diff --git a/types/exceljs/exceljs-tests.ts b/types/exceljs/exceljs-tests.ts
index 95147c7726..12b3337cb8 100644
--- a/types/exceljs/exceljs-tests.ts
+++ b/types/exceljs/exceljs-tests.ts
@@ -1,4 +1,7 @@
 import * as Excel from 'exceljs';
+import * as stream from 'stream';
+import * as fs from 'fs';
+import * as Bluebird from 'bluebird';
 
 // most examples taken and adapted from README.md
 
@@ -18,65 +21,446 @@ workbook.views = [
   }
 ];
 
-const worksheet: Excel.Worksheet = workbook.addWorksheet('My Sheet');
+const worksheet = workbook.addWorksheet('My Sheet');
+
+workbook.eachSheet((worksheet, sheetId) => null);
+
 const worksheet2 = workbook.getWorksheet('My Sheet');
 const worksheet3 = workbook.getWorksheet(1);
-const sheet = workbook.addWorksheet('My Sheet', {views: [{showGridLines: false}]});
+const sheet1 = workbook.addWorksheet('My Sheet', {
+  pageSetup: { fitToPage: true, fitToHeight: 5, fitToWidth: 7 },
+  properties: { tabColor: { argb: 'FFC0000' } },
+});
+const sheet2 = workbook.addWorksheet('My Sheet', {
+  pageSetup: { paperSize: 9, orientation: 'landscape' },
+  views: [
+    { state: 'frozen', xSplit: 1, ySplit: 1 },
+    { state: 'normal', showGridLines: false },
+    { state: 'split', activePane: 'bottomLeft', }
+  ]
+});
+
+worksheet.properties.outlineLevelCol = 2;
+worksheet.properties.defaultRowHeight = 15;
+
+worksheet.pageSetup.margins = {
+  left: 0.7, right: 0.7,
+  top: 0.75, bottom: 0.75,
+  header: 0.3, footer: 0.3
+};
+
+worksheet.pageSetup.printArea = 'A1:G20';
+worksheet.pageSetup.printTitlesRow = '1:3';
+
+worksheet.views = [
+  { state: 'frozen', xSplit: 2, ySplit: 3, topLeftCell: 'G10', activeCell: 'A1' },
+  { state: 'split', xSplit: 2000, ySplit: 3000, topLeftCell: 'G10', activeCell: 'A1' },
+];
+
+worksheet.autoFilter = { from: 'A1', to: 'C1' };
+worksheet.autoFilter = { from: { row: 3, column: 1 }, to: { row: 5, column: 12 } };
+worksheet.autoFilter = { from: 'D3', to: { row: 7, column: 5 } };
+
+worksheet.columns = [
+  { header: 'Id', key: 'id', width: 10 },
+  { header: 'Name', key: 'name', width: 32 },
+  { header: 'D.O.B.', key: 'DOB', width: 10, outlineLevel: 1 }
+];
+
+const idCol = worksheet.getColumn('id');
+const nameCol = worksheet.getColumn('B');
+const dobCol = worksheet.getColumn(3);
+
+dobCol.header = 'Date of Birth';
+dobCol.header = ['Date of Birth', 'A.K.A. D.O.B.'];
+dobCol.key = 'dob';
+dobCol.width = 15;
+dobCol.hidden = true;
+worksheet.getColumn(4).outlineLevel = 0;
+const cl1 = worksheet.getColumn(4).collapsed;
+
+dobCol.eachCell((cell, rowNumber) => null);
+
+dobCol.eachCell({ includeEmpty: true }, (cell, rowNumber) => null);
+
+worksheet.spliceColumns(3, 2);
+
+const newCol3Values = [1, 2, 3, 4, 5];
+const newCol4Values = ['one', 'two', 'three', 'four', 'five'];
+worksheet.spliceColumns(3, 1, newCol3Values, newCol4Values);
+
+worksheet.addRow({ id: 1, name: 'John Doe', dob: new Date(1970, 1, 1) });
+worksheet.addRow({ id: 2, name: 'Jane Doe', dob: new Date(1965, 1, 7) });
+worksheet.addRow([3, 'Sam', new Date()]);
+const rowValues = [];
+rowValues[1] = 4;
+rowValues[5] = 'Kyle';
+rowValues[9] = new Date();
+worksheet.addRow(rowValues);
+const rows = [
+  [5, 'Bob', new Date()],
+  { id: 6, name: 'Barbara', dob: new Date() },
+];
+worksheet.addRows(rows);
+
+const row = worksheet.getRow(5);
+const row1 = worksheet.lastRow;
+
+row.height = 42.5;
+row.hidden = true;
+worksheet.getRow(4).outlineLevel = 0;
+worksheet.getRow(5).outlineLevel = 1;
+worksheet.getRow(4).collapsed;
 
-const row: Excel.Row = worksheet.addRow([3, 'Sam', new Date()]);
 row.getCell(1).value = 5;
+row.getCell('name').value = 'Zeb';
+row.getCell('C').value = new Date();
 
-worksheet.eachRow((row: Excel.Row, rowNumber: number): void => {
-    // nothing
-});
+const row2 = worksheet.getRow(4).values;
 
-row.eachCell((cell: Excel.Cell, colNumber: number): void => {
-    // nothing
-});
+row.values = [1, 2, 3];
+
+const values = [];
+values[5] = 7;
+values[10] = 'Hello, World!';
+row.values = values;
+
+row.values = { id: 13, name: 'Thing 1', dob: new Date() };
+
+worksheet.eachRow((row, rowNumber) => null);
+worksheet.eachRow({ includeEmpty: true }, (row, rowNumber) => null);
+
+row.eachCell((cell, colNumber) => null);
+row.eachCell({ includeEmpty: true }, (cell, colNumber) => null);
+
+worksheet.spliceRows(4, 3);
+
+const newRow3Values = [1, 2, 3, 4, 5];
+const newRow4Values = ['one', 'two', 'three', 'four', 'five'];
+worksheet.spliceRows(3, 1, newRow3Values, newRow4Values);
+
+row.splice(3, 2);
+
+row.splice(4, 1, 'new value 1', 'new value 2');
+
+row.commit();
+
+const rowSize = row.cellCount;
+const numValues = row.actualCellCount;
+
+worksheet.getCell('C3').value = new Date(1968, 5, 1);
+const isDate = worksheet.getCell('C3').type === Excel.ValueType.Date;
 
 worksheet.mergeCells('A4:B5');
 
