docs: Update models to avoid including lazy defaults in the rendered man pages

Lazy defaults may return different results under different circumstances
and we always want man pages rendered consistently.

osc/conf.py

@@ -1324,6 +1324,10 @@ def _model_to_rst(cls, title=None, description=None, sections=None, output_file=
         if field.default is None:
             return None
 
+        if field.default_is_lazy:
+            # lazy default may return different results under different circumstances -> return nothing
+            return None
+
         ini_type = field.extra.get("ini_type", None)
         if ini_type:
             return None

osc/util/models.py

@@ -79,6 +79,9 @@ class Field(property):
         # model sets it to None if it equals to NotSet (for better usability)
         self.default = default
 
+        # a flag indicating, whether the default is a callable with lazy evalution
+        self.default_is_lazy = callable(self.default)
+
         # whether the field was set
         self.is_set = False
 

tests/test_models.py

@@ -60,6 +60,19 @@ class Test(unittest.TestCase):
 
         self.assertRaises(TypeError, TestModel)
 
+    def test_lazy_default(self):
+        class TestModel(BaseModel):
+            field: List[str] = Field(default=lambda: ["string"])
+
+        m = TestModel()
+        self.assertEqual(m.field, ["string"])
+
+    def test_lazy_default_invalid_type(self):
+        class TestModel(BaseModel):
+            field: List[str] = Field(default=lambda: None)
+
+        self.assertRaises(TypeError, TestModel)
+
     def test_is_set(self):
         class TestModel(BaseModel):
             field: Optional[str] = Field()