fix String.inc() and String.dec() not being inverse operations (#2355)

app/src/main/java/com/keylesspalace/tusky/components/timeline/viewmodel/CachedTimelineViewModel.kt

@@ -143,7 +143,7 @@ class CachedTimelineViewModel @Inject constructor(
 
                 val nextPlaceholderId = timelineDao.getNextPlaceholderIdAfter(activeAccount.id, placeholderId)
 
-                val response = api.homeTimeline(maxId = placeholderId.inc(), sinceId = nextPlaceholderId, limit = 20).await()
+                val response = api.homeTimeline(maxId = placeholderId.inc(), sinceId = nextPlaceholderId, limit = LOAD_AT_ONCE).await()
 
                 val statuses = response.body()
                 if (!response.isSuccessful || statuses == null) {

app/src/main/java/com/keylesspalace/tusky/util/StringUtils.kt

@@ -17,27 +17,39 @@ fun randomAlphanumericString(count: Int): String {
 }
 
 // We sort statuses by ID. Something we need to invent some ID for placeholder.
-// Not sure if inc()/dec() should be made `operator` or not
 
 /**
- * "Increment" string so that during sorting it's bigger than [this].
+ * "Increment" string so that during sorting it's bigger than [this]. Inverse operation to [dec].
  */
 fun String.inc(): String {
-    // We assume that we will stay in the safe range for now
     val builder = this.toCharArray()
-    builder[lastIndex] = builder[lastIndex].inc()
+    var i = builder.lastIndex
+
+    while (i >= 0) {
+        if (builder[i] < 'z') {
+            builder[i] = builder[i].inc()
             return String(builder)
+        } else {
+            builder[i] = '0'
+        }
+        i--
+    }
+    return String(
+        CharArray(builder.size + 1) { index ->
+            if (index == 0) '0' else builder[index - 1]
+        }
+    )
 }
 
 /**
- * "Decrement" string so that during sorting it's smaller than [this].
+ * "Decrement" string so that during sorting it's smaller than [this]. Inverse operation to [inc].
  */
 fun String.dec(): String {
     if (this.isEmpty()) return this
 
     val builder = this.toCharArray()
     var i = builder.lastIndex
-    while (i > 0) {
+    while (i >= 0) {
         if (builder[i] > '0') {
             builder[i] = builder[i].dec()
             return String(builder)
@@ -46,12 +58,7 @@ fun String.dec(): String {
         }
         i--
     }
-    return if (builder[0] > '1') {
+    return String(builder.copyOfRange(1, builder.size))
-        builder[0] = builder[0].dec()
-        String(builder)
-    } else {
-        String(builder.copyOfRange(1, builder.size))
-    }
 }
 
 /**
@@ -71,15 +78,6 @@ fun String.isLessThan(other: String): Boolean {
     }
 }
 
-fun String.idCompareTo(other: String): Int {
-    return when {
-        this === other -> 0
-        this.length < other.length -> -1
-        this.length > other.length -> 1
-        else -> this.compareTo(other)
-    }
-}
-
 fun Spanned.trimTrailingWhitespace(): Spanned {
     var i = length
     do {

app/src/test/java/com/keylesspalace/tusky/StringUtilsTest.kt

@@ -27,22 +27,37 @@ class StringUtilsTest {
     @Test
     fun inc() {
         listOf(
+            "10786565059022968z" to "107865650590229690",
             "122" to "123",
             "12A" to "12B",
-            "1" to "2"
+            "11z" to "120",
+            "0zz" to "100",
+            "zz" to "000",
+            "4zzbz" to "4zzc0",
+            "" to "0",
+            "1" to "2",
+            "0" to "1",
+            "AGdxwSQqT3pW4xrLJA" to "AGdxwSQqT3pW4xrLJB",
+            "AGdfqi1HnlBFVl0tkz" to "AGdfqi1HnlBFVl0tl0"
         ).forEach { (l, r) -> assertEquals("$l + 1 = $r", r, l.inc()) }
     }
 
     @Test
     fun dec() {
         listOf(
+            "" to "",
+            "107865650590229690" to "10786565059022968z",
             "123" to "122",
             "12B" to "12A",
             "120" to "11z",
-            "100" to "zz",
+            "100" to "0zz",
+            "000" to "zz",
+            "4zzc0" to "4zzbz",
             "0" to "",
-            "" to "",
+            "2" to "1",
-            "2" to "1"
+            "1" to "0",
+            "AGdxwSQqT3pW4xrLJB" to "AGdxwSQqT3pW4xrLJA",
+            "AGdfqi1HnlBFVl0tl0" to "AGdfqi1HnlBFVl0tkz"
         ).forEach { (l, r) -> assertEquals("$l - 1 = $r", r, l.dec()) }
     }
 }

app/src/test/java/com/keylesspalace/tusky/db/TimelineDaoTest.kt

@@ -144,7 +144,8 @@ class TimelineDaoTest {
             makeStatus(statusId = 1)
         )
 
