Fix issue #1261 WorkbookWriter sheet.protect() function doesn't exist

lib/stream/xlsx/worksheet-writer.js

@@ -3,6 +3,7 @@ const _ = require('../../utils/under-dash');
 const RelType = require('../../xlsx/rel-type');
 
 const colCache = require('../../utils/col-cache');
+const Encryptor = require('../../utils/encryptor');
 const Dimensions = require('../../doc/range');
 const StringBuf = require('../../utils/string-buf');
 
@@ -177,6 +178,9 @@ class WorksheetWriter {
 
     this._media = [];
 
+    // worksheet protection
+    this.sheetProtection = null;
+
     // start writing to stream now
     this._writeOpenWorksheet();
 
@@ -473,6 +477,39 @@ class WorksheetWriter {
     return this._background && this._background.imageId;
   }
 
+  // =========================================================================
+  // Worksheet Protection
+  protect(password, options) {
+    // TODO: make this function truly async
+    // perhaps marshal to worker thread or something
+    return new Promise(resolve => {
+      this.sheetProtection = {
+        sheet: true,
+      };
+      if (options && 'spinCount' in options) {
+        // force spinCount to be integer >= 0
+        options.spinCount = isFinite(options.spinCount) ? Math.round(Math.max(0, options.spinCount)) : 100000;
+      }
+      if (password) {
+        this.sheetProtection.algorithmName = 'SHA-512';
+        this.sheetProtection.saltValue = Encryptor.randomBytes(16).toString('base64');
+        this.sheetProtection.spinCount = options && 'spinCount' in options ? options.spinCount : 100000; // allow user specified spinCount
+        this.sheetProtection.hashValue = Encryptor.convertPasswordToHash(password, 'SHA512', this.sheetProtection.saltValue, this.sheetProtection.spinCount);
+      }
+      if (options) {
+        this.sheetProtection = Object.assign(this.sheetProtection, options);
+        if (!password && 'spinCount' in options) {
+          delete this.sheetProtection.spinCount;
+        }
+      }
+      resolve();
+    });
+  }
+
+  unprotect() {
+    this.sheetProtection = null;
+  }
+
   // ================================================================================
 
   _write(text) {

spec/integration/pr/test-pr-1262.spec.js

@@ -0,0 +1,30 @@
+const ExcelJS = verquire('exceljs');
+
+describe('github issues', () => {
+  it('pull request 1262 - protect should work with streaming workbook writer', async () => {
+    const workbook = new ExcelJS.stream.xlsx.WorkbookWriter({
+      filename: './test.xlsx',
+    });
+
+    const sheet = workbook.addWorksheet('data');
+    const row = sheet.addRow(['readonly cell']);
+    row.getCell(1).protection = {
+      locked: true,
+    };
+
+    expect(sheet.protect).to.exist();
+
+    sheet.protect('password', {
+      spinCount: 1,
+    });
+
+    await workbook.commit();
+
+    // read in file and ensure sheetProtection is there:
+    const checkBook = new ExcelJS.Workbook();
+    await checkBook.xlsx.readFile('./test.xlsx');
+
+    const checkSheet = checkBook.getWorksheet('data');
+    expect(checkSheet.sheetProtection.spinCount).to.equal(1);
+  });
+});