fix: Numeric input with variables conversion to StringResponse

[efortish]

Description

This PR adds support for numeric inputs containing variables by converting them to string response format when needed. The current implementation detects when a numeric input answer contains variables (letters other than 'e', which is used in scientific notation) and properly converts it to a string response format that can handle algebraic expressions.

Changes

• Added a flag convertedToStringResponse to track when a numeric problem has been converted to string response

• Implemented logic in buildNumericalResponse to detect variables in answers and generate string response format instead

• Extended buildNumericInput to check this flag and render the appropriate OLX output

Discussion

This solution detects whether, when creating a problem with Numerical Input, the problem's solution contains variables. If so, it converts the solution to stringResponse so that the OLX is properly constructed for the backend to process it as a string.

The issue with this solution is that the equation previewer provided by numericalResponse with its formulaequationinput stops working because the OLX has been modified to stringResponse. The main idea was to adapt a logic similar to the legacy editor, but the difference is that the legacy code handles these cases with a different structure in JavaScript.

In conclusion, the solution implemented in this PR ensures that problems containing variables work correctly, preventing the "undefined variables" error. However, as a consequence, the equation previewer no longer functions when entering a response.

Testing instructions

• Create a new problem with numerical input where the answer is a math expression like m*c^2:

The OLX will have an structure like this:

Related issues:

Numerical Input Component Incorrectly Handles Formulas as numericalresponse

[Test failure] TC_AUTHOR_50: Numerical input component generates an error with the formula shown in the usage example.

[openedx-webhooks]

Thanks for the pull request, @efortish!

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[codecov]

Codecov Report

Attention: Patch coverage is 21.21212% with 26 lines in your changes missing coverage. Please review.

Please upload report for BASE (open-release/sumac.master@4f04698). Learn more about missing BASE report.

Files with missing lines	Patch %	Lines
...ntainers/ProblemEditor/data/ReactStateOLXParser.js	21.21%	21 Missing and 5 partials ⚠️

Additional details and impacted files

@@                     Coverage Diff                      @@
##             open-release/sumac.master    #1767   +/-   ##
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  Coverage                             ?   93.14%           
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  Files                                ?     1051           
  Lines                                ?    20448           
  Branches                             ?     4377           
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  Hits                                 ?    19046           
  Misses                               ?     1340           
  Partials                             ?       62           

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[efortish]

@mariajgrimaldi hello, this is the PR I was talking about !

[mariajgrimaldi]

@efortish: thanks for the contribution! Can you also share the PR against the master branch? That should be merged first, then we can backport the changes to the releases we support :) thank you!

Also, can we add some tests for the approach? We'd really appreciate it!

[mariajgrimaldi]

@efortish: friendly ping to my comment above :) thanks!