feat(editor): paste copied files as Markdown links (#599)

Pasting files copied in the project view into a Markdown document now inserts `[](relative/path)`, one link per line, encoded the same way as Markdown images. Other editors and terminals keep inserting the raw path, copied images keep their ![](...) route, and remote windows keep raw paths because the clipboard holds client paths. A context-menu Paste that the native command rejects falls back to reading the clipboard.

Fixes #573

src/editor/core/cm/clipboard.test.ts

@@ -2,18 +2,102 @@ import { afterEach, beforeEach, expect, it, vi } from "vitest";
 import { EditorState } from "@codemirror/state";
 import { EditorView } from "@codemirror/view";
 import { commands } from "@/platform/ipc";
-import { clipboardFilesExtension, pasteEditorClipboard } from "./clipboard";
+import { isRemoteWindow } from "@/platform/remote";
+import { clipboardDocumentPath, clipboardFilesExtension, pasteEditorClipboard } from "./clipboard";
 import { markdownImages } from "./markdownImages";
 
+vi.mock("@/platform/remote", () => ({ isRemoteWindow: vi.fn(() => false) }));
+
 const views: EditorView[] = [];
-beforeEach(() => vi.stubGlobal("__TAURI_INTERNALS__", {}));
+beforeEach(() => {
+  vi.stubGlobal("__TAURI_INTERNALS__", {});
+  Object.defineProperty(document, "execCommand", { configurable: true, value: vi.fn(() => false) });
+  Object.defineProperty(document, "queryCommandSupported", { configurable: true, value: vi.fn(() => false) });
+});
 afterEach(() => {
   views.splice(0).forEach((view) => view.destroy());
   vi.restoreAllMocks();
   vi.unstubAllGlobals();
 });
 
-for (const route of ["event", "menu"]) {
+for (const route of ["event", "menu", "menu unsupported", "menu rejected"]) {
+  it.each([
+    { name: "file", paths: ["/p/docs/file.txt"], expected: "[](file.txt)" },
+    { name: "folder", paths: ["/p/docs/folder"], expected: "[](folder)" },
+    { name: "several", paths: ["/p/docs/a.txt", "/p/folder"], expected: "[](a.txt)\n[](../folder)" },
+    {
+      name: "spaces, Chinese, and delimiters",
+      paths: ["/p/docs/中文/a (1)#!'*.txt"],
+      expected: "[](%E4%B8%AD%E6%96%87/a%20%281%29%23%21%27%2A.txt)",
+    },
+    { name: "parent relative", paths: ["/p/file.txt"], expected: "[](../file.txt)" },
+    {
+      name: "Windows separators",
+      path: "C:\\p\\docs\\a.md",
+      paths: ["C:\\p\\folder\\a b.txt"],
+      expected: "[](../folder/a%20b.txt)",
+    },
+    { name: "no document path", path: "", paths: ["/p/file.txt"], expected: "/p/file.txt" },
+    { name: "non-Markdown", path: "/p/a.ts", paths: ["/p/file.txt"], expected: "/p/file.txt" },
+    {
+      name: "remote window with client file paths",
+      remote: true,
+      path: "/home/dev/a.md",
+      paths: ["/Users/me/file.txt", "/Users/me/中文 文件夹"],
+      expected: "/Users/me/file.txt\n/Users/me/中文 文件夹",
+    },
+    {
+      name: "remote window with matching text flavor",
+      remote: true,
+      path: "/home/dev/a.md",
+      text: "C:\\Users\\me\\file.txt",
+      paths: ["C:/Users/me/file.txt"],
+      expected: "C:\\Users\\me\\file.txt",
+    },
+    { name: "alternate extension", path: "/p/docs/a.MDX", paths: ["/p/docs/file"], expected: "[](file)" },
+    { name: "empty list", paths: [], expected: "" },
+    { name: "text path", text: "/p/file.txt", paths: ["/stale"], expected: "/p/file.txt" },
+    { name: "plain text", text: "plain text 你好", paths: [], expected: "plain text 你好" },
+    {
+      name: "file list with matching text flavor",
+      text: "C:\\p\\a.txt\r\nC:\\p\\folder",
+      path: "C:/p/docs/a.md",
+      paths: ["C:/p/a.txt", "C:/p/folder"],
+      expected: "[](../a.txt)\n[](../folder)",
+    },
+  ])(`${route}: Markdown $name`, async ({ path = "/p/docs/a.md", paths, text = "", expected, remote = false }) => {
+    vi.mocked(isRemoteWindow).mockReturnValue(remote);
+    const list = vi.spyOn(commands, "clipboardFileList").mockResolvedValue({ status: "ok", data: paths });
+    const view = new EditorView({
+      extensions: [clipboardDocumentPath.of(path), clipboardFilesExtension],
+      parent: document.body,
+    });
+    views.push(view);
+    const event = new Event("paste", { bubbles: true, cancelable: true });
+    Object.defineProperty(event, "clipboardData", {
+      value: { getData: () => text, files: [], types: ["Files"] },
+    });
+    if (route === "event") {
+      view.contentDOM.dispatchEvent(event);
+    } else {
+      if (route === "menu") {
+        vi.mocked(document.queryCommandSupported).mockReturnValue(true);
+        vi.mocked(document.execCommand).mockImplementation(() => {
+          view.contentDOM.dispatchEvent(event);
+          return true;
+        });
+      }
+      if (route === "menu rejected") vi.mocked(document.queryCommandSupported).mockReturnValue(true);
+      Object.defineProperty(navigator, "clipboard", { configurable: true, value: { readText: async () => text } });
+      await pasteEditorClipboard(view);
+    }
+    await vi.waitFor(() => expect(view.state.doc.toString()).toBe(expected));
+    expect(list).toHaveBeenCalledTimes(remote && text ? 0 : 1);
+    if (route === "menu rejected" && /\.(md|mdx)$/i.test(path)) {
+      expect(document.execCommand).toHaveBeenCalledExactlyOnceWith("paste");
+    }
+  });
+
   it.each([
     { name: "text present", text: "plain", paths: ["/stale"], expected: "plain", calls: 0 },
     { name: "files plus list", text: "", paths: ["/a b", "/中文"], expected: "/a b\n/中文", calls: 1 },
@@ -32,6 +116,7 @@ for (const route of ["event", "menu"]) {
       });
       view.contentDOM.dispatchEvent(event);
     } else {
+      if (route === "menu rejected") vi.mocked(document.queryCommandSupported).mockReturnValue(true);
       Object.defineProperty(navigator, "clipboard", { configurable: true, value: { readText: async () => text } });
       await pasteEditorClipboard(view);
     }
@@ -40,7 +125,35 @@ for (const route of ["event", "menu"]) {
   });
 }
 
