fix(desktop): honour the system proxy in main-process requests (#3270)

fluxer_desktop/src/main/DesktopOutboundHTTP.test.mjs

@@ -726,6 +726,116 @@ describe('DesktopSelectedInstanceClient', () => {
 	});
 });
 
+describe('DesktopOutboundHTTP system proxy routes', () => {
+	function proxiedOutboundHTTP() {
+		const sent = [];
+		const resolved = [];
+		const outboundHTTP = new DesktopOutboundHTTP({
+			resolveHostAddresses: async (hostname) => {
+				resolved.push(hostname);
+				throw Object.assign(new Error(`getaddrinfo ENOTFOUND ${hostname}`), {syscall: 'getaddrinfo'});
+			},
+			resolveProxy: async (url) =>
+				url.startsWith('https://direct.example') ? 'DIRECT' : 'PROXY 127.0.0.1:7890; DIRECT',
+			sendThroughSession: async (request) => {
+				sent.push({method: request.method, url: request.url.href, headers: request.headers});
+				return {
+					headers: {'content-type': 'image/png'},
+					message: Readable.from([PNG_BYTES]),
+					status: 200,
+					statusText: 'OK',
+				};
+			},
+		});
+		return {outboundHTTP, resolved, sent};
+	}
+
+	test('an instance behind the system proxy is anchored and fetched without a local lookup', async () => {
+		const {outboundHTTP, resolved, sent} = proxiedOutboundHTTP();
+		const requirement = await outboundHTTP.registerAnchoredOrigins({
+			anchorOrigin: 'https://api.blocked.example',
+			origins: ['https://media.blocked.example'],
+		});
+		assert.equal(requirement, 'public');
+		const message = await outboundHTTP.request({
+			body: null,
+			expectedOrigin: 'https://media.blocked.example',
+			headers: {Accept: 'image/png'},
+			method: 'GET',
+			originTrust: DesktopOriginTrust.REGISTERED,
+			serviceName: 'test',
+			signal: null,
+			timeoutMs: 500,
+			url: 'https://media.blocked.example/avatar.png',
+		});
+		assert.deepEqual(
+			await readBoundedMessage({
+				declaredBytes: null,
+				description: 'proxied',
+				maxBytes: 64,
+				maxChunks: 4,
+				message: message.message,
+			}),
+			PNG_BYTES,
+		);
+		assert.deepEqual(resolved, []);
+		assert.deepEqual(sent, [
+			{method: 'GET', url: 'https://media.blocked.example/avatar.png', headers: {Accept: 'image/png'}},
+		]);
+		outboundHTTP.cleanup();
+	});
+
+	test('a proxied download goes through the session and a direct one keeps the pinned lookup', async () => {
+		const {outboundHTTP, resolved, sent} = proxiedOutboundHTTP();
+		const message = await outboundHTTP.get({
+			context: 'test',
+			timeoutMs: 500,
+			url: new URL('https://cdn.blocked.example/icon.png'),
+		});
+		message.message.resume();
+		await assert.rejects(
+			outboundHTTP.get({context: 'test', timeoutMs: 500, url: new URL('https://direct.example/icon.png')}),
+			/could not be reached/,
+		);
+		assert.deepEqual(
+			sent.map((entry) => entry.url),
+			['https://cdn.blocked.example/icon.png'],
+		);
+		assert.deepEqual(resolved, ['direct.example']);
+		outboundHTTP.cleanup();
+	});
+
+	test('a proxied route keeps the cleartext and private address rules', async () => {
+		const {outboundHTTP, sent} = proxiedOutboundHTTP();
+		await outboundHTTP.registerAnchoredOrigins({
+			anchorOrigin: 'https://api.blocked.example',
+			origins: ['http://10.0.0.1'],
+		});
+		const request = (url, originTrust = DesktopOriginTrust.BOUND) => ({
+			body: null,
+			expectedOrigin: new URL(url).origin,
+			headers: null,
+			method: 'GET',
+			originTrust,
+			serviceName: 'test',
+			signal: null,
+			timeoutMs: 500,
+			url,
+		});
+		await assert.rejects(outboundHTTP.request(request('http://plain.blocked.example/x')), /requires https/);
+		await assert.rejects(
+			outboundHTTP.request(request('http://10.0.0.1/x', DesktopOriginTrust.REGISTERED)),
+			/cannot authorize the privately resolving origin/,
+		);
+		await assert.rejects(
+			outboundHTTP.get({context: 'test', timeoutMs: 500, url: new URL('https://10.0.0.1/x')}),
+			/could not be reached/,
+		);
+		assert.deepEqual(sent, []);
+		outboundHTTP.cleanup();
+	});
+});
+
 describe('desktop instance launch surfaces', () => {
 	test('--fluxer-instance is a development-only API endpoint flag', () => {
 		const originalDefaultApp = process.defaultApp;