fix(app): decode dropped file URLs

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

@@ -1,14 +1,15 @@
 import { onMount } from "solid-js"
 import { makeEventListener } from "@solid-primitives/event-listener"
 import { showToast } from "@/utils/toast"
-import { type ContentPart, type ImageAttachmentPart, type usePrompt } from "@/context/prompt"
+import { type ContentPart, type FileAttachmentPart, type ImageAttachmentPart, type usePrompt } from "@/context/prompt"
 import { useLanguage } from "@/context/language"
 import { usePlatform } from "@/context/platform"
 import { uuid } from "@/utils/uuid"
 import { getCursorPosition } from "./editor-dom"
 import { createBlobReference, type DraftStore } from "@/utils/draft-store"
 import { attachmentMime } from "./files"
 import { normalizePaste, pasteMode } from "./paste"
+import { parseFileURL } from "@/context/file/path"
 
 type PromptTarget = Pick<ReturnType<ReturnType<typeof usePrompt>["capture"]>, "current" | "cursor" | "set">
 type AttachmentTarget = { prompt: PromptTarget; cursor: number | undefined }
@@ -35,6 +36,17 @@ export type PromptAttachmentsInput = {
   getPathForFile?: (file: File) => string
 }
 
+export function filePartFromFileURL(input: string): FileAttachmentPart | undefined {
+  if (!input.startsWith("file:")) return undefined
+  if (input.startsWith("file://")) {
+    const file = parseFileURL(input)
+    if (!file) return undefined
+    return { type: "file", path: file.path, url: file.url, content: "@" + file.path, start: 0, end: 0 }
+  }
+  const filePath = input.slice("file:".length)
+  return { type: "file", path: filePath, content: "@" + filePath, start: 0, end: 0 }
+}
+
 export function createPromptAttachmentsCore(input: PromptAttachmentsCoreInput) {
   const capture = (): AttachmentTarget | undefined => {
     const prompt = input.capture()
@@ -189,11 +201,10 @@ export function createPromptAttachments(input: PromptAttachmentsInput) {
     input.setDraggingType(null)
 
     const plainText = event.dataTransfer?.getData("text/plain")
-    const filePrefix = "file:"
-    if (plainText?.startsWith(filePrefix)) {
-      const filePath = plainText.slice(filePrefix.length)
+    const file = plainText ? filePartFromFileURL(plainText) : undefined
+    if (file) {
       input.focusEditor()
-      input.addPart({ type: "file", path: filePath, content: "@" + filePath, start: 0, end: 0 })
+      input.addPart(file)
       return
     }
 

packages/app/src/components/prompt-input/build-request-parts.test.ts

@@ -1,5 +1,6 @@
 import { describe, expect, test } from "bun:test"
 import type { Prompt } from "@/context/prompt"
+import { filePartFromFileURL } from "./attachments"
 import { buildRequestParts } from "./build-request-parts"
 
 describe("buildRequestParts", () => {
@@ -258,6 +259,64 @@ describe("buildRequestParts", () => {
     }
   })
 
+  test("preserves decoded paths and canonical URLs from desktop file drops", () => {
+    const attachment = filePartFromFileURL("file:///home/carole/Bureau/%3F%3F%3F.png")
+    if (!attachment) throw new Error("Expected a file attachment")
+
+    const result = buildRequestParts({
+      prompt: [attachment],
+      context: [],
+      images: [],
+      text: attachment.content,
+      messageID: "msg_drop_1",
+      sessionID: "ses_drop_1",
+      sessionDirectory: "/repo",
+    })
+
+    expect(result.requestParts.find((part) => part.type === "file")).toMatchObject({
+      url: "file:///home/carole/Bureau/%3F%3F%3F.png",
+      source: {
+        type: "file",
+        path: "/home/carole/Bureau/???.png",
+        text: { value: "@/home/carole/Bureau/???.png" },
+      },
+    })
+  })
+
+  test("resolves relative paths from sidebar file-tree drags against sessionDirectory", () => {
+    const attachment = filePartFromFileURL("file:packages/app/src/foo.ts")
+    if (!attachment) throw new Error("Expected a file attachment")
+
+    const result = buildRequestParts({
+      prompt: [attachment],
+      context: [],
+      images: [],
+      text: attachment.content,
+      messageID: "msg_drop_2",
+      sessionID: "ses_drop_2",
+      sessionDirectory: "/repo",
+    })
+
+    expect(result.requestParts.find((part) => part.type === "file")).toMatchObject({
+      url: "file:///repo/packages/app/src/foo.ts",
+      source: {
+        type: "file",
+        path: "/repo/packages/app/src/foo.ts",
+        text: { value: "@packages/app/src/foo.ts" },
+      },
+    })
+  })
+
+  test("keeps reserved characters in relative file-tree drag paths", () => {
+    expect(filePartFromFileURL("file:packages/app/??.ts")).toEqual({
+      type: "file",
+      path: "packages/app/??.ts",
+      content: "@packages/app/??.ts",
+      start: 0,
+      end: 0,
+    })
+  })
+
   test("handles macOS paths correctly", () => {
     const prompt: Prompt = [{ type: "file", path: "README.md", content: "@README.md", start: 0, end: 9 }]
 

