new initial commit (history rewritten)

components/CustomSelect/option-map.ts

@@ -0,0 +1,50 @@
+import type { ReactNode } from 'react'
+import type { OptionWithDescription } from './select.js'
+
+type OptionMapItem<T> = {
+  label: ReactNode
+  value: T
+  description?: string
+  previous: OptionMapItem<T> | undefined
+  next: OptionMapItem<T> | undefined
+  index: number
+}
+
+export default class OptionMap<T> extends Map<T, OptionMapItem<T>> {
+  readonly first: OptionMapItem<T> | undefined
+  readonly last: OptionMapItem<T> | undefined
+
+  constructor(options: OptionWithDescription<T>[]) {
+    const items: Array<[T, OptionMapItem<T>]> = []
+    let firstItem: OptionMapItem<T> | undefined
+    let lastItem: OptionMapItem<T> | undefined
+    let previous: OptionMapItem<T> | undefined
+    let index = 0
+
+    for (const option of options) {
+      const item = {
+        label: option.label,
+        value: option.value,
+        description: option.description,
+        previous,
+        next: undefined,
+        index,
+      }
+
+      if (previous) {
+        previous.next = item
+      }
+
+      firstItem ||= item
+      lastItem = item
+
+      items.push([option.value, item])
+      index++
+      previous = item
+    }
+
+    super(items)
+    this.first = firstItem
+    this.last = lastItem
+  }
+}