if (infos == null || infos.isEmpty()) {
    return "Empty or not a directory: " + path;
}

if (!Files.exists(dirPath) || !Files.isDirectory(dirPath)) {
    return LsResult.success(List.of());
}

String cmd = "for f in " + escapedPath + "/*; do "
    + "  if [ -d \"$f\" ]; then ... "
    + "  elif [ -f \"$f\" ]; then ... "
    + "  fi; "
    + "done 2>/dev/null";

@org.junit.jupiter.api.Disabled(
        "Bug #TODO: LocalFilesystem.ls returns success(empty) for non-existent/file paths")
@Test
void ls_nonExistentPath_shouldReturnFail(@TempDir Path workspace) {
    LocalFilesystem fs = new LocalFilesystem(workspace);
    LsResult r = fs.ls(RuntimeContext.empty(), "/this/path/does/not/exist");
    assertFalse(r.isSuccess(), "ls on non-existent path should fail");
}

@org.junit.jupiter.api.Disabled(
        "Bug #TODO: LocalFilesystem.ls returns success(empty) for file paths")
@Test
void ls_filePath_shouldReturnFail(@TempDir Path workspace) throws IOException {
    Path file = workspace.resolve("foo.txt");
    Files.writeString(file, "content");
    LocalFilesystem fs = new LocalFilesystem(workspace);
    LsResult r = fs.ls(RuntimeContext.empty(), file.toAbsolutePath().toString());
    assertFalse(r.isSuccess(), "ls on a file path should fail");
}

@org.junit.jupiter.api.Disabled(
        "Bug #TODO: BaseSandboxFilesystem.ls shell glob + 2>/dev/null swallows errors")
@Test
void ls_nonExistentPath_shouldReturnFail() {
    LocalShellSandboxFilesystem fs = new LocalShellSandboxFilesystem();
    LsResult r = fs.ls(RT, "/this/path/does/not/exist/at/all");
    assertFalse(r.isSuccess(), "ls on non-existent path should fail");
}

@org.junit.jupiter.api.Disabled(
        "Bug #TODO: BaseSandboxFilesystem.ls shell glob + 2>/dev/null swallows errors")
@Test
void ls_filePath_shouldReturnFail() throws IOException {
    Path file = tmpDir.resolve("file.txt");
    Files.writeString(file, "content");
    LocalShellSandboxFilesystem fs = new LocalShellSandboxFilesystem();
    LsResult r = fs.ls(RT, file.toAbsolutePath().toString());
    assertFalse(r.isSuccess(), "ls on a file path should fail");
}

@org.junit.jupiter.api.Disabled(
        "Bug #TODO: need distinct messages for empty-dir / not-found / not-a-dir")
@Test
void listFiles_ambiguousMessageForNonExistentPath() {
    when(filesystem.ls(RT, "/nonexistent")).thenReturn(LsResult.success(List.of()));
    String result = tool.listFiles(RT, "/nonexistent");
    assertEquals("Empty or not a directory: /nonexistent", result);
}

@org.junit.jupiter.api.Disabled(
        "Bug #TODO: need distinct messages for empty-dir / not-found / not-a-dir")
@Test
void listFiles_ambiguousMessageForFilePath() {
    when(filesystem.ls(RT, "/path/to/file.txt")).thenReturn(LsResult.success(List.of()));
    String result = tool.listFiles(RT, "/path/to/file.txt");
    assertEquals("Empty or not a directory: /path/to/file.txt", result);
}

@org.junit.jupiter.api.Disabled(
        "Bug #TODO: need distinct messages for empty-dir / not-found / not-a-dir")
@Test
void listFiles_ambiguousMessageForEmptyDirectory() {
    when(filesystem.ls(RT, "/empty/dir")).thenReturn(LsResult.success(List.of()));
    String result = tool.listFiles(RT, "/empty/dir");
    assertEquals("Empty or not a directory: /empty/dir", result);
}