From 26de35ec4bab1627b3ffad45f8516dae99c76632 Mon Sep 17 00:00:00 2001
From: PendingReality <sunz.kim@carpenoctem.jp>
Date: Mon, 1 Dec 2025 17:48:22 +0900
Subject: [PATCH] fix: resolve webpack/Next.js WASM data URL compatibility
 issue (#95)

Add Vite plugin to remove unnecessary `import.meta.url` argument from
data: URLs during build.

## Problem
wasm-pack generates: `new URL("data:...", import.meta.url)`

The `import.meta.url` argument is unnecessary for data: URLs and causes:
- Webpack 5: "Invalid generator object" error
- Vite: Incorrectly rewrites URL as filesystem path

## Solution
Transform during build:
- Before: `new URL("data:...", import.meta.url)`
- After: `new URL("data:...")`

This allows Next.js/webpack users to import spark normally without errors.

Fixes #95
---
 vite.config.ts | 30 ++++++++++++++++++++++++++++++
 1 file changed, 30 insertions(+)

diff --git a/vite.config.ts b/vite.config.ts
index aae8fce..dd90c0e 100644
--- a/vite.config.ts
+++ b/vite.config.ts
@@ -1,9 +1,36 @@
 import fs from "node:fs";
 import path from "node:path";
+import type { Plugin } from "vite";
 import { defineConfig } from "vite";
 import dts from "vite-plugin-dts";
 import glsl from "vite-plugin-glsl";
 
+/**
+ * Vite plugin to fix WASM data URL compatibility with webpack/Next.js.
+ *
+ * wasm-pack generates code like: new URL("data:...", import.meta.url)
+ * The import.meta.url argument is unnecessary for data: URLs and causes
+ * webpack/Vite to incorrectly try to rewrite the URL as a file path.
+ *
+ * This plugin transforms:
+ *   new URL("data:...", import.meta.url) → new URL("data:...")
+ *
+ * See: https://github.com/sparkjsdev/spark/issues/95
+ */
+function fixWasmDataUrl(): Plugin {
+  return {
+    name: "fix-wasm-data-url",
+    renderChunk(code) {
+      // Match: new URL("data:...", import.meta.url)
+      // The data URL can contain any characters including quotes (escaped)
+      const dataUrlPattern =
+        /new\s+URL\(\s*("data:[^"]*")\s*,\s*import\.meta\.url\s*\)/g;
+      const result = code.replace(dataUrlPattern, "new URL($1)");
+      return result !== code ? result : null;
+    },
+  };
+}
+
 const assetsDirectory = "examples/assets";
 const localAssetsDirectoryExist = fs.existsSync(assetsDirectory);
 if (!localAssetsDirectoryExist) {
@@ -32,6 +59,9 @@ export default defineConfig(({ mode }) => {
       }),
 
       dts({ outDir: "dist/types" }),
+
+      // Fix webpack/Next.js compatibility for WASM data URLs
+      fixWasmDataUrl(),
       {
         name: "serve-node-modules-alias",
         configureServer(server) {