nuxt4-demo/app/utils/markdown-export.test.ts

import { describe, expect, test } from "bun:test";
import {
  buildMarkdownExportFileName,
  downloadMarkdownFile,
  normalizeMarkdownImageUrls,
} from "./markdown-export";

describe("normalizeMarkdownImageUrls", () => {
  test("converts /public/upload image links to absolute URLs", () => {
    const markdown = "![cover](/public/upload/posts/cover.png)";
    const result = normalizeMarkdownImageUrls(markdown, "https://example.com");

    expect(result).toBe("![cover](https://example.com/public/upload/posts/cover.png)");
  });

  test("converts other site-relative image links to absolute URLs", () => {
    const markdown = "![hero](/images/a.png)";
    const result = normalizeMarkdownImageUrls(markdown, "https://example.com");

    expect(result).toBe("![hero](https://example.com/images/a.png)");
  });

  test("keeps absolute http/https image links unchanged", () => {
    const markdown = [
      "![a](http://cdn.example.com/a.png)",
      "![b](https://cdn.example.com/b.png)",
    ].join("\n");

    const result = normalizeMarkdownImageUrls(markdown, "https://example.com");

    expect(result).toBe(markdown);
  });

  test("keeps protocol-relative and data URI image links unchanged", () => {
    const markdown = [
      "![protocol](//cdn.example.com/p.png)",
      "![inline](data:image/png;base64,AAAB)",
    ].join("\n");

    const result = normalizeMarkdownImageUrls(markdown, "https://example.com");

    expect(result).toBe(markdown);
  });

  test("does not change normal markdown links", () => {
    const markdown = "[read more](/public/upload/posts/cover.png)";
    const result = normalizeMarkdownImageUrls(markdown, "https://example.com");

    expect(result).toBe(markdown);
  });
});

describe("buildMarkdownExportFileName", () => {
  test("prefers slug when slug is not empty", () => {
    const result = buildMarkdownExportFileName({ slug: "hello-world", id: 42 });

    expect(result).toBe("hello-world.md");
  });

  test("falls back to post-<id>.md when slug is empty", () => {
    const result = buildMarkdownExportFileName({ slug: "", id: 42 });

    expect(result).toBe("post-42.md");
  });
});

describe("downloadMarkdownFile", () => {
  test("does not throw when window/document are unavailable", () => {
    const windowDescriptor = Object.getOwnPropertyDescriptor(globalThis, "window");
    const documentDescriptor = Object.getOwnPropertyDescriptor(globalThis, "document");

    Object.defineProperty(globalThis, "window", {
      value: undefined,
      configurable: true,
      writable: true,
    });
    Object.defineProperty(globalThis, "document", {
      value: undefined,
      configurable: true,
      writable: true,
    });

    try {
      expect(() => downloadMarkdownFile("post.md", "# hello")).not.toThrow();
    } finally {
      if (windowDescriptor) {
        Object.defineProperty(globalThis, "window", windowDescriptor);
      } else {
        Reflect.deleteProperty(globalThis, "window");
      }

      if (documentDescriptor) {
        Object.defineProperty(globalThis, "document", documentDescriptor);
      } else {
        Reflect.deleteProperty(globalThis, "document");
      }
    }
  });

  test("creates object URL, clicks anchor, and revokes URL in browser flow", () => {
    const windowDescriptor = Object.getOwnPropertyDescriptor(globalThis, "window");
    const documentDescriptor = Object.getOwnPropertyDescriptor(globalThis, "document");
    const urlDescriptor = Object.getOwnPropertyDescriptor(globalThis, "URL");

    let createElementArg = "";
    let appendedNode: unknown;
    let clicked = false;
    let removed = false;
    let revokedArg = "";
    const blobUrl = "blob:test-url";

    const anchor = {
      href: "",
      download: "",
      style: { display: "" },
      click: () => {
        clicked = true;
      },
      remove: () => {
        removed = true;
      },
    };

    Object.defineProperty(globalThis, "window", {
      value: {},
      configurable: true,
      writable: true,
    });

    Object.defineProperty(globalThis, "document", {
      value: {
        createElement: (tag: string) => {
          createElementArg = tag;
          return anchor;
        },
        body: {
          appendChild: (node: unknown) => {
            appendedNode = node;
          },
        },
      },
      configurable: true,
      writable: true,
    });

    Object.defineProperty(globalThis, "URL", {
      value: {
        createObjectURL: (_blob: Blob) => blobUrl,
        revokeObjectURL: (url: string) => {
          revokedArg = url;
        },
      },
      configurable: true,
      writable: true,
    });

    try {
      downloadMarkdownFile("hello.md", "# hello");

      expect(createElementArg).toBe("a");
      expect(appendedNode).toBe(anchor);
      expect(anchor.href).toBe(blobUrl);
      expect(anchor.download).toBe("hello.md");
      expect(anchor.style.display).toBe("none");
      expect(clicked).toBe(true);
      expect(removed).toBe(true);
      expect(revokedArg).toBe(blobUrl);
    } finally {
      if (windowDescriptor) {
        Object.defineProperty(globalThis, "window", windowDescriptor);
      } else {
        Reflect.deleteProperty(globalThis, "window");
      }

      if (documentDescriptor) {
        Object.defineProperty(globalThis, "document", documentDescriptor);
      } else {
        Reflect.deleteProperty(globalThis, "document");
      }

      if (urlDescriptor) {
        Object.defineProperty(globalThis, "URL", urlDescriptor);
      } else {
        Reflect.deleteProperty(globalThis, "URL");
      }
    }
  });

  test("still revokes object URL when anchor click throws", () => {
    const windowDescriptor = Object.getOwnPropertyDescriptor(globalThis, "window");
    const documentDescriptor = Object.getOwnPropertyDescriptor(globalThis, "document");
    const urlDescriptor = Object.getOwnPropertyDescriptor(globalThis, "URL");

    let revokedArg = "";
    let removed = false;
    const blobUrl = "blob:error-case";
    const clickError = new Error("click failed");

    const anchor = {
      href: "",
      download: "",
      style: { display: "" },
      click: () => {
        throw clickError;
      },
      remove: () => {
        removed = true;
      },
    };

    Object.defineProperty(globalThis, "window", {
      value: {},
      configurable: true,
      writable: true,
    });

    Object.defineProperty(globalThis, "document", {
      value: {
        createElement: (_tag: string) => anchor,
        body: {
          appendChild: (_node: unknown) => undefined,
        },
      },
      configurable: true,
      writable: true,
    });

    Object.defineProperty(globalThis, "URL", {
      value: {
        createObjectURL: (_blob: Blob) => blobUrl,
        revokeObjectURL: (url: string) => {
          revokedArg = url;
        },
      },
      configurable: true,
      writable: true,
    });

    try {
      expect(() => downloadMarkdownFile("broken.md", "# broken")).toThrow("click failed");
      expect(removed).toBe(true);
      expect(revokedArg).toBe(blobUrl);
    } finally {
      if (windowDescriptor) {
        Object.defineProperty(globalThis, "window", windowDescriptor);
      } else {
        Reflect.deleteProperty(globalThis, "window");
      }

      if (documentDescriptor) {
        Object.defineProperty(globalThis, "document", documentDescriptor);
      } else {
        Reflect.deleteProperty(globalThis, "document");
      }

      if (urlDescriptor) {
        Object.defineProperty(globalThis, "URL", urlDescriptor);
      } else {
        Reflect.deleteProperty(globalThis, "URL");
      }
    }
  });
});