test(scan): Add typed database format snapshots to the scanner (#8083)

* Refactor test data into functions

* Add a typed snapshot test for scanner storage

* Use standard hex serialization with SaplingScannedResult

* Simplify transaction::Hash hex serialization

* Sort HashMaps before snapshotting

* Add typed snapshot data

zebra-chain/src/block/hash.rs

@@ -85,10 +85,9 @@ impl FromHex for Hash {
     type Error = <[u8; 32] as FromHex>::Error;
 
     fn from_hex<T: AsRef<[u8]>>(hex: T) -> Result<Self, Self::Error> {
-        let mut hash = <[u8; 32]>::from_hex(hex)?;
+        let hash = <[u8; 32]>::from_hex(hex)?;
-        hash.reverse();
 
-        Ok(hash.into())
+        Ok(Self::from_bytes_in_display_order(&hash))
     }
 }
 
@@ -148,12 +147,6 @@ impl ZcashDeserialize for Hash {
 impl std::str::FromStr for Hash {
     type Err = SerializationError;
     fn from_str(s: &str) -> Result<Self, Self::Err> {
-        let mut bytes = [0; 32];
+        Ok(Self::from_hex(s)?)
-        if hex::decode_to_slice(s, &mut bytes[..]).is_err() {
-            Err(SerializationError::Parse("hex decoding error"))
-        } else {
-            bytes.reverse();
-            Ok(Hash(bytes))
-        }
     }
 }

zebra-chain/src/serialization/error.rs

@@ -2,6 +2,7 @@
 
 use std::{array::TryFromSliceError, io, num::TryFromIntError, str::Utf8Error};
 
+use hex::FromHexError;
 use thiserror::Error;
 
 /// A serialization error.
@@ -31,6 +32,10 @@ pub enum SerializationError {
     #[error("CompactSize too large: {0}")]
     TryFromIntError(#[from] TryFromIntError),
 
+    /// A string was not valid hexadecimal.
+    #[error("string was not hex: {0}")]
+    FromHexError(#[from] FromHexError),
+
     /// An error caused when validating a zatoshi `Amount`
     #[error("input couldn't be parsed as a zatoshi `Amount`: {source}")]
     Amount {

zebra-scan/Cargo.toml

@@ -25,6 +25,7 @@ proptest-impl = [
     "proptest-derive",
     "zebra-state/proptest-impl",
     "zebra-chain/proptest-impl",
+    "zebra-test",
     "bls12_381",
     "ff",
     "group",
@@ -63,6 +64,8 @@ jubjub = { version = "0.10.0", optional = true }
 rand = { version = "0.8.5", optional = true }
 zcash_note_encryption = { version = "0.4.0", optional = true }
 
+zebra-test = { path = "../zebra-test", version = "1.0.0-beta.31", optional = true }
+
 [dev-dependencies]
 
 insta = { version = "1.33.0", features = ["ron", "redactions"] }
@@ -78,4 +81,4 @@ rand = "0.8.5"
 zcash_note_encryption = "0.4.0"
 
 zebra-state = { path = "../zebra-state", version = "1.0.0-beta.31", features = ["proptest-impl"] }
-zebra-test = { path = "../zebra-test" }
+zebra-test = { path = "../zebra-test", version = "1.0.0-beta.31" }

zebra-scan/src/storage/db.rs

@@ -19,8 +19,8 @@ pub use zebra_state::{
 
 pub mod sapling;
 
-#[cfg(test)]
+#[cfg(any(test, feature = "proptest-impl"))]
-mod tests;
+pub mod tests;
 
 /// The directory name used to distinguish the scanner database from Zebra's other databases or
 /// flat files.

zebra-scan/src/storage/db/tests.rs

@@ -1,3 +1,58 @@
 //! General scanner database tests.
 
