Added tests for items when data contains more or less types than the schema

[iainbeeston]

What happens if you specify items as an array of types, but you don't include a value for every type? Right now we have no tests for that. We also don't have a test for when there are more values than defined item types.

I've assumed that if the data has fewer values than there are types in the schema, we validate the values that we have. If there are more values than types, we don't validate values that we haven't got schema items for. This might be wrong, but I'd like to open up the discussion (the RFC isn't very clear on how array items should be validated)

[jlfaber]

This looks good. I'd suggest adding an empty array test case as well since that should also be valid.

[iainbeeston]

Correction: as pointed out to me by @jlfaber this behaviour is defined in the validation RFC:

8.2.3.2. If "items" is an array
In this situation, the schema depends on the index: if the index is less than, or equal to, the size of "items", the child instance must be valid against the corresponding schema in the "items" array; otherwise, it must be valid against the schema defined by "additionalItems".

[Julian]

Looks great, thanks! Adding one for the empty array does sound like a reasonable idea, and also, if we don't already have it, for the end of that paragraph, i.e. for when there are fewer in the items array but additionalItems is defined.

[iainbeeston]

I've updated the tests to include an empty array, but I believe the other case is already covered by tests in additionalItems.json

[Julian]

Merged, appreciated! Sorry for the delay.