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Hi,
it seems that the missing parameter gets used on reading despite the documentation stating this:
NOTE: Marshmallow uses the
missingkeyword during deserialization, which occurs when we save
Or do I use it the wrong way? I want to test some behaviour of our application in cases where a new field was added to a model about how old entries behave.
First, I define the old structure and add the table:
class ReducedTestModel(DynaModel):
class Table:
name = "test-model"
hash_key = "name"
read = 25
write = 5
if dynamoDBHost():
resource_kwargs = {"endpoint_url": dynamoDBHost()}
class Schema:
name = fields.String()
foo = fields.String(missing=lambda: "afoo")
ReducedTestModel.Table.create_table()
Then an entry gets stored:
reducedEntity = ReducedTestModel()
reducedEntity.name = "theOldOne"
reducedEntity.save()
Now, I define a new model being the same as the old one except one added field:
class FullTestModel(DynaModel):
class Table:
name = "test-model"
hash_key = "name"
read = 25
write = 5
if dynamoDBHost():
resource_kwargs = {"endpoint_url": dynamoDBHost()}
class Schema:
name = fields.String()
foo = fields.String(missing=lambda: "afoo")
bar = fields.String(missing=lambda: "abar")
Read the stored "old" entity from the new model and print the new attribute:
fullEntity = FullTestModel.get(name=reducedEntity.name)
print(fullEntity.bar)
The output is "abar", so it used the missing attribute. But why? Expectation was actually a crash due to a missing attribute.
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