From 855ead8b54c070f287568ad32d8b4187372a448d Mon Sep 17 00:00:00 2001
From: Simon Holthausen <simon.holthausen@vercel.com>
Date: Sat, 9 Nov 2024 20:55:42 +0100
Subject: [PATCH 1/2] chore: provide option to pass Svelte compiler

Tooling can use this to work around some Svelte major version differences
---
 index.d.ts     |  1 +
 src/index.ts   | 12 ++++++++----
 src/options.ts |  6 ++++++
 3 files changed, 15 insertions(+), 4 deletions(-)

diff --git a/index.d.ts b/index.d.ts
index 9c8975a..1adfd0e 100644
--- a/index.d.ts
+++ b/index.d.ts
@@ -6,6 +6,7 @@ export interface PluginConfig {
     svelteBracketNewLine?: boolean;
     svelteAllowShorthand?: boolean;
     svelteIndentScriptAndStyle?: boolean;
+    svelte5CompilerPath?: string;
 }
 
 export type PrettierConfig = PluginConfig & Config;
diff --git a/src/index.ts b/src/index.ts
index e661d5f..7c10c61 100644
--- a/src/index.ts
+++ b/src/index.ts
@@ -31,9 +31,12 @@ export const languages: Partial<SupportLanguage>[] = [
 export const parsers: Record<string, Parser> = {
     svelte: {
         hasPragma,
-        parse: (text) => {
+        parse: async (text, options: ParserOptions) => {
             try {
-                return <ASTNode>{ ...parse(text), __isRoot: true };
+                const _parse = options.svelte5CompilerPath
+                    ? (await import(options.svelte5CompilerPath)).parse
+                    : parse;
+                return <ASTNode>{ ..._parse(text), __isRoot: true };
             } catch (err: any) {
                 if (err.start != null && err.end != null) {
                     // Prettier expects error objects to have loc.start and loc.end fields.
@@ -57,8 +60,9 @@ export const parsers: Record<string, Parser> = {
             // Therefore we do it ourselves here.
             options.originalText = text;
             // Only Svelte 5 can have TS in the template
-            options._svelte_ts = isSvelte5Plus && result.isTypescript;
-            options._svelte_is5Plus = isSvelte5Plus;
+            const is = !!options.svelte5CompilerPath || isSvelte5Plus;
+            options._svelte_ts = is && result.isTypescript;
+            options._svelte_is5Plus = is;
             return text;
         },
         locStart,
diff --git a/src/options.ts b/src/options.ts
index 18d65fd..f5c504b 100644
--- a/src/options.ts
+++ b/src/options.ts
@@ -19,6 +19,12 @@ function makeChoice(choice: string) {
 }
 
 export const options: Record<keyof PluginConfig, SupportOption> = {
+    svelte5CompilerPath: {
+        category: 'Svelte',
+        type: 'string',
+        default: '',
+        description: 'Only set this when using Svelte 5! Path to the Svelte 5 compiler',
+    },
     svelteSortOrder: {
         category: 'Svelte',
         type: 'choice',

From 2a39313bf0d61bdaf9daaac4daa9bee823941b45 Mon Sep 17 00:00:00 2001
From: Simon Holthausen <simon.holthausen@vercel.com>
Date: Sat, 9 Nov 2024 20:58:35 +0100
Subject: [PATCH 2/2] make robust

---
 src/index.ts | 16 +++++++++++++---
 1 file changed, 13 insertions(+), 3 deletions(-)

diff --git a/src/index.ts b/src/index.ts
index 7c10c61..dea7ba6 100644
--- a/src/index.ts
+++ b/src/index.ts
@@ -33,9 +33,19 @@ export const parsers: Record<string, Parser> = {
         hasPragma,
         parse: async (text, options: ParserOptions) => {
             try {
-                const _parse = options.svelte5CompilerPath
-                    ? (await import(options.svelte5CompilerPath)).parse
-                    : parse;
+                let _parse = parse;
+                if (options.svelte5CompilerPath) {
+                    try {
+                        _parse = (await import(options.svelte5CompilerPath)).parse;
+                    } catch (e) {
+                        console.warn(
+                            `Failed to load Svelte 5 compiler from ${options.svelte5CompilerPath}`,
+                        );
+                        console.warn(e);
+                        options.svelte5CompilerPath = undefined;
+                    }
+                }
+
                 return <ASTNode>{ ..._parse(text), __isRoot: true };
             } catch (err: any) {
                 if (err.start != null && err.end != null) {