Tests: Add test for Cow feature

Signed-off-by: Jon Doron <[email protected]>

tests/build.rs

@@ -172,6 +172,20 @@ fn main() {
         .compile_protos(&[src.join("boxed_field.proto")], includes)
         .unwrap();
 
+    prost_build::Config::new()
+        .cowed(".cowed_field.Foo")
+        .bytes([".cowed_field.Bar.myBarBytes"])
+        .cowed(".cowed_field.Bar.myBarCowBytes")
+        .cowed(".cowed_field.Bar.myBarCowStr")
+        .cowed(".cowed_field.Bar.myNormalCowMap")
+        .cowed(".cowed_field.Bar.myBtreeCowMap")
+        .btree_map([
+            ".cowed_field.Bar.myBtreeMap",
+            ".cowed_field.Bar.myBtreeCowMap",
+        ])
+        .compile_protos(&[src.join("cowed_field.proto")], includes)
+        .unwrap();
+
     // Check that attempting to compile a .proto without a package declaration does not result in an error.
     config
         .compile_protos(&[src.join("no_package.proto")], includes)

tests/src/cowed_field.proto

@@ -0,0 +1,38 @@
+syntax = "proto3";
+package cowed_field;
+
+import "google/protobuf/wrappers.proto";
+import "google/protobuf/timestamp.proto";
+
+message Bar {
+  string myBarStr = 1;
+  string myBarCowStr = 2;
+  bytes myBarBytes = 3;
+  bytes myBarVec = 4;
+  bytes myBarCowBytes = 5;
+  map<uint64, string> myNormalMap = 6;
+  map<uint64, string> myNormalCowMap = 7;
+  map<uint64, string> myBtreeMap = 8;
+  map<uint64, string> myBtreeCowMap = 9;
+}
+
+message Foo {
+    string myStr   = 1;
+    uint32 myInt   = 2;
+    repeated string myRepeat = 3;
+    map<uint64, string> myFirstMap = 4;
+    map<string, uint64> mySecondMap = 5;
+    map<string, string> myThirdMap = 6;
+    optional string myOptStr = 7;
+    google.protobuf.Timestamp before     = 8;
+    bytes myBytes = 9;
+    google.protobuf.StringValue googleStr     = 10;
+    map<uint32, bytes> myBytesMap = 11;
+    bytes myVecBytes = 12;
+    oneof extraDetails {
+      uint32 oneOfInt = 100;
+      string oneOfStr = 101;
+      bytes oneOfBytes = 102;
+      Bar oneOfBar = 103;
+    };
+}

