fix(extract/transpile): retains svelte(5+) dependencies used exclusively outside <script> sections (#1046)

## Description

- retains svelte dependencies used exclusively outside <script> sections

## Motivation and Context

addresses #1045 


## How Has This Been Tested?

- [x] green ci

## Types of changes

- [x] Bug fix (non-breaking change which fixes an issue)
- [ ] Documentation only change
- [ ] Refactor (non-breaking change which fixes an issue without
changing functionality)
- [ ] New feature (non-breaking change which adds functionality)
- [ ] Breaking change (fix or feature that would cause existing
functionality to change)

## Checklist

- [x] 📖

  - My change doesn't require a documentation update, or ...
  - it _does_ and I have updated it

- [x] ⚖️
- The contribution will be subject to [The MIT
license](https://github.com/sverweij/dependency-cruiser/blob/main/LICENSE),
and I'm OK with that.
  - The contribution is my own original work.
- I am ok with the stuff in
[**CONTRIBUTING.md**](https://github.com/sverweij/dependency-cruiser/blob/main/.github/CONTRIBUTING.md).

Author: sverweij

src/extract/transpile/svelte-wrap.mjs

@@ -1,3 +1,4 @@
+/* eslint-disable no-inline-comments */
 import preProcess from "./svelte-preprocess.mjs";
 import tryImport from "#utl/try-import.mjs";
 import meta from "#meta.cjs";
@@ -6,14 +7,19 @@ const { compile, VERSION } = await tryImport(
   "svelte/compiler",
   meta.supportedTranspilers.svelte,
 );
+/* c8 ignore next */
+const MAJOR_VERSION = VERSION ? Number(VERSION.split(".")[0]) : 0;
 
 function getTranspiler(pTranspilerWrapper) {
   return (pSource, _pFileName, pTranspilerOptions) => {
-    const lPreProcessedSource = preProcess(
-      pSource,
-      pTranspilerWrapper,
-      pTranspilerOptions,
-    );
+    // svelte 5 natively supports typescript directly, without
+    // the need for preprocessing.
+    const lPreProcessedSource =
+      // eslint-disable-next-line no-magic-numbers
+      MAJOR_VERSION < 5
+        ? /* c8 ignore next */
+          preProcess(pSource, pTranspilerWrapper, pTranspilerOptions)
+        : pSource;
     // in svelte 5 one must provide the second argument
     // lest it throws because it's accessing a property
     // in it. In svelte 4 (which also takes compiler

test/extract/transpile/__fixtures__/svelte.js

@@ -2,6 +2,7 @@ import "svelte/internal/disclose-version";
 import "svelte/internal/flags/legacy";
 import * as $ from "svelte/internal/client";
 import "./page.css";
+import Header from "./Header.svelte";
 
 var root = $.from_html(
   `<article><!> <section><h2>Pages in Storybook</h2> <img src="./my.png" alt="my alt"/></section></article>`,

test/extract/transpile/svelte-wrap.spec.mjs

@@ -11,11 +11,7 @@ describe("[I] svelte transpiler", () => {
     equal(wrap.isAvailable(), true);
   });
   [
-    [
-      "ts",
-      (pSource) =>
-        pSource.replace('import Header from "./Header.svelte";\n', ""),
-    ],
+    ["ts", (pSource) => pSource],
     ["js", (pSource) => pSource],
   ].forEach(([variant, transformExpected]) => {
     it(`'transpiles' svelte with "<script lang='${variant}'>"'`, async () => {