Don't throw exception on empty data in AndroidX Paging3 extension (#2219

)
cashapp · Mar 29, 2021 · de0ad1a · de0ad1a
1 parent ed0dc0e
commit de0ad1a
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Showing 2 changed files with 16 additions and 1 deletion.
diff --git a/...-paging3/src/main/java/com/squareup/sqldelight/android/paging3/OffsetQueryPagingSource.kt b/...-paging3/src/main/java/com/squareup/sqldelight/android/paging3/OffsetQueryPagingSource.kt
@@ -37,7 +37,7 @@ internal class OffsetQueryPagingSource<RowType : Any>(
       val key = params.key ?: 0L
       transacter.transactionWithResult {
         val count = countQuery.executeAsOne()
-        if (key >= count) throw IndexOutOfBoundsException()
+        if (count != 0L && key >= count) throw IndexOutOfBoundsException()
 
         val loadSize = if (key < 0) params.loadSize + key else params.loadSize
 

diff --git a/...ing3/src/test/java/com/squareup/sqldelight/android/paging3/OffsetQueryPagingSourceTest.kt b/...ing3/src/test/java/com/squareup/sqldelight/android/paging3/OffsetQueryPagingSourceTest.kt
@@ -69,6 +69,21 @@ class OffsetQueryPagingSourceTest {
     transacter = object : TransacterImpl(driver) {}
   }
 
+  @Test fun `empty page gives correct prevKey and nextKey`() {
+    driver.execute(null, "DELETE FROM testTable", 0)
+    val source = OffsetQueryPagingSource(
+      this::query,
+      countQuery(),
+      transacter,
+      TestCoroutineDispatcher()
+    )
+
+    val results = runBlocking { source.load(Refresh(null, 2, false)) }
+
+    assertNull((results as LoadResult.Page).prevKey)
+    assertNull(results.nextKey)
+  }
+
   @Test fun `aligned first page gives correct prevKey and nextKey`() {
     val source = OffsetQueryPagingSource(
       this::query,