+use std::sync::Arc;
+
+use zebra_chain::{
+    block::{Block, Height},
+    parameters::Network::{self, *},
+    serialization::ZcashDeserializeInto,
+};
+use zebra_state::TransactionIndex;
+
+use crate::{
+    storage::Storage,
+    tests::{FAKE_SAPLING_VIEWING_KEY, ZECPAGES_SAPLING_VIEWING_KEY},
+    Config,
+};
+
+#[cfg(test)]
 mod snapshot;
+
+/// Returns an empty `Storage` suitable for testing.
+pub fn new_test_storage(network: Network) -> Storage {
+    Storage::new(&Config::ephemeral(), network)
+}
+
+/// Add fake keys to `storage` for testing purposes.
+pub fn add_fake_keys(storage: &mut Storage) {
+    // Snapshot a birthday that is automatically set to activation height
+    storage.add_sapling_key(&ZECPAGES_SAPLING_VIEWING_KEY.to_string(), None);
+    // Snapshot a birthday above activation height
+    storage.add_sapling_key(&FAKE_SAPLING_VIEWING_KEY.to_string(), Height(1_000_000));
+}
+
+/// Add fake results to `storage` for testing purposes.
+pub fn add_fake_results(storage: &mut Storage, network: Network, height: Height) {
+    let blocks = match network {
+        Mainnet => &*zebra_test::vectors::CONTINUOUS_MAINNET_BLOCKS,
+        Testnet => &*zebra_test::vectors::CONTINUOUS_TESTNET_BLOCKS,
+    };
+
+    let block: Arc<Block> = blocks
+        .get(&height.0)
+        .expect("block height has test data")
+        .zcash_deserialize_into()
+        .expect("test data deserializes");
+
+    // Fake results from the first few blocks
+    storage.add_sapling_results(
+        &ZECPAGES_SAPLING_VIEWING_KEY.to_string(),
+        height,
+        block
+            .transactions
+            .iter()
+            .enumerate()
+            .map(|(index, tx)| (TransactionIndex::from_usize(index), tx.hash().into()))
+            .collect(),
+    );
+}

zebra-scan/src/storage/db/tests/snapshot.rs

@@ -24,40 +24,39 @@
 //! Due to `serde` limitations, some object types can't be represented exactly,
 //! so RON uses the closest equivalent structure.
 
-use std::{collections::BTreeMap, sync::Arc};
+use std::collections::BTreeMap;
+
+use itertools::Itertools;
 
 use zebra_chain::{
-    block::{Block, Height},
+    block::Height,
     parameters::Network::{self, *},
-    serialization::ZcashDeserializeInto,
 };
-use zebra_state::{RawBytes, ReadDisk, TransactionIndex, KV};
+use zebra_state::{RawBytes, ReadDisk, SaplingScannedDatabaseIndex, TransactionLocation, KV};
 
-use crate::{
+use crate::storage::{db::ScannerDb, Storage};
-    storage::{db::ScannerDb, Storage},
-    tests::{FAKE_SAPLING_VIEWING_KEY, ZECPAGES_SAPLING_VIEWING_KEY},
-    Config,
-};
 
-/// Snapshot test for RocksDB column families, and their key-value data.
+/// Snapshot test for:
+/// - RocksDB column families, and their raw key-value data, and
+/// - typed scanner result data using high-level storage methods.
 ///
 /// These snapshots contain the `default` column family, but it is not used by Zebra.
 #[test]
-fn test_raw_rocksdb_column_families() {
+fn test_database_format() {
     let _init_guard = zebra_test::init();
 
-    test_raw_rocksdb_column_families_with_network(Mainnet);
+    test_database_format_with_network(Mainnet);
-    test_raw_rocksdb_column_families_with_network(Testnet);
+    test_database_format_with_network(Testnet);
 }
 
-/// Snapshot raw column families for `network`.
+/// Snapshot raw and typed database formats for `network`.
 ///
-/// See [`test_raw_rocksdb_column_families`].
+/// See [`test_database_format()`] for details.
-fn test_raw_rocksdb_column_families_with_network(network: Network) {
+fn test_database_format_with_network(network: Network) {
     let mut net_suffix = network.to_string();
     net_suffix.make_ascii_lowercase();
 
