fix(store): Properly prune extended commits (#27)

* Deleted extended Commits from DB as well

* Added tests

* Moved extCommit deletion into check for evidence

---------

Co-authored-by: jmalicevic <jasmina@informal.systems>

Author: jmalicevic

store/store.go

@@ -423,10 +423,15 @@ func (bs *BlockStore) PruneBlocks(height int64, state sm.State) (uint64, int64,
 			if err := batch.Delete(calcBlockCommitKey(h)); err != nil {
 				return 0, -1, err
 			}
+			if err := batch.Delete(calcExtCommitKey(h)); err != nil {
+				return 0, -1, err
+			}
 		}
 		if err := batch.Delete(calcSeenCommitKey(h)); err != nil {
 			return 0, -1, err
+
 		}
+
 		for p := 0; p < int(meta.BlockID.PartSetHeader.Total); p++ {
 			if err := batch.Delete(calcBlockPartKey(h, p)); err != nil {
 				return 0, -1, err

store/store_test.go

@@ -668,7 +668,9 @@ func TestPruningService(t *testing.T) {
 		require.NotNil(t, bs.LoadBlockMeta(1100))
 		require.Nil(t, bs.LoadBlockMeta(1099))
 		require.NotNil(t, bs.LoadBlockCommit(1100))
+		require.NotNil(t, bs.LoadBlockExtendedCommit(1100))
 		require.Nil(t, bs.LoadBlockCommit(1099))
+		require.Nil(t, bs.LoadBlockExtendedCommit(1099))
 		for i := int64(1); i < 1200; i++ {
 			require.Nil(t, bs.LoadBlock(i))
 		}
@@ -706,7 +708,9 @@ func TestPruningService(t *testing.T) {
 		require.NotNil(t, bs.LoadBlockMeta(1100))
 		require.Nil(t, bs.LoadBlockMeta(1099))
 		require.NotNil(t, bs.LoadBlockCommit(1100))
+		require.NotNil(t, bs.LoadBlockExtendedCommit(1100))
 		require.Nil(t, bs.LoadBlockCommit(1099))
+		require.Nil(t, bs.LoadBlockExtendedCommit(1099))
 		t.Log("Done pruning up until 1300")
 	case <-time.After(5 * time.Second):
 		require.Fail(t, "timed out waiting for pruning run to complete")