fix: send long Windows Claude prompts via stdin

apps/desktop/src-tauri/src/claude.rs

@@ -3,7 +3,7 @@ use std::collections::HashMap;
 use std::path::PathBuf;
 use std::sync::Arc;
 use tauri::{Emitter, Manager, WebviewWindow};
-use tokio::io::{AsyncBufReadExt, BufReader};
+use tokio::io::{AsyncBufReadExt, AsyncWriteExt, BufReader};
 use tokio::process::{Child, Command};
 use tokio::sync::Mutex;
 
@@ -785,6 +785,19 @@ fn create_command(
     cmd
 }
 
+fn with_prompt_transport(mut args: Vec<String>, prompt: String) -> (Vec<String>, Option<String>) {
+    args.push("-p".to_string());
+    #[cfg(target_os = "windows")]
+    {
+        (args, Some(prompt))
+    }
+    #[cfg(not(target_os = "windows"))]
+    {
+        args.push(prompt);
+        (args, None)
+    }
+}
+
 // ─── Event payloads (include tab_id for multi-tab routing) ───
 
 #[derive(Clone, serde::Serialize)]
@@ -811,10 +824,15 @@ async fn spawn_claude_process(
     window: WebviewWindow,
     mut cmd: Command,
     tab_id: String,
+    stdin_payload: Option<String>,
 ) -> Result<(), String> {
     let window_label = window.label().to_string();
     let process_key = format!("{}:{}", window_label, tab_id);
 
+    if stdin_payload.is_some() {
+        cmd.stdin(std::process::Stdio::piped());
+    }
+
     // Spawn the process
     let mut child = cmd.spawn().map_err(|e| {
         eprintln!(
@@ -827,6 +845,15 @@ async fn spawn_claude_process(
         )
     })?;
 
+    if let Some(payload) = stdin_payload {
+        if let Some(mut stdin) = child.stdin.take() {
+            tokio::spawn(async move {
+                let _ = stdin.write_all(payload.as_bytes()).await;
+                let _ = stdin.shutdown().await;
+            });
+        }
+    }
+
     let stdout = child.stdout.take().ok_or("Failed to capture stdout")?;
     let stderr = child.stderr.take().ok_or("Failed to capture stderr")?;
 
@@ -1481,7 +1508,7 @@ pub async fn execute_claude_code(
 ) -> Result<(), String> {
     let claude_path = find_claude_binary()?;
 
-    let mut args = vec!["-p".to_string(), prompt];
+    let (mut args, stdin_payload) = with_prompt_transport(Vec::new(), prompt);
     if let Some(m) = model {
         args.push("--model".to_string());
         args.push(m);
@@ -1489,7 +1516,7 @@ pub async fn execute_claude_code(
     args.extend(common_claude_args());
 
     let cmd = create_command(&claude_path, args, &project_path, effort_level.as_deref());
-    spawn_claude_process(window, cmd, tab_id).await
+    spawn_claude_process(window, cmd, tab_id, stdin_payload).await
 }
 
 #[tauri::command]
@@ -1503,7 +1530,7 @@ pub async fn continue_claude_code(
 ) -> Result<(), String> {
     let claude_path = find_claude_binary()?;
 
-    let mut args = vec!["-c".to_string(), "-p".to_string(), prompt];
+    let (mut args, stdin_payload) = with_prompt_transport(vec!["-c".to_string()], prompt);
     if let Some(m) = model {
         args.push("--model".to_string());
         args.push(m);
@@ -1511,7 +1538,7 @@ pub async fn continue_claude_code(
     args.extend(common_claude_args());
 
     let cmd = create_command(&claude_path, args, &project_path, effort_level.as_deref());
-    spawn_claude_process(window, cmd, tab_id).await
+    spawn_claude_process(window, cmd, tab_id, stdin_payload).await
 }
 
 #[tauri::command]
@@ -1526,7 +1553,8 @@ pub async fn resume_claude_code(
 ) -> Result<(), String> {
     let claude_path = find_claude_binary()?;
 
-    let mut args = vec!["--resume".to_string(), session_id, "-p".to_string(), prompt];
+    let (mut args, stdin_payload) =
+        with_prompt_transport(vec!["--resume".to_string(), session_id], prompt);
     if let Some(m) = model {
         args.push("--model".to_string());
         args.push(m);
@@ -1534,7 +1562,7 @@ pub async fn resume_claude_code(
     args.extend(common_claude_args());
 
     let cmd = create_command(&claude_path, args, &project_path, effort_level.as_deref());
-    spawn_claude_process(window, cmd, tab_id).await
+    spawn_claude_process(window, cmd, tab_id, stdin_payload).await
 }
 
 #[tauri::command]
@@ -2012,6 +2040,23 @@ mod tests {
         assert!(prompt.contains("LaTeX"));
     }
 
+    #[test]
+    fn test_with_prompt_transport_always_includes_print_flag() {
+        let (args, stdin_payload) =
+            with_prompt_transport(vec!["--resume".to_string(), "abc".to_string()], "hello 文件".into());
+        assert!(args.contains(&"-p".to_string()));
+        #[cfg(target_os = "windows")]
+        {
+            assert_eq!(stdin_payload.as_deref(), Some("hello 文件"));
+            assert!(!args.contains(&"hello 文件".to_string()));
+        }
+        #[cfg(not(target_os = "windows"))]
+        {
+            assert_eq!(stdin_payload, None);
+            assert_eq!(args.last().map(String::as_str), Some("hello 文件"));
+        }
+    }
+
     // --- create_command ---
 