packages/app/src/context/file/path.test.ts

@@ -1,5 +1,5 @@
 import { describe, expect, test } from "bun:test"
-import { createPathHelpers, stripQueryAndHash, unquoteGitPath, encodeFilePath } from "./path"
+import { createPathHelpers, stripQueryAndHash, unquoteGitPath, encodeFilePath, parseFileURL } from "./path"
 
 describe("file path helpers", () => {
   test("normalizes file inputs against workspace root", () => {
@@ -57,6 +57,42 @@ describe("file path helpers", () => {
   })
 })
 
+describe("parseFileURL", () => {
+  test("decodes reserved characters in POSIX file URLs", () => {
+    expect(parseFileURL("file:///home/carole/Bureau/%3F%3F%3F.png")).toEqual({
+      path: "/home/carole/Bureau/???.png",
+      url: "file:///home/carole/Bureau/%3F%3F%3F.png",
+    })
+    expect(parseFileURL("file:///tmp/file%2520name%23.txt")?.path).toBe("/tmp/file%20name#.txt")
+  })
+
+  test("preserves Windows drives and UNC hosts", () => {
+    expect(parseFileURL("file:///C:/Users/test/file%3F.txt")?.path).toBe("/C:/Users/test/file?.txt")
+    expect(parseFileURL("file://server/share/file%23.txt")?.path).toBe("//server/share/file#.txt")
+  })
+
+  test("accepts localhost and rejects non-file URLs", () => {
+    expect(parseFileURL("file://localhost/tmp/file.txt")?.path).toBe("/tmp/file.txt")
+    expect(parseFileURL("https://example.com/file.txt")).toBeUndefined()
+    expect(parseFileURL("not a URL")).toBeUndefined()
+  })
+
+  test("falls back when URL.canParse is unavailable", () => {
+    const original = Object.getOwnPropertyDescriptor(URL, "canParse")
+    Object.defineProperty(URL, "canParse", { configurable: true, value: undefined })
+    try {
+      expect(parseFileURL("file:///home/carole/Bureau/%3F%3F%3F.png")).toEqual({
+        path: "/home/carole/Bureau/???.png",
+        url: "file:///home/carole/Bureau/%3F%3F%3F.png",
+      })
+      expect(parseFileURL("not a URL")).toBeUndefined()
+    } finally {
+      if (original) Object.defineProperty(URL, "canParse", original)
+      if (!original) Reflect.deleteProperty(URL, "canParse")
+    }
+  })
+})
+
 describe("encodeFilePath", () => {
   describe("Linux/Unix paths", () => {
     test("should handle Linux absolute path", () => {

packages/app/src/context/file/path.ts

@@ -80,6 +80,20 @@ export function decodeFilePath(input: string) {
   }
 }
 
+export function parseFileURL(input: string) {
+  if (typeof URL.canParse === "function" && !URL.canParse(input)) return undefined
+  let url: URL
+  try {
+    url = new URL(input)
+  } catch {
+    return undefined
+  }
+  if (url.protocol !== "file:") return undefined
+  const pathname = decodeFilePath(url.pathname)
+  const path = !url.hostname || url.hostname === "localhost" ? pathname : `//${url.hostname}${pathname}`
+  return { path, url: url.href }
+}
+
 export function encodeFilePath(filepath: string): string {
   // Normalize Windows paths: convert backslashes to forward slashes
   let normalized = filepath.replace(/\\/g, "/")