Disabling file concatenation

[dmail]

Context

For some projects I would like to use rollup to benefit from tree-shaking and url hashing without generating chunks (disable concatenation of files). From my understanding preserveModules is the option to use for that situation. According to my tests preserveModules behaviour is not what I expected.

The following code illustrates what I have in mind.

import { rollup } from "rollup"
import { fileURLToPath } from "url"

const start = async () => {
  const projectDirectoryUrl = new URL("./", import.meta.url)

  const fileContents = {
    "./main.js": `import { value } from "./dep.js"
console.log(value)`,
    "./dep.js": `export const value = 42`,
  }

  const rollupBundle = await rollup({
    input: ["./main.js"],
    plugins: [
      {
        resolveId: (id) => {
          return id
        },
        load: (id) => {
          return fileContents[id]
        },
      },
    ],
  })

  await rollupBundle.write({
    dir: fileURLToPath(`${projectDirectoryUrl}dist`),
    preserveModules: true,
    chunkFileNames: `[name]-[hash].js`,
  })
}

start()

Expected Behavior / Situation

Rollup write files with hash in their names such as

dist/main-25e95a00.js
dist/dep-5dd85f23.js

Actual Behavior / Situation

Rollup write files without hash under _virtual directory.

dist/_virtual/main.js
dist/_virtual/dep.js

Modification Proposal

Allow to disable chunks using preserveModules options or something else and update import paths to get hash in urls.

[lukastaegert]

This has been discussed in the past in different contexts, see e.g. #3684. The way forward will be to fully respect the entryFileNames and chunkFileNames options when preserving modules. Unfortunately due to some choices in the current implementation, this will be a breaking change and is therefore marked for an upcoming 3.0 release. No due date for that, unfortunately.

[dmail]

Thank you for the feedback 👍. I have no special urgency around this need, it's more for experimentation.
I saw the issue about node_modules but could not follow what was the root issue in that thread, sorry if that's a duplicate.

[lukastaegert]

It is now kind of tracked here: https://github.com/rollup/rollup/projects/3

[dmail]

By the way I found a way to disable concatenation by accident.

In short, inside the "load" hook, I emit a chunk for every js file.

async load(id) {
  if (id.endsWith('.js')) {
    this.emit({type: "chunk", id })
  }
}

.

[tirrth]

@dmail Your fix doesn't seem to be working for me. Does anyone's got some sorta workaround for this?

[lukastaegert]

Resolved in #4565

[lukastaegert]

This issue has been resolved via #4565 as part of rollup@3.0.0-3. Note that this is a pre-release, so to test it, you need to install Rollup via npm install rollup@3.0.0-3 or npm install rollup@beta. It will likely become part of a regular release later.

[lukastaegert]

This issue has been resolved via #4565 as part of rollup@3.0.0-4. Note that this is a pre-release, so to test it, you need to install Rollup via npm install rollup@3.0.0-4 or npm install rollup@beta. It will likely become part of a regular release later.

[rollup-bot]

This issue has been resolved via #4565 as part of rollup@3.0.0-5. Note that this is a pre-release, so to test it, you need to install Rollup via npm install rollup@3.0.0-5 or npm install rollup@beta. It will likely become part of a regular release later.

[rollup-bot]

This issue has been resolved via #4565 as part of rollup@3.0.0-6. Note that this is a pre-release, so to test it, you need to install Rollup via npm install rollup@3.0.0-6 or npm install rollup@beta. It will likely become part of a regular release later.

[rollup-bot]

This issue has been resolved via #4565 as part of rollup@3.0.0-7. Note that this is a pre-release, so to test it, you need to install Rollup via npm install rollup@3.0.0-7 or npm install rollup@beta. It will likely become part of a regular release later.

[rollup-bot]

This issue has been resolved via #4565 as part of rollup@3.0.0-8. Note that this is a pre-release, so to test it, you need to install Rollup via npm install rollup@3.0.0-8 or npm install rollup@beta. It will likely become part of a regular release later.

[rollup-bot]

This issue has been resolved via #4565 as part of rollup@3.0.0. You can test it via npm install rollup.