-    let mut storage = Storage::new(&Config::ephemeral(), network);
+    let mut storage = super::new_test_storage(network);
 
     // Snapshot the column family names
     let mut cf_names = storage.db.list_cf().expect("empty database is valid");
@@ -75,48 +74,32 @@ fn test_raw_rocksdb_column_families_with_network(network: Network) {
 
     settings.set_snapshot_suffix("empty");
     settings.bind(|| snapshot_raw_rocksdb_column_family_data(&storage.db, &cf_names));
+    settings.bind(|| snapshot_typed_result_data(&storage));
 
-    // Snapshot a birthday that is automatically set to activation height
+    super::add_fake_keys(&mut storage);
-    storage.add_sapling_key(&ZECPAGES_SAPLING_VIEWING_KEY.to_string(), None);
-    // Snapshot a birthday above activation height
-    storage.add_sapling_key(&FAKE_SAPLING_VIEWING_KEY.to_string(), Height(1_000_000));
 
+    // Assert that the key format doesn't change.
     settings.set_snapshot_suffix(format!("{net_suffix}_keys"));
     settings.bind(|| snapshot_raw_rocksdb_column_family_data(&storage.db, &cf_names));
+    settings.bind(|| snapshot_typed_result_data(&storage));
 
     // Snapshot raw database data for:
     // - mainnet and testnet
     // - genesis, block 1, and block 2
-    let blocks = match network {
+    //
-        Mainnet => &*zebra_test::vectors::CONTINUOUS_MAINNET_BLOCKS,
+    // We limit the number of blocks, because we create 2 snapshots per block, one for each network.
-        Testnet => &*zebra_test::vectors::CONTINUOUS_TESTNET_BLOCKS,
-    };
-
-    // We limit the number of blocks, because the serialized data is a few kilobytes per block.
     for height in 0..=2 {
-        let block: Arc<Block> = blocks
+        super::add_fake_results(&mut storage, network, Height(height));
-            .get(&height)
-            .expect("block height has test data")
-            .zcash_deserialize_into()
-            .expect("test data deserializes");
-
-        // Fake results from the first few blocks
-        storage.add_sapling_results(
-            &ZECPAGES_SAPLING_VIEWING_KEY.to_string(),
-            Height(height),
-            block
-                .transactions
-                .iter()
-                .enumerate()
-                .map(|(index, tx)| (TransactionIndex::from_usize(index), tx.hash().into()))
-                .collect(),
-        );
 
         let mut settings = insta::Settings::clone_current();
         settings.set_snapshot_suffix(format!("{net_suffix}_{height}"));
 
+        // Assert that the result format doesn't change.
         settings.bind(|| snapshot_raw_rocksdb_column_family_data(&storage.db, &cf_names));
+        settings.bind(|| snapshot_typed_result_data(&storage));
     }
+
+    // TODO: add an empty marker result after PR #8080 merges
 }
 
 /// Snapshot the data in each column family, using `cargo insta` and RON serialization.
@@ -150,15 +133,70 @@ fn snapshot_raw_rocksdb_column_family_data(db: &ScannerDb, original_cf_names: &[
         if cf_name == "default" {
             assert_eq!(cf_data.len(), 0, "default column family is never used");
         } else if cf_data.is_empty() {
-            // distinguish column family names from empty column families
+            // Distinguish column family names from empty column families
             empty_column_families.push(format!("{cf_name}: no entries"));
         } else {
-            // The note commitment tree snapshots will change if the trees do not have cached roots.
+            // Make sure the raw format doesn't accidentally change.
-            // But we expect them to always have cached roots,
-            // because those roots are used to populate the anchor column families.
             insta::assert_ron_snapshot!(format!("{cf_name}_raw_data"), cf_data);
         }
     }
 
