Document answeredOnArrival for client receivers and onRequest refusal (#85)

* Document answeredOnArrival for client receivers and onRequest refusal

* Apply stability review: correct the onRequest bind claim and teardown order

test/readme.test.ts

@@ -1,15 +1,18 @@
 import assert from 'node:assert/strict';
+import net from 'node:net';
 import test, { describe } from 'node:test';
 import type { Dlr } from '../src/dlr.ts';
-import type { Session } from '../src/session.ts';
+import type { PduObject } from '../src/pdu.ts';
 import type { Sms } from '../src/sms.ts';
 import type { SmppLog } from '../src/log.ts';
 import type { SmppServer } from '../src/server.ts';
 import type { TestContext } from 'node:test';
+import { PduFramer } from '../src/pdu-framer.ts';
 import { PduRefusedError } from '../src/pdu-refusal.ts';
-import { objToPdu } from '../src/pdu.ts';
+import { Session } from '../src/session.ts';
 import { client } from '../src/client.ts';
-import { closeAfter } from './teardown.ts';
+import { closeAfter, closeListenerAfter } from './teardown.ts';
+import { isCommand, objToPdu, pduToObj } from '../src/pdu.ts';
 import { server } from '../src/server.ts';
 
 function once<T>(register: (resolve: (value: T) => void) => void): Promise<T> {
@@ -218,9 +221,17 @@ describe('README: Server', () => {
 
 		closeAfter(t, smpp);
 
+		let answeredOnArrival: boolean | undefined;
+
 		smpp.on('session', session => {
 			session.on('sms', async sms => {
-				await sms.sendResp();
+				answeredOnArrival = sms.answeredOnArrival;
+
+				if (sms.answeredOnArrival) {
+					await sms.sendResp(); // multipart: only releases the shutdown drain
+				} else {
+					await sms.sendResp(); // ESME_ROK with a generated id
+				}
 
 				if (sms.dlr) {
 					await sms.sendDlr();
@@ -250,6 +261,71 @@ describe('README: Server', () => {
 
 		assert.equal(sent.err, undefined);
 		assert.equal((await reported).statusMsg, 'DELIVERED');
+		assert.equal(answeredOnArrival, false);
+	});
+
+	test('refusing a submission at onRequest, before this library would answer it', async t => {
+		const knownRecipients = new Set(['46709771337']);
+		const accepted: net.Socket[] = [];
+		const listener = net.createServer(sock => {
+			accepted.push(sock);
+
+			const session = new Session({
+				onRequest: async (bound, pduObj) => {
+					if (!isCommand(pduObj, 'submit_sm') || knownRecipients.has(pduObj.params.destination_addr)) {
+						return false;
+					}
+
+					await bound.sendReturn(pduObj, 'ESME_RINVDSTADR');
+
+					return true;
+				},
+				sock,
+			});
+
+			session.linkEnd = 'smsc';
+			closeAfter(t, session);
+		});
+
+		closeListenerAfter(t, listener, accepted);
+
+		await new Promise<void>(resolve => { listener.listen(0, resolve); });
+
+		const address = listener.address();
+		const port = typeof address === 'object' && address !== null ? address.port : 0;
+		const peer = net.connect({ port });
+
+		t.after(() => { peer.destroy(); });
+
+		const framer = new PduFramer();
+		const refused = once<PduObject>(resolve => {
+			peer.on('data', chunk => {
+				framer.push(chunk);
+
+				for (const pdu of framer.next().pdus ?? []) {
+					const { pduObj } = pduToObj(pdu);
+
+					if (pduObj) resolve(pduObj);
+				}
+			});
+		});
+
+		await once<true>(resolve => { peer.once('connect', () => { resolve(true); }); });
+
+		const { buffer } = objToPdu({
+			cmdName: 'submit_sm',
+			params: {
+				destination_addr: '46700000000',
+				short_message: 'Hello world',
+				source_addr: '46701113311',
+			},
+			seqNr: 1,
+		});
+
+		assert.ok(buffer);
+		peer.write(buffer);
+
+		assert.equal((await refused).cmdStatus, 'ESME_RINVDSTADR');
 	});
 });