#499@minor: Adds support for btoa and atob.

packages/happy-dom/src/exception/DOMExceptionNameEnum.ts

@@ -2,6 +2,7 @@ enum DOMExceptionNameEnum {
 	invalidStateError = 'InvalidStateError',
 	indexSizeError = 'IndexSizeError',
 	syntaxError = 'SyntaxError',
-	hierarchyRequestError = 'HierarchyRequestError'
+	hierarchyRequestError = 'HierarchyRequestError',
+	invalidCharacterError = 'InvalidCharacterError'
 }
 export default DOMExceptionNameEnum;

packages/happy-dom/src/window/Window.ts

@@ -92,6 +92,7 @@ import VMGlobalPropertyScript from './VMGlobalPropertyScript';
 import * as PerfHooks from 'perf_hooks';
 import VM from 'vm';
 import { Buffer } from 'buffer';
+import { atob, btoa } from './WindowBase64';
 
 /**
  * Browser window.
@@ -219,6 +220,10 @@ export default class Window extends EventTarget implements IWindow {
 	public readonly localStorage = new Storage();
 	public readonly performance = PerfHooks.performance;
 
+	// Atob & btoa
+	public atob = atob;
+	public btoa = btoa;
+
 	// Node.js Globals
 	public ArrayBuffer;
 	public Boolean;

packages/happy-dom/src/window/WindowBase64.ts

@@ -0,0 +1,95 @@
+import DOMException from '../exception/DOMException';
+import DOMExceptionNameEnum from '../exception/DOMExceptionNameEnum';
+
+const base64list = 'ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+/=';
+
+/**
+ * Btoa.
+ *
+ * Reference:
+ * https://developer.mozilla.org/en-US/docs/Web/API/btoa.
+ *
+ * @param data
+ */
+export const btoa = (data: unknown): string => {
+	const str = (<string>data).toString();
+	if (/[^\u0000-\u00ff]/.test(str)) {
+		throw new DOMException(
+			"Failed to execute 'btoa' on 'Window': The string to be encoded contains characters outside of the Latin1 range.",
+			DOMExceptionNameEnum.invalidCharacterError
+		);
+	}
+
+	let t = '';
+	let p = -6;
+	let a = 0;
+	let i = 0;
+	let v = 0;
+	let c;
+	while (i < str.length || p > -6) {
+		if (p < 0) {
+			if (i < str.length) {
+				c = str.charCodeAt(i++);
+				v += 8;
+			} else {
+				c = 0;
+			}
+			a = ((a & 255) << 8) | (c & 255);
+			p += 8;
+		}
+		t += base64list.charAt(v > 0 ? (a >> p) & 63 : 64);
+		p -= 6;
+		v -= 6;
+	}
+	return t;
+};
+
+/**
+ * Atob.
+ *
+ * Reference:
+ * https://infra.spec.whatwg.org/#forgiving-base64-encode.
+ * Https://html.spec.whatwg.org/multipage/webappapis.html#btoa.
+ *
+ * @param data
+ */
+export const atob = (data: unknown): string => {
+	const str = (<string>data).toString();
+
+	if (/[^\u0000-\u00ff]/.test(str)) {
+		throw new DOMException(
+			"Failed to execute 'atob' on 'Window': The string to be decoded contains characters outside of the Latin1 range.",
+			DOMExceptionNameEnum.invalidCharacterError
+		);
+	}
+
+	if (/[^A-Za-z\d+/=]/.test(str) || str.length % 4 == 1) {
+		throw new DOMException(
+			"Failed to execute 'atob' on 'Window': The string to be decoded is not correctly encoded.",
+			DOMExceptionNameEnum.invalidCharacterError
+		);
+	}
+
+	let t = '';
+	let p = -8;
+	let a = 0;
+	let c;
+	let d;
+	for (let i = 0; i < str.length; i++) {
+		if ((c = base64list.indexOf(str.charAt(i))) < 0) {
+			continue;
+		}
+		a = (a << 6) | (c & 63);
+		if ((p += 6) >= 0) {
+			d = (a >> p) & 255;
+			if (c !== 64) {
+				t += String.fromCharCode(d);
+			}
+			a &= 63;
+			p -= 8;
+		}
+	}
+	return t;
+};
+
+exports = { btoa: btoa, atob: atob };

packages/happy-dom/test/window/Window.test.ts

@@ -11,6 +11,9 @@ import Headers from '../../src/fetch/Headers';
 import Response from '../../src/fetch/Response';
 import Request from '../../src/fetch/Request';
 import Selection from '../../src/selection/Selection';
+import { atob, btoa } from '../../lib/window/WindowBase64';
+import DOMException from '../../src/exception/DOMException';
+import DOMExceptionNameEnum from '../../src/exception/DOMExceptionNameEnum';
 
 const MOCKED_NODE_FETCH = global['mockedModules']['node-fetch'];
 
@@ -535,4 +538,67 @@ describe('Window', () => {
 			}, 0);
 		});
 	});
+
+	describe('atob()', () => {
+		it('Decode "hello my happy dom!"', function () {
+			const encoded = 'aGVsbG8gbXkgaGFwcHkgZG9tIQ==';
+			const decoded = atob(encoded);
+			expect(decoded).toBe('hello my happy dom!');
+		});
+
+		it('Decode Unicode (throw error)', function () {
+			expect(() => {
+				const data = '😄 hello my happy dom! 🐛';
+				atob(data);
+			}).toThrowError(
+				new DOMException(
+					"Failed to execute 'atob' on 'Window': The string to be decoded contains characters outside of the Latin1 range.",
+					DOMExceptionNameEnum.invalidCharacterError
+				)
+			);
+		});
+
+		it('Data not in base64list', function () {
+			expect(() => {
+				const data = '\x11GVsbG8gbXkgaGFwcHkgZG9tIQ==';
+				atob(data);
+			}).toThrowError(
+				new DOMException(
+					"Failed to execute 'atob' on 'Window': The string to be decoded is not correctly encoded.",
+					DOMExceptionNameEnum.invalidCharacterError
+				)
+			);
+		});
+		it('Data length not valid', function () {
+			expect(() => {
+				const data = 'aGVsbG8gbXkgaGFwcHkgZG9tI';
+				atob(data);
+			}).toThrowError(
+				new DOMException(
+					"Failed to execute 'atob' on 'Window': The string to be decoded is not correctly encoded.",
+					DOMExceptionNameEnum.invalidCharacterError
+				)
+			);
+		});
+	});
+
+	describe('btoa()', () => {
+		it('Encode "hello my happy dom!"', function () {
+			const data = 'hello my happy dom!';
+			const encoded = btoa(data);
+			expect(encoded).toBe('aGVsbG8gbXkgaGFwcHkgZG9tIQ==');
+		});
+
+		it('Encode Unicode (throw error)', function () {
+			expect(() => {
+				const data = '😄 hello my happy dom! 🐛';
+				btoa(data);
+			}).toThrowError(
+				new DOMException(
+					"Failed to execute 'btoa' on 'Window': The string to be encoded contains characters outside of the Latin1 range.",
+					DOMExceptionNameEnum.invalidCharacterError
+				)
+			);
+		});
+	});
 });