Implement atob() and btoa()

.changeset/wise-dryers-swim.md

@@ -0,0 +1,5 @@
+---
+"@nx.js/runtime": patch
+---
+
+Implement `atob()` and `btoa()`

apps/tests/src/window.test.ts

@@ -4,10 +4,14 @@ import * as assert from 'uvu/assert';
 const test = suite('window');
 
 test('instanceof', () => {
-	assert.equal(window instanceof Window, true);
-	assert.equal(globalThis instanceof Window, true);
-	assert.equal(globalThis === window, true);
-	assert.equal(Object.prototype.toString.call(window), '[object Window]');
+	assert.instance(globalThis, Window);
+	assert.equal(Object.prototype.toString.call(globalThis), '[object Window]');
+
+	// Deno v2 doesn't have a `window` global
+	if (typeof window !== 'undefined') {
+		assert.equal(window instanceof Window, true);
+		assert.equal(globalThis === window, true);
+	}
 });
 
 test('throws illegal constructor', () => {
@@ -33,4 +37,22 @@ test('supports global events', () => {
 	assert.ok(e.defaultPrevented);
 });
 
+test('atob', () => {
+	assert.equal(globalThis.hasOwnProperty('atob'), true);
+
+	assert.equal(atob.length, 1);
+
+	const result = atob('SGVsbG8sIHdvcmxk');
+	assert.equal(result, 'Hello, world');
+});
+
+test('btoa', () => {
+	assert.equal(globalThis.hasOwnProperty('btoa'), true);
+
+	assert.equal(btoa.length, 1);
+
+	const result = btoa('Hello, world');
+	assert.equal(result, 'SGVsbG8sIHdvcmxk');
+});
+
 test.run();

packages/runtime/src/$.ts

@@ -41,6 +41,7 @@ import type { DOMPoint, DOMPointInit } from './dompoint';
 import type { DOMMatrix, DOMMatrixReadOnly, DOMMatrixInit } from './dommatrix';
 import type { Gamepad, GamepadButton } from './navigator/gamepad';
 import type { Crypto, CryptoKey, SubtleCrypto } from './crypto';
+import type { Window } from './window';
 import type { Algorithm, BufferSource } from './types';
 import type { PromiseState } from '@nx.js/inspect';
 
@@ -346,6 +347,9 @@ export interface Init {
 	wasmGlobalGet(g: WasmGlobalOpaque): any;
 	wasmGlobalSet(g: WasmGlobalOpaque, v: any): void;
 
+	// window.c
+	windowInit(c: Window): void;
+
 	applyPath: any;
 }
 

packages/runtime/src/window.ts

@@ -10,6 +10,7 @@ import type {
 	ErrorEvent,
 	PromiseRejectionEvent,
 } from './polyfills/event';
+import { $ } from './$';
 
 /**
  * The `Window` class represents the global scope within the application.
@@ -29,6 +30,7 @@ def(Window);
 
 export var window: Window & typeof globalThis = globalThis;
 def(proto(window, Window), 'window');
+$.windowInit(window);
 
 Object.defineProperty(window, Symbol.toStringTag, {
 	get() {
@@ -149,3 +151,18 @@ export declare function removeEventListener(
  * @see {@link https://developer.mozilla.org/docs/Web/API/EventTarget/dispatchEvent | MDN Reference}
  */
 export declare function dispatchEvent(event: Event): boolean;
+
+/**
+ * Decodes a string of data which has been encoded using Base64 encoding.
+ *
+ * @see https://developer.mozilla.org/docs/Web/API/Window/atob
+ */
+export declare function atob(s: string): string;
+
+/**
+ * Creates a Base64-encoded ASCII string from a binary string (i.e., a string in
+ * which each character in the string is treated as a byte of binary data).
+ *
+ * @see https://developer.mozilla.org/docs/Web/API/Window/btoa
+ */
+export declare function btoa(s: string): string;

source/main.c

@@ -34,6 +34,7 @@
 #include "types.h"
 #include "url.h"
 #include "wasm.h"
+#include "window.h"
 
 #define LOG_FILENAME "nxjs-debug.log"
 
@@ -644,6 +645,7 @@ int main(int argc, char *argv[]) {
 	nx_init_url(ctx, nx_ctx->init_obj);
 	nx_init_swkbd(ctx, nx_ctx->init_obj);
 	nx_init_wasm(ctx, nx_ctx->init_obj);
+	nx_init_window(ctx, nx_ctx->init_obj);
 	const JSCFunctionListEntry init_function_list[] = {
 		JS_CFUNC_DEF("exit", 0, js_exit),
 		JS_CFUNC_DEF("cwd", 0, js_cwd),

