Fix logic error in format validation

[jpmckinney]

If you want to raise an error if !data.is_a?(String), you can't wrap that code in a if data.is_a?(String) block...

[jpmckinney]

See the diff ignoring whitespace changes (since I had to unindent a lot) https://github.com/hoxworth/json-schema/pull/80/files?w=1

[hoxworth]

Hi @jpmckinney - sorry it has taken me so long to get to this, but I'm trying to finally clean up the pull requests and issues on this project. This pull request is failing a few tests, and with the recent pull request merges there is now a merge conflict. Mind updating this PR?

[jpmckinney]

Updated! Use this link to compare: https://github.com/hoxworth/json-schema/pull/80/files?w=1

[jpmckinney]

The old version of the code had pseudocode like this:

if data is a String:
  raise an exception if data is not a String

Obviously, that exception will never be raised. I removed the if-statement, which caused that exception to start being raised, and which caused four tests to fail. I've restored the behavior expected by the tests by removing both the if-statement and the exception-raising.

[hoxworth]

Thanks for the cleanup - and yes, those validation errors were never going to be thrown, considering that code could never be reached. However, I do still want to maintain the original check on each format type to ensure the data is a string. According to draft-04 spec,

A format attribute can generally only validate a given set of instance types. If the type of the instance to validate is not in this set, validation for this format attribute and instance SHOULD succeed.

Each format is then specified that it MUST be a string. However, if an attribute is defined as an integer, it shouldn't fail format validation. If I were to ignore checking for a string completely, the regex check would throw a TypeError and this would bubble up to the end user, which is outside of the JSON schema spec.

I updated your request to simply just remove the if !data.is_a?(String) checks, as those are silly to be doing at that point anyhow.

Thanks!