     insta::assert_ron_snapshot!("empty_column_families", empty_column_families);
 }
+
+/// Snapshot typed scanner result data using high-level storage methods,
+/// using `cargo insta` and RON serialization.
+fn snapshot_typed_result_data(storage: &Storage) {
+    // TODO: snapshot the latest scanned heights after PR #8080 merges
+    //insta::assert_ron_snapshot!("latest_heights", latest_scanned_heights);
+
+    // Make sure the typed key format doesn't accidentally change.
+    //
+    // TODO: update this after PR #8080
+    let sapling_keys_and_birthday_heights = storage.sapling_keys();
+    // HashMap has an unstable order across Rust releases, so we need to sort it here.
+    insta::assert_ron_snapshot!(
+        "sapling_keys",
+        sapling_keys_and_birthday_heights,
+        {
+                "." => insta::sorted_redaction()
+        }
+    );
+
+    // HashMap has an unstable order across Rust releases, so we need to sort it here as well.
+    for (key_index, (sapling_key, _birthday_height)) in sapling_keys_and_birthday_heights
+        .iter()
+        .sorted()
+        .enumerate()
+    {
+        let sapling_results = storage.sapling_results(sapling_key);
+
+        // Check internal database method consistency
+        for (height, results) in sapling_results.iter() {
+            let sapling_index_and_results =
+                storage.sapling_results_for_key_and_height(sapling_key, *height);
+
+            // The list of results for each height must match the results queried by that height.
+            let sapling_results_for_height: Vec<_> = sapling_index_and_results
+                .values()
+                .flatten()
+                .cloned()
+                .collect();
+            assert_eq!(results, &sapling_results_for_height);
+
+            for (index, result) in sapling_index_and_results {
+                let index = SaplingScannedDatabaseIndex {
+                    sapling_key: sapling_key.clone(),
+                    tx_loc: TransactionLocation::from_parts(*height, index),
+                };
+
+                // The result for each index must match the result queried by that index.
+                let sapling_result_for_index = storage.sapling_result_for_index(&index);
+                assert_eq!(result, sapling_result_for_index);
+            }
+        }
+
+        // Make sure the typed result format doesn't accidentally change.
+        insta::assert_ron_snapshot!(format!("sapling_key_{key_index}_results"), sapling_results);
+    }
+}

zebra-scan/src/storage/db/tests/snapshots/sapling_key_0_results@mainnet_0.snap

@@ -0,0 +1,10 @@
+---
+source: zebra-scan/src/storage/db/tests/snapshot.rs
+expression: sapling_results
+---
+{
+  Height(0): [
+    SaplingScannedResult("c4eaa58879081de3c24a7b117ed2b28300e7ec4c4c1dff1d3f1268b7857a4ddb"),
+  ],
+  Height(419199): [],
+}

zebra-scan/src/storage/db/tests/snapshots/sapling_key_0_results@mainnet_1.snap

@@ -0,0 +1,13 @@
+---
+source: zebra-scan/src/storage/db/tests/snapshot.rs
+expression: sapling_results
+---
+{
+  Height(0): [
+    SaplingScannedResult("c4eaa58879081de3c24a7b117ed2b28300e7ec4c4c1dff1d3f1268b7857a4ddb"),
+  ],
+  Height(1): [
+    SaplingScannedResult("851bf6fbf7a976327817c738c489d7fa657752445430922d94c983c0b9ed4609"),
+  ],
+  Height(419199): [],
+}

zebra-scan/src/storage/db/tests/snapshots/sapling_key_0_results@mainnet_2.snap

@@ -0,0 +1,16 @@
+---
+source: zebra-scan/src/storage/db/tests/snapshot.rs
+expression: sapling_results
+---
+{
+  Height(0): [
+    SaplingScannedResult("c4eaa58879081de3c24a7b117ed2b28300e7ec4c4c1dff1d3f1268b7857a4ddb"),
+  ],
+  Height(1): [
+    SaplingScannedResult("851bf6fbf7a976327817c738c489d7fa657752445430922d94c983c0b9ed4609"),
+  ],
+  Height(2): [
+    SaplingScannedResult("8974d08d1c5f9c860d8b629d582a56659a4a1dcb2b5f98a25a5afcc2a784b0f4"),
+  ],
+  Height(419199): [],
+}

zebra-scan/src/storage/db/tests/snapshots/sapling_key_0_results@mainnet_keys.snap

