refactor: extract icon normalization helper

Moved normalizeIconName out of CALEXT2_Event into lib/icon-helpers to keep Event focused on rendering.
CALEXT2_Event now uses IconHelpers.normalizeIconName, getScripts loads the new helper, and tests were added to cover both legacy and modern icon formats.

Author: KristjanESPERANTO

CALEXT2_Event.js

@@ -1,4 +1,4 @@
-/* global dayjs */
+/* global dayjs IconHelpers */
 // eslint-disable-next-line no-unused-vars
 class Event {
   constructor (data, slot) {
@@ -116,7 +116,7 @@ class Event {
     if (event.icon) {
       const iconDom = document.createElement("iconify-icon");
       iconDom.classList.add("eventIcon");
-      iconDom.setAttribute("icon", Event.normalizeIconName(event.icon));
+      iconDom.setAttribute("icon", IconHelpers.normalizeIconName(event.icon));
       mainDom.appendChild(iconDom);
     }
     const title = document.createElement("div");
@@ -166,25 +166,6 @@ class Event {
     return eventDom;
   }
 
-  /**
-   * Normalize icon name from legacy Iconify v1 format (prefix-name) to v2+
-   * format (prefix:name). If the name already contains ":", it is returned
-   * as-is to support the modern format directly.
-   * TODO: Remove this backwards-compatibility function after a suitable deprecation period (so maybe in 2028).
-   * @param {string} name - The icon name to normalize
-   * @returns {string} Normalized icon name with ":" separator
-   */
-  static normalizeIconName (name) {
-    if (name.includes(":")) return name;
-    const dashIndex = name.indexOf("-");
-    if (dashIndex > 0) {
-      const converted = `${name.substring(0, dashIndex)}:${name.substring(dashIndex + 1)}`;
-      // eslint-disable-next-line no-console
-      console.warn(`[CALEXT2] Deprecated icon name format "${name}" — use "${converted}" instead (prefix:name).`);
-      return converted;
-    }
-    return name;
-  }
 
   /**
    * Applies category CSS classes and data-attribute to eventDom,

MMM-CalendarExt2.js

@@ -224,6 +224,7 @@ Module.register("MMM-CalendarExt2", {
   getScripts () {
     const scripts = [
       this.file("lib/slot-date-helpers.js"),
+      this.file("lib/icon-helpers.js"),
       this.file("node_modules/dayjs/dayjs.min.js"),
       this.file("node_modules/dayjs/plugin/utc.js"),
       this.file("node_modules/dayjs/plugin/timezone.js"),

lib/icon-helpers.js

@@ -0,0 +1,30 @@
+/**
+ * Icon name normalization from Iconify v1 legacy format to v2+ format.
+ * Dual-mode: works as a browser global and Node.js module.
+ */
+
+/**
+ * Normalize icon name from legacy Iconify v1 format (prefix-name) to v2+
+ * format (prefix:name). If the name already contains ":", it is returned
+ * as-is to support the modern format directly.
+ * TODO: Remove this backwards-compatibility function after a suitable deprecation period (so maybe in 2028).
+ * @param {string} name - The icon name to normalize
+ * @returns {string} Normalized icon name with ":" separator
+ */
+const normalizeIconName = (name) => {
+  if (name.includes(":")) return name;
+  const dashIndex = name.indexOf("-");
+  if (dashIndex > 0) {
+    const converted = `${name.substring(0, dashIndex)}:${name.substring(dashIndex + 1)}`;
+    // eslint-disable-next-line no-console
+    console.warn(`[CALEXT2] Deprecated icon name format "${name}" — use "${converted}" instead (prefix:name).`);
+    return converted;
+  }
+  return name;
+};
+
+const IconHelpers = {normalizeIconName};
+
+if (typeof module !== "undefined" && module.exports) {
+  module.exports = IconHelpers;
+}

test/icon-helpers.test.js

@@ -0,0 +1,55 @@
+const assert = require("node:assert/strict");
+const {describe, it} = require("node:test");
+
+const IconHelpers = require("../lib/icon-helpers.js");
+
+describe("normalizeIconName", () => {
+  it("returns modern format unchanged", () => {
+    assert.equal(IconHelpers.normalizeIconName("mdi:home"), "mdi:home");
+  });
+
+  it("converts legacy format prefix-name to prefix:name", () => {
+    assert.equal(IconHelpers.normalizeIconName("mdi-home"), "mdi:home");
+  });
+
+  it("handles multiple dashes, converting only first to colon", () => {
+    assert.equal(IconHelpers.normalizeIconName("mdi-home-outline"), "mdi:home-outline");
+  });
+
+  it("returns name unchanged if no dash present", () => {
+    assert.equal(IconHelpers.normalizeIconName("home"), "home");
+  });
+
+  it("handles single-char prefix", () => {
+    assert.equal(IconHelpers.normalizeIconName("i-check"), "i:check");
+  });
+
+  it("warns to console on legacy format conversion", () => {
+    const messages = [];
+    // eslint-disable-next-line no-console
+    const originalWarn = console.warn;
+    // eslint-disable-next-line no-console
+    console.warn = (msg) => messages.push(msg);
+
+    IconHelpers.normalizeIconName("mdi-home");
+
+    // eslint-disable-next-line no-console
+    console.warn = originalWarn;
+    assert.equal(messages.length, 1);
+    assert.match(messages[0], /Deprecated icon name format/u);
+  });
+
+  it("does not warn on modern format", () => {
+    const messages = [];
+    // eslint-disable-next-line no-console
+    const originalWarn = console.warn;
+    // eslint-disable-next-line no-console
+    console.warn = (msg) => messages.push(msg);
+
+    IconHelpers.normalizeIconName("mdi:home");
+
+    // eslint-disable-next-line no-console
+    console.warn = originalWarn;
+    assert.equal(messages.length, 0);
+  });
+});