-worksheet.getCell('A1').numFmt = '0.00%';
-worksheet.getCell('A1').font = {
-    name: 'Comic Sans MS',
-    family: 4,
-    size: 16,
-    underline: true,
-    bold: true
+worksheet.getCell('B5').value = 'Hello, World!';
+const master = worksheet.getCell('B5').master === worksheet.getCell('A4');
+
+worksheet.unMergeCells('A4');
+
+worksheet.mergeCells('G10', 'H11');
+worksheet.mergeCells(10, 11, 12, 13);
+
+worksheet.getCell('A1').name = 'PI';
+worksheet.getCell('A1').names = ['thing1', 'thing2'];
+worksheet.getCell('A1').removeName('thing1');
+
+worksheet.getCell('A1').dataValidation = {
+  type: 'list',
+  allowBlank: true,
+  formulae: ['"One,Two,Three,Four"']
 };
 
+worksheet.getCell('A1').dataValidation = {
+  type: 'list',
+  allowBlank: true,
+  formulae: ['$D$5:$F$5']
+};
+
+worksheet.getCell('A1').dataValidation = {
+  type: 'whole',
+  operator: 'notEqual',
+  showErrorMessage: true,
+  formulae: [5],
+  errorStyle: 'error',
+  errorTitle: 'Five',
+  error: 'The value must not be Five'
+};
+
+worksheet.getCell('A1').dataValidation = {
+  type: 'decimal',
+  operator: 'between',
+  allowBlank: true,
+  showInputMessage: true,
+  formulae: [1.5, 7],
+  promptTitle: 'Decimal',
+  prompt: 'The value must between 1.5 and 7'
+};
+
+worksheet.getCell('A1').dataValidation = {
+  type: 'textLength',
+  operator: 'lessThan',
+  showErrorMessage: true,
+  allowBlank: true,
+  formulae: [15]
+};
+
+worksheet.getCell('A1').dataValidation = {
+  type: 'date',
+  operator: 'lessThan',
+  showErrorMessage: true,
+  allowBlank: true,
+  formulae: [new Date(2016, 0, 1)]
+};
+
+worksheet.getCell('A1').value = null;
+worksheet.getCell('A1').value = 5;
+worksheet.getCell('A2').value = 3.14159;
+worksheet.getCell('A1').value = 'Hello, World!';
+worksheet.getCell('A1').value = new Date(2017, 2, 15);
+worksheet.getCell('A1').value = { text: 'www.mylink.com', hyperlink: 'http://www.mylink.com' };
+worksheet.getCell('A1').value = { text: 'Sheet2', hyperlink: '#\\"Sheet2\\"!A1' };
+worksheet.getCell('A3').value = { formula: 'A1+A2', result: 7 };
+worksheet.getCell('B3').value = { sharedFormula: 'A3', result: 10 };
+worksheet.getCell('A1').value = true;
+worksheet.getCell('A2').value = false;
+worksheet.getCell('A1').value = { error: '#N/A' };
+worksheet.getCell('A2').value = { error: '#VALUE!' };
+worksheet.getCell('A1').value = {
+  richText: [
+    { text: 'This is ' },
+    { font: { italic: true }, text: 'italic' }
+  ],
+};
+worksheet.getCell('A3').formula === 'A1+A2';
+worksheet.getCell('A3').result === 7;
+
+const isMaster = worksheet.getCell('A3').formulaType === Excel.FormulaType.Master;
+const isShared = worksheet.getCell('B3').formulaType === Excel.FormulaType.Shared;
+
+worksheet.getCell('A1').numFmt = '0.00%';
+worksheet.columns = [
+  { header: 'Id', key: 'id', width: 10 },
+  { header: 'Name', key: 'name', width: 32, style: { font: { name: 'Arial Black' } } },
+  { header: 'D.O.B.', key: 'DOB', width: 10, style: { numFmt: 'dd/mm/yyyy' } }
+];
+
+worksheet.getColumn(3).numFmt = '"£"#,##0.00;[Red]\-"£"#,##0.00';
+
+worksheet.getRow(2).font = {
+  name: 'Comic Sans MS',
+  family: 4,
+  size: 16,
+  underline: 'double',
+  bold: true,
+};
+
+worksheet.getCell('A1').numFmt = '# ?/?';
+worksheet.getCell('B1').numFmt = '0.00%';
+
+worksheet.getCell('A1').font = {
+  name: 'Comic Sans MS',
+  family: 4,
+  size: 16,
+  underline: true,
+  bold: true
+};
+
+worksheet.getCell('A2').font = {
+  name: 'Arial Black',
+  color: { argb: 'FF00FF00' },
+  family: 2,
+  size: 14,
+  italic: true
+};
+
+const font = { name: 'Arial', size: 12 };
+worksheet.getCell('A3').font = font;
+font.size = 20;
+
 worksheet.getCell('A1').alignment = { vertical: 'top', horizontal: 'left' };
 worksheet.getCell('B1').alignment = { vertical: 'middle', horizontal: 'center' };
 worksheet.getCell('C1').alignment = { vertical: 'bottom', horizontal: 'right' };
 worksheet.getCell('D1').alignment = { wrapText: true };
 worksheet.getCell('E1').alignment = { indent: 1 };
+worksheet.getCell('F1').alignment = { textRotation: 30 };
+worksheet.getCell('G1').alignment = { textRotation: -45 };
+worksheet.getCell('H1').alignment = { textRotation: 'vertical' };
 
 worksheet.getCell('A1').border = {
-    top: {style: 'thin'},
-    left: {style: 'thin'},
-    bottom: {style: 'thin'},
-    right: {style: 'thin'}
+  top: { style: 'thin' },
+  left: { style: 'thin' },
+  bottom: { style: 'thin' },
+  right: { style: 'thin' }
 };
 
 worksheet.getCell('A3').border = {
-    top: {style: 'double', color: {argb: 'FF00FF00'}},
-    left: {style: 'double', color: {argb: 'FF00FF00'}},
-    bottom: {style: 'double', color: {argb: 'FF00FF00'}},
-    right: {style: 'double', color: {argb: 'FF00FF00'}}
+  top: { style: 'double', color: { argb: 'FF00FF00' } },
+  left: { style: 'double', color: { argb: 'FF00FF00' } },
+  bottom: { style: 'double', color: { argb: 'FF00FF00' } },
+  right: { style: 'double', color: { argb: 'FF00FF00' } }
+};
+
+worksheet.getCell('A5').border = {
+  diagonal: { up: true, down: true, style: 'thick', color: { argb: 'FFFF0000' } }
 };
 
 worksheet.getCell('A1').fill = {
-    type: 'pattern',
-    pattern: 'solid',
-    fgColor: {argb: 'FFFF0000'}
+  type: 'pattern',
+  pattern: 'darkVertical',
+  fgColor: { argb: 'FFFF0000' }
 };
 