@@ -0,0 +1,7 @@
+---
+source: zebra-scan/src/storage/db/tests/snapshot.rs
+expression: sapling_results
+---
+{
+  Height(419199): [],
+}

zebra-scan/src/storage/db/tests/snapshots/sapling_key_0_results@testnet_0.snap

@@ -0,0 +1,10 @@
+---
+source: zebra-scan/src/storage/db/tests/snapshot.rs
+expression: sapling_results
+---
+{
+  Height(0): [
+    SaplingScannedResult("c4eaa58879081de3c24a7b117ed2b28300e7ec4c4c1dff1d3f1268b7857a4ddb"),
+  ],
+  Height(279999): [],
+}

zebra-scan/src/storage/db/tests/snapshots/sapling_key_0_results@testnet_1.snap

@@ -0,0 +1,13 @@
+---
+source: zebra-scan/src/storage/db/tests/snapshot.rs
+expression: sapling_results
+---
+{
+  Height(0): [
+    SaplingScannedResult("c4eaa58879081de3c24a7b117ed2b28300e7ec4c4c1dff1d3f1268b7857a4ddb"),
+  ],
+  Height(1): [
+    SaplingScannedResult("f37e9f691fffb635de0999491d906ee85ba40cd36dae9f6e5911a8277d7c5f75"),
+  ],
+  Height(279999): [],
+}

zebra-scan/src/storage/db/tests/snapshots/sapling_key_0_results@testnet_2.snap

@@ -0,0 +1,16 @@
+---
+source: zebra-scan/src/storage/db/tests/snapshot.rs
+expression: sapling_results
+---
+{
+  Height(0): [
+    SaplingScannedResult("c4eaa58879081de3c24a7b117ed2b28300e7ec4c4c1dff1d3f1268b7857a4ddb"),
+  ],
+  Height(1): [
+    SaplingScannedResult("f37e9f691fffb635de0999491d906ee85ba40cd36dae9f6e5911a8277d7c5f75"),
+  ],
+  Height(2): [
+    SaplingScannedResult("5822c0532da8a008259ac39933d3210e508c17e3ba21d2b2c428785efdccb3d5"),
+  ],
+  Height(279999): [],
+}

zebra-scan/src/storage/db/tests/snapshots/sapling_key_0_results@testnet_keys.snap

@@ -0,0 +1,7 @@
+---
+source: zebra-scan/src/storage/db/tests/snapshot.rs
+expression: sapling_results
+---
+{
+  Height(279999): [],
+}

zebra-scan/src/storage/db/tests/snapshots/sapling_key_1_results@mainnet_0.snap

@@ -0,0 +1,7 @@
+---
+source: zebra-scan/src/storage/db/tests/snapshot.rs
+expression: sapling_results
+---
+{
+  Height(999999): [],
+}

zebra-scan/src/storage/db/tests/snapshots/sapling_key_1_results@mainnet_1.snap

@@ -0,0 +1,7 @@
+---
+source: zebra-scan/src/storage/db/tests/snapshot.rs
+expression: sapling_results
+---
+{
+  Height(999999): [],
+}

zebra-scan/src/storage/db/tests/snapshots/sapling_key_1_results@mainnet_2.snap

@@ -0,0 +1,7 @@
+---
+source: zebra-scan/src/storage/db/tests/snapshot.rs
+expression: sapling_results
+---
+{
+  Height(999999): [],
+}

zebra-scan/src/storage/db/tests/snapshots/sapling_key_1_results@mainnet_keys.snap

