neiam /apollos_crib

It's Apollo's Crib

Recognise the Plus board by the topic RabbitMQ actually delivers

e996024 · Gabriel Morell · 2026-09-08 20:09

18 files +58 -1

Message

{commit_body(@commit)}

modified clients/android/app/src/main/java/io/neiam/apolloscrib/mqtt/AnkyraClient.kt

+18 −1

@@ -125,7 +125,7 @@ class AnkyraClient(

125	125	// at the payload: the two boards carry the same query ids and
126	126	// mostly the same types, and guessing from content would be
127	127	// guessing.
128		− if (publish.topic.toString().endsWith(PLUS_SUFFIX)) {
	128	+ if (isPlusTopic(publish.topic.toString())) {
129	129	onPlus(payload)
130	130	} else {
131	131	onMessage(payload)

@@ -229,5 +229,22 @@ class AnkyraClient(

229	229
230	230	/** Where a Pythiae publishes its Plus reading, beside the Basic one. */
231	231	const val PLUS_SUFFIX = ".plus"
	232	+
	233	+ /**
	234	+ * Whether a delivered topic is the Plus one.
	235	+ *
	236	+ * The separator changes in flight. A Pythiae publishes to the AMQP
	237	+ * routing key `<topic>.plus`, and RabbitMQ's MQTT plugin maps dots in
	238	+ * a routing key to slashes in the topic it hands a subscriber -- so
	239	+ * what is subscribed to as `X.plus` arrives as `X/plus`.
	240	+ *
	241	+ * It went unnoticed because both boards still arrived: the Plus one
	242	+ * simply failed this test and was filed as the Basic board, which then
	243	+ * lost most of its cards, because nothing draws a `gtfs_plus` entry in
	244	+ * compact mode. Two boards alternating in the log at slightly
	245	+ * different sizes is what gave it away.
	246	+ */
	247	+ fun isPlusTopic(topic: String): Boolean =
	248	+ topic.replace('/', '.').endsWith(PLUS_SUFFIX)
232	249	}
233	250	}

added clients/android/app/src/test/java/io/neiam/apolloscrib/mqtt/TopicTest.kt

+40 −0

@@ -0,0 +1,40 @@

	1	+package io.neiam.apolloscrib.mqtt
	2	+
	3	+import org.junit.Assert.assertFalse
	4	+import org.junit.Assert.assertTrue
	5	+import org.junit.Test
	6	+
	7	+/**
	8	+ * Which board a message is, from the topic it arrived on.
	9	+ *
	10	+ * The separator changes in flight: a Pythiae publishes to the AMQP routing key
	11	+ * `<topic>.plus`, and RabbitMQ's MQTT plugin hands it to a subscriber as
	12	+ * `<topic>/plus`. Both spellings have to read as the same thing.
	13	+ */
	14	+class TopicTest {
	15	+
	16	+ @Test
	17	+ fun `the plus board as RabbitMQ delivers it`() {
	18	+ assertTrue(AnkyraClient.isPlusTopic("Iodized-Nutritious-Xenoposeidon/plus"))
	19	+ }
	20	+
	21	+ @Test
	22	+ fun `the plus board as it is subscribed to`() {
	23	+ assertTrue(AnkyraClient.isPlusTopic("Iodized-Nutritious-Xenoposeidon.plus"))
	24	+ }
	25	+
	26	+ @Test
	27	+ fun `the ordinary board is not the plus one`() {
	28	+ assertFalse(AnkyraClient.isPlusTopic("Iodized-Nutritious-Xenoposeidon"))
	29	+ }
	30	+
	31	+ @Test
	32	+ fun `a topic that merely mentions plus is not the plus board`() {
	33	+ assertFalse(AnkyraClient.isPlusTopic("Plus-Nutritious-Xenoposeidon"))
	34	+ }
	35	+
	36	+ @Test
	37	+ fun `an uplink is not a board at all`() {
	38	+ assertFalse(AnkyraClient.isPlusTopic("Iodized-Nutritious-Xenoposeidon/up/loc"))
	39	+ }
	40	+}

Parents: 725a8da