Cover the bookmark name commit rules

Pins the three cases the commit seam has to get right: a name resolved for a
live bookmark is stored, and a name that lands after remove or after a panic
clearAll is dropped, including across a reload from SharedPreferences.

createForTest builds an isolated store with reverse geocoding disabled so the
tests never reach the network.

app/src/test/kotlin/com/bitchat/android/geohash/GeohashBookmarkNameCommitTest.kt

@@ -0,0 +1,82 @@
+package com.bitchat.android.geohash
+
+import android.content.Context
+import androidx.test.core.app.ApplicationProvider
+import org.junit.Assert.assertEquals
+import org.junit.Assert.assertNull
+import org.junit.Before
+import org.junit.Test
+import org.junit.runner.RunWith
+import org.robolectric.RobolectricTestRunner
+
+/**
+ * A reverse geocode started for a bookmark runs on the IO dispatcher and can finish after
+ * the bookmark is gone. These tests pin the commit step: a resolved name is stored only
+ * while the geohash is still bookmarked.
+ */
+@RunWith(RobolectricTestRunner::class)
+class GeohashBookmarkNameCommitTest {
+
+    private lateinit var store: GeohashBookmarksStore
+
+    @Before
+    fun setUp() {
+        val context = ApplicationProvider.getApplicationContext<Context>()
+        store = GeohashBookmarksStore.createForTest(context)
+        store.clearAll()
+    }
+
+    @Test
+    fun `resolved name is stored for a bookmark that is still present`() {
+        store.add("u4pruy")
+
+        store.commitResolvedName("u4pruy", "Copenhagen")
+
+        assertEquals("Copenhagen", store.bookmarkNames.value["u4pruy"])
+    }
+
+    @Test
+    fun `resolved name is dropped when the bookmark was removed while in flight`() {
+        store.add("u4pruy")
+        store.remove("u4pruy")
+
+        store.commitResolvedName("u4pruy", "Copenhagen")
+
+        assertNull(store.bookmarkNames.value["u4pruy"])
+    }
+
+    @Test
+    fun `resolved name is dropped when a panic clear happened while in flight`() {
+        store.add("u4pruy")
+        store.clearAll()
+
+        store.commitResolvedName("u4pruy", "Copenhagen")
+
+        assertNull(store.bookmarkNames.value["u4pruy"])
+        assertEquals(emptyMap<String, String>(), store.bookmarkNames.value)
+    }
+
+    @Test
+    fun `a panic clear survives a restart when a lookup lands after the wipe`() {
+        store.add("u4pruy")
+        store.clearAll()
+        store.commitResolvedName("u4pruy", "Copenhagen")
+
+        // A fresh store reads back what was persisted, which is what the next launch sees.
+        val reloaded = GeohashBookmarksStore.createForTest(
+            ApplicationProvider.getApplicationContext<Context>()
+        )
+        assertEquals(emptyList<String>(), reloaded.bookmarks.value)
+        assertEquals(emptyMap<String, String>(), reloaded.bookmarkNames.value)
+    }
+
+    @Test
+    fun `an empty or blank name is never stored`() {
+        store.add("u4pruy")
+
+        store.commitResolvedName("u4pruy", null)
+        store.commitResolvedName("u4pruy", "")
+
+        assertNull(store.bookmarkNames.value["u4pruy"])
+    }
+}