feat(nano): Add HTTP API and CLI to re-run blocks and nano transactions

Author: msbrogli

hathor/builder/resources_builder.py

@@ -260,6 +260,7 @@ def create_resources(self) -> server.Site:
                 BlueprintSourceCodeResource,
                 NanoContractHistoryResource,
                 NanoContractStateResource,
+                NCDryRunResource,
             )
             nc_resource = Resource()
             root.putChild(b'nano_contract', nc_resource)
@@ -273,6 +274,7 @@ def create_resources(self) -> server.Site:
             nc_resource.putChild(b'state', NanoContractStateResource(self.manager))
             nc_resource.putChild(b'creation', NCCreationResource(self.manager))
             nc_resource.putChild(b'logs', NCExecLogsResource(self.manager))
+            nc_resource.putChild(b'dry_run', NCDryRunResource(self.manager))
 
         if self._args.enable_debug_api:
             debug_resource = Resource()

hathor/nanocontracts/execution/block_executor.py

@@ -132,6 +132,8 @@ def __init__(
     def execute_block(
         self,
         block: Block,
+        *,
+        dry_run: bool = False,
     ) -> Iterator[NCBlockEffect]:
         """Execute block as generator, yielding effects without applying them.
 
@@ -140,6 +142,8 @@ def execute_block(
 
         Args:
             block: The block to execute.
+            dry_run: If True, allows re-executing a block that has already been executed.
+                This is useful for debugging and inspection without modifying state.
 
         Yields:
             NCBlockEffect instances representing each step of execution.
@@ -151,7 +155,8 @@ def execute_block(
 
         meta = block.get_metadata()
         assert not meta.voided_by
-        assert meta.nc_block_root_id is None
+        if not dry_run:
+            assert meta.nc_block_root_id is None
 
         parent = block.get_block_parent()
         parent_meta = parent.get_metadata()
@@ -163,9 +168,11 @@ def execute_block(
             if not tx.is_nano_contract():
                 continue
             tx_meta = tx.get_metadata()
-            assert tx_meta.nc_execution in {None, NCExecutionState.PENDING}
+            if not dry_run:
+                assert tx_meta.nc_execution in {None, NCExecutionState.PENDING}
             if tx_meta.voided_by:
-                assert NC_EXECUTION_FAIL_ID not in tx_meta.voided_by
+                if not dry_run:
+                    assert NC_EXECUTION_FAIL_ID not in tx_meta.voided_by
             nc_calls.append(tx)
 
         nc_sorted_calls = self._nc_calls_sorter(block, nc_calls) if nc_calls else []