validate-content.mjs

import { access } from "node:fs/promises";
import { dirname, resolve } from "node:path";
import { fileURLToPath } from "node:url";
import { tutorial } from "../tutorial-data.js";

const root = resolve(dirname(fileURLToPath(import.meta.url)), "..");
const failures = [];

if (!tutorial?.lessons?.length) {
  failures.push("Tutorial data must contain at least one lesson.");
}

for (const lesson of tutorial?.lessons ?? []) {
  const label = lesson.id || "unnamed lesson";
  if (!/^[A-Za-z_$][A-Za-z0-9_$]*\.java$/.test(lesson.exercise?.filename || "")) {
    failures.push(`${label}: exercise needs a Java filename.`);
  }

  for (const check of lesson.exercise?.checks ?? []) {
    if (!new RegExp(check.pattern, "m").test(lesson.exercise.solutionCode)) {
      failures.push(`${label}: the provided solution fails the check “${check.message}”`);
    }
  }

  if (lesson.exercise?.guide) {
    const guidePath = lesson.exercise.guide.image.split(/[?#]/)[0];
    try {
      await access(resolve(root, guidePath));
    } catch {
      failures.push(`${label}: guide image does not exist: ${guidePath}`);
    }
  }

  for (const question of lesson.questions ?? []) {
    if (question.type === "radio") {
      if (!Array.isArray(question.choices) || !Number.isInteger(question.correct) || !question.choices[question.correct]) {
        failures.push(`${label}: radio question ${question.id} has an invalid correct answer.`);
      }
    } else if (question.type === "text") {
      if (!Array.isArray(question.accepted) || question.accepted.length === 0) {
        failures.push(`${label}: text question ${question.id} needs at least one accepted answer.`);
      }
    } else {
      failures.push(`${label}: question ${question.id} uses unsupported type ${question.type}.`);
    }
  }
}

if (failures.length) {
  console.error(failures.join("\n"));
  process.exit(1);
}

console.log(`Validated ${tutorial.lessons.length} lessons and their solutions.`);