Task system

The task system lives in src/server/domain/task-system/. It has no dependency on the web layer, so it is tested directly with Vitest.

Definitions and instances

A TaskDefinition describes a task type – typeId, category, grade, description – and generates instances. A TaskInstance is one concrete task:

interface TaskInstance<TData = unknown> {
  readonly id: string;
  readonly typeId: string;
  readonly category: TaskCategory;
  readonly grade: Grade; // 1 | 2 | 3 | 4 | 5
  readonly question: string;
  readonly locale: Locale;
  readonly data: TData;
  readonly inputType?: "text" | "multiple-choice" | "drag-drop";
  // … input label, choices, drag items, drop targets

  validate(userAnswer: string): ValidationResult;
  getHint(): string;
  getCorrectAnswer(): string | number;
}

Each task checks its own answer and supplies the hint shown after a wrong one. Validation accepts equivalent notations: a decimal comma or point, equivalent fractions (6/8 for 3/4), money compared in whole cents.

Registry and generator

All definitions from tasks/ are registered in one registry – 105 at the moment, listed in the task catalogue. The generator fills a run from the chosen grade and the grade below and avoids repeating a task type until all have been used. On the selection page (/auswahl) a child can instead pick individual task types and 10 to 50 tasks.

Session

A run is a TestSession: the serialised tasks, the results, the current index, the options and the counters. It is stored with Astro sessions, which the Cloudflare adapter keeps in the SESSION KV namespace.

Serialised tasks lose their class. rehydrate.ts restores each task through the class of its own type before validation, so a task like “57 ÷ 9 = ? (with remainder)” is checked by its own rules and a bare “6” does not pass for “6 Rest 3”.

Options

• Adaptive difficulty – three correct answers in a row raise the difficulty by one grade, three wrong ones lower it; up to three upcoming tasks are regenerated at the new level.
• Retry incorrect – tasks answered wrongly are asked again in a retry round at the end.