Files
Donny/강동윤andGitHub 3a5b73d2d6 perf(turbopack): Remove ImportBinding fragments (#78470)
### What?

Make the `ImportBinding` node a phantom node.

### Why?

Because they are not used. We have to import directly from the original
module because of the static analysis like `next/dynamic`. So I modified
the tree shaking to import directly with
https://github.com/vercel/next.js/pull/71704. But #71704 didn't remove
the concept of `ImportBinding`. This PR finishes the work of using
direct imports.

Additionally, this PR introduces `ReexportBinding` fragments because
these are not phantom nodes. I'll check if it would be possible to
remove `ReexportBinding` fragments with follow-up PRs.

### How?

 - Closes PACK-4366
2025-04-28 15:10:59 +00:00

1.6 KiB

Items

Count: 3

Item 1: Stmt 0, ImportOfModule

import { baz } from './module';

  • Hoisted
  • Side effects

Item 2: Stmt 0, ImportBinding(0)

import { baz } from './module';

  • Hoisted
  • Declares: baz

Item 3: Stmt 1, Normal

if (1 + 1 == 3) {
    baz();
}

  • Side effects
  • Reads: baz

Phase 1

graph TD
    Item1;
    Item2;
    Item3;

Phase 2

graph TD
    Item1;
    Item2;
    Item3;
    Item3 --> Item2;
    Item3 --> Item1;

Phase 3

graph TD
    Item1;
    Item2;
    Item3;
    Item3 --> Item2;
    Item3 --> Item1;

Phase 4

graph TD
    Item1;
    Item2;
    Item3;
    Item3 --> Item2;
    Item3 --> Item1;

Final

graph TD
    N0["Items: [ItemId(0, ImportOfModule), ItemId(1, Normal)]"];
    N1["Items: [ItemId(0, ImportBinding(0))]"];
    N0 --> N1;

Entrypoints

{
    ModuleEvaluation: 0,
    Exports: 1,
}

Modules (dev)

Part 0

import { baz } from './module';
import './module';
if (1 + 1 == 3) {
    baz();
}
export { };

Part 1


Merged (module eval)

import { baz } from './module';
import './module';
if (1 + 1 == 3) {
    baz();
}
export { };

Entrypoints

{
    ModuleEvaluation: 0,
    Exports: 1,
}

Modules (prod)

Part 0

import { baz } from './module';
import './module';
if (1 + 1 == 3) {
    baz();
}
export { };

Part 1


Merged (module eval)

import { baz } from './module';
import './module';
if (1 + 1 == 3) {
    baz();
}
export { };