@@ -0,0 +1,7 @@
+---
+source: zebra-scan/src/storage/db/tests/snapshot.rs
+expression: sapling_results
+---
+{
+  Height(999999): [],
+}

zebra-scan/src/storage/db/tests/snapshots/sapling_key_1_results@testnet_0.snap

@@ -0,0 +1,7 @@
+---
+source: zebra-scan/src/storage/db/tests/snapshot.rs
+expression: sapling_results
+---
+{
+  Height(999999): [],
+}

zebra-scan/src/storage/db/tests/snapshots/sapling_key_1_results@testnet_1.snap

@@ -0,0 +1,7 @@
+---
+source: zebra-scan/src/storage/db/tests/snapshot.rs
+expression: sapling_results
+---
+{
+  Height(999999): [],
+}

zebra-scan/src/storage/db/tests/snapshots/sapling_key_1_results@testnet_2.snap

@@ -0,0 +1,7 @@
+---
+source: zebra-scan/src/storage/db/tests/snapshot.rs
+expression: sapling_results
+---
+{
+  Height(999999): [],
+}

zebra-scan/src/storage/db/tests/snapshots/sapling_key_1_results@testnet_keys.snap

@@ -0,0 +1,7 @@
+---
+source: zebra-scan/src/storage/db/tests/snapshot.rs
+expression: sapling_results
+---
+{
+  Height(999999): [],
+}

zebra-scan/src/storage/db/tests/snapshots/sapling_keys@empty.snap

@@ -0,0 +1,5 @@
+---
+source: zebra-scan/src/storage/db/tests/snapshot.rs
+expression: sapling_keys_and_birthday_heights
+---
+{}

zebra-scan/src/storage/db/tests/snapshots/sapling_keys@mainnet_0.snap

@@ -0,0 +1,8 @@
+---
+source: zebra-scan/src/storage/db/tests/snapshot.rs
+expression: sapling_keys_and_birthday_heights
+---
+{
+  "zxviews1q0duytgcqqqqpqre26wkl45gvwwwd706xw608hucmvfalr759ejwf7qshjf5r9aa7323zulvz6plhttp5mltqcgs9t039cx2d09mgq05ts63n8u35hyv6h9nc9ctqqtue2u7cer2mqegunuulq2luhq3ywjcz35yyljewa4mgkgjzyfwh6fr6jd0dzd44ghk0nxdv2hnv4j5nxfwv24rwdmgllhe0p8568sgqt9ckt02v2kxf5ahtql6s0ltjpkckw8gtymxtxuu9gcr0swvz": Height(0),
+  "zxviewsfake": Height(1000000),
+}

zebra-scan/src/storage/db/tests/snapshots/sapling_keys@mainnet_1.snap

@@ -0,0 +1,8 @@
+---
+source: zebra-scan/src/storage/db/tests/snapshot.rs
+expression: sapling_keys_and_birthday_heights
+---
+{
+  "zxviews1q0duytgcqqqqpqre26wkl45gvwwwd706xw608hucmvfalr759ejwf7qshjf5r9aa7323zulvz6plhttp5mltqcgs9t039cx2d09mgq05ts63n8u35hyv6h9nc9ctqqtue2u7cer2mqegunuulq2luhq3ywjcz35yyljewa4mgkgjzyfwh6fr6jd0dzd44ghk0nxdv2hnv4j5nxfwv24rwdmgllhe0p8568sgqt9ckt02v2kxf5ahtql6s0ltjpkckw8gtymxtxuu9gcr0swvz": Height(0),
+  "zxviewsfake": Height(1000000),
+}

zebra-scan/src/storage/db/tests/snapshots/sapling_keys@mainnet_2.snap

@@ -0,0 +1,8 @@
+---
+source: zebra-scan/src/storage/db/tests/snapshot.rs
+expression: sapling_keys_and_birthday_heights
+---
+{
+  "zxviews1q0duytgcqqqqpqre26wkl45gvwwwd706xw608hucmvfalr759ejwf7qshjf5r9aa7323zulvz6plhttp5mltqcgs9t039cx2d09mgq05ts63n8u35hyv6h9nc9ctqqtue2u7cer2mqegunuulq2luhq3ywjcz35yyljewa4mgkgjzyfwh6fr6jd0dzd44ghk0nxdv2hnv4j5nxfwv24rwdmgllhe0p8568sgqt9ckt02v2kxf5ahtql6s0ltjpkckw8gtymxtxuu9gcr0swvz": Height(0),
+  "zxviewsfake": Height(1000000),
+}

