fix: prevent panic when scanning from genesis block (#408)

Parent block height (`u64`) is always set to `block - 1` which will result on a panic when trying to construct genesis parent's block height. Co-authored-by: Ludo Galabru <ludo@hiro.so>
hirosystems · Sep 15, 2023 · 1868a06 · 1868a06
1 parent 19f5310
commit 1868a06
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Showing 4 changed files with 31 additions and 12 deletions.
diff --git a/components/chainhook-sdk/src/indexer/bitcoin/mod.rs b/components/chainhook-sdk/src/indexer/bitcoin/mod.rs
@@ -548,7 +548,10 @@ pub fn standardize_bitcoin_block(
                     .previousblockhash
                     .unwrap_or(BlockHash::all_zeros().to_string())
             ),
-            index: block_height - 1,
+            index: match block_height {
+                0 => 0,
+                _ => block_height - 1,
+            },
         },
         timestamp: block.time as u32,
         metadata: BitcoinBlockMetadata {

diff --git a/components/chainhook-sdk/src/indexer/stacks/mod.rs b/components/chainhook-sdk/src/indexer/stacks/mod.rs
@@ -336,7 +336,10 @@ pub fn standardize_stacks_block(
         },
         parent_block_identifier: BlockIdentifier {
             hash: block.parent_index_block_hash.clone(),
-            index: block.block_height - 1,
+            index: match block.block_height {
+                0 => 0,
+                _ => block.block_height - 1,
+            }
         },
         timestamp: block.parent_burn_block_timestamp,
         metadata: StacksBlockMetadata {

diff --git a/components/chainhook-sdk/src/indexer/tests/helpers/bitcoin_blocks.rs b/components/chainhook-sdk/src/indexer/tests/helpers/bitcoin_blocks.rs
@@ -11,13 +11,19 @@ pub fn generate_test_bitcoin_block(
     let mut hash = vec![
         fork_id, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
     ];
+
+    let parent_height = match block_height {
+        0 => 0,
+        _ => block_height - 1,
+    };
+
     let parent_block_identifier = match parent {
         Some(parent) => {
-            assert_eq!(parent.block_identifier.index, block_height - 1);
+            assert_eq!(parent.block_identifier.index, parent_height);
             parent.block_identifier.clone()
         }
         _ => {
-            let mut parent_hash = if (block_height - 1) == 1 {
+            let mut parent_hash = if parent_height == 1 {
                 vec![
                     0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
                 ]
@@ -26,9 +32,10 @@ pub fn generate_test_bitcoin_block(
                     fork_id, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
                 ]
             };
-            parent_hash.append(&mut (block_height - 1).to_be_bytes().to_vec());
+
+            parent_hash.append(&mut parent_height.to_be_bytes().to_vec());
             BlockIdentifier {
-                index: block_height - 1,
+                index: parent_height,
                 hash: format!("0x{}", hex::encode(&parent_hash[..])),
             }
         }

diff --git a/components/chainhook-sdk/src/indexer/tests/helpers/stacks_blocks.rs b/components/chainhook-sdk/src/indexer/tests/helpers/stacks_blocks.rs
@@ -12,23 +12,29 @@ pub fn generate_test_stacks_block(
     let mut hash = vec![
         fork_id, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
     ];
+
+    let parent_height = match block_height {
+        0 => 0,
+        _ => block_height - 1,
+    };
+
     let (parent_block_identifier, confirm_microblock_identifier) = match parent {
         Some(BlockEvent::Block(parent)) => {
-            assert_eq!(parent.block_identifier.index, block_height - 1);
+            assert_eq!(parent.block_identifier.index, parent_height);
             (parent.block_identifier.clone(), None)
         }
         Some(BlockEvent::Microblock(microblock_parent)) => {
             assert_eq!(
                 microblock_parent.metadata.anchor_block_identifier.index,
-                block_height - 1
+                parent_height,
             );
             (
                 microblock_parent.metadata.anchor_block_identifier.clone(),
                 Some(microblock_parent.block_identifier.clone()),
             )
         }
         _ => {
-            let mut parent_hash = if (block_height - 1) == 1 {
+            let mut parent_hash = if parent_height == 1 {
                 vec![
                     0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
                 ]
@@ -37,10 +43,10 @@ pub fn generate_test_stacks_block(
                     fork_id, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
                 ]
             };
-            parent_hash.append(&mut (block_height - 1).to_be_bytes().to_vec());
+            parent_hash.append(&mut parent_height.to_be_bytes().to_vec());
             (
                 BlockIdentifier {
-                    index: block_height - 1,
+                    index: parent_height,
                     hash: hex::encode(&parent_hash[..]),
                 },
                 None,
@@ -58,7 +64,7 @@ pub fn generate_test_stacks_block(
         transactions,
         metadata: StacksBlockMetadata {
             bitcoin_anchor_block_identifier: BlockIdentifier {
-                index: block_height - 1,
+                index: parent_height,
                 hash: format!(""),
             },
             pox_cycle_index: 1,