test(config): re-use Vitest resolve.alias utility

Author: metonym

tests-svelte5/vite.config.ts

@@ -1,55 +1,16 @@
-import fs from "node:fs";
-import path from "node:path";
-import { fileURLToPath } from "node:url";
 import { svelte } from "@sveltejs/vite-plugin-svelte";
 import { defineConfig } from "vitest/config";
-import pkg from "../package.json";
+import { generateAliasesFromExports, getDirname } from "../vite.config";
 
-const __dirname = path.dirname(fileURLToPath(import.meta.url));
-
-/**
- * Generates Vite aliases from package.json exports for component subpath imports.
- * Resolves imports like `carbon-components-svelte/Theme/Theme.svelte` to
- * `./src/Theme/Theme.svelte` since these subpaths aren't in package.json
- * exports and Vite needs runtime resolution (tsconfig only handles types).
- */
-function generateAliasesFromExports() {
-  const aliases: Record<string, string> = {};
-  const exports = pkg.exports;
-
-  const srcSvelteExport = exports["./src/*.svelte"];
-  if (!srcSvelteExport) return aliases;
-
-  const srcDir = path.resolve(__dirname, "../src");
-  if (!fs.existsSync(srcDir)) return aliases;
-
-  function scanDirectory(dir: string, basePath: string = "") {
-    const entries = fs.readdirSync(dir, { withFileTypes: true });
-
-    for (const entry of entries) {
-      const fullPath = path.join(dir, entry.name);
-      const relativePath = path.join(basePath, entry.name);
-
-      if (entry.isDirectory()) {
-        scanDirectory(fullPath, relativePath);
-      } else if (entry.isFile() && entry.name.endsWith(".svelte")) {
-        const importPath = relativePath;
-        const aliasKey = `${pkg.name}/${importPath}`;
-        aliases[aliasKey] = path.resolve(__dirname, "../src", importPath);
-      }
-    }
-  }
-
-  scanDirectory(srcDir);
-  return aliases;
-}
+const __dirname = getDirname(import.meta.url);
 
 export default defineConfig({
-  plugins: [svelte()],
   resolve: {
     conditions: ["browser"],
-    alias: generateAliasesFromExports(),
+    alias: generateAliasesFromExports(__dirname, "../src"),
   },
+  // @ts-expect-error
+  plugins: [svelte()],
   server: {
     fs: {
       allow: [".."],

vite.config.ts

@@ -7,20 +7,35 @@ import pkg from "./package.json";
 
 const __dirname = path.dirname(fileURLToPath(import.meta.url));
 
+/**
+ * Gets the directory name from import.meta.url (ESM equivalent of __dirname).
+ * @param url - The import.meta.url from the calling file
+ * @returns The directory path
+ */
+export function getDirname(url: string): string {
+  return path.dirname(fileURLToPath(url));
+}
+
 /**
  * Generates Vite aliases from package.json exports for component subpath imports.
  * Resolves imports like `carbon-components-svelte/Theme/Theme.svelte` to
  * `./src/Theme/Theme.svelte` since these subpaths aren't in package.json
  * exports and Vite needs runtime resolution (tsconfig only handles types).
+ *
+ * @param baseDir - Base directory for resolving src path (defaults to __dirname)
+ * @param srcRelativePath - Relative path to src directory from baseDir (defaults to "./src")
  */
-function generateAliasesFromExports() {
+export function generateAliasesFromExports(
+  baseDir: string = __dirname,
+  srcRelativePath: string = "./src",
+) {
   const aliases: Record<string, string> = {};
   const exports = pkg.exports;
 
   const srcSvelteExport = exports["./src/*.svelte"];
   if (!srcSvelteExport) return aliases;
 
-  const srcDir = path.resolve(__dirname, "./src");
+  const srcDir = path.resolve(baseDir, srcRelativePath);
   if (!fs.existsSync(srcDir)) return aliases;
 
   function scanDirectory(dir: string, basePath: string = "") {
@@ -35,7 +50,7 @@ function generateAliasesFromExports() {
       } else if (entry.isFile() && entry.name.endsWith(".svelte")) {
         const importPath = relativePath;
         const aliasKey = `${pkg.name}/${importPath}`;
-        aliases[aliasKey] = path.resolve(__dirname, "./src", importPath);
+        aliases[aliasKey] = path.resolve(baseDir, srcRelativePath, importPath);
       }
     }
   }