Unknown reason why the import in the generated file does not have the .mjs suffix.

[DemoMacro]

The configuration is as follows.

import { defineBuildConfig } from "unbuild";

export default defineBuildConfig({
  declaration: true,
  entries: ["src/"],
});

Generate the wrong import in the file.

// dist/cli.mjs
import {} from "./example";

This should normally be the case.

// dist/cli.mjs
import {} from "./example.mjs";

I don't understand the reason for the problem, but when I use the function in this way it is normal.

// src/cli.ts
import * as exampleImport from "./example";

exampleImport.runCommand()

// dist/cli.mjs
import * as exampleImport from "./example.mjs";

exampleImport.runCommand()

[DemoMacro]

I think I found a magical reason for a line break due to too many imported functions, at which point the .mjs suffix would not be generated.

// This can cause problems.
import {
  exampleFunc1,
  exampleFunc2,
  exampleFunc3,
  exampleFunc4,
  exampleFunc5,
} from "./example";

// This, however, does not.
import { exampleFunc1, exampleFunc2, exampleFunc3 } from "./example.mjs";

[yzqdev]

The same issue, i use prettier to format the codes. Maybe I have to add a .prettierrc to avoid a line break.

[pi0]

Thanks for this issue. This is because mkdist (library unbuild uses for per-file transform) uses a simple regex to add the explicit extension (src) and it doesn't covers multiline. If your src uses .mjs, i strongly advice that you always add explicit extension in the source code imports too as this is a part of ESM syntax spec. For typescript is however not possible...

Upstream issue to fix: https://github.com/unjs/mkdist/issues/45

[pi0]

https://github.com/unjs/mkdist/pull/120 should cover most of cases. Please ping to reopen or make a new issue with reproduction if still in some cases this rewrite is not happening.