A few things:
1) yes, I found the bug in stage 8 level 3 (we were accidentally looking a penUp before penDown in the function. Thanks for reporting it! Unfortunately, I'm not sure when it will go live because things are locked down for the Hour of Code.
2) It's worth understanding what our puzzle validation does and doesn't do in app lab...
This is from our October Newsletter where we explained it and some of the rationale for why we do it this way.
This is explains why you don't have to do anything to make Stage 8 Puzzle 2 say congratulations. Hope this helps. Let me know if you have other questions.
Validation in Unit 3
Understanding the coding puzzles in Unit 3 that identify issues with student work
In the pilot year of the course, none of the programming exercises were checked for correctness.. This meant that a student could simply click ‘Finish’ and get a green bubble on any puzzle without actually writing any code., So there was a larger burden on teachers to check and verify that a student actually did something. In response to pilot feedback, we added a lightweight form of “validation” behind the scenes that acts as a partial checklist for a student’s code solution. For example, a “validated” coding level in App Lab checks for certain properties in the student code, such as the existence of a function definition and call to that function but it does NOT check the pixel-by-pixel output. Many automated testing programs do the opposite -- they check the output of the program, without regard to how it was implemented. With our programming unit, we want to emphasize the ‘how’, and also allow for more varied, creative student output.
What this means for you:
A green bubble still DOES NOT necessarily mean the solution is totally correct. It only means that the student wrote some code that contains at least the minimum elements necessary to produce a solution for the task at hand.
The most likely thing you’ll face in your classroom is a student claiming that they wrote the code perfectly but App Lab says it’s not right. This usually means that the student went about writing the code in a way we weren’t expecting or that’s not in line with the requirements of the task.
Note that if a student is stuck, or can't figure out why a solution isn't passing the validation, feel free to move on to the next puzzle and continue working.
But... this is a new feature
There may be cases where a student produces code that is in line with the requirements of the assignment but is done in a novel way that we did not capture with our tests. If you think this is the case, after double-checking, please report it by emailing firstname.lastname@example.org and include the share link to the student’s work!