test: cover how the PDF preview reports protected and unreadable files

src/lib/__tests__/pdf-pages.test.ts

@@ -0,0 +1,42 @@
+import { afterEach, describe, expect, it, vi } from 'vitest';
+import { NativeModules } from 'react-native';
+import { openPdfPages, PdfOpenError, renderPdfPage, canRenderPdfPages } from '../pdf-pages';
+
+const modules = NativeModules as Record<string, unknown>;
+
+function nativeError(code: string, message: string): Error {
+  return Object.assign(new Error(message), { code });
+}
+
+describe('pdf-pages', () => {
+  afterEach(() => { delete modules.BulwarkPdf; });
+
+  it('reports the page sizes the renderer returns', async () => {
+    modules.BulwarkPdf = { open: vi.fn(async () => ({ pages: [{ width: 595, height: 842 }] })) };
+    await expect(openPdfPages('file:///x.pdf')).resolves.toEqual([{ width: 595, height: 842 }]);
+  });
+
+  it('tells a password-protected PDF from an unreadable one', async () => {
+    modules.BulwarkPdf = { open: vi.fn(async () => { throw nativeError('E_PDF_PROTECTED', 'password'); }) };
+    await expect(openPdfPages('file:///x.pdf')).rejects.toMatchObject({ reason: 'protected' });
+
+    modules.BulwarkPdf = { open: vi.fn(async () => { throw nativeError('E_PDF_OPEN', 'not a PDF'); }) };
+    await expect(openPdfPages('file:///x.pdf')).rejects.toMatchObject({ reason: 'unreadable' });
+
+    modules.BulwarkPdf = { open: vi.fn(async () => ({ pages: [] })) };
+    await expect(openPdfPages('file:///x.pdf')).rejects.toBeInstanceOf(PdfOpenError);
+  });
+
+  it('fails cleanly in a build without the renderer', async () => {
+    expect(canRenderPdfPages()).toBe(false);
+    await expect(openPdfPages('file:///x.pdf')).rejects.toMatchObject({ reason: 'unreadable' });
+    await expect(renderPdfPage('file:///x.pdf', 0, 100, 'file:///p.png')).rejects.toThrow();
+  });
+
+  it('renders at a whole pixel width', async () => {
+    const renderPage = vi.fn(async () => 'file:///p.png');
+    modules.BulwarkPdf = { renderPage };
+    await renderPdfPage('file:///x.pdf', 2, 1620.6, 'file:///p.png');
+    expect(renderPage).toHaveBeenCalledWith('file:///x.pdf', 2, 1621, 'file:///p.png');
+  });
+});