tests/src/cowed_field.rs

@@ -0,0 +1,270 @@
+include!(concat!(env!("OUT_DIR"), "/cowed_field.rs"));
+
+#[test]
+/// Confirm `Foo` is cowed by creating an instance
+fn test_foo_is_cowed() {
+    use prost::Message;
+    use std::borrow::Cow;
+    use std::collections::{BTreeMap, HashMap};
+
+    // Define a static byte array for testing
+    static STATIC_ARRAY: [u8; 2] = [99, 98];
+    let cow: Cow<'static, [u8]> = Cow::Borrowed(&STATIC_ARRAY);
+
+    // Validate Bar different types
+    let _ = Bar {
+        my_bar_str: "test".to_string(),
+        my_bar_cow_str: Cow::Owned("cow_str".to_string()),
+        my_bar_bytes: prost::bytes::Bytes::from("Hello world"),
+        my_bar_vec: vec![1, 2, 3],
+        my_bar_cow_bytes: Cow::Borrowed(&STATIC_ARRAY),
+        my_normal_map: HashMap::from([(5, "normal_map".to_string())]),
+        my_normal_cow_map: HashMap::from([(5, Cow::Borrowed("normal_cow_map"))]),
+        my_btree_map: BTreeMap::from([(5, "btree_map".to_string())]),
+        my_btree_cow_map: BTreeMap::from([(5, Cow::Borrowed("btree_cow_map"))]),
+    };
+
+    // Build Foo with a mix of Owned and Borrowed Cow variants
+    let f = Foo {
+        my_str: Cow::Owned("world".to_string()),
+        my_int: 5,
+        my_repeat: vec![Cow::Borrowed("hello")],
+        my_first_map: HashMap::from([(5, Cow::Borrowed("first_map"))]),
+        my_second_map: HashMap::from([(Cow::Borrowed("second_map"), 5)]),
+        my_third_map: HashMap::from([(
+            Cow::Borrowed("third_map_key"),
+            Cow::Borrowed("third_map_value"),
+        )]),
+        my_opt_str: None,
+        before: None,
+        my_bytes: Cow::Borrowed(&[1, 2, 3]),
+        google_str: Some("google".to_string()),
+        my_bytes_map: HashMap::from([(7, cow)]),
+        my_vec_bytes: Cow::Borrowed(&[4, 5, 6]),
+        extra_details: Some(crate::cowed_field::foo::ExtraDetails::OneOfStr(
+            Cow::Borrowed("ExtraDetailsStr"),
+        )),
+    };
+
+    // Encode the Foo instance to a byte vector
+    let encoded = f.encode_to_vec();
+
+    let g = Foo::decode(encoded.as_ref()).expect("Decoding failed");
+
+    // === Assertions for Equality ===
+
+    // Assert that `my_str` fields are equal
+    assert_eq!(
+        f.my_str.as_ref(),
+        g.my_str.as_ref(),
+        "my_str fields do not match"
+    );
+
+    // Assert that `my_int` fields are equal
+    assert_eq!(f.my_int, g.my_int, "my_int fields do not match");
+
+    // Assert that `my_repeat` vectors are equal
+    assert_eq!(
+        f.my_repeat.len(),
+        g.my_repeat.len(),
+        "my_repeat lengths do not match"
+    );
+    for (i, (item_f, item_g)) in f.my_repeat.iter().zip(g.my_repeat.iter()).enumerate() {
+        assert_eq!(
+            item_f.as_ref(),
+            item_g.as_ref(),
+            "my_repeat[{}] elements do not match",
+            i
+        );
+    }
+
+    // Assert that `my_first_map` maps are equal
+    assert_eq!(
+        f.my_first_map.len(),
+        g.my_first_map.len(),
+        "my_first_map lengths do not match"
+    );
+    for (key, val_f) in &f.my_first_map {
+        let val_g = g
+            .my_first_map
+            .get(key)
+            .expect("Key missing in g.my_first_map");
+        assert_eq!(
+            val_f.as_ref(),
+            val_g.as_ref(),
+            "my_first_map values for key {:?} do not match",
+            key
+        );
+    }
+
+    // Assert that `my_second_map` maps are equal
+    assert_eq!(
+        f.my_second_map.len(),
+        g.my_second_map.len(),
+        "my_second_map lengths do not match"
+    );
+    for (key_f, val_f) in &f.my_second_map {
+        let val_g = g
+            .my_second_map
+            .get(key_f)
+            .expect("Key missing in g.my_second_map");
+        assert_eq!(
+            *val_f, *val_g,
+            "my_second_map values for key {:?} do not match",
+            key_f
+        );
+    }
+
+    // Assert that `my_third_map` maps are equal
+    assert_eq!(
+        f.my_third_map.len(),
+        g.my_third_map.len(),
+        "my_third_map lengths do not match"
+    );
+    for (key_f, val_f) in &f.my_third_map {
+        let (key_g, val_g) = g
+            .my_third_map
+            .get_key_value(key_f)
+            .expect("Key missing in g.my_third_map");
+        assert_eq!(
+            key_f.as_ref(),
+            key_g.as_ref(),
+            "my_third_map keys do not match"