-it.each([true, false])("keeps copied PNG and screenshot Markdown image handling (file: %s)", async (hasFile) => {
+it("does not fall back while a successful native paste is still pending", async () => {
+  const readText = vi.fn(async () => "fallback");
+  Object.defineProperty(navigator, "clipboard", { configurable: true, value: { readText } });
+  vi.mocked(document.queryCommandSupported).mockReturnValue(true);
+  vi.mocked(document.execCommand).mockReturnValue(true);
+  const view = new EditorView({
+    extensions: [clipboardDocumentPath.of("/p/a.md"), clipboardFilesExtension],
+    parent: document.body,
+  });
+  views.push(view);
+
+  await pasteEditorClipboard(view);
+  expect(view.state.doc.toString()).toBe("");
+  expect(readText).not.toHaveBeenCalled();
+
+  const event = new Event("paste", { bubbles: true, cancelable: true });
+  Object.defineProperty(event, "clipboardData", {
+    value: { getData: () => "native text", files: [], types: ["text/plain"] },
+  });
+  view.contentDOM.dispatchEvent(event);
+  expect(view.state.doc.toString()).toBe("native text");
+});
+
+it.each([
+  ["event", true],
+  ["event", false],
+  ["menu", true],
+  ["menu", false],
+])("%s: keeps copied PNG and screenshot Markdown image handling (file: %s)", async (route, hasFile) => {
   vi.stubGlobal(
     "Worker",
     class {
@@ -58,6 +171,7 @@ it.each([true, false])("keeps copied PNG and screenshot Markdown image handling
   const create = vi.spyOn(commands, "fsCreateFileBytes").mockResolvedValue({ status: "ok", data: null });
   const view = new EditorView({
     extensions: [
+      clipboardDocumentPath.of("/p/a.md"),
       clipboardFilesExtension,
       markdownImages({ path: "/p/a.md", folder: "assets", pattern: "image-{timestamp}" }),
     ],
@@ -68,7 +182,15 @@ it.each([true, false])("keeps copied PNG and screenshot Markdown image handling
   Object.defineProperty(event, "clipboardData", {
     value: { getData: () => "", files: [new File(["png"], "image.png", { type: "image/png" })], types: ["Files"] },
   });
-  view.contentDOM.dispatchEvent(event);
+  if (route === "menu") {
+    vi.mocked(document.queryCommandSupported).mockReturnValue(true);
+    vi.mocked(document.execCommand).mockImplementation(() => {
+      view.contentDOM.dispatchEvent(event);
+      return true;
+    });
+    await pasteEditorClipboard(view);
+    expect(document.execCommand).toHaveBeenCalledWith("paste");
+  } else view.contentDOM.dispatchEvent(event);
   await vi.waitFor(() => expect(view.state.doc.toString()).toMatch(/^!\[\]\(assets\/image.*\.png\)$/));
   expect(create.mock.calls[0]![0]).toMatch(hasFile ? /assets\/image\.png$/ : /assets\/image-\d{8}-\d{6}\.png$/);
 });

