Read a valueless count as unstated, and pin a CRLF receipt end to end

Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01Csos3Vfm66NrAywQUe3e4V

src/dlr.ts

@@ -66,12 +66,13 @@ const patterns = {
 	stat: field('stat'),
 	sub: field('sub'),
 	submitDate: field('submit date'),
-	// The last field, and the only one that may hold a space: it carries the message's own start.
+	// The one field that may hold a space, carrying the message's own start, so it ends at its line.
 	text: /\btext:([^\r\n]*)/i,
 };
 
 function toNumber(value: string | undefined): number | undefined {
-	if (value === undefined) return undefined;
+	// Number('') is 0, which would report a receipt that stated no count as one that stated none sent.
+	if (value === undefined || value === '') return undefined;
 
 	const parsed = Number(value);
 

test/dlr.test.ts

@@ -61,7 +61,7 @@ describe('parseReceipt()', () => {
 	});
 
 	test('leaves absent fields undefined rather than guessing', () => {
-		const receipt = parseReceipt('id:abc stat:UNDELIV');
+		const receipt = parseReceipt('id:abc sub: stat:UNDELIV');
 
 		assert.equal(receipt.id, 'abc');
 		assert.equal(receipt.stat, 'UNDELIV');
@@ -94,6 +94,7 @@ describe('dlrFromPdu()', () => {
 		assert.equal(dlr.statusId, 2);
 		assert.equal(dlr.errorCode, '000');
 		assert.equal(dlr.doneDate?.toISOString(), '2025-08-25T14:31:00.000Z');
+		assert.equal(dlrFromPdu(deliverSm('id:beef-1\r\nstat:DELIVRD'))?.smsId, 'beef-1');
 	});
 
 	test('maps every spec status code back to its message state and id', () => {