lint: node.test.ts

  assertEquals(results, expected_gray_idx);

});

async function createTestImage(color: number): Promise<Awaited<ReturnType<typeof Jimp.read>>> {

async function createTestImage(

  color: number,

): Promise<Awaited<ReturnType<typeof Jimp.read>>> {

  const image = new Jimp({ width: 1, height: 1, color });

  const imageBuffer = await image.getBuffer("image/webp");

  return Jimp.read(imageBuffer);