src/editor/core/cm/clipboard.ts

@@ -1,6 +1,17 @@
-import { Prec } from "@codemirror/state";
+import { Facet, Prec } from "@codemirror/state";
 import { EditorView } from "@codemirror/view";
 import { pasteClipboardFiles, readClipboardText } from "@/platform/clipboard";
+import { isRemoteWindow } from "@/platform/remote";
+import { isMarkdown, relativeImagePath } from "./markdownImages";
+
+export const clipboardDocumentPath = Facet.define<string, string>({ combine: (paths) => paths[0] ?? "" });
+
+function clipboardFileFormatter(view: EditorView): ((paths: string[]) => string) | undefined {
+  const path = view.state.facet(clipboardDocumentPath);
+  return isMarkdown(path) && !isRemoteWindow()
+    ? (paths) => paths.map((target) => `[](${relativeImagePath(path, target)})`).join("\n")
+    : undefined;
+}
 
 export function pasteEditorText(view: EditorView, text: string) {
   if (!text || !view.dom.isConnected || view.state.readOnly) return;
@@ -9,8 +20,14 @@ export function pasteEditorText(view: EditorView, text: string) {
 }
 
 export async function pasteEditorClipboard(view: EditorView) {
+  if (!view.dom.isConnected || view.state.readOnly) return;
   try {
-    pasteEditorText(view, await readClipboardText());
+    // Successful native paste preserves image blobs and may complete after execCommand returns.
+    if (isMarkdown(view.state.facet(clipboardDocumentPath)) && document.queryCommandSupported("paste")) {
+      view.focus();
+      if (document.execCommand("paste")) return;
+    }
+    pasteEditorText(view, await readClipboardText(undefined, clipboardFileFormatter(view)));
   } catch {
     if (!view.dom.isConnected || view.state.readOnly) return;
     view.focus();
@@ -23,7 +40,7 @@ export const clipboardFilesExtension = Prec.lowest(
   EditorView.domEventHandlers({
     paste(event, view) {
       if (view.state.readOnly) return false;
-      return pasteClipboardFiles(event, (text) => pasteEditorText(view, text));
+      return pasteClipboardFiles(event, (text) => pasteEditorText(view, text), clipboardFileFormatter(view));
     },
   }),
 );

src/editor/core/cm/setup.ts

@@ -51,7 +51,7 @@ import { editorBaseKeymap } from "./baseKeymap";
 import { occurrenceSearch } from "./editing";
 import { gutterLineDrag } from "./gutterDrag";
 import { overwriteField } from "./overwrite";
-import { clipboardFilesExtension } from "./clipboard";
+import { clipboardDocumentPath, clipboardFilesExtension } from "./clipboard";
 import { clipboardHistoryExtension } from "../clipboardHistory";
 import type { LanguageInfo } from "../backend";
 import { tx } from "@/platform/i18n";
@@ -337,6 +337,7 @@ export function baseExtensions(o: SetupOptions): Extension {
     overwriteField,
     gutterLineDrag,
     clipboardHistoryExtension,
+    clipboardDocumentPath.of(o.ctx.path),
     clipboardFilesExtension,
     indentOnInput(),
     syntaxHighlighting(openideaHighlightStyle),