All exercise test files should reference canonical data version

Currently some of the test files reference x-common//canonical-data.json with a version number, and a few test files lack any such a reference. Additionally, x-common was recently renamed to problem-specifications, so references to x-common are inherently outdated and potentially confusing.

Having a consistent version string should help with maintenance, since a script can fairly easily be written to compare the version numbers in the test file and the canonical data, and manual checks for how up to date it is are similarly easy. It also makes it easier for exercism users to find and check the canonical data, and thus to be able to contribute any changes they think are necessary if they identify problems or additional tests that would be useful.

Suggested wording

The currently adopted form for the version string seems to be: # test cases adapted from `x-common//canonical-data.json` @ version: 1.0.1

To conform to PEP8, we should aim to limit the string to 79 characters, so I propose the following wording (75 chars): # Tests adapted from `problem-specifications//canonical-data.json` @ v2.0.0

Does anyone have any alternatives or suggestions for improvements to this wording?

How to proceed

There are a couple of options for how to go about updating the test files:

1. Only update version strings when the tests are next updated, and update tests when the canonical data change.
2. Systematically update each test file to match the most recent canonical data version (or verify that it’s already up-to-date), and update the version strings in the process.

Option 1 is obviously the less work-intensive one, but it would leave some inconsistency for quite a while. Option 2 is more work-intensive and should get everything up-to-date quicker, but it might burn people out a bit.

[N-Parsons]

@m-a-ge, all of the issues should now be created and correctly labelled 😃

[N-Parsons]

I had some free time this evening, so I put together a fairly rough script for checking the state of version numbering. I put the results into a gist to save making a very long post here, and I have summarised the results below.

Up-to-date: 33 Out-of-date: 8 Unknown: 31 (no version tag) Unimplemented: 27 No canonical data: 14 No data needed: 5 (maybe more - requires manual checks)