refactor: extract buildPdfOptions to DRY up renderPdf/renderUrlPdf (TDD)

- Extract shared PDF options construction into buildPdfOptions()
- Both renderPdf and renderUrlPdf now use the shared builder
- 5 TDD tests added (pdf-options-builder.test.ts)
- 633 tests passing, 0 tsc errors

src/__tests__/pdf-options-builder.test.ts

@@ -0,0 +1,68 @@
+import { describe, it, expect } from "vitest";
+import { buildPdfOptions, PdfRenderOptions } from "../services/browser.js";
+
+describe("buildPdfOptions", () => {
+  it("returns sensible defaults when no options given", () => {
+    const result = buildPdfOptions({});
+    expect(result).toEqual({
+      format: "A4",
+      landscape: false,
+      printBackground: true,
+      margin: { top: "0", right: "0", bottom: "0", left: "0" },
+    });
+  });
+
+  it("passes through all provided options", () => {
+    const opts: PdfRenderOptions = {
+      format: "Letter",
+      landscape: true,
+      printBackground: false,
+      margin: { top: "10mm", bottom: "10mm" },
+      scale: 1.5,
+      pageRanges: "1-3",
+      preferCSSPageSize: true,
+      width: "210mm",
+      height: "297mm",
+      headerTemplate: "<span>Header</span>",
+      footerTemplate: "<span>Footer</span>",
+      displayHeaderFooter: true,
+    };
+    const result = buildPdfOptions(opts);
+    expect(result.format).toBe("Letter");
+    expect(result.landscape).toBe(true);
+    expect(result.printBackground).toBe(false);
+    expect(result.margin).toEqual({ top: "10mm", bottom: "10mm" });
+    expect(result.scale).toBe(1.5);
+    expect(result.pageRanges).toBe("1-3");
+    expect(result.preferCSSPageSize).toBe(true);
+    expect(result.width).toBe("210mm");
+    expect(result.height).toBe("297mm");
+    expect(result.headerTemplate).toBe("<span>Header</span>");
+    expect(result.footerTemplate).toBe("<span>Footer</span>");
+    expect(result.displayHeaderFooter).toBe(true);
+  });
+
+  it("omits undefined optional fields from output", () => {
+    const result = buildPdfOptions({ format: "A4" });
+    expect(result).not.toHaveProperty("scale");
+    expect(result).not.toHaveProperty("pageRanges");
+    expect(result).not.toHaveProperty("preferCSSPageSize");
+    expect(result).not.toHaveProperty("width");
+    expect(result).not.toHaveProperty("height");
+    expect(result).not.toHaveProperty("headerTemplate");
+    expect(result).not.toHaveProperty("footerTemplate");
+  });
+
+  it("handles printBackground false explicitly", () => {
+    const result = buildPdfOptions({ printBackground: false });
+    expect(result.printBackground).toBe(false);
+  });
+
+  it("defaults displayHeaderFooter to false only when explicitly set", () => {
+    const r1 = buildPdfOptions({});
+    expect(r1).not.toHaveProperty("displayHeaderFooter");
+
+    const r2 = buildPdfOptions({ displayHeaderFooter: false });
+    expect(r2.displayHeaderFooter).toBe(false);
+  });
+});

src/__tests__/setup.ts

@@ -53,7 +53,10 @@ vi.mock("../services/keys.js", () => {
 });
 
 // Mock browser service
-vi.mock("../services/browser.js", () => ({
+vi.mock("../services/browser.js", async (importOriginal) => {
+  const actual = await importOriginal<Record<string, unknown>>();
+  return {
+  buildPdfOptions: actual.buildPdfOptions,
   initBrowser: vi.fn().mockResolvedValue(undefined),
   closeBrowser: vi.fn().mockResolvedValue(undefined),
   renderPdf: vi.fn().mockResolvedValue({ pdf: Buffer.from("%PDF-1.4 mock pdf content here"), durationMs: 10 }),
@@ -68,7 +71,8 @@ vi.mock("../services/browser.js", () => ({
     uptimeMs: 10000,
     browsers: [],
   }),
-}));
+};
+});
 
 // Mock verification service
 vi.mock("../services/verification.js", () => ({