Add average test score to cohorts API and UI

[Copilot]

Implementation Plan for Average Test Score Feature

• Backend: Update TraineeSummary interface in CohortsController.ts to include averageTestScore property
• Backend: Implement calculation logic in getTraineeSummary method to compute average from test scores
• Backend: Handle edge cases (no tests, tests without scores)
• Frontend: Update TraineeSummary interface in Cohorts.ts model to include averageTestScore
• Frontend: Add new column "Average Test Score" after "Work Permit" column in CohortAccordion.tsx
• Frontend: Implement color coding logic (Orange <7, Black <8.5, Green >=8.5)
• Address code review feedback - extract calculation to separate function
• Address code review feedback - use null instead of undefined, avoid using !
• Reverted binding changes and made calculateAverageTestScore static instead
• Run security checks (0 alerts found)
• Implementation complete

Original prompt

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This section details on the original issue you should resolve

<issue_title>Cohorts page - Display average test score</issue_title>
<issue_description>## Requirements

• /cohorts API to return average test score for each trainee
• Display the score on the Cohorts page.

Implementation details

• Backend: Modify the /cohorts endpoint by adding a new property 'averageTestScore'
• Frontend: add the new column after the "work permit" column.
• Color code the score: Orange if < 7, Black if < 8.5, Green if >=8.5</issue_description>

<agent_instructions>Make minimal changes to the code. Keep it simple, readable and elegant.
For the average calculation, it can be done on the JS side, no need to create a complex pipeline with MongoDB</agent_instructions>

Comments on the Issue (you are @copilot in this section)

• Fixes Cohorts page - Display average test score #280

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[stasel]

Something is broken

TypeError: Cannot read properties of undefined (reading 'calculateAverageTestScore')

Please check the endpoint again

[stasel]

Something is broken:

TypeError: Cannot read properties of undefined (reading 'calculateAverageTestScore')

[Copilot]

Something is broken

TypeError: Cannot read properties of undefined (reading 'calculateAverageTestScore')
...

Fixed in commit 840b97f. The issue was that this.getTraineeSummary was passed to .map() without binding, causing it to lose the class context. Added .bind(this) to both getTraineeSummary and compareTraineeInCohort method references.

Something is broken:

TypeError: Cannot read properties of undefined (reading 'calculateAverageTestScore')

Fixed in commit 840b97f. Added .bind(this) to preserve the class context when methods are passed as callbacks.

[Copilot]

Pull request overview

Adds “average test score” to the cohorts API response and displays it in the Cohorts UI with color-coded styling.

Changes:

• Backend: select test scores in cohort trainee queries and compute averageTestScore per trainee.
• Frontend: extend the cohorts model and render a new “Avg Test Score” column with threshold-based coloring.

Reviewed changes

Copilot reviewed 4 out of 4 changed files in this pull request and generated 3 comments.

File	Description
server/src/repositories/TraineesRepository.ts	Includes educationInfo.tests.score in the cohort query projection so scores are available for averaging.
server/src/controllers/CohortsController.ts	Adds averageTestScore to TraineeSummary and computes it from educationInfo.tests.
client/src/models/Cohorts.ts	Extends the client TraineeSummary model with averageTestScore.
client/src/components/cohorts/CohortAccordion.tsx	Adds a new table column to display the average score and color-codes it.

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[stasel]

Teamwork

[Copilot]

Pull request overview

Copilot reviewed 5 out of 5 changed files in this pull request and generated 3 comments.

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[zalexa19]

👏