bobbyno/ruby_drills

A deliberate practice framework to help you learn Ruby

ruby_drills's Issues

Array#map Drill

newlines are different in instructions vs reference solution

In the instructions, newlines are shown as "\n", but in the reference implementation the newlines actually break to the next line. Is this intentional?

Array#select Drill

Array#reduce Drill

Are multiple alternate solutions acceptable?

@value = "bobcat"

Remove 'bob' from this string in order to return a much tamer version.

Use a non-destructive method to remove 'bob' from this string and return "cat":

>> @value.sub("bob", "")

Not yet...

I would expect any of these (and more) to work:

• @value.sub("bob", "")
• @value.gsub("bob", "")
• @value.tr("bo", "")
• @value[3..-1]
• @value.gsub(/[bo]/, '')
• etc

Enumerable methods on Array and Hash

Enumerable methods behave slightly differently on Array and Hash. I think the Enumerable drills that exist (which are all based on Array) should move to Array and we should add separate drills for the same methods on Hash. WDYT?

Please ignore random crap in your data collection

My .inputrc settings make the REPL blow up when I try using vim keybindings to navigate. I know I shouldn't do this, but my fingers type it before my brain is on board.

I don't expect this to be fixed, I just wanted to give you a heads up that the data my sessions are providing are not going to be very helpful to your statistical analysis. (feel free to close this as soon as you've seen it).

Decide on testing strategy

RSpec?
Aruba?

Code snippets in instructions are ambiguous

One of the instructions for a String drill said:

Take this string and turn it into a symbol. The output should be
:mouse:

Knowing beginners, there is reason to believe that they might expect the output to be :mouse: rather than :mouse.

Would it be worth adding backticks around code snippets to make it clear what is code vs what is English text?

UPDATE: I had to put backticks in the quoted text, because GitHub turns :mouse: into 🐭.

The right answer to the merge drill is treatead like the wrong one

It seems like comparison of an input and a reference is done the wrong way, since comparing hashes - unordered collections - as strings simply won't work as expected.
Consider the reference solution from the merge drill:

"@matched_animals.merge(@mismatched_animals) { |key, v1, v2| v1 }"

Passed through to Pry.run_command, it produces the following result:

"=> {\"cat\"=>\"meow\", \"dog\"=>\"woof\", \"frog\"=>\"ribbit\", \"pig\"=>\"oink\"}"

My proposed solution

"@mismatched_animals.merge(@matched_animals)"

gives the following result:

"=> {\"cat\"=>\"meow\", \"dog\"=>\"woof\", \"pig\"=>\"oink\", \"frog\"=>\"ribbit\"}"

Hence comparison of the two strings results in false.