-workbook.xlsx.readFile("/home/john/bla.xlsx")
-    .then((): void => {
-        // use workbook
-    });
+worksheet.getCell('A2').fill = {
+  type: 'pattern',
+  pattern: 'darkTrellis',
+  fgColor: { argb: 'FFFFFF00' },
+  bgColor: { argb: 'FF0000FF' }
+};
 
-workbook.xlsx.writeFile("/home/john/bla.xlsx")
-    .then((): void => {
-        // done
-    });
+worksheet.getCell('A3').fill = {
+  type: 'gradient',
+  gradient: 'angle',
+  degree: 0,
+  stops: [
+    { position: 0, color: { argb: 'FF0000FF' } },
+    { position: 0.5, color: { argb: 'FFFFFFFF' } },
+    { position: 1, color: { argb: 'FF0000FF' } }
+  ]
+};
+
+worksheet.getCell('A2').fill = {
+  type: 'gradient',
+  gradient: 'path',
+  center: { left: 0.5, top: 0.5 },
+  stops: [
+    { position: 0, color: { argb: 'FFFF0000' } },
+    { position: 1, color: { argb: 'FF00FF00' } }
+  ]
+};
+
+worksheet.getCell('A1').value = {
+  richText: [
+    {
+      text: 'This is ',
+      font: { name: 'Calibri', size: 12, color: { theme: 0 }, family: 2, scheme: 'minor' },
+    },
+    {
+      text: 'a',
+      font: { italic: true, size: 12, color: { theme: 0 }, name: 'Calibri', scheme: 'minor' },
+    },
+    {
+      text: ' ',
+      font: { size: 12, color: { theme: 1 }, name: 'Calibri', family: 2, scheme: 'minor' },
+    },
+    {
+      text: 'colorful',
+      font: { size: 12, color: { argb: 'FFFF6600' }, name: 'Calibri', scheme: 'minor' },
+    },
+    {
+      text: ' text ',
+      font: { size: 12, color: { theme: 1 }, name: 'Calibri', family: 2, scheme: 'minor' },
+    },
+    {
+      text: 'with',
+      font: { size: 12, color: { argb: 'FFCCFFCC' }, name: 'Calibri', scheme: 'minor' },
+    },
+    {
+      text: ' in-cell ',
+      font: { size: 12, color: { theme: 1 }, name: 'Calibri', family: 2, scheme: 'minor' },
+    },
+    {
+      text: 'format',
+      font: { bold: true, size: 12, name: 'Calibri', family: 2, scheme: 'minor' },
+    }
+  ]
+};
+
+worksheet.columns = [
+  { header: 'Id', key: 'id', width: 10 },
+  { header: 'Name', key: 'name', width: 32 },
+  { header: 'D.O.B.', key: 'DOB', width: 10, outlineLevel: 1 }
+];
+worksheet.getColumn(3).outlineLevel = 1;
+worksheet.getRow(3).outlineLevel = 1;
+worksheet.properties.outlineLevelCol = 1;
+worksheet.properties.outlineLevelRow = 1;
+
+const imageId1 = workbook.addImage({
+  filename: 'path/to/image.jpg',
+  extension: 'jpeg',
+});
+const imageId2 = workbook.addImage({
+  buffer: fs.readFileSync('path/to.image.png'),
+  extension: 'png',
+});
+
+worksheet.addBackgroundImage(imageId1);
+worksheet.addImage(imageId2, 'B2:D6');
+worksheet.addImage(imageId2, {
+  tl: { col: 1.5, row: 1.5 },
+  br: { col: 3.5, row: 5.5 }
+});
+
+workbook.xlsx.readFile('./1.xlsx').then(() => null);
+(new stream.Stream()).pipe(workbook.xlsx.createInputStream());
+
+workbook.xlsx.writeFile('./1.xlsx').then(() => null);
+workbook.xlsx.write(new stream.Stream()).then(() => null);
+
+workbook.csv.readFile('./1.xlsx').then(worksheet => null);
+workbook.csv.read(new stream.Stream()).then(worksheet => null);
+
+(new stream.Stream()).pipe(workbook.csv.createInputStream());
+
+const options1 = { dateFormats: ['DD/MM/YYYY'] };
+workbook.csv.readFile('./1.xlsx', options1).then(worksheet => null);
+
+const options2 = {
+  map(value: any, index: number) {
+    switch (index) {
+      case 0:
+        // column 1 is string
+        return value;
+      case 1:
+        // column 2 is a date
+        return new Date(value);
+      case 2:
+        // column 3 is JSON of a formula value
+        return JSON.parse(value);
+      default:
+        // the rest are numbers
+        return parseFloat(value);
+    }
+  }
+};
+workbook.csv.readFile('./1.xlsx', options2).then(worksheet => null);
+
+workbook.csv.writeFile('./1.xlsx').then(() => null);
+
+// write to a stream
+workbook.csv.write(new stream.Stream()).then(() => null);
+
+const workbookWriter = new Excel.stream.xlsx.WorkbookWriter({
+  filename: './streamed-workbook.xlsx',
+  useStyles: true,
+  useSharedStrings: true
+});
+
+worksheet.addRow({
+  id: 'i',
+  name: 'theName',
+  etc: 'someOtherDetail'
+}).commit();
+
+worksheet.mergeCells('A1:B2');
+worksheet.getCell('A1').value = 'I am merged';
+worksheet.getCell('C1').value = 'I am not';
+worksheet.getCell('C2').value = 'Neither am I';
+worksheet.getRow(2).commit();
+
+worksheet.commit();
+
+workbook.commit().then(() => null);
+
+Excel.config.setValue('promise', Bluebird);
diff --git a/types/exceljs/index.d.ts b/types/exceljs/index.d.ts
index 259eaccae1..be82b7d7f9 100644
--- a/types/exceljs/index.d.ts
+++ b/types/exceljs/index.d.ts
@@ -1,7 +1,353 @@
-// Type definitions for exceljs 0.4
+// Type definitions for exceljs 0.5
 // Project: https://github.com/guyonroche/exceljs
 // Definitions by: Rogier Schouten <https://github.com/rogierschouten>
+//                 Ali Taheri Moghaddar <https://github.com/alitaheri>
 // Definitions: https://github.com/DefinitelyTyped/DefinitelyTyped
+// TypeScript Version: 2.3
+
+/// <reference types="node" />
+
+import { Writable, Stream } from 'stream';
+
+export const enum RelationshipType {
+	None = 0,
+	OfficeDocument = 1,
+	Worksheet = 2,
+	CalcChain = 3,
+	SharedStrings = 4,
+	Styles = 5,
+	Theme = 6,
+	Hyperlink = 7
+}
+
+export const enum DocumentType {
+	Xlsx = 1
+}
+
+export const enum PaperSize {
+	Legal = 5,
+	Executive = 7,
+	A4 = 9,
+	A5 = 11,
+	B5 = 13,
+	Envelope_10 = 20,
+	Envelope_DL = 27,
+	Envelope_C5 = 28,
+	Envelope_B5 = 34,
+	Envelope_Monarch = 37,
+	Double_Japan_Postcard_Rotated = 82,
+	K16_197x273_mm = 119,
+}
+
+export interface WorksheetViewCommon {
+	/**
+	 * Sets the worksheet view's orientation to right-to-left, `false` by default
+	 */
+	rightToLeft?: boolean;
+
+	/**
+	 * The currently selected cell
+	 */
+	activeCell?: string;
+
+	/**
+	 * Shows or hides the ruler in Page Layout, `true` by default
+	 */
+	showRuler?: boolean;
+
+	/**
+	 * Shows or hides the row and column headers (e.g. A1, B1 at the top and 1,2,3 on the left,
+	 * `true` by default
+	 */
+	showRowColHeaders?: boolean;
+
+	/**
+	 * Shows or hides the gridlines (shown for cells where borders have not been defined),
+	 * `true` by default
+	 */
+	showGridLines?: boolean;
+
+	/**
+	 * 	Percentage zoom to use for the view, `100` by default
+	 */
+	zoomScale?: number;
+
+	/**
+	 * 	Normal zoom for the view, `100` by default
