fix: we have a warning for every sub-variant

Signed-off-by: Luka Peschke <mail@lukapeschke.com>

src/serializers/type_serializers/union.rs

@@ -132,19 +132,15 @@ fn to_python(
     let mut new_extra = extra.clone();
     new_extra.check = SerCheck::Strict;
 
-    let res = to_python_extractor(value, include, exclude, &new_extra, choices);
-
-    let errors = match res {
+    let errors = match to_python_extractor(value, include, exclude, &new_extra, choices) {
         ToPythonExtractorResult::Success(obj) => return Ok(obj),
         ToPythonExtractorResult::Errors(errs) => errs,
     };
 
     if retry_with_lax_check {
         new_extra.check = SerCheck::Lax;
-        for comb_serializer in choices {
-            if let Ok(v) = comb_serializer.to_python(value, include, exclude, &new_extra) {
-                return Ok(v);
-            }
+        if let ToPythonExtractorResult::Success(v) = to_python_extractor(value, include, exclude, &new_extra, choices) {
+            return Ok(v);
         }
     }
 

tests/serializers/test_union.py

@@ -790,6 +790,11 @@ def __init__(self, type_: Literal['cat']) -> None:
         self.type_ = 'cat'
 
 
+class ModelAlien:
+    def __init__(self, type_: Literal['alien']) -> None:
+        self.type_ = 'alien'
+
+
 @pytest.fixture
 def model_a_b_union_schema() -> core_schema.UnionSchema:
     return core_schema.union_schema(
@@ -850,6 +855,20 @@ def test_union_of_unions_of_models(model_a_b_union_schema: core_schema.UnionSche
     assert s.to_python(ModelCat(type_='cat'), warnings='error') == {'type_': 'cat'}
     assert s.to_python(ModelDog(type_='dog'), warnings='error') == {'type_': 'dog'}
 
+    # All warnings should be available
+    messages = [
+        'Expected `ModelA` but got `ModelAlien`',
+        'Expected `ModelB` but got `ModelAlien`',
+        'Expected `ModelCat` but got `ModelAlien`',
+        'Expected `ModelDog` but got `ModelAlien`',
+    ]
+
+    with warnings.catch_warnings(record=True) as w:
+        warnings.simplefilter('always')
+        s.to_python(ModelAlien(type_='alien'))
+        for m in messages:
+            assert m in str(w[0].message)
+
 
 def test_union_of_unions_of_models_with_tagged_union(model_a_b_union_schema: core_schema.UnionSchema) -> None:
     s = SchemaSerializer(
@@ -885,3 +904,17 @@ def test_union_of_unions_of_models_with_tagged_union(model_a_b_union_schema: cor
     assert s.to_python(ModelB(c='c', d='d'), warnings='error') == {'c': 'c', 'd': 'd'}
     assert s.to_python(ModelCat(type_='cat'), warnings='error') == {'type_': 'cat'}
     assert s.to_python(ModelDog(type_='dog'), warnings='error') == {'type_': 'dog'}
+
+    # All warnings should be available
+    messages = [
+        'Expected `ModelA` but got `ModelAlien`',
+        'Expected `ModelB` but got `ModelAlien`',
+        'Expected `ModelCat` but got `ModelAlien`',
+        'Expected `ModelDog` but got `ModelAlien`',
+    ]
+
+    with warnings.catch_warnings(record=True) as w:
+        warnings.simplefilter('always')
+        s.to_python(ModelAlien(type_='alien'))
+        for m in messages:
+            assert m in str(w[0].message)