breaking: remove support for svelte3 (#746)

* chore(node): drop support for 14 and 16

* chore(updates): remove support for svelte 3

Author: dominikg

.changeset/grumpy-planets-crash.md

@@ -0,0 +1,6 @@
+---
+'@sveltejs/vite-plugin-svelte-inspector': major
+'@sveltejs/vite-plugin-svelte': major
+---
+
+breaking: remove support for svelte 3

.github/workflows/ci.yml

@@ -75,11 +75,9 @@ jobs:
       matrix:
         node: [18]
         os: [ubuntu-latest, macos-latest, windows-latest]
-        svelte: [4]
         include:
           - node: 20
             os: ubuntu-latest
-            svelte: 4
     steps:
       - uses: actions/checkout@v4
       - uses: actions/setup-node@v3
@@ -91,10 +89,6 @@ jobs:
           PNPM_VER=$(jq -r '.packageManager | if .[0:5] == "pnpm@" then .[5:] else "packageManager in package.json does not start with pnpm@\n" | halt_error(1)  end' package.json)
           echo installing pnpm version $PNPM_VER
           npm i -g pnpm@$PNPM_VER
-      - name: use svelte 3
-        if: matrix.svelte == 3
-        run: |
-          tmppkg="$(jq '.devDependencies.svelte = "^3.59.2"' package.json)" && echo -E "${tmppkg}" > package.json && tmppkg=""
       - uses: actions/setup-node@v3
         with:
           node-version: ${{ matrix.node }}
@@ -113,7 +107,7 @@ jobs:
       - uses: actions/upload-artifact@v3
         if: failure()
         with:
-          name: test-failure-${{github.run_id}}-${{ matrix.os }}-${{ matrix.node }}-${{ matrix.svelte }}
+          name: test-failure-${{github.run_id}}-${{ matrix.os }}-${{ matrix.node }}
           path: |
             test-temp.tar
             pnpm-debug.log

packages/vite-plugin-svelte-inspector/package.json

@@ -41,7 +41,7 @@
   },
   "peerDependencies": {
     "@sveltejs/vite-plugin-svelte": "^2.2.0",
-    "svelte": "^3.54.0 || ^4.0.0",
+    "svelte": "^4.0.0",
     "vite": "^5.0.0-beta.1 || ^5.0.0"
   },
   "devDependencies": {

packages/vite-plugin-svelte/package.json

@@ -47,7 +47,7 @@
     "vitefu": "^0.2.4"
   },
   "peerDependencies": {
-    "svelte": "^3.54.0 || ^4.0.0",
+    "svelte": "^4.0.0",
     "vite": "^5.0.0-beta.1 || ^5.0.0"
   },
   "devDependencies": {

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

@@ -1,5 +1,4 @@
 import fs from 'node:fs';
-import { version as viteVersion } from 'vite';
 
 import { svelteInspector } from '@sveltejs/vite-plugin-svelte-inspector';
 
@@ -24,9 +23,6 @@ import { saveSvelteMetadata } from './utils/optimizer.js';
 import { VitePluginSvelteCache } from './utils/vite-plugin-svelte-cache.js';
 import { loadRaw } from './utils/load-raw.js';
 import { FAQ_LINK_CONFLICTS_IN_SVELTE_RESOLVE } from './utils/constants.js';
-import { isSvelte3 } from './utils/svelte-version.js';
-
-const isVite4_0 = viteVersion.startsWith('4.0');
 
 /** @type {import('./index.d.ts').svelte} */
 export function svelte(inlineOptions) {
@@ -47,8 +43,6 @@ export function svelte(inlineOptions) {
 	let compileSvelte;
 	/* eslint-enable no-unused-vars */
 
-	/** @type {Promise<import('vite').Rollup.PartialResolvedId | null>} */
-	let resolvedSvelteSSR;
 	/** @type {Set<string>} */
 	let packagesWithResolveWarnings;
 	/** @type {import('./types/plugin-api.d.ts').PluginAPI} */
@@ -145,25 +139,6 @@ export function svelte(inlineOptions) {
 					}
 				}
 
