Fix Long overflow in TackDetector: var lastTackMs = Long.MIN_VALUE caused subtraction overflow, filtering every tack

1 files changed, 25 insertions, 0 deletions

diff --git a/android-app/app/src/test/kotlin/org/terst/nav/track/TackDetectorGpxTest.kt b/android-app/app/src/test/kotlin/org/terst/nav/track/TackDetectorGpxTest.kt
new file mode 100644
index 0000000..83ca259
--- /dev/null
+++ b/android-app/app/src/test/kotlin/org/terst/nav/track/TackDetectorGpxTest.kt
@@ -0,0 +1,25 @@
+package org.terst.nav.track
+
+import org.junit.Assert.assertEquals
+import org.junit.Assert.assertTrue
+import org.junit.Test
+
+class TackDetectorGpxTest {
+
+    @Test
+    fun `detects 6 tacks in April 22 test file`() {
+        val stream = javaClass.classLoader!!
+            .getResourceAsStream("nav_20260422_190543.gpx")
+            ?: error("GPX test file not found in test resources")
+        val points = GpxParser.parse(stream)
+        assertTrue("Expected >100 points, got ${points.size}", points.size > 100)
+
+        val tacks = TackDetector.detectTacks(points)
+        assertEquals(
+            "Expected 6 tacks in test track; got ${tacks.size}: ${
+                tacks.map { "%.0f→%.0f".format(it.cogBefore, it.cogAfter) }
+            }",
+            6, tacks.size
+        )
+    }
+}