+	 */
+	zoomScaleNormal?: number;
+}
+
+export interface WorksheetViewNormal {
+	/**
+	 * Controls the view state
+	 */
+	state?: 'normal';
+
+	/**
+	 * Presentation style
+	 */
+	style?: 'pageBreakPreview' | 'pageLayout';
+}
+
+export interface WorksheetViewFrozen {
+	/**
+	 * Where a number of rows and columns to the top and left are frozen in place.
+	 * Only the bottom left section will scroll
+	 */
+	state: 'frozen';
+
+	/**
+	 * Presentation style
+	 */
+	style?: 'pageBreakPreview';
+
+	/**
+	 * How many columns to freeze. To freeze rows only, set this to 0 or undefined
+	 */
+	xSplit?: number;
+
+	/**
+	 * How many rows to freeze. To freeze columns only, set this to 0 or undefined
+	 */
+	ySplit?: number;
+
+	/**
+	 * Which cell will be top-left in the bottom-right pane. Note: cannot be a frozen cell.
+	 * Defaults to first unfrozen cell
+	 */
+	topLeftCell?: string;
+}
+
+export interface WorksheetViewSplit {
+	/**
+	 * Where the view is split into 4 sections, each semi-independently scrollable.
+	 */
+	state: 'split';
+
+	/**
+	 * Presentation style
+	 */
+	style?: 'pageBreakPreview' | 'pageLayout';
+
+	/**
+	 * How many points from the left to place the splitter.
+	 * To split vertically, set this to 0 or undefined
+	 */
+	xSplit?: number;
+
+	/**
+	 * How many points from the top to place the splitter.
+	 * To split horizontally, set this to 0 or undefined
+	 */
+	ySplit?: number;
+
+	/**
+	 * Which cell will be top-left in the bottom-right pane
+	 */
+	topLeftCell?: string;
+
+	/**
+	 * Which pane will be active
+	 */
+	activePane?: 'topLeft' | 'topRight' | 'bottomLeft' | 'bottomRight';
+}
+
+export type WorksheetView =
+	& WorksheetViewCommon
+	& (WorksheetViewNormal | WorksheetViewFrozen | WorksheetViewSplit);
+
+export interface WorkbookView {
+	x?: number;
+	y?: number;
+	width?: number;
+	height?: number;
+	firstSheet?: number;
+	activeTab?: number;
+	visibility?: string;
+}
+
+export type FillPatterns =
+	| 'none' | 'solid'
+	| 'darkVertical' | 'darkHorizontal' | 'darkGrid' | 'darkTrellis' | 'darkDown' | 'darkUp'
+	| 'lightVertical' | 'lightHorizontal' | 'lightGrid' | 'lightTrellis' | 'lightDown' | 'lightUp'
+	| 'darkGray' | 'mediumGray' | 'lightGray' | 'gray125' | 'gray0625';
+
+export interface FillPattern {
+	type: 'pattern';
+	pattern: FillPatterns;
+	fgColor?: Color;
+	bgColor?: Color;
+}
+
+export interface GradientStop {
+	position: number;
+	color: Color;
+}
+
+export interface FillGradientAngle {
+	type: 'gradient';
+	gradient: 'angle';
+
+	/**
+	 * For 'angle' gradient, specifies the direction of the gradient. 0 is from the left to the right.
+	 * Values from 1 - 359 rotates the direction clockwise
+	 */
+	degree: number;
+
+	/**
+	 * Specifies the gradient colour sequence. Is an array of objects containing position and
+	 * color starting with position 0 and ending with position 1.
+	 * Intermediary positions may be used to specify other colours on the path.
+	 */
+	stops: GradientStop[];
+}
+
+export interface FillGradientPath {
+	type: 'gradient';
+	gradient: 'path';
+
+	/**
+	 * For 'path' gradient. Specifies the relative coordinates for the start of the path.
+	 * 'left' and 'top' values range from 0 to 1
+	 */
+	center: { left: number; top: number };
+
+	/**
+	 * Specifies the gradient colour sequence. Is an array of objects containing position and
+	 * color starting with position 0 and ending with position 1.
+	 * Intermediary positions may be used to specify other colours on the path.
+	 */
+	stops: GradientStop[];
+}
+
+export type Fill = FillPattern | FillGradientAngle | FillGradientPath;
+
+export interface Font {
+	name?: string;
+	size?: number;
+	family?: number;
+	scheme?: 'minor' | 'major' | 'none';
+	charset?: number;
+	color?: Color;
+	bold?: boolean;
+	italic?: boolean;
+	underline?: boolean | 'none' | 'single' | 'double' | 'singleAccounting' | 'doubleAccounting';
+	strike?: boolean;
+	outline?: boolean;
+}
+
+export type BorderStyle =
+	| 'thin' | 'dotted' | 'hair' | 'medium' | 'double' | 'thick' | 'dashDot'
+	| 'dashDotDot' | 'slantDashDot' | 'mediumDashed' | 'mediumDashDotDot' | 'mediumDashDot';
+
+export interface Color {
+	/**
+	 * Hex string for alpha-red-green-blue e.g. FF00FF00
+	 */
+	argb?: string;
+
+	/**
+	 * Choose a theme by index
+	 */
+	theme?: number;
+}
+
+export interface Border {
+	style?: BorderStyle;
+	color?: Color;
+}
+
+export interface BorderDiagonal extends Border {
+	up?: boolean;
+	down?: boolean;
+}
+
+export interface Borders {
+	top?: Border;
+	left?: Border;
+	bottom?: Border;
+	right?: Border;
+	diagonal?: BorderDiagonal;
+}
+
+export interface Margins {
+	top?: number;
+	left?: number;
+	bottom?: number;
+	right?: number;
+	header?: number;
+	footer?: number;
+}
+
+export const enum ReadingOrder {
+	LeftToRight = 1,
+	RightToLeft = 2,
+}
+
+export interface Alignment {
+	horizontal?: 'left' | 'center' | 'right' | 'fill' | 'justify' | 'centerContinuous' | 'distributed';
+	vertical?: 'top' | 'middle' | 'bottom' | 'distributed' | 'justify';
+	wrapText?: boolean;
+	indent?: number;
+	readingOrder?: 'rtl' | 'ltr';
+	textRotation?: number | 'vertical';
+}
+
+export interface Style {
+	numFmt?: string;
+	font?: Font;
+	alignment?: Alignment;
+	border?: Borders;
+	fill?: Fill;
+}
+
+export type DataValidationOperator =
+	| 'between' | 'notBetween' | 'equal' | 'notEqual' | 'greaterThan' | 'lessThan'
+	| 'greaterThanOrEqual' | 'lessThanOrEqual';
+
+export interface DataValidation {
+	type: 'list' | 'whole' | 'decimal' | 'date' | 'textLength' | 'custom';
+	formulae: any[];
+	allowBlank?: boolean;
+	operator?: DataValidationOperator;
+	error?: string;
+	errorTitle?: string;
+	errorStyle?: string;
+	prompt?: string;
+	promptTitle?: string;
+	showErrorMessage?: boolean;
+	showInputMessage?: boolean;
+}
+
+export interface CellErrorValue {
+	error: '#N/A' | '#REF!' | '#NAME?' | '#DIV/0!' | '#NULL!' | '#VALUE!' | '#NUM!';
+}
+
+export interface RichText {
+	text: string;
+	font?: Font;
+}
+
+export interface CellRichTextValue {
+	richText: RichText[];
+}
+
+export interface CellHyperlinkValue {
+	text: string;
+	hyperlink: string;
+}
+
+export interface CellFormulaValue {
+	formula: string;
+	result: number | string | Date;
+}
+
+export interface CellSharedFormulaValue {
+	sharedFormula: string;
+	readonly formula?: string;
+	result: number | string | Date;
+}
 
