extracted some dom manipulation from board-game to dom-utils

src/frontend/components/board-game.ts

@@ -13,6 +13,7 @@ import { GameVariantName, gamesRules } from "../../shared/game-variants/index.ts
 import { replaceLocation } from "../utils/navigation-utils.ts";
 import { TrackingTools } from "../utils/query-tracking-utils.ts";
 import { updateWithQueryParams } from "../utils/url-utils.ts";
+import { ensureColumnsNumber, ensureRowsNumber, ensureSlotTemplate } from "../utils/dom-utils.ts";
 
 class BoardGameComponent extends HTMLElement {
   private readonly trackingTools = new TrackingTools(this);
@@ -38,18 +39,7 @@ class BoardGameComponent extends HTMLElement {
     // because both slotName and templateName originate from getSlotTemplateNames and is not actually arbitrary
     for (const [slotName, templateName] of Object.entries(slotTemplateNames)) {
       this.querySelectorAll(`.${slotName}`).forEach((slot) => {
-        if (slot.getAttribute("data-current-template") !== templateName) {
-          while (slot.lastChild) {
-            slot.removeChild(slot.lastChild);
-          }
-
-          const template = this.querySelector(`template[name="${templateName}"]`);
-          if (template) {
-            slot.appendChild(template.content.cloneNode(true));
-          }
-
-          slot.setAttribute("data-current-template", templateName);
-        }
+        ensureSlotTemplate(slot, templateName, () => this.querySelector(`template[name="${templateName}"]`));
       });
     }
 
@@ -74,33 +64,17 @@ class BoardGameComponent extends HTMLElement {
     }
 
     this.querySelectorAll("tbody.game-board").forEach((tbody) => {
-      while (gameState.rows < tbody.rows.length) {
-        tbody.rows[0]?.remove();
-      }
-
-      while (gameState.rows > tbody.rows.length) {
-        tbody.insertRow();
-      }
+      ensureRowsNumber(tbody, gameState.rows);
 
       for (let rowNumber = 0; rowNumber < tbody.rows.length; rowNumber++) {
-        const row = tbody.rows[rowNumber];
-        if (!row) {
-          continue;
-        }
-
-        while (gameState.columns < row.cells.length) {
-          row.cells[0]?.remove();
-        }
+        // eslint-disable-next-line @typescript-eslint/no-non-null-assertion -- should not be empty by the definition of rowNumber
+        const row = tbody.rows[rowNumber]!;
 
-        while (gameState.columns > row.cells.length) {
-          row.insertCell();
-        }
+        ensureColumnsNumber(row, gameState.columns);
 
         for (let columnNumber = 0; columnNumber < row.cells.length; columnNumber++) {
-          const cell = row.cells[columnNumber];
-          if (!cell) {
-            continue;
-          }
+          // eslint-disable-next-line @typescript-eslint/no-non-null-assertion -- should not be empty by the definition of columnNumber
+          const cell = row.cells[columnNumber]!;
 
           if (!cell.childNodes.length) {
             const button = document.createElement("button");

src/frontend/utils/dom-utils.ts

@@ -0,0 +1,38 @@
+export const ensureSlotTemplate = (
+  slot: Element,
+  templateName: string,
+  getTemplate: () => HTMLTemplateElement | null,
+) => {
+  if (slot.getAttribute("data-current-template") !== templateName) {
+    while (slot.lastChild) {
+      slot.removeChild(slot.lastChild);
+    }
+
+    const template = getTemplate();
+    if (template) {
+      slot.appendChild(template.content.cloneNode(true));
+    }
+
+    slot.setAttribute("data-current-template", templateName);
+  }
+};
+
+export const ensureRowsNumber = (tbody: HTMLTableSectionElement, targetRowsNumber: number) => {
+  while (targetRowsNumber < tbody.rows.length) {
+    tbody.deleteRow(0);
+  }
+
+  while (targetRowsNumber > tbody.rows.length) {
+    tbody.insertRow();
+  }
+};
+
+export const ensureColumnsNumber = (row: HTMLTableRowElement, targetColumnsNumber: number) => {
+  while (targetColumnsNumber < row.cells.length) {
+    row.cells[0]?.remove();
+  }
+
+  while (targetColumnsNumber > row.cells.length) {
+    row.insertCell();
+  }
+};