widget: fixes #90 (0.1.26)

widget/src/package.json

@@ -1,6 +1,6 @@
 {
   "name": "@cap.js/widget",
-  "version": "0.1.25",
+  "version": "0.1.26",
   "description": "Client-side widget for Cap, a lightweight, modern open-source CAPTCHA alternative designed using SHA-256 PoW.",
   "keywords": [
     "security",

widget/src/src/worker.js

@@ -1,69 +1,71 @@
 (() => {
+	const solveFallback = async ({ salt, target }) => {
+		let nonce = 0;
+		const batchSize = 50000;
+		const encoder = new TextEncoder();
+
+		const targetBytes = new Uint8Array(target.length / 2);
+		for (let k = 0; k < targetBytes.length; k++) {
+			targetBytes[k] = parseInt(target.substring(k * 2, k * 2 + 2), 16);
+		}
+		const targetBytesLength = targetBytes.length;
+
+		while (true) {
+			try {
+				for (let i = 0; i < batchSize; i++) {
+					const inputString = salt + nonce;
+					const inputBytes = encoder.encode(inputString);
+
+					const hashBuffer = await crypto.subtle.digest("SHA-256", inputBytes);
+
+					const hashBytes = new Uint8Array(hashBuffer, 0, targetBytesLength);
+
+					let matches = true;
+					for (let k = 0; k < targetBytesLength; k++) {
+						if (hashBytes[k] !== targetBytes[k]) {
+							matches = false;
+							break;
+						}
+					}
+
+					if (matches) {
+						self.postMessage({ nonce, found: true });
+						return;
+					}
+
+					nonce++;
+				}
+			} catch (error) {
+				console.error("[cap worker]", error);
+				self.postMessage({
+					found: false,
+					error: error.message,
+				});
+				return;
+			}
+		}
+	};
+
 	if (
 		typeof WebAssembly !== "object" ||
 		typeof WebAssembly?.instantiate !== "function"
 	) {
-		// fallback worker for environments without wasm
-		// this is much slower than the wasm version
-
-		self.onmessage = async ({ data: { salt, target } }) => {
-			let nonce = 0;
-			const batchSize = 50000;
-			const encoder = new TextEncoder();
-
-			const targetBytes = new Uint8Array(target.length / 2);
-			for (let k = 0; k < targetBytes.length; k++) {
-				targetBytes[k] = parseInt(target.substring(k * 2, k * 2 + 2), 16);
-			}
-			const targetBytesLength = targetBytes.length;
-
-			while (true) {
-				try {
-					for (let i = 0; i < batchSize; i++) {
-						const inputString = salt + nonce;
-						const inputBytes = encoder.encode(inputString);
-
-						const hashBuffer = await crypto.subtle.digest(
-							"SHA-256",
-							inputBytes,
-						);
-
-						const hashBytes = new Uint8Array(hashBuffer, 0, targetBytesLength);
-
-						let matches = true;
-						for (let k = 0; k < targetBytesLength; k++) {
-							if (hashBytes[k] !== targetBytes[k]) {
-								matches = false;
-								break;
-							}
-						}
-
-						if (matches) {
-							self.postMessage({ nonce, found: true });
-							return;
-						}
-
-						nonce++;
-					}
-				} catch (error) {
-					console.error("[cap worker]", error);
-					self.postMessage({
-						found: false,
-						error: error.message,
-					});
-					return;
-				}
-			}
-		};
-
-		return console.warn(
+		console.warn(
 			"[cap worker] wasm not supported, falling back to alternative solver. this will be significantly slower.",
 		);
+
+		self.onmessage = async ({ data: { salt, target } }) => {
+			return solveFallback({ salt, target });
+		};
+
+		return;
 	}
 
 	let wasmCacheUrl, solve_pow_function;
 
 	self.onmessage = async ({ data: { salt, target, wasmUrl } }) => {
+		let fb;
+
 		if (wasmCacheUrl !== wasmUrl) {
 			wasmCacheUrl = wasmUrl;
 			await import(wasmUrl)
@@ -76,7 +78,12 @@
 				})
 				.catch((e) => {
 					console.error("[cap worker] using fallback solver due to error:", e);
+					fb = true;
+
+					return solveFallback({ salt, target });
 				});
+
+			if (fb) return;
 		}
 
 		try {
@@ -91,6 +98,7 @@
 			});
 		} catch (error) {
 			console.error("[cap worker]", error);
+			
 			self.postMessage({
 				found: false,
 				error: error.message || String(error),