-        timelineDao.deleteRange(1, newStatuses.last().first.serverId, newStatuses.first().first.serverId)
+        val deletedCount = timelineDao.deleteRange(1, newStatuses.last().first.serverId, newStatuses.first().first.serverId)
+        assertEquals(3, deletedCount)
 
         for ((status, author, reblogAuthor) in newStatuses) {
             timelineDao.insertAccount(author)
@@ -169,9 +170,11 @@ class TimelineDaoTest {
     fun deleteRange() = runBlocking {
         val statuses = listOf(
             makeStatus(statusId = 100),
+            makeStatus(statusId = 50),
             makeStatus(statusId = 15),
             makeStatus(statusId = 14),
             makeStatus(statusId = 13),
+            makeStatus(statusId = 13, accountId = 2),
             makeStatus(statusId = 12),
             makeStatus(statusId = 11),
             makeStatus(statusId = 9)
@@ -185,20 +188,31 @@ class TimelineDaoTest {
             timelineDao.insertStatus(status)
         }
 
-        timelineDao.deleteRange(1, "12", "14")
+        assertEquals(3, timelineDao.deleteRange(1, "12", "14"))
+        assertEquals(0, timelineDao.deleteRange(1, "80", "80"))
+        assertEquals(0, timelineDao.deleteRange(1, "60", "80"))
+        assertEquals(0, timelineDao.deleteRange(1, "5", "8"))
+        assertEquals(0, timelineDao.deleteRange(1, "101", "1000"))
+        assertEquals(1, timelineDao.deleteRange(1, "50", "50"))
 
-        val pagingSource = timelineDao.getStatusesForAccount(1)
+        val loadParams: PagingSource.LoadParams<Int> = PagingSource.LoadParams.Refresh(null, 100, false)
-        val loadResult = pagingSource.load(PagingSource.LoadParams.Refresh(null, 100, false))
-        val loadedStatuses = (loadResult as PagingSource.LoadResult.Page).data
 
-        val remainingStatuses = listOf(
+        val statusesAccount1 = (timelineDao.getStatusesForAccount(1).load(loadParams) as PagingSource.LoadResult.Page).data
+        val statusesAccount2 = (timelineDao.getStatusesForAccount(2).load(loadParams) as PagingSource.LoadResult.Page).data
+
+        val remainingStatusesAccount1 = listOf(
             makeStatus(statusId = 100),
             makeStatus(statusId = 15),
             makeStatus(statusId = 11),
             makeStatus(statusId = 9)
         )
 
-        assertStatuses(remainingStatuses, loadedStatuses)
+        val remainingStatusesAccount2 = listOf(
+            makeStatus(statusId = 13, accountId = 2)
+        )
+
+        assertStatuses(remainingStatusesAccount1, statusesAccount1)
+        assertStatuses(remainingStatusesAccount2, statusesAccount2)
     }
 
     @Test
@@ -325,7 +339,7 @@ class TimelineDaoTest {
         }
 
         assertEquals("99", timelineDao.getNextPlaceholderIdAfter(1, "1000"))
-        assertEquals("94", timelineDao.getNextPlaceholderIdAfter(1, "97"))
+        assertEquals("94", timelineDao.getNextPlaceholderIdAfter(1, "99"))
         assertNull(timelineDao.getNextPlaceholderIdAfter(1, "90"))
     }
 
@@ -364,28 +378,28 @@ class TimelineDaoTest {
         domain: String = "mastodon.example"
     ): Triple<TimelineStatusEntity, TimelineAccountEntity, TimelineAccountEntity?> {
         val author = TimelineAccountEntity(
-            authorServerId,
+            serverId = authorServerId,
-            accountId,
+            timelineUserId = accountId,
-            "localUsername@$domain",
+            localUsername = "localUsername@$domain",
-            "username@$domain",
+            username = "username@$domain",
-            "displayName",
+            displayName = "displayName",
-            "blah",
+            url = "blah",
-            "avatar",
+            avatar = "avatar",
-            "[\"tusky\": \"http://tusky.cool/emoji.jpg\"]",
+            emojis = "[\"tusky\": \"http://tusky.cool/emoji.jpg\"]",
-            false
+            bot = false
         )
 
         val reblogAuthor = if (reblog) {
             TimelineAccountEntity(
-                "R$authorServerId",
+                serverId = "R$authorServerId",
-                accountId,
+                timelineUserId = accountId,
-                "RlocalUsername",
+                localUsername = "RlocalUsername",
-                "Rusername",
+                username = "Rusername",
-                "RdisplayName",
+                displayName = "RdisplayName",
-                "Rblah",
+                url = "Rblah",
-                "Ravatar",
+                avatar = "Ravatar",
-                "[]",
+                emojis = "[]",
-                false
+                bot = false
             )
         } else null