Add Feature flag for language-directory

[loyaltypollution]

Simple proof-of-concept for adding additional languages via a language-directory.

• Wrote as feature flag to avoid breaking changes.

To-Do?

• Add UI support to allow users to view language directory URLs in frontend.

Questions:

• Is SourceAcademy planning to make conductors a “first-class” concept?
  • removing the hardcoding of languages in drop down?
  • ensuring that all -slang variants support conductors?

Happy to collaborate with relevant people on making conductors first-class if that’s the direction we are taking 👍

[martin-henz]

Yes, the Source Academy frontends should be configurable to provide a desired set of languages and their implementations. The purpose of the language directory is to provide a mapping from language names to the "official" x-slang implementations.

What remains to be worked out is to configure what languages should be provided by sourceacademy.org and sourceacademy.nus.edu.sg and other frontends.

Should that be done in a config file at build time, or should this also come from a github page?

Any proposals?

[s-kybound]

Should that be done in a config file at build time, or should this also come from a github page?
Any proposals?

@martin-henz best to be done in a config file i think, less layers of indirection especially when setting up new frontends.

[coveralls]

Pull Request Test Coverage Report for Build 17511560243

Details

• 303 of 2359 (12.84%) changed or added relevant lines in 18 files are covered.
• 4 unchanged lines in 1 file lost coverage.
• Overall coverage decreased (-1.4%) to 42.462%

---

Changes Missing Coverage	Covered Lines	Changed/Added Lines	%
src/commons/controlBar/LegacyControlBarChapterSelect.tsx	68	69	98.55%
public/evaluators/pie-slang/pie.js	0	2	0.0%
src/commons/navigationBar/subcomponents/NavigationBarLangSelectButton.tsx	22	27	81.48%
src/commons/controlBar/ControlBarChapterSelect.tsx	43	49	87.76%
src/commons/featureFlags/publicFlags.ts	0	6	0.0%
public/evaluators/py-slang/standard.js	0	694	0.0%
public/evaluators/py-slang/pyscript.js	0	1342	0.0%

Files with Coverage Reduction	New Missed Lines	%
src/commons/navigationBar/subcomponents/NavigationBarLangSelectButton.tsx	4	81.82%

Totals
Change from base Build 17424153377:	-1.4%
Covered Lines:	21065
Relevant Lines:	51962

---

💛 - Coveralls

[s-kybound]

minor nits, after resolution LGTM! please make sure the frontend has been tested first.

[s-kybound]

LGTM. please verify that the current build works one more time, but afterward OK to merge.