Improved average calculation

Author: stasel

server/src/controllers/CohortsController.ts

@@ -80,9 +80,21 @@ export class CohortsController implements CohortsControllerType {
     };
   }
 
+  // Calculate average of all test scores, taking only the highest score for each test type
   private calculateAverageTestScore(tests: Test[]): number | null {
+    // Group by test type
+    const testTypes = Object.groupBy(tests, (test) => test.type);
+
+    // Select highest test for each type
+    const scores = Object.values(testTypes)
+      .map((testsWithTheSameType) => {
+        return this.getTestWithMaxScore(testsWithTheSameType);
+      })
+      .filter((test) => test !== null)
+      .map((test) => test.score)
+      .filter((score) => score !== null);
+
     // Filter out tests without scores
-    const scores = tests.map((test) => test.score).filter((score) => score !== undefined);
     if (scores.length === 0) {
       return null;
     }
@@ -101,4 +113,15 @@ export class CohortsController implements CohortsControllerType {
     // Primary sort by status, secondary sort by display name
     return statusIndexA - statusIndexB || a.displayName.localeCompare(b.displayName);
   }
+
+  private getTestWithMaxScore(tests: Test[]): Test | null {
+    const sortedByScore = tests
+      .filter((test: Test) => test.score !== null)
+      .sort((a, b) => (b.score ?? 0) - (a.score ?? 0));
+
+    if (sortedByScore.length === 0) {
+      return null;
+    }
+    return sortedByScore[0];
+  }
 }

server/src/models/Test.ts

@@ -4,7 +4,7 @@ export interface Test {
   readonly id: string;
   date: Date;
   type: TestType;
-  score?: number;
+  score: number | null;
   result: TestResult;
   comments?: string;
 }

server/src/repositories/TraineesRepository.ts

@@ -71,6 +71,7 @@ export class MongooseTraineesRepository implements TraineesRepository {
         'educationInfo.learningStatus',
         'educationInfo.strikes.id',
         'educationInfo.tests.score',
+        'educationInfo.tests.type',
         'educationInfo.currentCohort',
         'employmentInfo.jobPath',
       ])