Restricted Source Gauntlet

(async function* (context: Context): Challenge {
  // Single Test
  const solutions = context.code.split(/##########\r?\n/);

  if (solutions.length !== 4) {
    yield context.registerTestCase(
      new TestCase("Expressions count", "Fail", {
        Text: `Expected 4 solutions, found ${solutions.length}.`,
      }),
    );
    return context.noFailures();
  }

  const asciiOnly = [...context.code].every((x) => x.codePointAt(0)! < 128);
  if (!asciiOnly) {
    yield context.registerTestCase(
      new TestCase("Ascii only", "Fail", {
        Text: `Expected only ascii characters.`,
      }),
    );
    return context.noFailures();
  }

  const problems = ["eir", "ctv", ").c", "(dt"];

  for (let i = 0; i < problems.length; i++) {
    if (!solutions[i]) continue;

    // check matches format
    const usesBanned = [...problems[i]].some((char) =>
      solutions[i].includes(char),
    );

    yield context.registerTestCase(
      new TestCase("Banned characters", !usesBanned ? "Pass" : "Fail", {
        Text: `Solution ${i} (${JSON.stringify(solutions[i])}) uses one of the banned characters \`${problems[i]}\``,
      }),
    );

    if (usesBanned) continue;

    // check outputs "Hello, World!"
    // TODO: await here or no?
    yield (await context.runCode(solutions[i]))
      .assertEquals("Hello, World!")
      .setName(`Solution ${i} output`);
  }

  // give 1000 points for each empty solution
  const score = solutions
    .map((sol) => sol.length + (!sol ? 1000 : 0))
    .reduce((a, b) => a + b);

  // Finally, the challenge is passed if no test cases failed
  return context.noFailures(score);
});

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