 export const enum ValueType {
 	Null = 0,
@@ -23,170 +369,449 @@ export const enum FormulaType {
 	Shared = 2
 }
 
-export const enum RelationshipType {
-	None = 0,
-	OfficeDocument = 1,
-	Worksheet = 2,
-	CalcChain = 3,
-	SharedStrings = 4,
-	Styles = 5,
-	Theme = 6,
-	Hyperlink = 7
-}
+export type CellValue =
+	| null | number | string | boolean | Date
+	| CellErrorValue
+	| CellRichTextValue | CellHyperlinkValue
+	| CellFormulaValue | CellSharedFormulaValue;
 
-export const enum DocumentType {
-	Xlsx = 1
-}
-
-export const enum ReadingOrder {
-	RightToLeft = 1,
-	LeftToRight = 2,
-}
-
-export interface ErrorValue {
-	error: "#N/A" | "#REF!" | "#NAME?" | "#DIV/0!" | "#NULL!" | "#VALUE!" | "#NUM!";
-}
-
-export interface WorksheetView {
-	state?: "normal" | "split" | "frozen";
-	showRuler?: boolean;
-	showRowColHeaders?: boolean;
-	showGridLines?: boolean;
-	zoomScale?: number;
-	zoomScaleNormal?: number;
-	style?: "pageBreakPreview" | "pageLayout";
-}
-
-export interface WorkbookView {
-	x?: number;
-	y?: number;
-	width?: number;
-	height?: number;
-	firstSheet?: number;
-	activeTab?: number;
-	visibility?: string;
-}
-
-export interface Fill {
-	type: "pattern" | "gradient";
-	pattern?: "none" | "solid";
-	fgColor?: Color;
-	bgColor?: Color;
-}
-
-export interface Font {
-	name: string;
-	size?: number;
-	family?: number;
-	schema?: "minor" | "major" | "none";
-	charset?: number;
-	color?: Color;
-	bold?: boolean;
-	italic?: boolean;
-	underline?: true | false | "none" | "single" | "double" | "singleAccounting" | "doubleAccounting";
-	strike?: boolean;
-	outline?: boolean;
-}
-
-export type BorderStyle =
-	"thin" | "dotted" | "dashDot" | "hair" | "dashDotDot" | "slantDashDot" | "mediumDashed"  | "mediumDashDotDot" |
-	"mediumDashDot" | "medium" | "double" | "thick";
-
-export interface Color {
+export interface Cell extends Style {
 	/**
-	 * Hex string for alpha-red-green-blue e.g. FF00FF00
+	 * Assign (or get) a name for a cell (will overwrite any other names that cell had)
 	 */
-	argb: string;
-}
+	name?: string;
 
