chore: refactoring and tests (#12468)

packages/app/src/components/prompt-input/editor-dom.ts

@@ -0,0 +1,135 @@
+export function createTextFragment(content: string): DocumentFragment {
+  const fragment = document.createDocumentFragment()
+  const segments = content.split("\n")
+  segments.forEach((segment, index) => {
+    if (segment) {
+      fragment.appendChild(document.createTextNode(segment))
+    } else if (segments.length > 1) {
+      fragment.appendChild(document.createTextNode("\u200B"))
+    }
+    if (index < segments.length - 1) {
+      fragment.appendChild(document.createElement("br"))
+    }
+  })
+  return fragment
+}
+
+export function getNodeLength(node: Node): number {
+  if (node.nodeType === Node.ELEMENT_NODE && (node as HTMLElement).tagName === "BR") return 1
+  return (node.textContent ?? "").replace(/\u200B/g, "").length
+}
+
+export function getTextLength(node: Node): number {
+  if (node.nodeType === Node.TEXT_NODE) return (node.textContent ?? "").replace(/\u200B/g, "").length
+  if (node.nodeType === Node.ELEMENT_NODE && (node as HTMLElement).tagName === "BR") return 1
+  let length = 0
+  for (const child of Array.from(node.childNodes)) {
+    length += getTextLength(child)
+  }
+  return length
+}
+
+export function getCursorPosition(parent: HTMLElement): number {
+  const selection = window.getSelection()
+  if (!selection || selection.rangeCount === 0) return 0
+  const range = selection.getRangeAt(0)
+  if (!parent.contains(range.startContainer)) return 0
+  const preCaretRange = range.cloneRange()
+  preCaretRange.selectNodeContents(parent)
+  preCaretRange.setEnd(range.startContainer, range.startOffset)
+  return getTextLength(preCaretRange.cloneContents())
+}
+
+export function setCursorPosition(parent: HTMLElement, position: number) {
+  let remaining = position
+  let node = parent.firstChild
+  while (node) {
+    const length = getNodeLength(node)
+    const isText = node.nodeType === Node.TEXT_NODE
+    const isPill =
+      node.nodeType === Node.ELEMENT_NODE &&
+      ((node as HTMLElement).dataset.type === "file" || (node as HTMLElement).dataset.type === "agent")
+    const isBreak = node.nodeType === Node.ELEMENT_NODE && (node as HTMLElement).tagName === "BR"
+
+    if (isText && remaining <= length) {
+      const range = document.createRange()
+      const selection = window.getSelection()
+      range.setStart(node, remaining)
+      range.collapse(true)
+      selection?.removeAllRanges()
+      selection?.addRange(range)
+      return
+    }
+
+    if ((isPill || isBreak) && remaining <= length) {
+      const range = document.createRange()
+      const selection = window.getSelection()
+      if (remaining === 0) {
+        range.setStartBefore(node)
+      }
+      if (remaining > 0 && isPill) {
+        range.setStartAfter(node)
+      }
+      if (remaining > 0 && isBreak) {
+        const next = node.nextSibling
+        if (next && next.nodeType === Node.TEXT_NODE) {
+          range.setStart(next, 0)
+        }
+        if (!next || next.nodeType !== Node.TEXT_NODE) {
+          range.setStartAfter(node)
+        }
+      }
+      range.collapse(true)
+      selection?.removeAllRanges()
+      selection?.addRange(range)
+      return
+    }
+
+    remaining -= length
+    node = node.nextSibling
+  }
+
+  const fallbackRange = document.createRange()
+  const fallbackSelection = window.getSelection()
+  const last = parent.lastChild
+  if (last && last.nodeType === Node.TEXT_NODE) {
+    const len = last.textContent ? last.textContent.length : 0
+    fallbackRange.setStart(last, len)
+  }
+  if (!last || last.nodeType !== Node.TEXT_NODE) {
+    fallbackRange.selectNodeContents(parent)
+  }
+  fallbackRange.collapse(false)
+  fallbackSelection?.removeAllRanges()
+  fallbackSelection?.addRange(fallbackRange)
+}
+
+export function setRangeEdge(parent: HTMLElement, range: Range, edge: "start" | "end", offset: number) {
+  let remaining = offset
+  const nodes = Array.from(parent.childNodes)
+
+  for (const node of nodes) {
+    const length = getNodeLength(node)
+    const isText = node.nodeType === Node.TEXT_NODE
+    const isPill =
+      node.nodeType === Node.ELEMENT_NODE &&
+      ((node as HTMLElement).dataset.type === "file" || (node as HTMLElement).dataset.type === "agent")
+    const isBreak = node.nodeType === Node.ELEMENT_NODE && (node as HTMLElement).tagName === "BR"
+
+    if (isText && remaining <= length) {
+      if (edge === "start") range.setStart(node, remaining)
+      if (edge === "end") range.setEnd(node, remaining)
+      return
+    }
+
+    if ((isPill || isBreak) && remaining <= length) {
+      if (edge === "start" && remaining === 0) range.setStartBefore(node)
+      if (edge === "start" && remaining > 0) range.setStartAfter(node)
+      if (edge === "end" && remaining === 0) range.setEndBefore(node)
+      if (edge === "end" && remaining > 0) range.setEndAfter(node)
+      return
+    }
+
+    remaining -= length
+  }
+}