datatable: Replace wildcard type with its upper bound #829
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When registering steps in Kotlin using Kotlin collections as an argument e.g: ```kotlin @given("orders with an order item and the following attributes:") fun statusFilterOrdersInEs(attributes: Map<String, Map<String, String>>) ``` This argument is translated to Java type as ```java Map<java.lang.String, ? extends java.util.Map<java.lang.String, java.lang.String>> ``` To handle this gracefully the simplified type system used by `DataTable` should understand upper bounds. We do this by replacing the wild card type with its upper bound. We can assume this is safe because when registering a transformer to `type ? extends SomeType` the transformer is guaranteed to produce an object that is an instance of `SomeType`. When transforming a data table to ``? extends SomeType` a transformer that produces `SomeType` is sufficient. This will result in ambiguity between a transformers for `SomeType` and transformers for ``? extends SomeType` but that seems reasonable and might be resolved by using a more specific producer.
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Summary
When registering steps in Kotlin using Kotlin collections as an argument e.g:
This argument is translated to Java type as
To handle this gracefully the simplified type system used by
DataTableshould understand upper bounds. We do this by replacing the wild card type
with its upper bound.
We can assume this is safe because when registering a transformer to
type ? extends SomeTypethe transformer is guaranteed to produce anobject that is an instance of
SomeType.When transforming a data table to
? extends SomeTypea transformer thatproduces
SomeTypeis sufficient.This will result in ambiguity between a transformers for
SomeTypeandtransformers for ``? extends SomeType` but that seems reasonable and might be
resolved by using a more specific producer.
Motivation and Context
cucumber/cucumber-jvm#1838
Types of changes