-export interface Border {
-	style?: BorderStyle;
-	color?: Color;
-}
-
-export interface Borders {
-	top?: Border;
-	left?: Border;
-	bottom?: Border;
-	right?: Border;
-}
-
-export interface Alignment {
-	horizontal?: "left" | "center" | "right" | "fill" | "justify" | "centerContinuous" | "distributed";
-	vertical?: "top" | "middle" | "bottom" | "distributed" | "justify";
-	wrapText?: boolean;
-	indent?: number;
-	readingOrder?: "rtl" | "ltr";
-	textrotation?: number | "vertical";
-}
-
-export interface Cell {
-	border?: Borders;
-	font?: Font;
-	alignment?: Alignment;
-	numFmt?: string;
-	value?: any;
-	fill?: Fill;
-}
-
-export interface Row {
 	/**
-	 * The row number
+	 * Assign (or get) an array of names for a cell (cells can have more than one name)
+	 */
+	names?: string[];
+
+	/**
+	 * Cells can define what values are valid or not and provide
+	 * prompting to the user to help guide them.
+	 */
+	dataValidation?: DataValidation;
+
+	/**
+	 * Value of the cell
+	 */
+	value: CellValue;
+
+	/**
+	 * convenience getter to access the formula
+	 */
+	readonly formula: string;
+
+	/**
+	 * convenience getter to access the formula result
+	 */
+	readonly result: number | string | Date;
+
+	/**
+	 * The type of the cell's value
+	 */
+	readonly type: ValueType;
+
+	/**
+	 * The type of the cell's formula
+	 */
+	readonly formulaType: FormulaType;
+
+	/**
+	 * The master cell when the current cell is a merge cell
+	 */
+	master?: Cell;
+
+	/**
+	 * The styles of the cell
+	 */
+	style: Style;
+
+	/**
+	 * Remove a name from a cell
+	 */
+	removeName(name: string): void;
+}
+
+export interface Row extends Style {
+	/**
+	 * Set a specific row height
 	 */
-	number: number;
 	height: number;
+
+	/**
+	 * Make row hidden
+	 */
 	hidden: boolean;
-	collapsed: boolean;
-	values: any[];
+
+	/**
+	 * Get a row as a sparse array
+	 */
+	values: any[] | any;
+
+	/**
+	 * Set an outline level for rows
+	 */
 	outlineLevel?: number;
 
+	/**
+	 * Indicate the collapsed state based on outlineLevel
+	 */
+	readonly collapsed: boolean;
+
+	/**
+	 * Number of non-empty cells
+	 */
 	readonly cellCount: number;
+
+	/**
+	 * Number of cells including empty ones
+	 */
 	readonly actualCellCount: number;
 
-	getCell(index: number): Cell;
+	/**
+	 * Get cell by number, column letter or column key
+	 */
+	getCell(indexOrKey: number | string): Cell;
 
+	/**
+	 * Iterate over all non-null cells in a row
+	 */
 	eachCell(callback: (cell: Cell, colNumber: number) => void): void;
-	eachCell(opts: { includeEmpty: boolean}, callback: (cell: Cell, colNumber: number) => void): void;
+
+	/**
+	 * Iterate over all cells in a row (including empty cells)
+	 */
+	eachCell(opt: { includeEmpty: boolean }, callback: (cell: Cell, colNumber: number) => void): void;
+
+	/**
+	 * Cut one or more cells (cells to the right are shifted left)
+	 *
+	 * Note: this operation will not affect other rows
+	 */
+	splice(start: number, count: number, ...insert: any[]): void;
+
+	/**
+	 * Commit a completed row to stream
+	 */
+	commit(): void;
 }
 