zebra-scan/src/storage/db/tests/snapshots/sapling_keys@mainnet_keys.snap

@@ -0,0 +1,8 @@
+---
+source: zebra-scan/src/storage/db/tests/snapshot.rs
+expression: sapling_keys_and_birthday_heights
+---
+{
+  "zxviews1q0duytgcqqqqpqre26wkl45gvwwwd706xw608hucmvfalr759ejwf7qshjf5r9aa7323zulvz6plhttp5mltqcgs9t039cx2d09mgq05ts63n8u35hyv6h9nc9ctqqtue2u7cer2mqegunuulq2luhq3ywjcz35yyljewa4mgkgjzyfwh6fr6jd0dzd44ghk0nxdv2hnv4j5nxfwv24rwdmgllhe0p8568sgqt9ckt02v2kxf5ahtql6s0ltjpkckw8gtymxtxuu9gcr0swvz": Height(419200),
+  "zxviewsfake": Height(1000000),
+}

zebra-scan/src/storage/db/tests/snapshots/sapling_keys@testnet_0.snap

@@ -0,0 +1,8 @@
+---
+source: zebra-scan/src/storage/db/tests/snapshot.rs
+expression: sapling_keys_and_birthday_heights
+---
+{
+  "zxviews1q0duytgcqqqqpqre26wkl45gvwwwd706xw608hucmvfalr759ejwf7qshjf5r9aa7323zulvz6plhttp5mltqcgs9t039cx2d09mgq05ts63n8u35hyv6h9nc9ctqqtue2u7cer2mqegunuulq2luhq3ywjcz35yyljewa4mgkgjzyfwh6fr6jd0dzd44ghk0nxdv2hnv4j5nxfwv24rwdmgllhe0p8568sgqt9ckt02v2kxf5ahtql6s0ltjpkckw8gtymxtxuu9gcr0swvz": Height(0),
+  "zxviewsfake": Height(1000000),
+}

zebra-scan/src/storage/db/tests/snapshots/sapling_keys@testnet_1.snap

@@ -0,0 +1,8 @@
+---
+source: zebra-scan/src/storage/db/tests/snapshot.rs
+expression: sapling_keys_and_birthday_heights
+---
+{
+  "zxviews1q0duytgcqqqqpqre26wkl45gvwwwd706xw608hucmvfalr759ejwf7qshjf5r9aa7323zulvz6plhttp5mltqcgs9t039cx2d09mgq05ts63n8u35hyv6h9nc9ctqqtue2u7cer2mqegunuulq2luhq3ywjcz35yyljewa4mgkgjzyfwh6fr6jd0dzd44ghk0nxdv2hnv4j5nxfwv24rwdmgllhe0p8568sgqt9ckt02v2kxf5ahtql6s0ltjpkckw8gtymxtxuu9gcr0swvz": Height(0),
+  "zxviewsfake": Height(1000000),
+}

zebra-scan/src/storage/db/tests/snapshots/sapling_keys@testnet_2.snap

@@ -0,0 +1,8 @@
+---
+source: zebra-scan/src/storage/db/tests/snapshot.rs
+expression: sapling_keys_and_birthday_heights
+---
+{
+  "zxviews1q0duytgcqqqqpqre26wkl45gvwwwd706xw608hucmvfalr759ejwf7qshjf5r9aa7323zulvz6plhttp5mltqcgs9t039cx2d09mgq05ts63n8u35hyv6h9nc9ctqqtue2u7cer2mqegunuulq2luhq3ywjcz35yyljewa4mgkgjzyfwh6fr6jd0dzd44ghk0nxdv2hnv4j5nxfwv24rwdmgllhe0p8568sgqt9ckt02v2kxf5ahtql6s0ltjpkckw8gtymxtxuu9gcr0swvz": Height(0),
+  "zxviewsfake": Height(1000000),
+}

