automaker/apps/server/tests/unit/lib/image-handler.test.ts

import { describe, it, expect, vi, beforeEach } from "vitest";
import {
  getMimeTypeForImage,
  readImageAsBase64,
  convertImagesToContentBlocks,
  formatImagePathsForPrompt,
} from "@/lib/image-handler.js";
import { pngBase64Fixture } from "../../fixtures/images.js";
import * as fs from "fs/promises";

vi.mock("fs/promises");

describe("image-handler.ts", () => {
  beforeEach(() => {
    vi.clearAllMocks();
  });

  describe("getMimeTypeForImage", () => {
    it("should return correct MIME type for .jpg", () => {
      expect(getMimeTypeForImage("test.jpg")).toBe("image/jpeg");
      expect(getMimeTypeForImage("/path/to/test.jpg")).toBe("image/jpeg");
    });

    it("should return correct MIME type for .jpeg", () => {
      expect(getMimeTypeForImage("test.jpeg")).toBe("image/jpeg");
    });

    it("should return correct MIME type for .png", () => {
      expect(getMimeTypeForImage("test.png")).toBe("image/png");
    });

    it("should return correct MIME type for .gif", () => {
      expect(getMimeTypeForImage("test.gif")).toBe("image/gif");
    });

    it("should return correct MIME type for .webp", () => {
      expect(getMimeTypeForImage("test.webp")).toBe("image/webp");
    });

    it("should be case-insensitive", () => {
      expect(getMimeTypeForImage("test.PNG")).toBe("image/png");
      expect(getMimeTypeForImage("test.JPG")).toBe("image/jpeg");
      expect(getMimeTypeForImage("test.GIF")).toBe("image/gif");
      expect(getMimeTypeForImage("test.WEBP")).toBe("image/webp");
    });

    it("should default to image/png for unknown extensions", () => {
      expect(getMimeTypeForImage("test.unknown")).toBe("image/png");
      expect(getMimeTypeForImage("test.txt")).toBe("image/png");
      expect(getMimeTypeForImage("test")).toBe("image/png");
    });

    it("should handle paths with multiple dots", () => {
      expect(getMimeTypeForImage("my.image.file.jpg")).toBe("image/jpeg");
    });
  });

  describe("readImageAsBase64", () => {
    it("should read image and return base64 data", async () => {
      const mockBuffer = Buffer.from(pngBase64Fixture, "base64");
      vi.mocked(fs.readFile).mockResolvedValue(mockBuffer);

      const result = await readImageAsBase64("/path/to/test.png");

      expect(result).toMatchObject({
        base64: pngBase64Fixture,
        mimeType: "image/png",
        filename: "test.png",
        originalPath: "/path/to/test.png",
      });
      expect(fs.readFile).toHaveBeenCalledWith("/path/to/test.png");
    });

    it("should handle different image formats", async () => {
      const mockBuffer = Buffer.from("jpeg-data");
      vi.mocked(fs.readFile).mockResolvedValue(mockBuffer);

      const result = await readImageAsBase64("/path/to/photo.jpg");

      expect(result.mimeType).toBe("image/jpeg");
      expect(result.filename).toBe("photo.jpg");
      expect(result.base64).toBe(mockBuffer.toString("base64"));
    });

    it("should extract filename from path", async () => {
      const mockBuffer = Buffer.from("data");
      vi.mocked(fs.readFile).mockResolvedValue(mockBuffer);

      const result = await readImageAsBase64("/deep/nested/path/image.webp");

      expect(result.filename).toBe("image.webp");
    });

    it("should throw error if file cannot be read", async () => {
      vi.mocked(fs.readFile).mockRejectedValue(new Error("File not found"));

      await expect(readImageAsBase64("/nonexistent.png")).rejects.toThrow(
        "File not found"
      );
    });
  });

  describe("convertImagesToContentBlocks", () => {
    it("should convert single image to content block", async () => {
      const mockBuffer = Buffer.from(pngBase64Fixture, "base64");
      vi.mocked(fs.readFile).mockResolvedValue(mockBuffer);

