fix(web): prevent duplicate terminal paste

apps/web/src/terminal/ghostty/surface.test.ts

@@ -4,6 +4,7 @@ import type { GhosttyCell, GhosttyRow } from "./core";
 import {
   DEFAULT_TERMINAL_FONT_FAMILY,
   DEFAULT_TERMINAL_FONT_SIZE,
+  GhosttyTerminalSurface,
   advanceTerminalSelectionClickSequence,
   applyTerminalCopyEvent,
   clearPrimedTerminalCopyInput,
@@ -33,6 +34,25 @@ import {
   terminalWheelDeltaRows,
 } from "./surface";
 
+const terminalSurfaceForPaste = (onData: (data: string) => void) => {
+  const surface = Object.create(GhosttyTerminalSurface.prototype) as GhosttyTerminalSurface;
+  Object.assign(surface, {
+    disposed: false,
+    pasteShortcutToken: 0,
+    options: { onData },
+    core: { encodePaste: (data: string) => `[paste]${data}` },
+  });
+  return surface;
+};
+
+const deferredClipboardText = () => {
+  let resolve: (text: string) => void = () => {};
+  const promise = new Promise<string>((next) => {
+    resolve = next;
+  });
+  return { promise, resolve };
+};
+
 const cell = (text: string): GhosttyCell => ({
   text,
   wide: 0,
@@ -349,6 +369,50 @@ describe("isTerminalPasteShortcut", () => {
   });
 });
 
+describe("GhosttyTerminalSurface paste races", () => {
+  it("lets a keyboard paste supersede a pending context-menu read", async () => {
+    const onData = vi.fn();
+    const surface = terminalSurfaceForPaste(onData);
+    const clipboard = deferredClipboardText();
+    const contextMenuPaste = surface.pasteFromClipboard(() => clipboard.promise);
+
+    surface.paste("keyboard");
+    clipboard.resolve("context menu");
+    await contextMenuPaste;
+
+    expect(onData).toHaveBeenCalledOnce();
+    expect(onData).toHaveBeenCalledWith("[paste]keyboard");
+  });
+
+  it("lets a native paste supersede a pending shortcut read", async () => {
+    const onData = vi.fn();
+    const surface = terminalSurfaceForPaste(onData);
+    const clipboard = deferredClipboardText();
+    const shortcutPaste = surface.pasteFromClipboard(() => clipboard.promise);
+
+    surface.paste("native");
+    clipboard.resolve("shortcut");
+    await shortcutPaste;
+
+    expect(onData).toHaveBeenCalledOnce();
+    expect(onData).toHaveBeenCalledWith("[paste]native");
+  });
+
+  it("keeps a pending clipboard read current after an empty paste", async () => {
+    const onData = vi.fn();
+    const surface = terminalSurfaceForPaste(onData);
+    const clipboard = deferredClipboardText();
+    const shortcutPaste = surface.pasteFromClipboard(() => clipboard.promise);
+
+    surface.paste("");
+    clipboard.resolve("shortcut");
+    await shortcutPaste;
+
+    expect(onData).toHaveBeenCalledOnce();
+    expect(onData).toHaveBeenCalledWith("[paste]shortcut");
+  });
+});
+
 describe("isTerminalCompositionCommitInput", () => {
   it("identifies browser composition follow-up input", () => {
     expect(isTerminalCompositionCommitInput({ inputType: "" })).toBe(true);

apps/web/src/terminal/ghostty/surface.ts

@@ -885,6 +885,12 @@ export class GhosttyTerminalSurface {
     this.input.focus({ preventScroll: true });
   }
 
+  paste(data: string): void {
+    if (this.disposed || data.length === 0) return;
+    this.pasteShortcutToken += 1;
+    this.options.onData(this.core.encodePaste(data));
+  }
+
   /**
    * Pastes clipboard text read by the host (context menu) with the same
    * bracketed-paste encoding as a native paste event. The read joins the same
@@ -899,12 +905,7 @@ export class GhosttyTerminalSurface {
     const token = ++this.pasteShortcutToken;
     const text = await readText();
     if (this.disposed || this.pasteShortcutToken !== token || !isCurrent()) return;
-    // As in every paste path, delivering bumps the token so a clipboard read
-    // still in flight cannot land after this text reaches the shell.
-    this.pasteShortcutToken += 1;
-    if (text.length === 0) return;
-    const encoded = this.core.encodePaste(text);
-    if (encoded.length > 0) this.options.onData(encoded);
+    this.paste(text);
   }
 
   hasSelection(): boolean {
@@ -1077,8 +1078,7 @@ export class GhosttyTerminalSurface {
         void clipboard.readText().then(
           (text) => {
             if (this.disposed || this.pasteShortcutToken !== token) return;
-            this.pasteShortcutToken += 1;
-            if (text.length > 0) this.options.onData(this.core.encodePaste(text));
+            this.paste(text);
           },
           () => {
             // Clipboard read denied; the native paste event remains the path.
@@ -1187,8 +1187,7 @@ export class GhosttyTerminalSurface {
     if (data.length === 0) return;
     // The native paste won the race with actual text; a pending clipboard read
     // must not double. An empty native paste leaves the read as the only path.
-    this.pasteShortcutToken += 1;
-    this.options.onData(this.core.encodePaste(data));
+    this.paste(data);
   };
 
   private readonly onCompositionStart = () => {