rna-transcription: add invalid strand tests

[beatorizu]

I wrote those test cases because the exercise description tells you that the code need to be able to handle invalid inputs by raising a ValueError.

[cmccandless]

Once upon a time, there were test cases for invalid input. These were removed in exercism/problem-specifications#1027.

Rather than restoring cases that were intentionally removed, I would prefer to revise incorrect documentation. I looked at the exercise README, but saw no mention of handling invalid input. Which description were you referring to?

[beatorizu]

I read ValueError in exercism site.

[cmccandless]

I do not see what you're seeing on the Exercism.io exercise page either. Can you provide a screenshot of what you're seeing?

Also, please check if your exercise is "out-of-date"; if it is, you will see the following below your submission:

[yawpitch]

@cmccandless it looks like the reference to ValueError was removed some time ago, however the example.py still includes a section that raises ValueError... should we remove that?

[cmccandless]

should we remove that?

Wouldn't hurt to remove it, since modifying the example solution shouldn't prompt students to update their exercise.

AFAIK, the reason example solutions exist so that tests can be verified in CI. Students are not prohibited from reading example solutions, of course, but it is hardly required reading.

[yawpitch]

AFAIK, the reason example solutions exist so that tests can be verified in CI. Students are not prohibited from reading example solutions, of course, but it is hardly required reading.

Fair enough, but it might be good to keep them somewhat in sync with the "Recommended Solution" in the Mentor Notes and the tests.

[beatorizu]

I do not see what you're seeing on the Exercism.io exercise page either. Can you provide a screenshot of what you're seeing?

Also, please check if your exercise is "out-of-date"; if it is, you will see the following below your submission:

Yep, I got this message. When I updated the exercise the ValueError is no longer mentioned.

[yawpitch]

I do not see what you're seeing on the Exercism.io exercise page either. Can you provide a screenshot of what you're seeing?
Also, please check if your exercise is "out-of-date"; if it is, you will see the following below your submission:

Yep, I got this message. When I updated the exercise the ValueError is no longer mentioned.

Good. As the requirement has been removed from the copy and from the exercise I'm going to close this PR. I'll open another PR to remove the ValueError from the example.py.