diff --git a/crates/tui/src/prompts.rs b/crates/tui/src/prompts.rs index cf70c98f..3cc6f5cf 100644 --- a/crates/tui/src/prompts.rs +++ b/crates/tui/src/prompts.rs @@ -160,6 +160,31 @@ pub(crate) fn locale_reinforcement_preamble(locale_tag: &str) -> Option<&'static } } +/// Locale-native closing reinforcement appended to the very end of the +/// system prompt — the bookend MuMu described in the WeChat thread that +/// prompted #1118 follow-up work. +/// +/// The opening preamble alone is not enough: as the model accumulates +/// English context turn-over-turn (code, error logs, search results, +/// file listings), the recency bias of the transformer's attention +/// drifts thinking back toward English even when the user keeps writing +/// in their own language. A closing native-script reinforcement sits at +/// the position closest to the user's next message — where attention +/// weight is highest — and re-asserts the language rule right before +/// the model generates `reasoning_content` for the turn. +/// +/// Like the opening preamble, English (and unknown) locales return +/// `None` and the system prompt is byte-identical to the pre-bookend +/// behavior. +pub(crate) fn locale_reinforcement_closer(locale_tag: &str) -> Option<&'static str> { + match locale_tag { + "zh-Hans" | "zh-CN" | "zh" => Some(LOCALE_CLOSER_ZH_HANS), + "ja" | "ja-JP" => Some(LOCALE_CLOSER_JA), + "pt-BR" | "pt" => Some(LOCALE_CLOSER_PT_BR), + _ => None, + } +} + const LOCALE_PREAMBLE_ZH_HANS: &str = "## 语言要求\n\n\ 你正在 DeepSeek TUI 中运行。无论任务上下文（代码、错误日志、文件名）\ 是英文，无论系统提示的其余部分是英文，你都必须用简体中文进行 \ @@ -194,6 +219,35 @@ Se o usuário mudar de idioma no meio da sessão, mude no próximo turno. \ Se o usuário pedir explicitamente (por exemplo, \"think in English\"), \ isso sobrescreve esta regra."; +// ── Closing bookends (appended to the very end of the system prompt) ── + +const LOCALE_CLOSER_ZH_HANS: &str = "## 语言再次提醒\n\n\ +**重要：你的 `reasoning_content`（内部思考）和最终回复必须保持简体中文。** \ +无论你在这次会话中读到了多少英文代码、错误日志或文档，无论项目上下文 \ +是英文，思考过程不能漂移到英文。这是会话级硬性要求 —— 用户的语言决定 \ +你的语言，与上下文中累积的英文内容无关。除非用户明确要求切换（例如 \ +\"think in English\"），否则继续用简体中文思考和回答。"; + +const LOCALE_CLOSER_JA: &str = "## 言語再確認\n\n\ +**重要：`reasoning_content`（内部思考）と最終的な返信は日本語で行ってください。** \ +このセッションで読み込んだ英語のコード、エラーログ、ドキュメントの量に \ +関係なく、プロジェクトコンテキストが英語であっても、思考プロセスを \ +英語に逸らさないでください。これはセッションレベルの厳格な要件であり、 \ +ユーザーの言語があなたの言語を決定します。ユーザーが明示的に切り替えを \ +要求しない限り（例：\"think in English\"）、日本語で思考し、回答し続けて \ +ください。"; + +const LOCALE_CLOSER_PT_BR: &str = "## Reforço de Idioma\n\n\ +**Importante: seu `reasoning_content` (pensamento interno) e a resposta \ +final devem permanecer em português do Brasil.** Independentemente de \ +quanto código em inglês, logs de erro ou documentação você ler nesta \ +sessão, e independentemente de o contexto do projeto ser em inglês, o \ +processo de pensamento não pode derivar para o inglês. Este é um \ +requisito rígido em nível de sessão — o idioma do usuário define seu \ +idioma. A menos que o usuário peça explicitamente a troca (por exemplo, \ +\"think in English\"), continue pensando e respondendo em português do \ +Brasil."; + /// Personality overlays — voice and tone. pub const CALM_PERSONALITY: &str = include_str!("prompts/personalities/calm.md"); pub const PLAYFUL_PERSONALITY: &str = include_str!("prompts/personalities/playful.md"); @@ -553,6 +607,21 @@ pub fn system_prompt_for_mode_with_context_skills_session_and_approval( full_prompt = format!("{full_prompt}\n\n{handoff_block}"); } + // 7. Locale-native closing reinforcement (#1118 follow-up #2). The + // opening preamble alone wasn't enough — community feedback (the + // WeChat thread about XML-tagged bilingual bookends) flagged that as + // English context accumulates turn-over-turn, the model's recency + // bias pulls thinking back to English. Putting the same directive at + // the END of the system prompt — right before the user's next + // message — uses recency bias *in our favor*: the model sees the + // native-script "keep thinking in Chinese / Japanese / Portuguese" + // rule immediately before it generates `reasoning_content` for the + // turn. English (and unknown) locales return `None` and the prompt + // stays byte-identical to the pre-bookend behavior. + if let Some(closer) = locale_reinforcement_closer(session_context.locale_tag) { + full_prompt = format!