internal/ethapi: add more testcases for block/header rpc (#27325)

Signed-off-by: jsvisa <delweng@gmail.com>
Co-authored-by: Sina Mahmoodi <1591639+s1na@users.noreply.github.com>

internal/ethapi/api.go

@@ -731,8 +731,10 @@ func decodeHash(s string) (common.Hash, error) {
 }
 
 // GetHeaderByNumber returns the requested canonical block header.
-// * When blockNr is -1 the chain head is returned.
-// * When blockNr is -2 the pending chain head is returned.
+//   - When blockNr is -1 the chain pending header is returned.
+//   - When blockNr is -2 the chain latest header is returned.
+//   - When blockNr is -3 the chain finalized header is returned.
+//   - When blockNr is -4 the chain safe header is returned.
 func (s *BlockChainAPI) GetHeaderByNumber(ctx context.Context, number rpc.BlockNumber) (map[string]interface{}, error) {
 	header, err := s.b.HeaderByNumber(ctx, number)
 	if header != nil && err == nil {
@@ -758,8 +760,10 @@ func (s *BlockChainAPI) GetHeaderByHash(ctx context.Context, hash common.Hash) m
 }
 
 // GetBlockByNumber returns the requested canonical block.
-//   - When blockNr is -1 the chain head is returned.
-//   - When blockNr is -2 the pending chain head is returned.
+//   - When blockNr is -1 the chain pending block is returned.
+//   - When blockNr is -2 the chain latest block is returned.
+//   - When blockNr is -3 the chain finalized block is returned.
+//   - When blockNr is -4 the chain safe block is returned.
 //   - When fullTx is true all transactions in the block are returned, otherwise
 //     only the transaction hash is returned.
 func (s *BlockChainAPI) GetBlockByNumber(ctx context.Context, number rpc.BlockNumber, fullTx bool) (map[string]interface{}, error) {