Collect strings from BubbleChoice sub-levels for translation

[hacodeorg]

FND-1250
Collect strings from BubbleChoice sub-levels for translation. This is the first step in making BubbleChoice sub-levels translatable. (The next step is to display translations properly in the Code studio.)

Example

The last lesson of Course D - 2020 is a end-of-course project. It is a BubbleChoice level, which allow students to choose from 1 of 4 types of project. Each specific project is a sub-level, for example this basketball project. Currently, i18n strings from a sub-level project such as its display name and instructions are not collected by the sync-in process.

Testing story

Test the get_i18n_strings function from the Rails console

load "../bin/i18n/sync-in.rb";
bc = Level.find_by_name('courseD_EOC_2020');  # a BubbleChoice level at https://levelbuilder-studio.code.org/s/coursed-2020/stage/19/puzzle/2
get_i18n_strings bc   # extract i18n strings from the BubbleChoice level and its sub-levels
# Finally, verify that the results include strings from both the BubbleChoice level and its sub-levels (such as https://levelbuilder-studio.code.org/s/coursed-2020/stage/19/puzzle/2/sublevel/1)

Test the sync-in process:

• From the repo root, run bin/i18n/sync-in.rb
• Verify that i18n/locales/source/course_content/2020/coursed-2020.json contains strings from all BubbleChoice levels and their sub-levels. The result looks like this

  {
    "https://studio.code.org/s/coursed-2020/stage/19/puzzle/2": {
      "dsls": {
        "description": "You have reached the last lesson of Course D! Choose a project to create.",
        "display_name": "End of Course Project"
      },
      "sublevels": {
        "CourseD_EOC_bounce1": {
          "display_name": "Create a basketball game",
          "short_instructions": "Create your own basketball game!",
          "long_instructions": "Create your own basketball game!"
        },
        "CourseD_EOC_starwars": {
          "display_name": "Create a Star Wars game",
          "short_instructions": "Create your own Star Wars game!",
          "long_instructions": "Create your own Star Wars game!",
        },
        "CourseD_EOC_dance": {
          "display_name": "Create a dance",
          "short_instructions": "Create your own dance!",
          "long_instructions": "Create your own dance!",
        },
        "CourseD_EOC_artist": {
          "display_name": "Create a drawing",
          "short_instructions": "Create your own drawing!",
          "long_instructions": "Create your own drawing!",
        }
      }
    }
  }

[hacodeorg]

@Hamms I'd appreciate it if you could take a quick look at this PR :)

[Hamms]

LGTM!

[hacodeorg]

@daynew This will address your concern that translations should not depend on order of the sublevels. I've updated the PR description with a new output.

Btw, Level.name is unique because of this validation:

code-dot-org/dashboard/app/models/levels/level.rb

Line 55 in 772f5d5

validates_uniqueness_of :name, case_sensitive: false, conditions: -> {where.not(user_id: nil)}

[daynew]

Looks good as long as name isn't something which changes often.

[Hamms]

Looks good as long as name isn't something which changes often.

We're totally safe to depend on level names to be unique and immutable; many more critical things than the i18n sync would break if that assumption were to be violated