import { describe, it, expect, beforeEach, afterEach, vi } from "vitest";
import { mkdtemp, writeFile, mkdir, rm } from "fs/promises";
import { tmpdir } from "os";
import { join } from "path";
import { resetServerState, mockFetch } from "./server-setup.js";
import { ensureLiveServer, closeLiveServer } from "../../src/live-server.js";
import { DEFAULT_DIAGRAM_OPTIONS } from "../../src/file-utils.js";
import { renderDiagram } from "../../src/handlers.js";
vi.mock("../../src/handlers.js", async (importOriginal) => {
const original = await importOriginal<typeof import("../../src/handlers.js")>();
return {
...original,
renderDiagram: vi.fn(),
};
});
const mockedRenderDiagram = vi.mocked(renderDiagram);
// Minimal valid PNG (1x1 transparent pixel)
const FAKE_PNG = Buffer.from(
"iVBORw0KGgoAAAANSUhEUgAAAAEAAAABCAYAAAAfFcSJAAAAC0lEQVQI12NgAAIABQAB" +
"Nl7BcQAAAABJRU5ErkJggg==",
"base64"
);
let configDir: string;
async function createDiagramFiles(
diagramId: string,
options: { source?: string; options?: object } = {}
): Promise<string> {
const diagramDir = join(configDir, "claude-mermaid", "live", diagramId);
await mkdir(diagramDir, { recursive: true });
await writeFile(join(diagramDir, "diagram.mmd"), options.source ?? "graph TD;A-->B;", "utf-8");
await writeFile(
join(diagramDir, "options.json"),
JSON.stringify(options.options ?? DEFAULT_DIAGRAM_OPTIONS),
"utf-8"
);
return diagramDir;
}
describe("PNG export endpoint", () => {
beforeEach(async () => {
configDir = await mkdtemp(join(tmpdir(), "claude-mermaid-export-test-"));
process.env.XDG_CONFIG_HOME = configDir;
await closeLiveServer();
resetServerState();
mockedRenderDiagram.mockReset();
});
afterEach(async () => {
await closeLiveServer();
await rm(configDir, { recursive: true, force: true }).catch(() => {});
delete process.env.XDG_CONFIG_HOME;
resetServerState();
});
it("returns PNG with correct headers", async () => {
const port = await ensureLiveServer();
const diagramId = "export-test";
await createDiagramFiles(diagramId);
mockedRenderDiagram.mockImplementation(async (_options, outputPath) => {
await writeFile(outputPath, FAKE_PNG);
});
const response = await mockFetch(`http://localhost:${port}/export/${diagramId}`);
expect(response.status).toBe(200);
expect(response.headers.get("content-type")).toBe("image/png");
expect(response.headers.get("content-disposition")).toBe(
`attachment; filename="${diagramId}.png"`
);
expect(response.headers.get("cache-control")).toBe("no-store");
});
it("passes diagram source and options to renderer", async () => {
const port = await ensureLiveServer();
const diagramId = "options-test";
const diagramSource = "sequenceDiagram\nA->>B: Hello";
const diagramOptions = { ...DEFAULT_DIAGRAM_OPTIONS, theme: "dark" };
await createDiagramFiles(diagramId, {
source: diagramSource,
options: diagramOptions,
});
mockedRenderDiagram.mockImplementation(async (_options, outputPath) => {
await writeFile(outputPath, FAKE_PNG);
});
await mockFetch(`http://localhost:${port}/export/${diagramId}`);
expect(mockedRenderDiagram).toHaveBeenCalledOnce();
const renderOptions = mockedRenderDiagram.mock.calls[0][0];
expect(renderOptions.diagram).toBe(diagramSource);
expect(renderOptions.format).toBe("png");
expect(renderOptions.theme).toBe("dark");
expect(renderOptions.previewId).toBe(diagramId);
});
it("returns 400 for invalid diagram ID", async () => {
const port = await ensureLiveServer();
const response = await mockFetch(`http://localhost:${port}/export/../etc/passwd`);
expect(response.status).toBe(400);
expect(await response.text()).toBe("Invalid diagram ID");
});
it("returns 400 for empty diagram ID", async () => {
const port = await ensureLiveServer();
const response = await mockFetch(`http://localhost:${port}/export/`);
expect(response.status).toBe(400);
expect(await response.text()).toBe("Diagram ID is required");
});
it("returns 500 when diagram source is missing", async () => {
const port = await ensureLiveServer();
const response = await mockFetch(`http://localhost:${port}/export/nonexistent`);
expect(response.status).toBe(500);
expect(await response.text()).toBe("Failed to export PNG");
});
it("returns 500 when rendering fails", async () => {
const port = await ensureLiveServer();
const diagramId = "render-fail";
await createDiagramFiles(diagramId);
mockedRenderDiagram.mockRejectedValue(new Error("mermaid-cli crashed"));
const response = await mockFetch(`http://localhost:${port}/export/${diagramId}`);
expect(response.status).toBe(500);
expect(await response.text()).toBe("Failed to export PNG");
});
});
