typescript-gradebook-name-resolution

Answer

Problem: getGradebookView displayed names via a hardcoded alpha stub ("Student " + uuid8) even though classService.getEnrollments(classId) — already invoked at line 149 — SELECTs student_name (a snapshot of users.full_name). The data existed; the wiring was the gap.

Fix: Build a Map<studentId, fullName> from the enrollment snapshot, resolve names from it, split the full name at the last space (so multi-word first names like "Mary Jane Watson" survive), and keep the stub only as a fallback for unenrolled/anonymous students.

// types.ts — shape of the snapshot already fetched at line 149
interface EnrollmentRow {
  student_id: string;
  student_name: string | null;   // snapshot of users.full_name at enrollment time
  users?: { full_name: string | null };
}

interface ResolvedName {
  fullName: string;
  firstName: string;
  lastName: string;
  isStub: boolean;
}

const STUB_PREFIX = 'Student';
const uuid8 = (id: string) => id.slice(0, 8);

// Split at the LAST space — "Mary Jane Watson" -> first "Mary Jane", last "Watson".
// A single-token name yields lastName: '' (and the stub "Student xxxxxxxx" stays
// one token, so it sorts safely under "S").
export function splitAtLastSpace(fullName: string): { firstName: string; lastName: string } {
  const idx = fullName.lastIndexOf(' ');
  if (idx <= 0) return { firstName: fullName.trim(), lastName: '' };
  return {
    firstName: fullName.slice(0, idx).trim(),
    lastName: fullName.slice(idx + 1).trim(),
  };
}

// Map<studentId, fullName> from the enrollment snapshot. Prefers the
// student_name snapshot; falls back to users.full_name for the alias.
export function makeStudentNameMap(enrollments: EnrollmentRow[]): Map<string, string> {
  const map = new Map<string, string>();
  for (const e of enrollments) {
    const name = e.student_name ?? e.users?.full_name ?? null;
    if (name && name.trim()) map.set(e.student_id, name.trim());
  }
  return map;
}

// Replaces the hardcoded stub. Real name when the student is enrolled;
// stub only for students absent from the snapshot.
export function createStudentNameResolver(enrollments: EnrollmentRow[]) {
  const nameMap = makeStudentNameMap(enrollments);
  return (studentId: string): ResolvedName => {
    const fullName = nameMap.get(studentId);
    if (fullName) {
      const { firstName, lastName } = splitAtLastSpace(fullName);
      return { fullName, firstName, lastName, isStub: false };
    }
    const stub = `${STUB_PREFIX} ${uuid8(studentId)}`;
    return { fullName: stub, firstName: stub, lastName: '', isStub: true };
  };
}

// getGradebookView — line 149 already fetches the snapshot; just pass it in.
export function getGradebookView(classId: string) {
  const enrollments = classService.getEnrollments(classId); // line 149 (unchanged)
  const resolveStudentName = createStudentNameResolver(enrollments);

  const rows = /* ...gradebook rows... */ [];
  return rows.map((row) => {
    const name = resolveStudentName(row.studentId);
    return {
      ...row,
      displayName: name.lastName ? `${name.lastName}, ${name.firstName}` : name.fullName,
      name, // firstName/lastName available for sort keys and columns
    };
  });
}

Test updates (per DOGFOOD-010): the old alpha-stub assertion now asserts real names (e.g. resolveStudentName(...).fullName === 'Mary Jane Watson' and lastName === 'Watson'), and the e2e teacher-workflow spec asserts the rendered gradebook shows the enrolled student's actual name rather than Student <uuid8>.