feat: update GitHub Actions workflow for PDF engine and viewer

src/tests/redact-document-data.test.ts

@@ -0,0 +1,210 @@
+import { describe, it, expect, vi } from 'vitest';
+import { readFileSync } from 'fs';
+import { resolve } from 'path';
+import {
+  PDFArray,
+  PDFDict,
+  PDFDocument,
+  PDFHexString,
+  PDFName,
+  PDFObject,
+  PDFRawStream,
+  PDFString,
+  decodePDFRawStream,
+} from 'pdf-lib';
+
+vi.mock('../js/utils/helpers.js', async () => {
+  const { default: createModule } = await import('@neslinesli93/qpdf-wasm');
+  const wasmPath = resolve(
+    'node_modules/@neslinesli93/qpdf-wasm/dist/qpdf.wasm'
+  );
+  const options = {
+    locateFile: () => wasmPath,
+    wasmBinary: readFileSync(wasmPath),
+    print: () => {},
+    printErr: () => {},
+  };
+  const qpdf = await createModule(options);
+  return { initializeQpdf: async () => qpdf };
+});
+
+const { redactDocumentData } =
+  await import('../js/utils/redact-document-data.js');
+
+const SECRET = 'SECRET-4471';
+
+async function buildDocument(): Promise<Uint8Array> {
+  const doc = await PDFDocument.create();
+  const page = doc.addPage([300, 300]);
+  const ctx = doc.context;
+  doc.setTitle(`Report for ${SECRET}`);
+  doc.setAuthor('Keep Author');
+
+  doc.catalog.set(
+    PDFName.of('Metadata'),
+    ctx.register(
+      ctx.flateStream(`<x:xmpmeta><dc:title>${SECRET}</dc:title></x:xmpmeta>`, {
+        Type: 'Metadata',
+        Subtype: 'XML',
+      })
+    )
+  );
+
+  const outlines = ctx.nextRef();
+  const first = ctx.nextRef();
+  const second = ctx.nextRef();
+  ctx.assign(
+    first,
+    ctx.obj({
+      Title: PDFString.of(`${SECRET} chapter`),
+      Parent: outlines,
+      Next: second,
+    })
+  );
+  ctx.assign(
+    second,
+    ctx.obj({
+      Title: PDFString.of('Keep chapter'),
+      Parent: outlines,
+      Prev: first,
+    })
+  );
+  ctx.assign(
+    outlines,
+    ctx.obj({ Type: 'Outlines', First: first, Last: second, Count: 2 })
+  );
+  doc.catalog.set(PDFName.of('Outlines'), outlines);
+
+  doc.catalog.set(
+    PDFName.of('StructTreeRoot'),
+    ctx.register(
+      ctx.obj({
+        Type: 'StructTreeRoot',
+        K: ctx.obj({
+          S: 'Figure',
+          Alt: PDFHexString.fromText(`Photo of ${SECRET}`),
+        }),
+      })
+    )
+  );
+
+  const secretNote = ctx.register(
+    ctx.obj({
+      Type: 'Annot',
+      Subtype: 'Text',
+      Rect: [10, 10, 30, 30],
+      Contents: PDFString.of(`note about ${secret()}`),
+    })
+  );
+  const keepNote = ctx.register(
+    ctx.obj({
+      Type: 'Annot',
+      Subtype: 'Text',
+      Rect: [40, 10, 60, 30],
+      Contents: PDFString.of('keep note'),
+    })
+  );
+  const appearance = ctx.register(
+    ctx.flateStream(`BT /Helv 10 Tf (${SECRET}) Tj ET`, {
+      Type: 'XObject',
+      Subtype: 'Form',
+      BBox: [0, 0, 100, 20],
+    })
+  );
+  const widget = ctx.register(
+    ctx.obj({
+      Type: 'Annot',
+      Subtype: 'Widget',
+      FT: 'Tx',
+      T: PDFString.of('ssn'),
+      V: PDFString.of(SECRET),
+      Rect: [10, 100, 110, 120],
+      AP: { N: appearance },
+    })
+  );
+  doc.catalog.set(PDFName.of('AcroForm'), ctx.obj({ Fields: [widget] }));
+  page.node.set(PDFName.of('Annots'), ctx.obj([secretNote, keepNote, widget]));
+  page.node.set(
+    PDFName.of('Thumb'),
+    ctx.register(ctx.flateStream(SECRET, { Width: 1, Height: 1 }))
+  );
+
+  await doc.attach(
+    new Uint8Array(Buffer.from(`payroll ${SECRET}`)),
+    'payroll.txt',
+    {
+      mimeType: 'text/plain',
+    }
+  );
+  await doc.attach(new Uint8Array(Buffer.from('harmless')), 'readme.txt', {
+    mimeType: 'text/plain',
+  });
+
+  return doc.save();
+}
+
+function secret() {
+  return SECRET.toLowerCase();
+}
+
+function collectText(value: PDFObject, out: string[]) {
+  if (value instanceof PDFString || value instanceof PDFHexString) {
+    out.push(value.decodeText());
+  } else if (value instanceof PDFDict) {
+    for (const [, v] of value.entries()) collectText(v, out);
+  } else if (value instanceof PDFArray) {
+    for (const v of value.asArray()) collectText(v, out);
+  }
+}
+
+async function allText(bytes: Uint8Array): Promise<string> {
+  const doc = await PDFDocument.load(bytes, { updateMetadata: false });
+  const out: string[] = [new TextDecoder('latin1').decode(bytes)];
+  for (const [, object] of doc.context.enumerateIndirectObjects()) {
+    if (object instanceof PDFRawStream) {
+      collectText(object.dict, out);
+      try {
+        out.push(
+          new TextDecoder('latin1').decode(decodePDFRawStream(object).decode())
+        );
+      } catch {
+        continue;
+      }
+    } else {
+      collectText(object, out);
+    }
+  }
+  return out.join('\n');
+}
+
+describe('redactDocumentData', () => {
+  it('removes the redacted text from every place outside the page content', async () => {
+    const input = await buildDocument();
+    expect((await allText(input)).toLowerCase()).toContain(
+      SECRET.toLowerCase()
+    );
+
+    const output = await redactDocumentData(input, secret());
+    const text = await allText(output);
+
+    expect(text.toLowerCase()).not.toContain(SECRET.toLowerCase());
+    expect(text).toContain('Keep chapter');
+    expect(text).toContain('keep note');
+    expect(text).toContain('Keep Author');
+    expect(text).toContain('harmless');
+    expect(text).toContain('readme.txt');
+
+    const result = await PDFDocument.load(output, { updateMetadata: false });
+    const annots = result.getPages()[0].node.Annots();
+    expect(annots?.size()).toBe(2);
+    expect(result.getPages()[0].node.get(PDFName.of('Thumb'))).toBeUndefined();
+  });
+
+  it('only drops thumbnails and leftovers when no search text is given', async () => {
+    const input = await buildDocument();
+    const output = await redactDocumentData(input);
+    const result = await PDFDocument.load(output, { updateMetadata: false });
+    expect(result.getPages()[0].node.get(PDFName.of('Thumb'))).toBeUndefined();
+    expect(result.getTitle()).toBe(`Report for ${SECRET}`);
+  });
+});