chore: add test_segment_config_backwards (#13394)

Cargo.lock

@@ -9393,6 +9393,7 @@ dependencies = [
  "alloy-primitives",
  "clap",
  "derive_more",
+ "reth-nippy-jar",
  "serde",
  "strum",
 ]

crates/static-file/types/Cargo.toml

@@ -19,5 +19,8 @@ derive_more.workspace = true
 serde = { workspace = true, features = ["derive"] }
 strum = { workspace = true, features = ["derive"] }
 
+[dev-dependencies]
+reth-nippy-jar.workspace = true
+
 [features]
-clap = ["dep:clap"]
+clap = ["dep:clap"]

crates/static-file/types/src/segment.rs

@@ -353,6 +353,8 @@ impl From<SegmentRangeInclusive> for RangeInclusive<u64> {
 #[cfg(test)]
 mod tests {
     use super::*;
+    use alloy_primitives::hex;
+    use reth_nippy_jar::NippyJar;
     use strum::IntoEnumIterator;
 
     #[test]
@@ -410,4 +412,49 @@ mod tests {
             assert_eq!(Some((segment, dummy_range)), StaticFileSegment::parse_filename(&filename));
         }
     }
+
+    #[test]
+    fn test_segment_config_backwards() {
+        let headers = hex!("010000000000000000000000000000001fa10700000000000100000000000000001fa10700000000000000000000030000000000000020a107000000000001010000004a02000000000000");
+        let transactions = hex!("010000000000000000000000000000001fa10700000000000100000000000000001fa107000000000001000000000000000034a107000000000001000000010000000000000035a1070000000000004010000000000000");
+        let receipts = hex!("010000000000000000000000000000001fa10700000000000100000000000000000000000000000000000200000001000000000000000000000000000000000000000000000000");
+
+        {
+            let headers = NippyJar::<SegmentHeader>::load_from_reader(&headers[..]).unwrap();
+            assert_eq!(
+                &SegmentHeader {
+                    expected_block_range: SegmentRangeInclusive::new(0, 499999),
+                    block_range: Some(SegmentRangeInclusive::new(0, 499999)),
+                    tx_range: None,
+                    segment: StaticFileSegment::Headers,
+                },
+                headers.user_header()
+            );
+        }
+        {
+            let transactions =
+                NippyJar::<SegmentHeader>::load_from_reader(&transactions[..]).unwrap();
+            assert_eq!(
+                &SegmentHeader {
+                    expected_block_range: SegmentRangeInclusive::new(0, 499999),
+                    block_range: Some(SegmentRangeInclusive::new(0, 499999)),
+                    tx_range: Some(SegmentRangeInclusive::new(0, 500020)),
+                    segment: StaticFileSegment::Transactions,
+                },
+                transactions.user_header()
+            );
+        }
+        {
+            let receipts = NippyJar::<SegmentHeader>::load_from_reader(&receipts[..]).unwrap();
+            assert_eq!(
+                &SegmentHeader {
+                    expected_block_range: SegmentRangeInclusive::new(0, 499999),
+                    block_range: Some(SegmentRangeInclusive::new(0, 0)),
+                    tx_range: None,
+                    segment: StaticFileSegment::Receipts,
+                },
+                receipts.user_header()
+            );
+        }
+    }
 }

crates/storage/nippy-jar/src/lib.rs

@@ -17,6 +17,7 @@ use serde::{Deserialize, Serialize};
 use std::{
     error::Error as StdError,
     fs::File,
+    io::Read,
     ops::Range,
     path::{Path, PathBuf},
 };
@@ -201,11 +202,16 @@ impl<H: NippyJarHeader> NippyJar<H> {
         let config_file = File::open(&config_path)
             .map_err(|err| reth_fs_util::FsPathError::open(err, config_path))?;
 
-        let mut obj: Self = bincode::deserialize_from(&config_file)?;
+        let mut obj = Self::load_from_reader(config_file)?;
         obj.path = path.to_path_buf();
         Ok(obj)
     }
 
+    /// Deserializes an instance of [`Self`] from a [`Read`] type.
+    pub fn load_from_reader<R: Read>(reader: R) -> Result<Self, NippyJarError> {
+        Ok(bincode::deserialize_from(reader)?)
+    }
+
     /// Returns the path for the data file
     pub fn data_path(&self) -> &Path {
         self.path.as_ref()