feat: resolve svelte in exports. prefer exports to svelte field

.changeset/fair-beds-fail.md

@@ -0,0 +1,5 @@
+---
+'@sveltejs/vite-plugin-svelte': minor
+---
+
+feat: resolve `svelte` in `exports`. prefer `exports` to `svelte` field

packages/e2e-tests/_test_dependencies/svelte-nested/package.json

@@ -9,7 +9,10 @@
     "package.json"
   ],
   "exports": {
-    "./package.json": "./package.json"
+    "./package.json": "./package.json",
+    ".": {
+      "svelte": "./src/index.js"
+    }
   },
   "dependencies": {
     "e2e-test-dep-svelte-simple": "workspace:*",

packages/vite-plugin-svelte/src/index.ts

@@ -16,7 +16,6 @@ import {
 import { VitePluginSvelteCache } from './utils/vite-plugin-svelte-cache';
 
 import { ensureWatchedFile, setupWatchers } from './utils/watch';
-import { resolveViaPackageJsonSvelte } from './utils/resolve';
 import { PartialResolvedId } from 'rollup';
 import { toRollupError } from './utils/error';
 import { saveSvelteMetadata } from './utils/optimizer';
@@ -67,6 +66,7 @@ export function svelte(inlineOptions?: Partial<Options>): Plugin[] {
 				}
 				// @ts-expect-error temporarily lend the options variable until fixed in configResolved
 				options = await preResolveOptions(inlineOptions, config, configEnv);
+
 				// extra vite config
 				const extraViteConfig = buildExtraViteConfig(options, config);
 				log.debug('additional vite config', extraViteConfig);
@@ -154,22 +154,6 @@ export function svelte(inlineOptions?: Partial<Options>): Plugin[] {
 					}
 					return resolvedSvelteSSR;
 				}
-				try {
-					const resolved = resolveViaPackageJsonSvelte(importee, importer, cache);
-					if (resolved) {
-						log.debug(
-							`resolveId resolved ${resolved} via package.json svelte field of ${importee}`
-						);
-						return resolved;
-					}
-				} catch (e) {
-					log.debug.once(
-						`error trying to resolve ${importee} from ${importer} via package.json svelte field `,
-						e
-					);
-					// this error most likely happens due to non-svelte related importee/importers so swallow it here
-					// in case it really way a svelte library, users will notice anyway. (lib not working due to failed resolve)
-				}
 			},
 
 			async transform(code, id, opts) {

packages/vite-plugin-svelte/src/utils/constants.ts

@@ -1,5 +1,7 @@
 const VITE_RESOLVE_MAIN_FIELDS = ['module', 'jsnext:main', 'jsnext'];
 
+export const SVELTE_RESOLVE_CONDITIONS = ['svelte'];
+
 export const SVELTE_RESOLVE_MAIN_FIELDS = ['svelte', ...VITE_RESOLVE_MAIN_FIELDS];
 
 export const SVELTE_IMPORTS = [

packages/vite-plugin-svelte/src/utils/dependencies.ts

@@ -66,10 +66,7 @@ function getSvelteDependencies(
 	return result;
 }
 
-export function resolveDependencyData(
-	dep: string,
-	localRequire: NodeRequire
-): DependencyData | void {
+function resolveDependencyData(dep: string, localRequire: NodeRequire): DependencyData | void {
 	try {
 		const pkgJson = `${dep}/package.json`;
 		const pkg = localRequire(pkgJson);
@@ -173,7 +170,7 @@ const COMMON_PREFIXES_WITHOUT_SVELTE_FIELD = [
  * @param dependency {string}
  * @returns {boolean} true if it is a dependency without a svelte field
  */
-export function is_common_without_svelte_field(dependency: string): boolean {
+function is_common_without_svelte_field(dependency: string): boolean {
 	return (
 		COMMON_DEPENDENCIES_WITHOUT_SVELTE_FIELD.includes(dependency) ||
 		COMMON_PREFIXES_WITHOUT_SVELTE_FIELD.some(

packages/vite-plugin-svelte/src/utils/options.ts

@@ -9,7 +9,12 @@ import {
 } from 'vite';
 import { log } from './log';
 import { loadSvelteConfig } from './load-svelte-config';
-import { SVELTE_HMR_IMPORTS, SVELTE_IMPORTS, SVELTE_RESOLVE_MAIN_FIELDS } from './constants';
+import {
+	SVELTE_HMR_IMPORTS,
+	SVELTE_IMPORTS,
+	SVELTE_RESOLVE_CONDITIONS,
+	SVELTE_RESOLVE_MAIN_FIELDS
+} from './constants';
 // eslint-disable-next-line node/no-missing-import
 import type { CompileOptions, Warning } from 'svelte/types/compiler/interfaces';
 import type {
@@ -303,7 +308,8 @@ export function buildExtraViteConfig(
 	const svelteDeps = findRootSvelteDependencies(options.root);
 	const extraViteConfig: Partial<UserConfig> = {
 		resolve: {
-			mainFields: [...SVELTE_RESOLVE_MAIN_FIELDS],
+			conditions: SVELTE_RESOLVE_CONDITIONS,
+			mainFields: SVELTE_RESOLVE_MAIN_FIELDS,
 			dedupe: [...SVELTE_IMPORTS, ...SVELTE_HMR_IMPORTS]
 		}
 		// this option is still awaiting a PR in vite to be supported

packages/vite-plugin-svelte/src/utils/vite-plugin-svelte-cache.ts

@@ -105,23 +105,4 @@ export class VitePluginSvelteCache {
 		const dependants = this._dependants.get(path);
 		return dependants ? [...dependants] : [];
 	}
-
-	public getResolvedSvelteField(name: string, importer?: string): string | void {
-		return this._resolvedSvelteFields.get(this._getResolvedSvelteFieldKey(name, importer));
-	}
-
-	public setResolvedSvelteField(
-		importee: string,
-		importer: string | undefined = undefined,
-		resolvedSvelte: string
-	) {
-		this._resolvedSvelteFields.set(
-			this._getResolvedSvelteFieldKey(importee, importer),
-			resolvedSvelte
-		);
-	}
-
-	private _getResolvedSvelteFieldKey(importee: string, importer?: string): string {
-		return importer ? `${importer} > ${importee}` : importee;
-	}
 }