Custom parameter type’s encode function is not called for array params

[rluba]

The problem

1. Define a custom type using the definitionFn instead of the definition object
2. Use this new type for a state parameter that does not explicitly set array: false
3. The parameter type’s encode function is never invoked during state transitions, so the parameter is not encoded correctly.

The reason
Because the parameter does not declare array: false its type is wrapped into an ArrayType during state declaration – that’s before the type’s definitionFn is invoked.

But ArrayType defines its encode function (and others) based on the wrapped type’s functions at the time when ArrayType is instantiated. ArrayType stores a reference to the old encode function (which was undefined, so it’s the identity function) instead of looking up the actual function when ArrayType.encode is called.

Later, the type’s definitionFn is invoked and redefines the encode function, but the array params still reference the identity function.

The solution

• Either defer the instantiation of ArrayType until after all definitionFns were invoked (probably compilcated)
• Or define the ArrayType’s functions based on the run-time value of the wrapped type’s functions instead of capturing them locally.

[christopherthielen]

I appreciate the detailed bug report!

[stale]

This issue has been automatically marked as stale because it has not had
recent activity. It will be closed if no further activity occurs.

This does not mean that the issue is invalid. Valid issues
may be reopened.

Thank you for your contributions.