Implement API for Learner Progress

[ji-mmyliu]

Notion ticket link

Learner Course Progress Tracking

Implementation description

• Added an activitiesCompleted field for learners that specifies the object IDs of course pages that a learner has viewed (or completed if it's an activity)
  • Added API endpoints for marking a page as completed and also querying the learner's progress (including a full list of the modules that they have completed)
• Added a nextPage field to track the next page that the learner should be directed to when they return to the site
  • Added an API endpoint for marking the most recently viewed page. This will calculate and update the nextPage field.

Steps to test

1. Try playing around with the API endpoints to ensure their functionality. Namely: PUT /users/learner/markActivityCompleted, GET /users/learner/progress, and PUT /users/learner/viewedPage

What should reviewers focus on?

• Functionality and structure of the code, including edge cases or foreseeable issues when implementing the frontend

Checklist

• My PR name is descriptive and in imperative tense
• My commit messages are descriptive and in imperative tense. My commits are atomic and trivial commits are squashed or fixup'd into non-trivial commits
• I have run the appropriate linter(s)
• I have requested a review from the PL, as well as other devs who have background knowledge on this PR or who will be building on top of this PR

[Copilot]

Copilot reviewed 20 out of 21 changed files in this pull request and generated 1 comment.

Files not reviewed (1)

• backend/package.json: Language not supported

Comments suppressed due to low confidence (2)

backend/types/userTypes.ts:44

• The 'activitiesCompleted' field in LearnerDTO uses string arrays, but the corresponding field in the user model uses ObjectId arrays. Consider aligning these types or clearly documenting the conversion to ensure consistency.

+  activitiesCompleted: Map<string, Map<string, string[]>>;

backend/services/implementations/courseModuleService.ts:66

• The identifier 'Schema' is used in fetchPage without a corresponding import. Import 'Schema' from 'mongoose' (or reference mongoose.Schema) to avoid runtime errors.

  private static async fetchPage(page: Schema.Types.ObjectId): Promise<CoursePage> {