to bundle this (through browserify -r or the API equivalent).
I am trying to switch to rollup and I don't figure out how to do this with rollup. Basically, I just want to force some modules into the bundle, and make them available globally through the require statement.

Answer 1

I think the key here is to use the new ES6 module syntax as described in the Rollup documentation. This will also give Rollup the possibility to apply features like chunking and tree-shaking.
Another important thing is to make it explicit what might get imported. By that I mean to use statements like 'import('./module1.js')' instead of 'import(some_variable)'. It is hard for Rollup to figure out all possible contents of the variable which gets used in the import. Therefore I would use explicit file names here but wrap everything in some kind of if/else condition.
Consider the following example:
File ./src/main.js:
let num = Math.random() * 10;
let condition = Math.round(num % 3);
let mod;
if (condition === 1) {
import('./module1.js').then((module)=> {
log(module);
});
} else if (condition === 2) {
import('./module2.js').then((module)=> {
log(module);
});
} else {
import('./module3.js').then((module)=> {
log(module);
});
}
function log(module) {
mod = module;
console.log(mod.test());
console.log('Done');
}
File ./src/module1.js:
function test() {
return 'This is 1!';
}
export { test };
The files module2.js and module3.js are the same like module1. The only difference is that they log 'This is 2!' and 'This is 3!'.
The Rollup config looks like this:
const production = !process.env.ROLLUP_WATCH;
export default {
inlineDynamicImports: true,
input: 'src/main.js',
output: {
dir: 'public/',
format: 'esm',
sourcemap: true
}
};
If you run 'rollup -c' then there will be one file './public/main.js'. This bundle will include all three modules. Usually Rollup would create main.js and three chunks. By using the setting 'inlineDynamicImports=true', Rollup puts everything in one file.
You can also change the format in the Rollup config to 'iife' (or amd, cjs, umd) if you want to.