source/window.c

@@ -0,0 +1,143 @@
+#include "window.h"
+
+static JSValue nx_atob(JSContext *ctx, JSValueConst this_val, int argc,
+					   JSValueConst *argv) {
+	size_t input_len;
+	const char *input = JS_ToCStringLen(ctx, &input_len, argv[0]);
+	if (!input)
+		return JS_EXCEPTION;
+
+	// Calculate decoded length (removing padding)
+	size_t padding = 0;
+	if (input_len > 0 && input[input_len - 1] == '=')
+		padding++;
+	if (input_len > 1 && input[input_len - 2] == '=')
+		padding++;
+	size_t output_len = (input_len * 3) / 4 - padding;
+
+	// Allocate output buffer
+	uint8_t *output = js_malloc(ctx, output_len + 1);
+	if (!output) {
+		JS_FreeCString(ctx, input);
+		return JS_EXCEPTION;
+	}
+
+	// Base64 decoding lookup table
+	static const int8_t b64_table[256] = {
+		-1, -1, -1, -1, -1, -1, -1, -1,
+		-1, -1, -1, -1, -1, -1, -1, -1, // 0-15
+		-1, -1, -1, -1, -1, -1, -1, -1,
+		-1, -1, -1, -1, -1, -1, -1, -1, // 16-31
+		-1, -1, -1, -1, -1, -1, -1, -1,
+		-1, -1, -1, 62, -1, -1, -1, 63, // 32-47
+		52, 53, 54, 55, 56, 57, 58, 59,
+		60, 61, -1, -1, -1, -1, -1, -1, // 48-63
+		-1, 0,  1,  2,  3,  4,  5,  6,
+		7,  8,  9,  10, 11, 12, 13, 14, // 64-79
+		15, 16, 17, 18, 19, 20, 21, 22,
+		23, 24, 25, -1, -1, -1, -1, -1, // 80-95
+		-1, 26, 27, 28, 29, 30, 31, 32,
+		33, 34, 35, 36, 37, 38, 39, 40, // 96-111
+		41, 42, 43, 44, 45, 46, 47, 48,
+		49, 50, 51, -1, -1, -1, -1, -1 // 112-127
+	};
+
+	// Decode
+	size_t i = 0, j = 0;
+	uint32_t accum = 0;
+	int bits = 0;
+
+	while (i < input_len) {
+		int c = input[i++];
+		int x = b64_table[c & 0x7F];
+
+		if (x == -1) {
+			js_free(ctx, output);
+			JS_FreeCString(ctx, input);
+			return JS_ThrowSyntaxError(ctx, "Invalid base64 character");
+		}
+
+		accum = (accum << 6) | x;
+		bits += 6;
+
+		if (bits >= 8) {
+			bits -= 8;
+			output[j++] = (accum >> bits) & 0xFF;
+		}
+	}
+
+	output[output_len] = 0;
+	JS_FreeCString(ctx, input);
+
+	JSValue result = JS_NewStringLen(ctx, (char *)output, output_len);
+	js_free(ctx, output);
+	return result;
+}
+
+static JSValue nx_btoa(JSContext *ctx, JSValueConst this_val, int argc,
+					   JSValueConst *argv) {
+	const char *input = JS_ToCString(ctx, argv[0]);
+	if (!input) {
+		return JS_EXCEPTION;
+	}
+
+	size_t input_len = strlen(input);
+	size_t output_len = ((input_len + 2) / 3) * 4;
+	unsigned char *output = js_malloc(ctx, output_len + 1);
+	if (!output) {
+		JS_FreeCString(ctx, input);
+		return JS_EXCEPTION;
+	}
+
+	static const char b64_chars[] =
+		"ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+/";
+
+	// Encode
+	size_t i = 0, j = 0;
+	uint32_t accum = 0;
+	int bits = 0;
+
+	while (i < input_len) {
+		accum = (accum << 8) | (input[i++] & 0xFF);
+		bits += 8;
+
+		while (bits >= 6) {
+			bits -= 6;
+			output[j++] = b64_chars[(accum >> bits) & 0x3F];
+		}
+	}
+
+	// Handle remaining bits
+	if (bits > 0) {
+		accum <<= (6 - bits);
+		output[j++] = b64_chars[accum & 0x3F];
+	}
+
+	// Add padding
+	while (j < output_len) {
+		output[j++] = '=';
+	}
+
+	output[output_len] = 0;
+	JS_FreeCString(ctx, input);
+
+	JSValue result = JS_NewString(ctx, (char *)output);
+	js_free(ctx, output);
+	return result;
+}
+
+static JSValue nx_window_init(JSContext *ctx, JSValueConst this_val, int argc,
+							  JSValueConst *argv) {
+	NX_DEF_FUNC(argv[0], "atob", nx_atob, 1);
+	NX_DEF_FUNC(argv[0], "btoa", nx_btoa, 1);
+	return JS_UNDEFINED;
+}
+
+static const JSCFunctionListEntry function_list[] = {
+	JS_CFUNC_DEF("windowInit", 1, nx_window_init),
+};
+
+void nx_init_window(JSContext *ctx, JSValueConst init_obj) {
+	JS_SetPropertyFunctionList(ctx, init_obj, function_list,
+							   countof(function_list));
+}

source/window.h

@@ -0,0 +1,4 @@
+#pragma once
+#include "types.h"
+
+void nx_init_window(JSContext *ctx, JSValueConst init_obj);