Introduce some functional programming techniques

src/file/paragraph/formatting/alignment.ts

@@ -1,10 +1,18 @@
 // http://officeopenxml.com/WPalignment.php
 import { XmlAttributeComponent, XmlComponent } from "file/xml-components";
 
-export type AlignmentOptions = "start" | "end" | "center" | "both" | "distribute" | "left" | "right";
+export enum AlignmentOptions {
+    START = "start",
+    END = "end",
+    CENTER = "center",
+    BOTH = "both",
+    DISTRIBUTE = "distribute",
+    LEFT = "left",
+    RIGHT = "right",
+}
 
-export class AlignmentAttributes extends XmlAttributeComponent<{ val: AlignmentOptions }> {
-    protected xmlKeys = { val: "w:val" };
+export class AlignmentAttributes extends XmlAttributeComponent<{ readonly val: AlignmentOptions }> {
+    protected readonly xmlKeys = { val: "w:val" };
 }
 
 export class Alignment extends XmlComponent {

src/file/paragraph/formatting/indent.ts

@@ -2,15 +2,15 @@
 import { XmlAttributeComponent, XmlComponent } from "file/xml-components";
 
 export interface IIndentAttributesProperties {
-    left?: number;
-    hanging?: number;
-    firstLine?: number;
-    start?: number;
-    end?: number;
+    readonly left?: number;
+    readonly hanging?: number;
+    readonly firstLine?: number;
+    readonly start?: number;
+    readonly end?: number;
 }
 
 class IndentAttributes extends XmlAttributeComponent<IIndentAttributesProperties> {
-    protected xmlKeys = {
+    protected readonly xmlKeys = {
         left: "w:left",
         hanging: "w:hanging",
         firstLine: "w:firstLine",

src/file/paragraph/formatting/spacing.ts

@@ -2,14 +2,14 @@
 import { Attributes, XmlAttributeComponent, XmlComponent } from "file/xml-components";
 
 export interface ISpacingProperties {
-    after?: number;
-    before?: number;
-    line?: number;
-    lineRule?: string;
+    readonly after?: number;
+    readonly before?: number;
+    readonly line?: number;
+    readonly lineRule?: string;
 }
 
 class SpacingAttributes extends XmlAttributeComponent<ISpacingProperties> {
-    protected xmlKeys = {
+    protected readonly xmlKeys = {
         after: "w:after",
         before: "w:before",
         line: "w:line",

src/file/paragraph/formatting/tab-stop.spec.ts

@@ -2,7 +2,7 @@ import { assert } from "chai";
 
 import { Utility } from "tests/utility";
 
-import { LeftTabStop, MaxRightTabStop, RightTabStop } from "./tab-stop";
+import { LeaderType, LeftTabStop, MaxRightTabStop, RightTabStop } from "./tab-stop";
 
 describe("LeftTabStop", () => {
     let tabStop: LeftTabStop;
@@ -32,7 +32,7 @@ describe("RightTabStop", () => {
     let tabStop: RightTabStop;
 
     beforeEach(() => {
-        tabStop = new RightTabStop(100, "dot");
+        tabStop = new RightTabStop(100, LeaderType.DOT);
     });
 
     describe("#constructor()", () => {

src/file/paragraph/formatting/tab-stop.ts

@@ -8,11 +8,32 @@ export class TabStop extends XmlComponent {
     }
 }
 
-export type TabValue = "left" | "right" | "center" | "bar" | "clear" | "decimal" | "end" | "num" | "start";
-export type LeaderType = "dot" | "hyphen" | "middleDot" | "none" | "underscore";
+export enum TabValue {
+    LEFT = "left",
+    RIGHT = "right",
+    CENTER = "center",
+    BAR = "bar",
+    CLEAR = "clear",
+    DECIMAL = "decimal",
+    END = "end",
+    NUM = "num",
+    START = "start",
+}
 
-export class TabAttributes extends XmlAttributeComponent<{ val: TabValue; pos: string | number; leader?: LeaderType }> {
-    protected xmlKeys = { val: "w:val", pos: "w:pos", leader: "w:leader" };
+export enum LeaderType {
+    DOT = "dot",
+    HYPHEN = "hyphen",
+    MIDDLE_DOT = "middleDot",
+    NONE = "none",
+    UNDERSCORE = "underscore",
+}
+
+export class TabAttributes extends XmlAttributeComponent<{
+    readonly val: TabValue;
+    readonly pos: string | number;
+    readonly leader?: LeaderType;
+}> {
+    protected readonly xmlKeys = { val: "w:val", pos: "w:pos", leader: "w:leader" };
 }
 
 export class TabStopItem extends XmlComponent {
@@ -30,24 +51,24 @@ export class TabStopItem extends XmlComponent {
 
 export class MaxRightTabStop extends TabStop {
     constructor(leader?: LeaderType) {
-        super(new TabStopItem("right", 9026, leader));
+        super(new TabStopItem(TabValue.RIGHT, 9026, leader));
     }
 }
 
 export class LeftTabStop extends TabStop {
     constructor(position: number, leader?: LeaderType) {
-        super(new TabStopItem("left", position, leader));
+        super(new TabStopItem(TabValue.LEFT, position, leader));
     }
 }
 
 export class RightTabStop extends TabStop {
     constructor(position: number, leader?: LeaderType) {
-        super(new TabStopItem("right", position, leader));
+        super(new TabStopItem(TabValue.RIGHT, position, leader));
     }
 }
 
 export class CenterTabStop extends TabStop {
     constructor(position: number, leader?: LeaderType) {
-        super(new TabStopItem("center", position, leader));
+        super(new TabStopItem(TabValue.CENTER, position, leader));
     }
 }