Reuse logic in center pad calculation

Author: darkriszty

src/padCalculation/center/centerPadCalculator.ts

@@ -0,0 +1,24 @@
+import { Table } from "../../models/table";
+import { Cell } from "../../models/cell";
+import { BasePadCalculator } from "../basePadCalculator";
+
+export abstract class CenterPadCalculator extends BasePadCalculator {
+    public getLeftPadding(paddingChar: string, table: Table, row: number, column: number): string {
+        return paddingChar.repeat(Math.floor(this.totalPadCount(table, column, row)));
+    }
+
+    public getRightPadding(paddingChar: string, table: Table, row: number, column: number): string {
+        return paddingChar.repeat(Math.ceil(this.totalPadCount(table, column, row)));
+    }
+
+    protected totalPadCount(table: Table, column: number, row: number): number {
+        const longestColumnLength = table.getLongestColumnLengths()[column];
+        let padCount = longestColumnLength > 0
+            ? longestColumnLength - table.rows[row][column].getLength()
+            : 1;
+        padCount += this.extraPadCount(table);
+        return padCount / 2;
+    }
+
+    protected abstract extraPadCount(table: Table): number;
+}

src/padCalculation/center/firstColumnPadCalculator.ts

@@ -1,24 +1,9 @@
-import { BasePadCalculator } from "../basePadCalculator";
 import { Table } from "../../models/table";
-import { Cell } from "../../models/cell";
+import { CenterPadCalculator } from "./centerPadCalculator";
 
-export class FirstColumnPadCalculator extends BasePadCalculator {
-    public getLeftPadding(paddingChar: string, table: Table, row: number, column: number): string {
-        return paddingChar.repeat(Math.floor(this.totalPadCount(table, column, row)));
-    }
-
-    public getRightPadding(paddingChar: string, table: Table, row: number, column: number): string {
-        return paddingChar.repeat(Math.ceil(this.totalPadCount(table, column, row)));
-    }
+export class FirstColumnPadCalculator extends CenterPadCalculator {
 
-    private totalPadCount(table: Table, column: number, row: number): number {
-        const longestColumnLength = table.getLongestColumnLengths()[column];
-        let padCount = longestColumnLength > 0
-            ? longestColumnLength - table.rows[row][column].getLength()
-            : 1;
-        padCount++;
-        if (table.hasLeftBorder)
-            padCount++;
-        return padCount / 2;
+    protected extraPadCount(table: Table): number {
+        return table.hasLeftBorder ? 2 : 1;
     }
 }

src/padCalculation/center/lastColumnPadCalculator.ts

@@ -1,23 +1,14 @@
-import { BasePadCalculator } from "../basePadCalculator";
 import { Table } from "../../models/table";
-import { Cell } from "../../models/cell";
+import { CenterPadCalculator } from "./centerPadCalculator";
 
-export class LastColumnPadCalculator extends BasePadCalculator {
-    public getLeftPadding(paddingChar: string, table: Table, row: number, column: number): string {
-        return paddingChar.repeat(Math.floor(this.totalPadCount(table, column, row)));
-    }
+export class LastColumnPadCalculator extends CenterPadCalculator {
 
     public getRightPadding(paddingChar: string, table: Table, row: number, column: number): string {
         if (!table.hasRightBorder) return "";
-        return paddingChar.repeat(Math.ceil(this.totalPadCount(table, column, row)));
+        return super.getRightPadding(paddingChar, table, row, column);
     }
 
-    private totalPadCount(table: Table, column: number, row: number): number {
-        const longestColumnLength = table.getLongestColumnLengths()[column];
-        let padCount = longestColumnLength > 0
-            ? longestColumnLength - table.rows[row][column].getLength()
-            : 1;
-        padCount += 2;
-        return padCount / 2;
+    protected extraPadCount(table: Table): number {
+        return 2;
     }
 }

src/padCalculation/center/middleColumnPadCalculator.ts

@@ -1,22 +1,8 @@
-import { BasePadCalculator } from "../basePadCalculator";
 import { Table } from "../../models/table";
-import { Cell } from "../../models/cell";
+import { CenterPadCalculator } from "./centerPadCalculator";
 
-export class MiddleColumnPadCalculator extends BasePadCalculator {
-    public getLeftPadding(paddingChar: string, table: Table, row: number, column: number): string {
-        return paddingChar.repeat(Math.floor(this.totalPadCount(table, column, row)));
-    }
-
-    public getRightPadding(paddingChar: string, table: Table, row: number, column: number): string {
-        return paddingChar.repeat(Math.ceil(this.totalPadCount(table, column, row)));
-    }
-
-    private totalPadCount(table: Table, column: number, row: number): number {
-        const longestColumnLength = table.getLongestColumnLengths()[column];
-        let padCount = longestColumnLength > 0
-            ? longestColumnLength - table.rows[row][column].getLength()
-            : 1;
-        padCount += 2;
-        return padCount / 2;
+export class MiddleColumnPadCalculator extends CenterPadCalculator {
+    protected extraPadCount(table: Table): number {
+        return 2;
     }
 }