 export interface Column {
+	/**
+	 * Can be a string to set one row high header or an array to set multi-row high header
+	 */
+	header: string | string[];
+
+	/**
+	 * The name of the properties associated with this column in each row
+	 */
+	key: string;
+
+	/**
+	 * The width of the column
+	 */
 	width: number;
+
+	/**
+	 * Set an outline level for columns
+	 */
+	outlineLevel?: number;
+
+	/**
+	 * Hides the column
+	 */
+	hidden?: boolean;
+
+	/**
+	 * Styles applied to the column
+	 */
+	style?: Style;
+}
+
+export interface ColumnExtension extends Style {
+	/**
+	 * indicate the collapsed state based on outlineLevel
+	 */
+	readonly collapsed: boolean;
+
+	/**
+	 * Iterate over all current cells in this column
+	 */
+	eachCell(callback: (cell: Cell, rowNumber: number) => void): void;
+
+	/**
+	 * Iterate over all current cells in this column including empty cells
+	 */
+	eachCell(opt: { includeEmpty: boolean }, callback: (cell: Cell, rowNumber: number) => void): void;
+}
+
+export interface PageSetup {
+	/**
+	 * Whitespace on the borders of the page. Units are inches.
+	 */
+	margins?: Margins;
+
+	/**
+	 * Orientation of the page - i.e. taller (`'portrait'`) or wider (`'landscape'`).
+	 *
+	 * `'portrait'` by default
+	 */
+	orientation?: 'portrait' | 'landscape';
+
+	/**
+	 * Horizontal Dots per Inch. Default value is 4294967295
+	 */
+	horizontalDpi?: number;
+
+	/**
+	 * Vertical Dots per Inch. Default value is 4294967295
+	 */
+	verticalDpi?: number;
+
+	/**
+	 * Whether to use fitToWidth and fitToHeight or scale settings.
+	 *
+	 * Default is based on presence of these settings in the pageSetup object - if both are present,
+	 * scale wins (i.e. default will be false)
+	 */
+	fitToPage?: boolean;
+
+	/**
+	 * How many pages wide the sheet should print on to. Active when fitToPage is true
+	 *
+	 * Default is 1
+	 */
+	fitToWidth?: number;
+
+	/**
+	 * How many pages high the sheet should print on to. Active when fitToPage is true
+	 *
+	 * Default is 1
+	 */
+	fitToHeight?: number;
+
+	/**
+	 * Percentage value to increase or reduce the size of the print. Active when fitToPage is false
+	 *
+	 * Default is 100
+	 */
+	scale?: number;
+
+	/**
+	 * Which order to print the pages.
+	 *
+	 * Default is `downThenOver`
+	 */
+	pageOrder?: 'downThenOver' | 'overThenDown';
+
+	/**
+	 * Print without colour
+	 *
+	 * false by default
+	 */
+	blackAndWhite?: boolean;
+
+	/**
+	 * Print with less quality (and ink)
+	 *
+	 * false by default
+	 */
+	draft?: boolean;
+
+	/**
+	 * Where to place comments
+	 *
+	 * Default is `None`
+	 */
+	cellComments?: 'atEnd' | 'asDisplayed' | 'None';
+
+	/**
+	 * Where to show errors
+	 *
+	 * Default is `displayed`
+	 */
+	errors?: 'dash' | 'blank' | 'NA' | 'displayed';
+
+	/**
+	 * 	What paper size to use (see below)
+	 *
+	 * | Name                          | Value       |
+	 * | ----------------------------- | ---------   |
+	 * | Letter                        | `undefined` |
+	 * | Legal                         |  `5`        |
+	 * | Executive                     |  `7`        |
+	 * | A4                            |  `9`        |
+	 * | A5                            |  `11`       |
+	 * | B5 (JIS)                      |  `13`       |
+	 * | Envelope #10                  |  `20`       |
+	 * | Envelope DL                   |  `27`       |
+	 * | Envelope C5                   |  `28`       |
+	 * | Envelope B5                   |  `34`       |
+	 * | Envelope Monarch              |  `37`       |
+	 * | Double Japan Postcard Rotated |  `82`       |
+	 * | 16K 197x273 mm                |  `119`      |
+	 */
+	paperSize?: PaperSize;
+
+	/**
+	 * Whether to show the row numbers and column letters, `false` by default
+	 */
+	showRowColHeaders?: boolean;
+
+	/**
+	 * Whether to show grid lines, `false` by default
+	 */
+	showGridLines?: boolean;
+
+	/**
+	 * Which number to use for the first page
+	 */
+	firstPageNumber?: number;
+
+	/**
+	 * 	Whether to center the sheet data horizontally, `false` by default
+	 */
+	horizontalCentered?: boolean;
+
+	/**
+	 * 	Whether to center the sheet data vertically, `false` by default
+	 */
+	verticalCentered?: boolean;
+
+	/**
+	 * Set Print Area for a sheet, e.g. `'A1:G20'`
+	 */
+	printArea?: string;
+
+	/**
+	 * Repeat specific rows on every printed page, e.g. `'1:3'`
+	 */
+	printTitlesRow?: string;
+}
+
+export type AutoFilter = string | {
+	from: string | { row: number; column: number };
+	to: string | { row: number; column: number };
+};
+
+export interface Image {
+	extension: 'jpeg' | 'png' | 'gif';
+	filename?: string;
+	buffer?: Buffer;
+}
+
+export interface ImageRange {
+	tl: { col: number; row: number };
+	br: { col: number; row: number };
 }
 
 export interface Worksheet {
+	/**
+	 * Contains information related to how a worksheet is printed
+	 */
+	pageSetup: PageSetup;
+
+	/**
+	 * Worksheet Properties
+	 */
+	properties: WorksheetProperties;
+
+	/**
+	 * Open panes representing the sheet
+	 */
+	views: WorksheetView[];
+
+	/**
+	 * Apply an auto filter to your worksheet.
+	 */
+	autoFilter?: AutoFilter;
+
+	/**
+	 * Add column headers and define column keys and widths.
+	 *
+	 * Note: these column structures are a workbook-building convenience only,
+	 * apart from the column width, they will not be fully persisted.
+	 */
+	columns?: Column[];
+
 	/**
 	 * The total row size of the document. Equal to the row number of the last row that has values.
 	 */
-	rowCount: number;
+	readonly rowCount: number;
+
 	/**
 	 * A count of the number of rows that have values. If a mid-document row is empty, it will not be included in the count.
 	 */
-	actualRowCount: number;
+	readonly actualRowCount: number;
+
 	/**
 	 * The total column size of the document. Equal to the maximum cell count from all of the rows
 	 */
-	columnCount: number;
+	readonly columnCount: number;
+
 	/**
 	 * A count of the number of columns that have values.
 	 */
-	actualColumnCount: number;
+	readonly actualColumnCount: number;
 
 	/**
-	 * Get or create a column
+	 * Get the last editable row in a worksheet (or undefined if there are none)
 	 */
-	getColumn(index: number): Column;
+	readonly lastRow: Row | undefined;
 
 	/**
-	 * Create a new row
+	 * Access an individual columns by key, letter and 1-based column number
 	 */
-	addRow(data: any[]): Row;
+	getColumn(indexOrKey: number | string): Column & ColumnExtension;
+
+	/**
+	 * Cut one or more columns (columns to the right are shifted left)
+	 * and optionally insert more
+	 *
+	 * If column properties have been definde, they will be cut or moved accordingly
+	 *
+	 * Known Issue: If a splice causes any merged cells to move, the results may be unpredictable
+	 *
+	 * Also: If the worksheet has more rows than values in the colulmn inserts,
+	 * the rows will still be shifted as if the values existed
+	 */
+	spliceColumns(start: number, count: number, ...insert: any[][]): void;
+
+	/**
+	 * Cut one or more rows (rows below are shifted up)
+	 * and optionally insert more
+	 *
+	 * Known Issue: If a splice causes any merged cells to move, the results may be unpredictable
+	 */
+	spliceRows(start: number, count: number, ...insert: any[][]): void;
+
+	/**
+	 * Add a couple of Rows by key-value, after the last current row, using the column keys,
+	 * or add a row by contiguous Array (assign to columns A, B & C)
+	 */
+	addRow(data: any[] | any): Row;
+
+	/**
+	 * Add multiple rows by providing an array of arrays or key-value pairs
+	 */
+	addRows(rows: any[]): void;
 
