[fenix] For issue https://github.com/mozilla-mobile/fenix/issues/5298 the same page appears in the History section multiple times

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

@@ -4,6 +4,7 @@
 
 package org.mozilla.fenix.components.history
 
+import androidx.annotation.VisibleForTesting
 import mozilla.components.browser.storage.sync.PlacesHistoryStorage
 import mozilla.components.concept.storage.VisitInfo
 import mozilla.components.concept.storage.VisitType
@@ -203,7 +204,8 @@ class DefaultPagedHistoryProvider(
             }
         )
 
-        return result.sortedByDescending { it.visitedAt }
+        return result.removeConsecutiveDuplicates()
+            .sortedByDescending { it.visitedAt }
     }
 
     private fun transformVisitInfoToHistoryItem(offset: Int): (id: Int, visit: VisitInfo) -> History.Regular {
@@ -221,3 +223,18 @@ class DefaultPagedHistoryProvider(
         }
     }
 }
+
+@VisibleForTesting
+internal fun List<History>.removeConsecutiveDuplicates(): List<History> {
+    var previousURL = ""
+    return filter {
+        var isNotDuplicate = true
+        previousURL = if (it is History.Regular) {
+            isNotDuplicate = it.url != previousURL
+            it.url
+        } else {
+            ""
+        }
+        isNotDuplicate
+    }
+}

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

@@ -452,4 +452,74 @@ class PagedHistoryProviderTest {
         )
         assertEquals(results, actualResults)
     }
+
+    @Test
+    fun `WHEN removeConsecutiveDuplicates is called THEN all consecutive duplicates must be removed`() {
+        val results = listOf(
+            History.Group(
+                id = 1,
+                title = "Group 1",
+                visitedAt = 0,
+                items = emptyList()
+            ),
+            History.Regular(
+                id = 2,
+                title = "No duplicate item",
+                url = "url",
+                visitedAt = 0
+            ),
+            History.Regular(
+                id = 3,
+                title = "Duplicate item 1",
+                url = "url",
+                visitedAt = 0
+            ),
+            History.Regular(
+                id = 4,
+                title = "Duplicate item 2",
+                url = "url",
+                visitedAt = 0
+            ),
+            History.Group(
+                id = 5,
+                title = "Group 5",
+                visitedAt = 0,
+                items = emptyList()
+            ),
+            History.Regular(
+                id = 6,
+                title = "No duplicate item",
+                url = "url",
+                visitedAt = 0
+            ),
+        ).removeConsecutiveDuplicates()
+
+        val expectedList = listOf(
+            History.Group(
+                id = 1,
+                title = "Group 1",
+                visitedAt = 0,
+                items = emptyList()
+            ),
+            History.Regular(
+                id = 2,
+                title = "No duplicate item",
+                url = "url",
+                visitedAt = 0
+            ),
+            History.Group(
+                id = 5,
+                title = "Group 5",
+                visitedAt = 0,
+                items = emptyList()
+            ),
+            History.Regular(
+                id = 6,
+                title = "No duplicate item",
+                url = "url",
+                visitedAt = 0
+            ),
+        )
+        assertEquals(expectedList, results)
+    }
 }