koc-loop/tests/workbook-image.test.mjs

import assert from "node:assert/strict";
import test from "node:test";
import sharp from "sharp";
import { normalizeWorkbookImage } from "../lib/workbook-image.ts";

test("bakes EXIF orientation into exported workbook image pixels", async () => {
  const source = await sharp({
    create: {
      width: 8,
      height: 4,
      channels: 3,
      background: "#e95420",
    },
  })
    .jpeg()
    .withMetadata({ orientation: 6 })
    .toBuffer();

  const normalized = await normalizeWorkbookImage({
    bytes: new Uint8Array(source),
    contentType: "image/jpeg",
    width: 8,
    height: 4,
    description: "手机照片",
  });
  const metadata = await sharp(normalized.bytes).metadata();

  assert.equal(normalized.contentType, "image/png");
  assert.equal(normalized.width, 4);
  assert.equal(normalized.height, 8);
  assert.equal(metadata.width, 4);
  assert.equal(metadata.height, 8);
  assert.equal(metadata.orientation, undefined);
});

test("keeps unsupported image bytes unchanged", async () => {
  const bytes = Uint8Array.from([1, 2, 3]);
  const normalized = await normalizeWorkbookImage({
    bytes,
    contentType: "application/octet-stream",
    description: "未知文件",
  });
  assert.equal(normalized.bytes, bytes);
  assert.equal(normalized.contentType, "application/octet-stream");
});

test("normalizes recognizable images even when storage metadata has no image MIME type", async () => {
  const source = await sharp({
    create: {
      width: 8,
      height: 4,
      channels: 3,
      background: "#22c55e",
    },
  })
    .jpeg()
    .withMetadata({ orientation: 6 })
    .toBuffer();
  const normalized = await normalizeWorkbookImage({
    bytes: new Uint8Array(source),
    contentType: "application/octet-stream",
    description: "方向元数据缺失测试",
  });

  assert.equal(normalized.contentType, "image/png");
  assert.equal(normalized.width, 4);
  assert.equal(normalized.height, 8);
});

test("can downsize full-resolution source images for compact workbook exports", async () => {
  const source = await sharp({
    create: {
      width: 4000,
      height: 3000,
      channels: 3,
      background: "#d4a72c",
    },
  })
    .png({ compressionLevel: 0 })
    .toBuffer();
  const normalized = await normalizeWorkbookImage(
    {
      bytes: new Uint8Array(source),
      contentType: "image/png",
      width: 4000,
      height: 3000,
      description: "批量回填原图",
    },
    { maxDimension: 1600, outputFormat: "jpeg", jpegQuality: 82 },
  );
  const metadata = await sharp(normalized.bytes).metadata();

  assert.equal(normalized.contentType, "image/jpeg");
  assert.equal(normalized.width, 1600);
  assert.equal(normalized.height, 1200);
  assert.equal(metadata.format, "jpeg");
  assert.ok(normalized.bytes.byteLength < source.byteLength / 20);
});