zebra-scan/src/storage/db/tests/snapshots/sapling_keys@testnet_keys.snap

@@ -0,0 +1,8 @@
+---
+source: zebra-scan/src/storage/db/tests/snapshot.rs
+expression: sapling_keys_and_birthday_heights
+---
+{
+  "zxviews1q0duytgcqqqqpqre26wkl45gvwwwd706xw608hucmvfalr759ejwf7qshjf5r9aa7323zulvz6plhttp5mltqcgs9t039cx2d09mgq05ts63n8u35hyv6h9nc9ctqqtue2u7cer2mqegunuulq2luhq3ywjcz35yyljewa4mgkgjzyfwh6fr6jd0dzd44ghk0nxdv2hnv4j5nxfwv24rwdmgllhe0p8568sgqt9ckt02v2kxf5ahtql6s0ltjpkckw8gtymxtxuu9gcr0swvz": Height(280000),
+  "zxviewsfake": Height(1000000),
+}

zebra-state/src/service/finalized_state/disk_format/scan.rs

@@ -7,6 +7,9 @@
 //! `zebra_scan::Storage::database_format_version_in_code()` must be incremented
 //! each time the database format (column, serialization, etc) changes.
 
+use std::fmt;
+
+use hex::{FromHex, ToHex};
 use zebra_chain::{block::Height, transaction};
 
 use crate::{FromDisk, IntoDisk, TransactionLocation};
@@ -27,9 +30,58 @@ pub type SaplingScanningKey = String;
 ///
 /// Currently contains a TXID in "display order", which is big-endian byte order following the u256
 /// convention set by Bitcoin and zcashd.
-#[derive(Copy, Clone, Debug, Eq, PartialEq)]
+#[derive(Copy, Clone, Eq, PartialEq)]
-#[cfg_attr(any(test, feature = "proptest-impl"), derive(Arbitrary, Default))]
+#[cfg_attr(
-pub struct SaplingScannedResult([u8; 32]);
+    any(test, feature = "proptest-impl"),
+    derive(Arbitrary, Default, serde::Serialize, serde::Deserialize)
+)]
+pub struct SaplingScannedResult(
+    #[cfg_attr(any(test, feature = "proptest-impl"), serde(with = "hex"))] [u8; 32],
+);
+
+impl fmt::Display for SaplingScannedResult {
+    fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
+        f.write_str(&self.encode_hex::<String>())
+    }
+}
+
+impl fmt::Debug for SaplingScannedResult {
+    fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
+        f.debug_tuple("SaplingScannedResult")
+            .field(&self.encode_hex::<String>())
+            .finish()
+    }
+}
+
+impl ToHex for &SaplingScannedResult {
+    fn encode_hex<T: FromIterator<char>>(&self) -> T {
+        self.bytes_in_display_order().encode_hex()
+    }
+
+    fn encode_hex_upper<T: FromIterator<char>>(&self) -> T {
+        self.bytes_in_display_order().encode_hex_upper()
+    }
+}
+
+impl ToHex for SaplingScannedResult {
+    fn encode_hex<T: FromIterator<char>>(&self) -> T {
+        (&self).encode_hex()
+    }
+
+    fn encode_hex_upper<T: FromIterator<char>>(&self) -> T {
+        (&self).encode_hex_upper()
+    }
+}
+
+impl FromHex for SaplingScannedResult {
+    type Error = <[u8; 32] as FromHex>::Error;
+
+    fn from_hex<T: AsRef<[u8]>>(hex: T) -> Result<Self, Self::Error> {
+        let result = <[u8; 32]>::from_hex(hex)?;
+
+        Ok(Self::from_bytes_in_display_order(result))
+    }
+}
 
 impl From<SaplingScannedResult> for transaction::Hash {
     fn from(scanned_result: SaplingScannedResult) -> Self {