test(store): add forward compatibility test

Serialize newer versioned changeset and deserialize into alternative not
versioned changeset.

crates/file_store/src/store.rs

@@ -465,4 +465,171 @@ mod test {
  assert_eq!(aggregation, exp_aggregation);
  }
  }
+
+ #[test]
+ fn deserialize_newer_changeset_version_with_old_code() {
+ #[derive(PartialEq, Debug, Default, Clone, serde::Deserialize, serde::Serialize)]
+ struct TestChangeSetV1 {
+ field_a: BTreeSet<String>,
+ }
+ impl Merge for TestChangeSetV1 {
+ fn merge(&mut self, other: Self) {
+ self.field_a.extend(other.field_a);
+ }
+
+ fn is_empty(&self) -> bool {
+ self.field_a.is_empty()
+ }
+ }
+
+ #[derive(Debug, Default, Clone, serde::Deserialize, serde::Serialize)]
+ struct TestChangeSetV2 {
+ field_a: BTreeSet<String>,
+ field_b: Option<BTreeSet<String>>,
+ }
+
+ impl Merge for TestChangeSetV2 {
+ fn merge(&mut self, other: Self) {
+ self.field_a.extend(other.field_a);
+ if let Some(ref mut field_b) = self.field_b {
+ if let Some(other_field_b) = other.field_b {
+ field_b.extend(other_field_b)
+ }
+ }
+ }
+
+ fn is_empty(&self) -> bool {
+ if self.field_b.is_none() {
+ false
+ } else {
+ self.field_a.is_empty()
+ }
+ }
+ }
+
+ let temp_dir = tempfile::tempdir().unwrap();
+ let file_path = temp_dir.path().join("20.dat");
+ println!("Test file: {:?}", file_path);
+
+ let new_code_aggregation = {
+ #[derive(serde::Serialize, serde::Deserialize)]
+ enum VersionedTestChangeSet {
+ V1(TestChangeSetV1),
+ V2(TestChangeSetV2),
+ }
+
+ impl Default for VersionedTestChangeSet {
+ fn default() -> Self {
+ VersionedTestChangeSet::V2(TestChangeSetV2::default())
+ }
+ }
+
+ impl From<VersionedTestChangeSet> for TestChangeSetV1 {
+ fn from(versioned_change_set: VersionedTestChangeSet) -> Self {
+ match versioned_change_set {
+ VersionedTestChangeSet::V1(changeset) => changeset,
+ _ => panic!(),
+ }
+ }
+ }
+
+ impl From<TestChangeSetV1> for VersionedTestChangeSet {
+ fn from(test_change_set: TestChangeSetV1) -> Self {
+ VersionedTestChangeSet::V1(test_change_set)
+ }
+ }
+
+ impl From<VersionedTestChangeSet> for TestChangeSetV2 {
+ fn from(_: VersionedTestChangeSet) -> Self {
+ Self::default()
+ }
+ }
+
+ impl From<TestChangeSetV2> for VersionedTestChangeSet {
+ fn from(_: TestChangeSetV2) -> Self {
+ VersionedTestChangeSet::default()
+ }
+ }
+
+ let changesets = (0..2)
+ .map(|n| TestChangeSetV2 {
+ field_a: BTreeSet::from([format!("{}", n)]),
+ field_b: None,
+ })
+ .collect::<Vec<_>>();
+
+ // First, we create the file with all the versioned changesets!
+ let mut db = Store::<TestChangeSetV2, VersionedTestChangeSet>::create_new(
+ &TEST_MAGIC_BYTES,
+ &file_path,
+ )
+ .unwrap();
+ for changeset in &changesets {
+ db.append_changeset(changeset).unwrap();
+ }
+
+ // Get aggregated changeset with new code
+ db.iter_changesets()
+ .map(|r| r.expect("must read valid changeset"))
+ .fold(TestChangeSetV2::default(), |mut acc, v| {
+ Merge::merge(&mut acc, v);
+ acc
+ })
+ };
+ let old_code_aggregation = {
+ #[derive(serde::Serialize, serde::Deserialize)]
+ enum VersionedTestChangeSet {
+ V1(TestChangeSetV1),
+ }
+
+ impl Default for VersionedTestChangeSet {
+ fn default() -> Self {
+ VersionedTestChangeSet::V1(TestChangeSetV1::default())
+ }
+ }
+
+ impl From<VersionedTestChangeSet> for TestChangeSetV1 {
+ fn from(versioned_change_set: VersionedTestChangeSet) -> Self {
+ match versioned_change_set {
+ VersionedTestChangeSet::V1(changeset) => changeset,
+ }
+ }
+ }
+
+ impl From<TestChangeSetV1> for VersionedTestChangeSet {
+ fn from(test_change_set: TestChangeSetV1) -> Self {
+ VersionedTestChangeSet::V1(test_change_set)
+ }
+ }
+
+ impl From<VersionedTestChangeSet> for TestChangeSetV2 {
+ fn from(_: VersionedTestChangeSet) -> Self {
+ Self::default()
+ }
+ }
+
+ impl From<TestChangeSetV2> for VersionedTestChangeSet {
+ fn from(_: TestChangeSetV2) -> Self {
+ VersionedTestChangeSet::default()
+ }
+ }
+
+ // We re-open the file and read all the versioned changesets using the "old"
+ // VersionedTestChangeSet
+ let mut db = Store::<TestChangeSetV2, VersionedTestChangeSet>::open(
+ &TEST_MAGIC_BYTES,
+ &file_path,
+ )
+ .unwrap();
+ // Merge all versioned changesets in the aggregated correct changeset
+ db.iter_changesets()
+ .map(|r| r.expect("must read valid changeset"))
+ .fold(TestChangeSetV2::default(), |mut acc, v| {
+ Merge::merge(&mut acc, v);
+ acc
+ })
+ };
+
+ assert_eq!(new_code_aggregation.field_a, old_code_aggregation.field_a);
+ }
 }