      const result = await convertImagesToContentBlocks(["/path/test.png"]);

      expect(result).toHaveLength(1);
      expect(result[0]).toMatchObject({
        type: "image",
        source: {
          type: "base64",
          media_type: "image/png",
          data: pngBase64Fixture,
        },
      });
    });

    it("should convert multiple images to content blocks", async () => {
      const mockBuffer = Buffer.from("test-data");
      vi.mocked(fs.readFile).mockResolvedValue(mockBuffer);

      const result = await convertImagesToContentBlocks([
        "/a.png",
        "/b.jpg",
        "/c.webp",
      ]);

      expect(result).toHaveLength(3);
      expect(result[0].source.media_type).toBe("image/png");
      expect(result[1].source.media_type).toBe("image/jpeg");
      expect(result[2].source.media_type).toBe("image/webp");
    });

    it("should resolve relative paths with workDir", async () => {
      const mockBuffer = Buffer.from("data");
      vi.mocked(fs.readFile).mockResolvedValue(mockBuffer);

      await convertImagesToContentBlocks(["relative.png"], "/work/dir");

      // Use path-agnostic check since Windows uses backslashes
      const calls = vi.mocked(fs.readFile).mock.calls;
      expect(calls[0][0]).toMatch(/relative\.png$/);
      expect(calls[0][0]).toContain("work");
      expect(calls[0][0]).toContain("dir");
    });

    it("should handle absolute paths without workDir", async () => {
      const mockBuffer = Buffer.from("data");
      vi.mocked(fs.readFile).mockResolvedValue(mockBuffer);

      await convertImagesToContentBlocks(["/absolute/path.png"]);

      expect(fs.readFile).toHaveBeenCalledWith("/absolute/path.png");
    });

    it("should continue processing on individual image errors", async () => {
      vi.mocked(fs.readFile)
        .mockResolvedValueOnce(Buffer.from("ok1"))
        .mockRejectedValueOnce(new Error("Failed"))
        .mockResolvedValueOnce(Buffer.from("ok2"));

      const consoleSpy = vi.spyOn(console, "error").mockImplementation(() => {});

      const result = await convertImagesToContentBlocks([
        "/a.png",
        "/b.png",
        "/c.png",
      ]);

      expect(result).toHaveLength(2); // Only successful images
      expect(consoleSpy).toHaveBeenCalled();

      consoleSpy.mockRestore();
    });

    it("should return empty array for empty input", async () => {
      const result = await convertImagesToContentBlocks([]);
      expect(result).toEqual([]);
    });

    it("should handle undefined workDir", async () => {
      const mockBuffer = Buffer.from("data");
      vi.mocked(fs.readFile).mockResolvedValue(mockBuffer);

      const result = await convertImagesToContentBlocks(["/test.png"], undefined);

      expect(result).toHaveLength(1);
      expect(fs.readFile).toHaveBeenCalledWith("/test.png");
    });
  });

  describe("formatImagePathsForPrompt", () => {
    it("should format single image path as bulleted list", () => {
      const result = formatImagePathsForPrompt(["/path/image.png"]);

      expect(result).toContain("\n\nAttached images:");
      expect(result).toContain("- /path/image.png");
    });

    it("should format multiple image paths as bulleted list", () => {
      const result = formatImagePathsForPrompt([
        "/path/a.png",
        "/path/b.jpg",
        "/path/c.webp",
      ]);

      expect(result).toContain("Attached images:");
      expect(result).toContain("- /path/a.png");
      expect(result).toContain("- /path/b.jpg");
      expect(result).toContain("- /path/c.webp");
    });

    it("should return empty string for empty array", () => {
      const result = formatImagePathsForPrompt([]);
      expect(result).toBe("");
    });

    it("should start with double newline", () => {
      const result = formatImagePathsForPrompt(["/test.png"]);
      expect(result.startsWith("\n\n")).toBe(true);
    });

    it("should handle paths with special characters", () => {
      const result = formatImagePathsForPrompt(["/path/with spaces/image.png"]);
      expect(result).toContain("- /path/with spaces/image.png");
    });
  });
});