Finish off #130

- Add more test cases using the standard test pattern
- Add sorted_field_names to message subclass metadata to support stable ordering
  of keys in repr.
- Tweak code in new message methods

Author: nat-n

src/betterproto/__init__.py

@@ -428,6 +428,7 @@ class ProtoClassMetadata:
         "cls_by_field",
         "field_name_by_number",
         "meta_by_field_name",
+        "sorted_field_names",
     )
 
     def __init__(self, cls: Type["Message"]):
@@ -453,6 +454,9 @@ def __init__(self, cls: Type["Message"]):
         self.oneof_field_by_group = by_group
         self.field_name_by_number = by_field_number
         self.meta_by_field_name = by_field_name
+        self.sorted_field_names = tuple(
+            by_field_number[number] for number in sorted(by_field_number.keys())
+        )
 
         self.default_gen = self._get_default_gen(cls, fields)
         self.cls_by_field = self._get_cls_by_field(cls, fields)
@@ -529,17 +533,16 @@ def __post_init__(self) -> None:
     def __raw_get(self, name: str) -> Any:
         return super().__getattribute__(name)
 
-    def __eq__(self, other: T) -> bool:
+    def __eq__(self, other) -> bool:
         if type(self) is not type(other):
             return False
 
         for field_name in self._betterproto.meta_by_field_name:
             self_val = self.__raw_get(field_name)
             other_val = other.__raw_get(field_name)
-            if self_val is PLACEHOLDER and other_val is PLACEHOLDER:
-                continue
-
             if self_val is PLACEHOLDER:
+                if other_val is PLACEHOLDER:
+                    continue
                 self_val = self._get_field_default(field_name)
             elif other_val is PLACEHOLDER:
                 other_val = other._get_field_default(field_name)
@@ -550,16 +553,19 @@ def __eq__(self, other: T) -> bool:
         return True
 
     def __repr__(self) -> str:
-        parts = []
-        for field_name in self._betterproto.meta_by_field_name:
-            value = self.__raw_get(field_name)
-            if value is PLACEHOLDER:
-                continue
-            parts.append(f"{field_name}={value!r}")
-
+        parts = [
+            f"{field_name}={value!r}"
+            for field_name in self._betterproto.sorted_field_names
+            for value in (self.__raw_get(field_name),)
+            if value is not PLACEHOLDER
+        ]
         return f"{self.__class__.__name__}({', '.join(parts)})"
 
     def __getattribute__(self, name: str) -> Any:
+        """
+        Lazily initialize default values to avoid infinite recursion for recursive
+        message types
+        """
         value = super().__getattribute__(name)
         if value is not PLACEHOLDER:
             return value

tests/inputs/recursivemessage/recursivemessage.json

@@ -0,0 +1,12 @@
+{
+  "name": "Zues",
+  "child": {
+    "name": "Hercules"
+  },
+  "intermediate": {
+    "child": {
+      "name": "Douglas Adams"
+    },
+    "number": 42
+  }
+}

tests/inputs/recursivemessage/recursivemessage.proto

@@ -0,0 +1,13 @@
+syntax = "proto3";
+
+message Test {
+    string name = 1;
+    Test child = 2;
+    Intermediate intermediate = 3;
+}
+
+
+message Intermediate {
+    int32 number = 1;
+    Test child = 2;
+}

tests/test_features.py

@@ -319,13 +319,9 @@ def _round_trip_serialization(foo: Foo) -> Foo:
     )
 
 
-@dataclass(eq=False, repr=False)
-class RecursiveMessage(betterproto.Message):
-    child: "RecursiveMessage" = betterproto.message_field(1)
-    foo: int = betterproto.int32_field(2)
-
-
 def test_recursive_message():
+    from tests.output_betterproto.recursivemessage import Test as RecursiveMessage
+
     msg = RecursiveMessage()
 
     assert msg.child == RecursiveMessage()
@@ -337,9 +333,35 @@ def test_recursive_message():
     assert bytes(msg) == b""
 
 
-def test_message_repr():
-    assert repr(RecursiveMessage(foo=1)) == "RecursiveMessage(foo=1)"
-    assert (
-        repr(RecursiveMessage(child=RecursiveMessage(), foo=1))
-        == "RecursiveMessage(child=RecursiveMessage(), foo=1)"
+def test_recursive_message_defaults():
+    from tests.output_betterproto.recursivemessage import (
+        Test as RecursiveMessage,
+        Intermediate,
     )
+
+    msg = RecursiveMessage(name="bob", intermediate=Intermediate(42))
+
+    # set values are as expected
+    assert msg == RecursiveMessage(name="bob", intermediate=Intermediate(42))
+
+    # lazy initialized works modifies the message
+    assert msg != RecursiveMessage(
+        name="bob", intermediate=Intermediate(42), child=RecursiveMessage(name="jude")
+    )
+    msg.child.child.name = "jude"
+    assert msg == RecursiveMessage(
+        name="bob",
+        intermediate=Intermediate(42),
+        child=RecursiveMessage(child=RecursiveMessage(name="jude")),
+    )
+
+    # lazily initialization recurses as needed
+    assert msg.child.child.child.child.child.child.child == RecursiveMessage()
+    assert msg.intermediate.child.intermediate == Intermediate()
+
+
+def test_message_repr():
+    from tests.output_betterproto.recursivemessage import Test
+
+    assert repr(Test(name="Loki")) == "Test(name='Loki')"
+    assert repr(Test(child=Test(), name="Loki")) == "Test(name='Loki', child=Test())"