("{full_prompt}\n\n{closer}"); + } + SystemPrompt::Text(full_prompt) } @@ -696,6 +765,81 @@ mod tests { ); } + #[test] + fn locale_reinforcement_closer_returns_native_script_for_supported_locales() { + // English (and unknown locales) get None. + assert!(locale_reinforcement_closer("en").is_none()); + assert!(locale_reinforcement_closer("fr-FR").is_none()); + assert!(locale_reinforcement_closer("").is_none()); + + // Each supported locale gets a closer in its own script that + // explicitly tells the model "don't drift to English even as + // English context accumulates" — that's the load-bearing claim + // behind the bookend pattern. + let zh = locale_reinforcement_closer("zh-Hans").expect("zh closer"); + assert!( + zh.contains("简体中文"), + "zh closer must be in Simplified Chinese" + ); + assert!( + zh.contains("reasoning_content"), + "zh closer must steer reasoning_content" + ); + let ja = locale_reinforcement_closer("ja").expect("ja closer"); + assert!(ja.contains("日本語"), "ja closer must be in Japanese"); + assert!(ja.contains("reasoning_content")); + let pt = locale_reinforcement_closer("pt-BR").expect("pt-BR closer"); + assert!(pt.contains("português do Brasil")); + assert!(pt.contains("reasoning_content")); + } + + #[test] + fn system_prompt_bookends_zh_hans_with_preamble_and_closer() { + // The full system prompt for zh-Hans must contain BOTH the + // opening preamble (`## 语言要求`) and the closing reinforcement + // (`## 语言再次提醒`), with the closer appearing AFTER the + // preamble — i.e. the prompt is "bookended" in native script, + // matching the empirical finding from the WeChat thread that + // motivated the closer. + let tmp = tempdir().expect("tempdir"); + let text = match system_prompt_for_mode_with_context_skills_session_and_approval( + AppMode::Agent, + tmp.path(), + None, + None, + None, + PromptSessionContext { + user_memory_block: None, + goal_objective: None, + project_context_pack_enabled: false, + locale_tag: "zh-Hans", + }, + ApprovalMode::Suggest, + ) { + SystemPrompt::Text(text) => text, + SystemPrompt::Blocks(_) => panic!("expected text system prompt"), + }; + let preamble_pos = text + .find("## 语言要求") + .expect("zh-Hans preamble must be in prompt"); + let closer_pos = text + .find("## 语言再次提醒") + .expect("zh-Hans closer must be in prompt"); + assert!( + preamble_pos < closer_pos, + "closer must come after preamble (preamble={preamble_pos}, closer={closer_pos})", + ); + // The closer must be the very last block — anything else after + // it defeats the recency-bias purpose. Skip the closer's own + // `## ` header before scanning. + let closer_header_end = closer_pos + "## 语言再次提醒".len(); + let after_closer_body = &text[closer_header_end..]; + assert!( + !after_closer_body.contains("\n## "), + "no other top-level section should follow the closer; got: {after_closer_body:?}", + ); + } + #[test] fn system_prompt_skips_locale_preamble_for_english() { // English locale → no preamble injected. Asserts the @@ -730,6 +874,19 @@ mod tests { !text.contains("Requisito de Idioma"), "English locale must not get a pt-BR preamble: {text:?}" ); + // Closer too — same bookend rule. + assert!( + !text.contains("语言再次提醒"), + "English locale must not get a zh closer: {text:?}" + ); + assert!( + !text.contains("言語再確認"), + "English locale must not get a ja closer: {text:?}" + ); + assert!( + !text.contains("Reforço de Idioma"), + "English locale must not get a pt-BR closer: {text:?}" + ); } #[test]