2 files changed, 139 insertions, 0 deletions
diff --git a/src/templates/assets/javascripts/utilities/h/.eslintrc b/src/templates/assets/javascripts/utilities/h/.eslintrc
new file mode 100644
index 00000000..d79b45b0
--- /dev/null
+++ b/src/templates/assets/javascripts/utilities/h/.eslintrc
@@ -0,0 +1,7 @@
+{
+  "rules": {
+    "@typescript-eslint/no-explicit-any": "off",
+    "@typescript-eslint/no-namespace": "off",
+    "jsdoc/require-jsdoc": "off"
+  }
+}
diff --git a/src/templates/assets/javascripts/utilities/h/index.ts b/src/templates/assets/javascripts/utilities/h/index.ts
new file mode 100644
index 00000000..08d809f1
--- /dev/null
+++ b/src/templates/assets/javascripts/utilities/h/index.ts
@@ -0,0 +1,132 @@
+/*
+ * Copyright (c) 2016-2023 Martin Donath <martin.donath@squidfunk.com>
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy
+ * of this software and associated documentation files (the "Software"), to
+ * deal in the Software without restriction, including without limitation the
+ * rights to use, copy, modify, merge, publish, distribute, sublicense, and/or
+ * sell copies of the Software, and to permit persons to whom the Software is
+ * furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in
+ * all copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NON-INFRINGEMENT. IN NO EVENT SHALL THE
+ * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
+ * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS
+ * IN THE SOFTWARE.
+ */
+
+import { JSX as JSXInternal } from "preact"
+
+/* ----------------------------------------------------------------------------
+ * Helper types
+ * ------------------------------------------------------------------------- */
+
+/**
+ * HTML attributes
+ */
+type Attributes =
+  & JSXInternal.HTMLAttributes
+  & JSXInternal.SVGAttributes
+  & Record<string, any>
+
+/**
+ * Child element
+ */
+type Child =
+  | ChildNode
+  | HTMLElement
+  | Text
+  | string
+  | number
+
+/* ----------------------------------------------------------------------------
+ * Helper functions
+ * ------------------------------------------------------------------------- */
+
+/**
+ * Append a child node to an element
+ *
+ * @param el - Element
+ * @param child - Child node(s)
+ */
+function appendChild(el: HTMLElement, child: Child | Child[]): void {
+
+  /* Handle primitive types (including raw HTML) */
+  if (typeof child === "string" || typeof child === "number") {
+    el.innerHTML += child.toString()
+
+  /* Handle nodes */
+  } else if (child instanceof Node) {
+    el.appendChild(child)
+
+  /* Handle nested children */
+  } else if (Array.isArray(child)) {
+    for (const node of child)
+      appendChild(el, node)
+  }
+}
+
+/* ----------------------------------------------------------------------------
+ * Functions
+ * ------------------------------------------------------------------------- */
+
+/**
+ * JSX factory
+ *
+ * @template T - Element type
+ *
+ * @param tag - HTML tag
+ * @param attributes - HTML attributes
+ * @param children - Child elements
+ *
+ * @returns Element
+ */
+export function h<T extends keyof HTMLElementTagNameMap>(
+  tag: T, attributes?: Attributes | null, ...children: Child[]
+): HTMLElementTagNameMap[T]
+
+export function h<T extends h.JSX.Element>(
+  tag: string, attributes?: Attributes | null, ...children: Child[]
+): T
+
+export function h<T extends h.JSX.Element>(
+  tag: string, attributes?: Attributes | null, ...children: Child[]
+): T {
+  const el = document.createElement(tag)
+
+  /* Set attributes, if any */
+  if (attributes)
+    for (const attr of Object.keys(attributes)) {
+      if (typeof attributes[attr] === "undefined")
+        continue
+
+      /* Set default attribute or boolean */
+      if (typeof attributes[attr] !== "boolean")
+        el.setAttribute(attr, attributes[attr])
+      else
+        el.setAttribute(attr, "")
+    }
+
+  /* Append child nodes */
+  for (const child of children)
+    appendChild(el, child)
+
+  /* Return element */
+  return el as T
+}
+
+/* ----------------------------------------------------------------------------
+ * Namespace
+ * ------------------------------------------------------------------------- */
+
+export declare namespace h {
+  namespace JSX {
+    type Element = HTMLElement
+    type IntrinsicElements = JSXInternal.IntrinsicElements
+  }
+}