refactor: add root static source files

static/discover.ts

@@ -0,0 +1,52 @@
+export {}
+
+const parseClassList = (value: string | null): string[] => {
+  if (!value) {
+    return []
+  }
+
+  return value
+    .split(' ')
+    .map((entry: string): string => entry.trim())
+    .filter((entry: string): boolean => entry.length > 0)
+}
+
+const setActiveDiscoverTab = (clickedTab: Element): void => {
+  const group = clickedTab.closest('[data-tab-group="discover"]')
+  if (!group) {
+    return
+  }
+
+  const triggers = group.querySelectorAll('[data-tab-trigger]')
+  triggers.forEach((tab: Element): void => {
+    const activeClasses = parseClassList(tab.getAttribute('data-tab-active-classes'))
+    const inactiveClasses = parseClassList(tab.getAttribute('data-tab-inactive-classes'))
+    tab.classList.remove(...activeClasses)
+    tab.classList.add(...inactiveClasses)
+  })
+
+  const activeClasses = parseClassList(clickedTab.getAttribute('data-tab-active-classes'))
+  const inactiveClasses = parseClassList(clickedTab.getAttribute('data-tab-inactive-classes'))
+  clickedTab.classList.remove(...inactiveClasses)
+  clickedTab.classList.add(...activeClasses)
+}
+
+const onDiscoverTabClick = (event: MouseEvent): void => {
+  const target = event.target
+  if (!(target instanceof Element)) {
+    return
+  }
+
+  const trigger = target.closest('[data-tab-trigger]')
+  if (!trigger) {
+    return
+  }
+
+  setActiveDiscoverTab(trigger)
+}
+
+const initDiscoverTabs = (): void => {
+  document.addEventListener('click', onDiscoverTabClick)
+}
+
+initDiscoverTabs()