fix(app): support text attachments (#17335)

packages/app/src/components/prompt-input/files.ts

@@ -0,0 +1,119 @@
+export const ACCEPTED_IMAGE_TYPES = ["image/png", "image/jpeg", "image/gif", "image/webp"]
+
+const IMAGE_MIMES = new Set(ACCEPTED_IMAGE_TYPES)
+const IMAGE_EXTS = new Map([
+  ["gif", "image/gif"],
+  ["jpeg", "image/jpeg"],
+  ["jpg", "image/jpeg"],
+  ["png", "image/png"],
+  ["webp", "image/webp"],
+])
+const TEXT_MIMES = new Set([
+  "application/json",
+  "application/ld+json",
+  "application/toml",
+  "application/x-toml",
+  "application/x-yaml",
+  "application/xml",
+  "application/yaml",
+])
+
+export const ACCEPTED_FILE_TYPES = [
+  ...ACCEPTED_IMAGE_TYPES,
+  "application/pdf",
+  "text/*",
+  "application/json",
+  "application/ld+json",
+  "application/toml",
+  "application/x-toml",
+  "application/x-yaml",
+  "application/xml",
+  "application/yaml",
+  ".c",
+  ".cc",
+  ".cjs",
+  ".conf",
+  ".cpp",
+  ".css",
+  ".csv",
+  ".cts",
+  ".env",
+  ".go",
+  ".gql",
+  ".graphql",
+  ".h",
+  ".hh",
+  ".hpp",
+  ".htm",
+  ".html",
+  ".ini",
+  ".java",
+  ".js",
+  ".json",
+  ".jsx",
+  ".log",
+  ".md",
+  ".mdx",
+  ".mjs",
+  ".mts",
+  ".py",
+  ".rb",
+  ".rs",
+  ".sass",
+  ".scss",
+  ".sh",
+  ".sql",
+  ".toml",
+  ".ts",
+  ".tsx",
+  ".txt",
+  ".xml",
+  ".yaml",
+  ".yml",
+  ".zsh",
+]
+
+const SAMPLE = 4096
+
+function kind(type: string) {
+  return type.split(";", 1)[0]?.trim().toLowerCase() ?? ""
+}
+
+function ext(name: string) {
+  const idx = name.lastIndexOf(".")
+  if (idx === -1) return ""
+  return name.slice(idx + 1).toLowerCase()
+}
+
+function textMime(type: string) {
+  if (!type) return false
+  if (type.startsWith("text/")) return true
+  if (TEXT_MIMES.has(type)) return true
+  if (type.endsWith("+json")) return true
+  return type.endsWith("+xml")
+}
+
+function textBytes(bytes: Uint8Array) {
+  if (bytes.length === 0) return true
+  let count = 0
+  for (const byte of bytes) {
+    if (byte === 0) return false
+    if (byte < 9 || (byte > 13 && byte < 32)) count += 1
+  }
+  return count / bytes.length <= 0.3
+}
+
+export async function attachmentMime(file: File) {
+  const type = kind(file.type)
+  if (IMAGE_MIMES.has(type)) return type
+  if (type === "application/pdf") return type
+
+  const suffix = ext(file.name)
+  const fallback = IMAGE_EXTS.get(suffix) ?? (suffix === "pdf" ? "application/pdf" : undefined)
+  if ((!type || type === "application/octet-stream") && fallback) return fallback
+
+  if (textMime(type)) return "text/plain"
+  const bytes = new Uint8Array(await file.slice(0, SAMPLE).arrayBuffer())
+  if (!textBytes(bytes)) return
+  return "text/plain"
+}