test: test with-serde feature in CI

Do a build-test of the `with-serde` feature. Also do some simple
round-trip testing to ensure consistent serialization (particularly, for
the items that have manual (De)Serialize implementations).

Signed-off-by: Patrick Roy <roypat@amazon.co.uk>

.buildkite/custom-tests.json

@@ -1,24 +1,24 @@
 {
     "tests": [
         {
-            "test_name": "build-fam-gnu",
-            "command": "cargo build --release --features=fam-wrappers",
+            "test_name": "build-all-features-gnu",
+            "command": "cargo build --release --all-features --tests",
             "platform": [
                 "x86_64",
                 "aarch64"
             ]
         },
         {
-            "test_name": "build-fam-musl",
-            "command": "cargo build --release --features=fam-wrappers --target {target_platform}-unknown-linux-musl",
+            "test_name": "build-all-features-musl",
+            "command": "cargo build --release --all-features --target {target_platform}-unknown-linux-musl --tests",
             "platform": [
                 "x86_64",
                 "aarch64"
             ]
         },
         {
-            "test_name": "check-warnings-fam",
-            "command": "RUSTFLAGS=\"-D warnings\" cargo check --features=fam-wrappers",
+            "test_name": "check-warnings-all-features",
+            "command": "RUSTFLAGS=\"-D warnings\" cargo check --all-features",
             "platform": [
                 "x86_64",
                 "aarch64"

Cargo.toml

@@ -22,3 +22,6 @@ with-serde = ["dep:serde", "serde/derive"]
 [dependencies]
 vmm-sys-util = { version = "0.12.1", optional = true }
 serde = { version = "1.0.0", optional = true, features = ["derive"] }
+
+[dev-dependencies]
+bincode = "1.3.3"

coverage_config_aarch64.json

@@ -1,5 +1,5 @@
 {
   "coverage_score": 60.9,
   "exclude_path": "",
-  "crate_features": "fam-wrappers"
+  "crate_features": "fam-wrappers,with-serde"
 }

coverage_config_x86_64.json

@@ -1,5 +1,5 @@
 {
   "coverage_score": 100,
   "exclude_path": ".*bindings\\.rs",
-  "crate_features": "fam-wrappers"
+  "crate_features": "fam-wrappers,with-serde"
 }

src/arm64/serialize.rs

@@ -3,7 +3,14 @@ mod tests {
     use bindings::*;
     use serde::{Deserialize, Serialize};
 
-    fn is_serde<T: Serialize + for<'de> Deserialize<'de>>() {}
+    fn is_serde<T: Serialize + for<'de> Deserialize<'de> + Default>() {
+        let serialized = bincode::serialize(&T::default()).unwrap();
+        let deserialized = bincode::deserialize::<T>(serialized.as_ref()).unwrap();
+        let serialized_again = bincode::serialize(&deserialized).unwrap();
+        // Compare the serialized state after a roundtrip, to work around issues with
+        // bindings not implementing `PartialEq`.
+        assert_eq!(serialized, serialized_again);
+    }
 
     #[test]
     fn static_assert_serde_implementations() {

src/x86_64/serialize.rs

@@ -109,7 +109,14 @@ mod tests {
     use super::*;
     use bindings::*;
 
-    fn is_serde<T: Serialize + for<'de> Deserialize<'de>>() {}
+    fn is_serde<T: Serialize + for<'de> Deserialize<'de> + Default>() {
+        let serialized = bincode::serialize(&T::default()).unwrap();
+        let deserialized = bincode::deserialize::<T>(serialized.as_ref()).unwrap();
+        let serialized_again = bincode::serialize(&deserialized).unwrap();
+        // Compare the serialized state after a roundtrip, to work around issues with
+        // bindings not implementing `PartialEq`.
+        assert_eq!(serialized, serialized_again);
+    }
 
     #[test]
     fn static_assert_serde_implementations() {