+        );
+        assert_eq!(
+            val_f.as_ref(),
+            val_g.as_ref(),
+            "my_third_map values do not match"
+        );
+    }
+
+    // Assert that `my_opt_str` fields are equal
+    assert_eq!(f.my_opt_str, g.my_opt_str, "my_opt_str fields do not match");
+
+    // Assert that `before` fields are equal
+    assert_eq!(f.before, g.before, "before fields do not match");
+
+    // Assert that `my_bytes` fields are equal
+    assert_eq!(
+        f.my_bytes.as_ref(),
+        g.my_bytes.as_ref(),
+        "my_bytes fields do not match"
+    );
+
+    // Assert that `google_str` fields are equal
+    assert_eq!(f.google_str, g.google_str, "google_str fields do not match");
+
+    // Assert that `my_bytes_map` maps are equal
+    assert_eq!(
+        f.my_bytes_map.len(),
+        g.my_bytes_map.len(),
+        "my_bytes_map lengths do not match"
+    );
+    for (key, val_f) in &f.my_bytes_map {
+        let val_g = g
+            .my_bytes_map
+            .get(key)
+            .expect("Key missing in g.my_bytes_map");
+        assert_eq!(
+            val_f.as_ref(),
+            val_g.as_ref(),
+            "my_bytes_map values for key {:?} do not match",
+            key
+        );
+    }
+
+    // Assert that `my_vec_bytes` fields are equal
+    assert_eq!(
+        f.my_vec_bytes.as_ref(),
+        g.my_vec_bytes.as_ref(),
+        "my_vec_bytes fields do not match"
+    );
+
+    // Assert that `extra_details` fields are equal
+    match (&f.extra_details, &g.extra_details) {
+        (
+            Some(crate::cowed_field::foo::ExtraDetails::OneOfStr(a)),
+            Some(crate::cowed_field::foo::ExtraDetails::OneOfStr(b)),
+        ) => {
+            assert_eq!(
+                a.as_ref(),
+                b.as_ref(),
+                "extra_details OneOfStr variants do not match"
+            );
+        }
+        (None, None) => {} // Both are None, which is fine
+        _ => panic!("extra_details variants do not match"),
+    }
+
+    // === Additional Assertions for Cow::Owned in Decoded Instance (`g`) ===
+
+    // Assert that `g.my_repeat` elements are `Cow::Owned`
+    for (i, item_g) in g.my_repeat.iter().enumerate() {
+        assert!(
+            matches!(item_g, Cow::Owned(_)),
+            "g.my_repeat[{}] should be Cow::Owned",
+            i
+        );
+    }
+
+    // Assert that `g.my_first_map` values are `Cow::Owned`
+    for (key, val_g) in &g.my_first_map {
+        assert!(
+            matches!(val_g, Cow::Owned(_)),
+            "g.my_first_map[{}] should be Cow::Owned",
+            key
+        );
+    }
+
+    // Assert that `g.my_second_map` keys are `Cow::Owned`
+    for (key_g, _) in &g.my_second_map {
+        assert!(
+            matches!(key_g, Cow::Owned(_)),
+            "g.my_second_map key {:?} should be Cow::Owned",
+            key_g
+        );
+    }
+
+    // Assert that `g.my_third_map` keys and values are `Cow::Owned`
+    for (key_g, val_g) in &g.my_third_map {
+        assert!(
+            matches!(key_g, Cow::Owned(_)),
+            "g.my_third_map key {:?} should be Cow::Owned",
+            key_g
+        );
+        assert!(
+            matches!(val_g, Cow::Owned(_)),
+            "g.my_third_map value {:?} should be Cow::Owned",
+            val_g
+        );
+    }
+
+    // Assert that `g.my_bytes` is `Cow::Owned`
+    assert!(
+        matches!(g.my_bytes, Cow::Owned(_)),
+        "g.my_bytes should be Cow::Owned"
+    );
+
+    // Assert that `g.my_bytes_map` values are `Cow::Owned`
+    for (key, val_g) in &g.my_bytes_map {
+        assert!(
+            matches!(val_g, Cow::Owned(_)),
+            "g.my_bytes_map[{}] should be Cow::Owned",
+            key
+        );
+    }
+
+    // Assert that `g.my_vec_bytes` is `Cow::Owned`
+    assert!(
+        matches!(g.my_vec_bytes, Cow::Owned(_)),
+        "g.my_vec_bytes should be Cow::Owned"
+    );
+
+    // Assert that `g.extra_details` variants are `Cow::Owned` if present
+    if let Some(crate::cowed_field::foo::ExtraDetails::OneOfStr(b)) = &g.extra_details {
+        assert!(
+            matches!(b, Cow::Owned(_)),
+            "g.extra_details OneOfStr should be Cow::Owned"
+        );
+    }
+}

tests/src/lib.rs

@@ -56,6 +56,10 @@ mod type_names;
 #[cfg(test)]
 mod boxed_field;
 
+#[cfg(feature = "std")]
+#[cfg(test)]
+mod cowed_field;
+
 #[cfg(test)]
 mod custom_debug;