-				// TODO: remove this after bumping peerDep on Vite to 4.1+ or Svelte to 4.0+
-				if (isVite4_0 && isSvelte3 && ssr && importee === 'svelte') {
-					if (!resolvedSvelteSSR) {
-						resolvedSvelteSSR = this.resolve('svelte/ssr', undefined, { skipSelf: true }).then(
-							(svelteSSR) => {
-								log.debug('resolved svelte to svelte/ssr');
-								return svelteSSR;
-							},
-							(err) => {
-								log.debug(
-									'failed to resolve svelte to svelte/ssr. Update svelte to a version that exports it',
-									err
-								);
-								return null; // returning null here leads to svelte getting resolved regularly
-							}
-						);
-					}
-					return resolvedSvelteSSR;
-				}
 				//@ts-expect-error scan
 				const scan = !!opts?.scan; // scanner phase of optimizeDeps
 				const isPrebundled =

packages/vite-plugin-svelte/src/utils/compile.js

@@ -9,8 +9,6 @@ import { mapToRelative } from './sourcemaps.js';
 
 const scriptLangRE = /<script [^>]*lang=["']?([^"' >]+)["']?[^>]*>/;
 
-import { isSvelte3 } from './svelte-version.js';
-
 /**
  * @param {Function} [makeHot]
  * @returns {import('../types/compile.d.ts').CompileSvelte}
@@ -55,10 +53,7 @@ export const _createCompileSvelte = (makeHot) => {
 			filename,
 			generate: ssr ? 'ssr' : 'dom'
 		};
-		if (isSvelte3) {
-			// @ts-ignore
-			compileOptions.format = 'esm';
-		}
+
 		if (options.hot && options.emitCss) {
 			const hash = `s-${safeBase64Hash(normalizedFilename)}`;
 			log.debug(`setting cssHash ${hash} for ${normalizedFilename}`);
@@ -125,15 +120,6 @@ export const _createCompileSvelte = (makeHot) => {
 		const endStat = stats?.start(filename);
 		const compiled = compile(finalCode, finalCompileOptions);
 
-		if (isSvelte3) {
-			// prevent dangling pure comments
-			// see https://github.com/sveltejs/kit/issues/9492#issuecomment-1487704985
-			// uses regex replace with whitespace to keep sourcemap/character count unmodified
-			compiled.js.code = compiled.js.code.replace(
-				/\/\* [@#]__PURE__ \*\/(\s*)$/gm,
-				'               $1'
-			);
-		}
 		if (endStat) {
 			endStat();
 		}

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

@@ -1,5 +1,3 @@
-import { isSvelte3 } from './svelte-version.js';
-
 export const VITE_RESOLVE_MAIN_FIELDS = ['module', 'jsnext:main', 'jsnext'];
 
 export const SVELTE_RESOLVE_MAIN_FIELDS = ['svelte'];
@@ -8,16 +6,13 @@ export const SVELTE_IMPORTS = [
 	'svelte/animate',
 	'svelte/easing',
 	'svelte/internal',
+	'svelte/internal/disclose-version',
 	'svelte/motion',
 	'svelte/ssr',
 	'svelte/store',
 	'svelte/transition',
 	'svelte'
 ];
-// TODO add to global list after dropping svelte 3
-if (!isSvelte3) {
-	SVELTE_IMPORTS.push('svelte/internal/disclose-version');
-}
 
 export const SVELTE_HMR_IMPORTS = [
 	'svelte-hmr/runtime/hot-api-esm.js',

packages/vite-plugin-svelte/src/utils/esbuild.js

@@ -2,7 +2,6 @@ import { readFileSync } from 'node:fs';
 import { compile, preprocess } from 'svelte/compiler';
 import { log } from './log.js';
 import { toESBuildError } from './error.js';
-import { isSvelte3 } from './svelte-version.js';
 
 /**
  * @typedef {NonNullable<import('vite').DepOptimizationOptions['esbuildOptions']>} EsbuildOptions
@@ -67,10 +66,7 @@ async function compileSvelte(options, { filename, code }, statsCollection) {
 		filename,
 		generate: 'dom'
 	};
-	if (isSvelte3) {
-		// @ts-ignore
-		compileOptions.format = 'esm';
-	}
+
 	let preprocessed;
 
 	if (options.preprocess) {