ai-chatbot/tests/routes/replacement-layout-lock.test.ts

import { expect, test } from "@playwright/test";
import sharp from "sharp";
import {
  buildReplacementInputBoundingBoxList,
  compositeReplacementWithReferenceLocks,
  expandReplacementSubjectBoundingBoxForGeneration,
  parseReplacementLayoutLockRegions,
} from "@/lib/ai/replacement-layout-lock";

test("parses normalized subject and protected text regions", () => {
  const result = parseReplacementLayoutLockRegions(`
    \`\`\`json
    {
      "subjectBoundingBox": [200, 250, 800, 900],
      "textBoundingBoxes": [[100, 80, 700, 160], [20, 20, 20, 40], [-20, 900, 1100, 980]]
    }
    \`\`\`
  `);

  expect(result).toEqual({
    subjectBoundingBox: [200, 250, 800, 900],
    textBoundingBoxes: [
      [100, 80, 700, 160],
      [0, 900, 1000, 980],
    ],
    analyzed: true,
  });
});

test("marks incomplete layout analysis for a safe fallback", () => {
  expect(
    parseReplacementLayoutLockRegions({
      subjectBoundingBox: [200, 250, 800, 900],
    }),
  ).toEqual({
    subjectBoundingBox: [200, 250, 800, 900],
    textBoundingBoxes: [],
    analyzed: false,
  });
});

test("expands the replacement subject horizontally and aligns it with the layout input", () => {
  expect(
    expandReplacementSubjectBoundingBoxForGeneration([379, 240, 628, 917]),
  ).toEqual([354, 230, 653, 927]);
  expect(
    buildReplacementInputBoundingBoxList({
      imageUrls: [
        "https://example.com/product.png",
        "https://example.com/layout.png",
      ],
      referenceImageUrl: "https://example.com/layout.png",
      subjectBoundingBox: [379, 240, 628, 917],
    }),
  ).toEqual([[], [[354, 230, 653, 927]]]);
});

test("keeps the reference outside the subject and inside protected text", async () => {
  const width = 100;
  const height = 100;
  const reference = await sharp({
    create: {
      width,
      height,
      channels: 3,
      background: { r: 255, g: 0, b: 0 },
    },
  })
    .png()
    .toBuffer();
  const generated = await sharp({
    create: {
      width,
      height,
      channels: 3,
      background: { r: 0, g: 0, b: 255 },
    },
  })
    .png()
    .toBuffer();

  const result = await compositeReplacementWithReferenceLocks({
    generatedBuffer: generated,
    referenceBuffer: reference,
    width,
    height,
    preserveReferenceOutsideSubject: true,
    subjectBoundingBox: [300, 300, 700, 700],
    textBoundingBoxes: [[450, 450, 550, 550]],
  });
  const { data, info } = await sharp(result)
    .removeAlpha()
    .raw()
    .toBuffer({ resolveWithObject: true });
  const pixel = (x: number, y: number) =>
    Array.from(
      data.subarray(
        (y * width + x) * info.channels,
        (y * width + x) * info.channels + 3,
      ),
    );

  expect(pixel(5, 5)).toEqual([255, 0, 0]);
  expect(pixel(35, 50)).toEqual([0, 0, 255]);
  expect(pixel(50, 50)).toEqual([255, 0, 0]);
});

test("restores original text pixels while retaining a regenerated scene", async () => {
  const width = 100;
  const height = 100;
  const reference = await sharp({
    create: {
      width,
      height,
      channels: 3,
      background: { r: 255, g: 0, b: 0 },
    },
  })
    .png()
    .toBuffer();
  const generated = await sharp({
    create: {
      width,
      height,
      channels: 3,
      background: { r: 0, g: 0, b: 255 },
    },
  })
    .png()
    .toBuffer();

  const result = await compositeReplacementWithReferenceLocks({
    generatedBuffer: generated,
    referenceBuffer: reference,
    width,
    height,
    preserveReferenceOutsideSubject: false,
    textBoundingBoxes: [[400, 400, 600, 600]],
  });
  const { data, info } = await sharp(result)
    .removeAlpha()
    .raw()
    .toBuffer({ resolveWithObject: true });
  const pixel = (x: number, y: number) =>
    Array.from(
      data.subarray(
        (y * width + x) * info.channels,
        (y * width + x) * info.channels + 3,
      ),
    );

  expect(pixel(5, 5)).toEqual([0, 0, 255]);
  expect(pixel(50, 50)).toEqual([255, 0, 0]);
});