     #[test]

apps/desktop/src/__tests__/stores/claude-chat-send-prompt.test.ts

@@ -0,0 +1,172 @@
+import { beforeEach, describe, expect, it, vi } from "vitest";
+import { invoke } from "@tauri-apps/api/core";
+
+const { mockDocumentState, getDocumentState, createSnapshotMock } = vi.hoisted(
+  () => ({
+    mockDocumentState: {} as any,
+    getDocumentState: vi.fn(),
+    createSnapshotMock: vi.fn(() => Promise.resolve(null)),
+  }),
+);
+
+vi.mock("@/stores/document-store", () => ({
+  useDocumentStore: {
+    getState: getDocumentState,
+  },
+}));
+
+vi.mock("@/stores/history-store", () => ({
+  useHistoryStore: {
+    getState: vi.fn(() => ({
+      createSnapshot: createSnapshotMock,
+    })),
+  },
+}));
+
+import { useClaudeChatStore } from "@/stores/claude-chat-store";
+
+function resetClaudeChatStore() {
+  useClaudeChatStore.setState({
+    messages: [],
+    sessionId: null,
+    isStreaming: false,
+    error: null,
+    totalInputTokens: 0,
+    totalOutputTokens: 0,
+    tabs: [
+      {
+        id: "tab-default",
+        title: "New Chat",
+        sessionId: null,
+        messages: [],
+        isStreaming: false,
+        error: null,
+        totalInputTokens: 0,
+        totalOutputTokens: 0,
+        draft: { input: "", pinnedContexts: [] },
+      },
+    ],
+    activeTabId: "tab-default",
+    pendingInitialPrompt: null,
+    pendingAttachments: [],
+    selectedModel: "opus",
+    effortLevel: "medium",
+    _cancelledByUser: false,
+  });
+}
+
+function setMockDocumentState(overrides: Partial<any> = {}) {
+  const content = [
+    "Line 1",
+    "Line 2",
+    "Line 3",
+    "Line 4",
+  ].join("\n");
+
+  const state = {
+    projectRoot: "/project",
+    files: [
+      {
+        id: "main.tex",
+        name: "main.tex",
+        relativePath: "main.tex",
+        absolutePath: "/project/main.tex",
+        type: "tex",
+        content,
+        isDirty: false,
+      },
+    ],
+    activeFileId: "main.tex",
+    selectionRange: null,
+    saveAllFiles: vi.fn(() => Promise.resolve()),
+    refreshFiles: vi.fn(() => Promise.resolve()),
+    reloadFile: vi.fn(() => Promise.resolve()),
+    ...overrides,
+  };
+
+  Object.keys(mockDocumentState).forEach((key) => delete mockDocumentState[key]);
+  Object.assign(mockDocumentState, state);
+  getDocumentState.mockImplementation(() => mockDocumentState);
+  return state;
+}
+
+describe("useClaudeChatStore.sendPrompt context assembly", () => {
+  beforeEach(() => {
+    vi.clearAllMocks();
+    resetClaudeChatStore();
+    setMockDocumentState();
+  });
+
+  it("uses a plain file label and full file content for whole-file mentions", async () => {
+    const wholeFileText =
+      "\\section{Intro}\nThis is the full file.\n\\textbf{Important note}";
+
+    await useClaudeChatStore.getState().sendPrompt("Please revise this", {
+      label: "@main.tex",
+      filePath: "main.tex",
+      selectedText: wholeFileText,
+    });
+
+    expect(invoke).toHaveBeenCalledWith(
+      "execute_claude_code",
+      expect.objectContaining({
+        projectPath: "/project",
+        tabId: "tab-default",
+        prompt: expect.stringContaining("[Selection: @main.tex]"),
+      }),
+    );
+
+    const prompt = (vi.mocked(invoke).mock.calls[0]?.[1] as any)?.prompt as string;
+    expect(prompt).toContain("[Currently open file: main.tex]");
+    expect(prompt).toContain("[Selection: @main.tex]");
+    expect(prompt).toContain(wholeFileText);
+
+    const userText =
+      useClaudeChatStore.getState().messages[0].message?.content?.[0].text;
+    expect(userText).toBe("@main.tex\nPlease revise this");
+  });
+
+  it("uses a line-range label and only the selected slice for selection context", async () => {
+    const state = setMockDocumentState({
+      files: [
+        {
+          id: "main.tex",
+          name: "main.tex",
+          relativePath: "main.tex",
+          absolutePath: "/project/main.tex",
+          type: "tex",
+          content: "alpha\nbeta\ngamma\ndelta",
+          isDirty: false,
+        },
+      ],
+      selectionRange: { start: 6, end: 16 },
+    });
+
+    await useClaudeChatStore.getState().sendPrompt("Please revise this");
+
+    expect(invoke).toHaveBeenCalledWith(
+      "execute_claude_code",
+      expect.objectContaining({
+        projectPath: "/project",
+        tabId: "tab-default",
+        prompt: expect.stringContaining("[Selection: @main.tex:2:1-3:6]"),
+      }),
+    );
+
+    const prompt = (vi.mocked(invoke).mock.calls[0]?.[1] as any)?.prompt as string;
+    expect(prompt).toContain("[Currently open file: main.tex]");
+    expect(prompt).toContain("[Selection: @main.tex:2:1-3:6]");
+    expect(prompt).toContain("[Selected text:\nbeta\ngamma\n]");
+    expect(prompt).not.toContain("alpha\na");
+    expect(prompt).not.toContain("\ndelta");
+
+    const userText =
+      useClaudeChatStore.getState().messages[0].message?.content?.[0].text;
+    expect(userText).toBe("@main.tex:2:1-3:6\nPlease revise this");
+    expect(state.saveAllFiles).not.toHaveBeenCalled();
+    expect(createSnapshotMock).toHaveBeenCalledWith(
+      "/project",
+      "[claude] Before Claude edit",
+    );
+  });
+});