Merge pull request #193 from SiaFoundation/christopher/404-no-block

HTTP error 404 if block doesn't exist instead of 500

Author: chris124567

api/server.go

@@ -278,7 +278,10 @@ func (s *server) blocksIDHandler(jc jape.Context) {
 		return
 	}
 	block, err := s.e.Block(id)
-	if jc.Check("failed to get block", err) != nil {
+	if errors.Is(err, explorer.ErrNoBlock) {
+		jc.Error(err, http.StatusNotFound)
+		return
+	} else if jc.Check("failed to get block", err) != nil {
 		return
 	}
 	jc.Encode(block)

explorer/explorer.go

@@ -20,6 +20,10 @@ var (
 	// database or there is no tips at all.
 	ErrNoTip = errors.New("no tip found")
 
+	// ErrNoBlock is returned when we are unable to find the block in the
+	// database.
+	ErrNoBlock = errors.New("block not found")
+
 	// ErrContractNotFound is returned when ContractRevisions is unable to find
 	// the specified contract ID.
 	ErrContractNotFound = errors.New("contract not found")

persist/sqlite/blocks.go

@@ -15,7 +15,9 @@ func (s *Store) Block(id types.BlockID) (result explorer.Block, err error) {
 		var v2Height uint64
 		var v2Commitment types.Hash256
 		err := tx.QueryRow(`SELECT parent_id, nonce, timestamp, height, leaf_index, v2_height, v2_commitment FROM blocks WHERE id = ?`, encode(id)).Scan(decode(&result.ParentID), decode(&result.Nonce), decode(&result.Timestamp), &result.Height, decode(&result.LeafIndex), decodeNull(&v2Height), decodeNull(&v2Commitment))
-		if err != nil {
+		if errors.Is(err, sql.ErrNoRows) {
+			return explorer.ErrNoBlock
+		} else if err != nil {
 			return fmt.Errorf("failed to get block: %w", err)
 		}
 		result.MinerPayouts, err = blockMinerPayouts(tx, id)
@@ -56,6 +58,22 @@ func (s *Store) Block(id types.BlockID) (result explorer.Block, err error) {
 	return
 }
 
+// Tip implements explorer.Store.
+func (s *Store) Tip() (result types.ChainIndex, err error) {
+	const query = `SELECT id, height FROM blocks ORDER BY height DESC LIMIT 1`
+	err = s.transaction(func(dbTxn *txn) error {
+		err := dbTxn.QueryRow(query).Scan(decode(&result.ID), &result.Height)
+		if errors.Is(err, sql.ErrNoRows) {
+			return explorer.ErrNoTip
+		} else if err != nil {
+			return err
+		}
+
+		return nil
+	})
+	return
+}
+
 // BestTip implements explorer.Store.
 func (s *Store) BestTip(height uint64) (result types.ChainIndex, err error) {
 	err = s.transaction(func(tx *txn) error {

persist/sqlite/consensus.go

@@ -1192,15 +1192,3 @@ func (s *Store) UpdateChainState(reverted []chain.RevertUpdate, applied []chain.
 		return nil
 	})
 }
-
-// Tip implements explorer.Store.
-func (s *Store) Tip() (result types.ChainIndex, err error) {
-	const query = `SELECT id, height FROM blocks ORDER BY height DESC LIMIT 1`
-	err = s.transaction(func(dbTxn *txn) error {
-		return dbTxn.QueryRow(query).Scan(decode(&result.ID), &result.Height)
-	})
-	if errors.Is(err, sql.ErrNoRows) {
-		return types.ChainIndex{}, explorer.ErrNoTip
-	}
-	return
-}

persist/sqlite/consensus_test.go

@@ -506,6 +506,22 @@ func TestTip(t *testing.T) {
 	}
 }
 
+func TestMissingBlock(t *testing.T) {
+	_, _, cm, db := newStore(t, false, nil)
+
+	id := cm.Tip().ID
+	_, err := db.Block(id)
+	if err != nil {
+		t.Fatalf("error retrieving genesis block: %v", err)
+	}
+
+	id[0] ^= 255
+	_, err = db.Block(id)
+	if !errors.Is(err, explorer.ErrNoBlock) {
+		t.Fatalf("did not get ErrNoBlock retrieving missing block: %v", err)
+	}
+}
+
 func TestFileContract(t *testing.T) {
 	pk1 := types.GeneratePrivateKey()
 	addr1 := types.StandardUnlockHash(pk1.PublicKey())