For #20893: Dedupe urls/site in history groups

app/src/main/java/org/mozilla/fenix/components/history/PagedHistoryProvider.kt

@@ -132,10 +132,14 @@ class DefaultPagedHistoryProvider(
         // item.
         result.addAll(history.filter { item -> historyMetadata.find { it.url == item.url } == null })
 
-        // Filter history metadata items with no view time.
+        // Filter history metadata items with no view time and dedupe by url.
+        // Note that distinctBy is sufficient here as it keeps the order of the source
+        // collection, and we're only sorting by visitedAt (=updatedAt) currently.
+        // If we needed the view time we'd have to aggregate it for entries with the same
+        // url, but we don't have a use case for this currently in the history view.
         result.addAll(
             historyGroupsInOffset.map { group ->
-                group.copy(items = group.items.filter { it.totalViewTime > 0 })
+                group.copy(items = group.items.filter { it.totalViewTime > 0 }.distinctBy { it.url })
             }
         )
 

app/src/test/java/org/mozilla/fenix/components/history/PagedHistoryProviderTest.kt

@@ -73,8 +73,20 @@ class PagedHistoryProviderTest {
             previewImageUrl = null
         )
 
+        // Adding a third entry with same url to test deduping
+        val historyMetadataKey3 = HistoryMetadataKey("http://www.firefox.com", "mozilla", null)
+        val historyEntry3 = HistoryMetadata(
+            key = historyMetadataKey3,
+            title = "firefox",
+            createdAt = 3,
+            updatedAt = 3,
+            totalViewTime = 30,
+            documentType = DocumentType.Regular,
+            previewImageUrl = null
+        )
+
         coEvery { storage.getVisitsPaginated(any(), any(), any()) } returns listOf(visitInfo1, visitInfo2, visitInfo3)
-        coEvery { storage.getHistoryMetadataSince(any()) } returns listOf(historyEntry1, historyEntry2)
+        coEvery { storage.getHistoryMetadataSince(any()) } returns listOf(historyEntry1, historyEntry2, historyEntry3)
 
         var actualResults: List<History>? = null
         provider.getHistory(10L, 5) {