fix: skip injecting __vite__mapDeps when it's not used

[hi-ogawa]

Description

Following the suggestion #15732 (comment), I skipped injecting __vite__mapDeps when it's not used.

This will cover non browser cases where preload is not used at all (see insertPreload) since fileDeps will be empty in the end for those cases as well.

vite/packages/vite/src/node/plugins/importAnalysisBuild.ts

Line 161 in 716c766

const insertPreload = !(ssr || !!config.build.lib || isWorker)

Here is a change of playground/js-sourcemap/after-preload-dynamic-no-dep.js build output:

before

function __vite__mapDeps(indexes) {
  if (!__vite__mapDeps.viteFileDeps) {
    __vite__mapDeps.viteFileDeps = [];
  }
  return indexes.map((i) => __vite__mapDeps.viteFileDeps[i]);
}
import { _ as o } from "./after-preload-dynamic-BAkr0czH.js";
o(() => import("./dynamic-no-dep-BZ-YzFGU.js"), __vite__mapDeps([]));
console.log("after preload dynamic no dep");
//# sourceMappingURL=after-preload-dynamic-no-dep-Df4YzL2T.js.map

after

import{_ as o}from"./after-preload-dynamic-BAkr0czH.js";
o(()=>import("./dynamic-no-dep-BZ-YzFGU.js"),[]);
console.log("after preload dynamic no dep");
//# sourceMappingURL=after-preload-dynamic-no-dep-Df4YzL2T.js.map

What is the purpose of this pull request?

• Bug fix
• New Feature
• Documentation update
• Other

Before submitting the PR, please make sure you do the following

• Read the Contributing Guidelines, especially the Pull Request Guidelines.
• Check that there isn't already a PR that solves the problem the same way to avoid creating a duplicate.
• Provide a description in this PR that addresses what the PR is solving, or reference the issue that it solves (e.g. fixes #123).
• Update the corresponding documentation if needed.
• Ideally, include relevant tests that fail without this PR but pass with it.

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[patak-dev]

/ecosystem-ci run

[vite-ecosystem-ci]

📝 Ran ecosystem CI on 716c766: Open

✅ analogjs, astro, histoire, ladle, laravel, marko, nuxt, previewjs, quasar, qwik, rakkas, remix, sveltekit, unocss, vike, vite-plugin-pwa, vite-plugin-react, vite-plugin-react-pages, vite-plugin-react-swc, vite-plugin-svelte, vite-plugin-vue, vite-setup-catalogue, vitepress, vitest

[patak-dev]

Nice! I think this looks good to be merged in a patch to me.

[sapphi-red]

Thanks!