 	/**
 	 * Get or create row by 0-based index
 	 */
 	getRow(index: number): Row;
+
+	/**
+	 * Iterate over all rows that have values in a worksheet
+	 */
 	eachRow(callback: (row: Row, rowNumber: number) => void): void;
 
+	/**
+	 * Iterate over all rows (including empty rows) in a worksheet
+	 */
+	eachRow(opt: { includeEmpty: boolean }, callback: (row: Row, rowNumber: number) => void): void;
+
 	/**
 	 * Get or create cell
 	 */
@@ -194,38 +819,222 @@ export interface Worksheet {
 
 	/**
 	 * Merge cells, either:
-	 * tlbr string
-	 * tl string, br string
-	 * t, l, b, r numbers
+	 *
+	 * tlbr string, e.g. `'A4:B5'`
+	 *
+	 * tl string, br string, e.g. `'G10', 'H11'`
+	 *
+	 * t, l, b, r numbers, e.g. `10,11,12,13`
 	 */
 	mergeCells(a: number | string, b?: number | string, c?: number, d?: number): void;
+
+	/**
+	 * unmerging the cells breaks the style links
+	 */
+	unMergeCells(cell: string): void;
+
+	/**
+	 * Using the image id from `Workbook.addImage`, set the background to the worksheet
+	 */
+	addBackgroundImage(imageId: string): void;
+
+	/**
+	 * Using the image id from `Workbook.addImage`,
+	 * embed an image within the worksheet to cover a range
+	 */
+	addImage(imageId: string, range: string | ImageRange): void;
+
+	/**
+	 * Commit a completed worksheet to stream
+	 */
+	commit(): void;
+}
+
+export interface WorksheetProperties {
+	/**
+	 * Color of the tab
+	 */
+	tabColor?: Color;
+
+	/**
+	 * The worksheet column outline level (default: 0)
+	 */
+	outlineLevelCol?: number;
+
+	/**
+	 * The worksheet row outline level (default: 0)
+	 */
+	outlineLevelRow?: number;
+
+	/**
+	 * Default row height (default: 15)
+	 */
+	defaultRowHeight?: number;
+
+	/**
+	 * default: 55
+	 */
+	dyDescent?: number;
+}
+
+export interface AddWorksheetOptions {
+	properties?: WorksheetProperties;
+	pageSetup?: PageSetup;
+	views?: WorksheetView[];
+}
+
+export interface WorkbookProperties {
+	/**
+	 * Set workbook dates to 1904 date system
+	 */
+	date1904: boolean;
 }
 
 export interface Xlsx {
+	/**
+	 * read from a file
+	 */
 	readFile(path: string): Promise<void>;
+
+	/**
+	 * Create input stream for reading
+	 */
+	createInputStream(): Writable;
+
+	/**
+	 * write to a file
+	 */
 	writeFile(path: string): Promise<void>;
+
+	/**
+	 * write to a stream
+	 */
+	write(stream: Stream): Promise<void>;
 }
 
-export interface WorksheetProps {
-	showGridLines: boolean;
+export interface CsvReadOptions {
+	dateFormats?: string[];
+	map?(value: any, index: number): any;
+}
+
+export interface CsvWriteOptions {
+	dateFormat?: string;
+}
+
+export interface Csv {
+	/**
+	 * read from a file
+	 */
+	readFile(path: string, options?: CsvReadOptions): Promise<Worksheet>;
+
+	/**
+	 * read from a stream
+	 */
+	read(stream: Stream, options?: CsvReadOptions): Promise<Worksheet>;
+
+	/**
+	 * Create input stream for reading
+	 */
+	createInputStream(): Writable;
+
+	/**
+	 * write to a file
+	 */
+	writeFile(path: string, options?: CsvWriteOptions): Promise<void>;
+
+	/**
+	 * write to a stream
+	 */
+	write(stream: Stream, options?: CsvWriteOptions): Promise<void>;
 }
 
 export class Workbook {
-	constructor();
-
 	creator: string;
 	lastModifiedBy: string;
 	created: Date;
 	modified: Date;
 	lastPrinted: Date;
-	properties: {
-		date1904: boolean;
-	};
+	properties: WorkbookProperties;
+
+	/**
+	 * xlsx file format operations
+	 */
+	readonly xlsx: Xlsx;
+
+	/**
+	 * csv file format operations
+	 */
+	readonly csv: Csv;
+
+	/**
+	 * The Workbook views controls how many separate windows Excel will open when viewing the workbook.
+	 */
 	views: WorkbookView[];
 
-	addWorksheet(name: string, opts?: { properties?: WorksheetProps, views?: WorksheetView[] }): Worksheet;
+	/**
+	 * The list of worksheets added to this workbook
+	 */
+	worksheets: Worksheet[];
 
+	/**
+	 * Add a new worksheet and return a reference to it
+	 */
+	addWorksheet(name: string, options?: AddWorksheetOptions): Worksheet;
+
+	/**
+	 * fetch sheet by name or id
+	 */
 	getWorksheet(indexOrName: number | string): Worksheet;
 
-	xlsx: Xlsx;
+	/**
+	 * Iterate over all sheets.
+	 *
+	 * Note: `workbook.worksheets.forEach` will still work but this is better.
+	 */
+	eachSheet(callback: (worksheet: Worksheet, id: number) => void): void;
+
+	/**
+	 * Add Image to Workbook and return the id
+	 */
+	addImage(img: Image): string;
+
+	/**
+	 * Commit a completed workbook to stream and close the stream
+	 */
+	commit(): Promise<void>;
+}
+
+export namespace config {
+	function setValue(key: 'promise', promise: any): void;
+}
+
+export namespace stream {
+	namespace xlsx {
+		interface WorkbookWriterOptions {
+			/**
+			 * Specifies a writable stream to write the XLSX workbook to.
+			 */
+			stream?: Stream;
+
+			/**
+			 * 	If stream not specified, this field specifies the path to a file to write the XLSX workbook to.
+			 */
+			filename?: string;
+
+			/**
+			 * 	Specifies whether to use shared strings in the workbook. Default is false
+			 */
+			useSharedStrings?: boolean;
+
+			/**
+			 * Specifies whether to add style information to the workbook.
+			 * Styles can add some performance overhead. Default is false
+			 */
+			useStyles?: boolean;
+		}
+
+		class WorkbookWriter extends Workbook {
+			constructor(options: WorkbookWriterOptions);
+		}
+	}
 }