ljos 0.29.0

//! A standing choice the person states in chat.
//!
//! "From now on always use bun, never yarn" is the person telling the seat
//! something to keep. The prompt hook saves that sentence, in the person's
//! words, as a standing preference, and says so in one line with the id
//! that takes it back. The person wrote it, so it stands at once: there is
//! no review to wait for.
//!
//! An agent's `ljos remember` of words the person typed in their latest
//! prompt is the same case, so [`said_in_latest_prompt`] lets it stand.
//!
//! `LJOS_CAPTURE` picks what happens: `save` (the default), `nudge` (one
//! line asking the agent to write it), or `off`.

use serde_json::Value;

use super::{
    add_entities, admit, atom_body, mark_seen, pack, pasted_or_quoted, runtime_dir, seen_ids,
    stamp_horizon, with_pack_timeout, HookCall,
};

/// What the prompt hook does with a standing choice it reads.
#[derive(Debug, Clone, Copy, PartialEq, Eq)]
pub enum CaptureMode {
    /// Write it as the person's preference and say so.
    Save,
    /// Ask the agent, in one line, to write it.
    Nudge,
    /// Leave it.
    Off,
}

/// The mode `LJOS_CAPTURE` names. Unset or unknown is [`CaptureMode::Save`].
#[must_use]
pub fn capture_mode() -> CaptureMode {
    match std::env::var("LJOS_CAPTURE")
        .unwrap_or_default()
        .trim()
        .to_ascii_lowercase()
        .as_str()
    {
        "nudge" => CaptureMode::Nudge,
        "off" | "0" | "no" | "false" => CaptureMode::Off,
        _ => CaptureMode::Save,
    }
}

/// A standing choice read from a prompt: what kind of claim it is and the
/// person's sentence.
#[derive(Debug, Clone, PartialEq, Eq)]
pub struct Stated {
    /// `preference`, or `lesson` for "remember that ...".
    pub kind: &'static str,
    pub text: String,
}

/// The longest sentence read as a standing choice. A longer one is a
/// paragraph of context, not a rule.
pub const STATED_MAX_CHARS: usize = 200;

/// Openings that state a standing choice when a clause starts with them.
const LEADS: &[&str] = &[
    "from now on",
    "from here on",
    "henceforth",
    "always ",
    "never ",
    "remember that ",
    "remember to ",
    "do not ever ",
    "don't ever ",
    "dont ever ",
    "make sure to always ",
    "make sure you always ",
    "make sure you never ",
    "i prefer ",
    "we prefer ",
    "we always ",
    "we never ",
    "stop using ",
];

/// Openings that state a standing choice when a comma follows them:
/// "going forward, ..." but not "going forward is ...".
const COMMA_LEADS: &[&str] = &["going forward,", "in future,", "in the future,"];

/// Phrases that make a sentence standing wherever they sit in it.
const ANYWHERE: &[&str] = &["from now on", "from here on", "henceforth"];

/// Phrases that make a sentence standing when they end it: "use bun going
/// forward".
const ENDINGS: &[&str] = &["from now on", "going forward", "in future", "from here on"];

/// Words after "always" or "never" that make it a remark, not a rule:
/// "never mind", "always the same", "never seen this".
const NOT_A_RULE: &[&str] = &[
    "mind", "again", "the", "a", "an", "been", "seen", "heard", "was", "were", "is", "are", "had",
    "did", "worked", "works", "work", "happened", "happens", "thought", "knew", "got", "gets",
    "fails", "failed", "breaks", "broke", "on", "in", "at", "for", "with", "by", "when", "since",
    "before", "after", "really", "quite", "sure", "ever", "once", "seems", "seemed",
];

/// Words that open a sentence and some filler before it.
const FILLER: &[&str] = &[
    "ok", "okay", "so", "also", "and", "btw", "oh", "hey", "note", "fyi", "please", "but",
];

/// Openings of a question that the person did not end with `?`.
const QUESTION_OPENINGS: &[&str] = &[
    "what", "why", "how", "can", "could", "should", "would", "do", "does", "did", "is", "are",
    "will", "which", "who", "where", "when", "was", "were", "shall",
];

/// The prompt's sentences: lines split after `.`, `!` and `?` that a space
/// or the line's end follows. `Cargo.toml` and `e.g.` stay whole.
fn sentences(prompt: &str) -> Vec<String> {
    let mut out = Vec::new();
    for line in prompt.lines() {
        let mut cur = String::new();
        let chars: Vec<char> = line.chars().collect();
        for (i, c) in chars.iter().enumerate() {
            cur.push(*c);
            let ends =
                matches!(c, '.' | '!' | '?') && chars.get(i + 1).is_none_or(|n| n.is_whitespace());
            if ends {
                let s = cur.trim().to_string();
                if !s.is_empty() {
                    out.push(s);
                }
                cur.clear();
            }
        }
        let s = cur.trim().to_string();
        if !s.is_empty() {
            out.push(s);
        }
    }
    out
}

/// `text` with every backtick span blanked, so a lead inside code
/// (`` `--always-retry` ``) does not count.
fn outside_code(text: &str) -> String {
    let mut out = String::with_capacity(text.len());
    let mut inside = false;
    for c in text.chars() {
        if c == '`' {
            inside = !inside;
            out.push(' ');
        } else if inside {
            out.push('x');
        } else {
            out.push(c);
        }
    }
    out
}

/// The sentence with filler words at its front taken off: "ok, from now
/// on ..." reads as "from now on ...".
fn strip_filler(s: &str) -> &str {
    let mut rest = s.trim_start();
    loop {
        let word_end = rest
            .find(|c: char| !c.is_alphanumeric() && c != '\'')
            .unwrap_or(rest.len());
        let word = rest[..word_end].to_ascii_lowercase();
        if word.is_empty() || !FILLER.contains(&word.as_str()) {
            return rest;
        }
        let after = &rest[word_end..];
        let after = after.trim_start_matches(|c: char| c == ',' || c == ':' || c.is_whitespace());
        if after.len() == rest.len() || after.is_empty() {
            return rest;
        }
        rest = after;
    }
}

/// Whether one clause, lowercased, opens with a standing lead.
fn clause_leads(clause: &str) -> bool {
    let c = clause.trim_start();
    LEADS.iter().any(|lead| {
        let Some(rest) = c.strip_prefix(lead) else {
            return false;
        };
        if matches!(*lead, "always " | "never ") {
            let next = rest
                .split(|ch: char| !ch.is_alphanumeric() && ch != '\'')
                .next()
                .unwrap_or("");
            return !next.is_empty() && !NOT_A_RULE.contains(&next);
        }
        true
    })
}

/// Whether a sentence, as typed, states a standing choice.
fn states_a_rule(sentence: &str) -> bool {
    let words = sentence.split_whitespace().count();
    if !(3..=40).contains(&words) || sentence.chars().count() > STATED_MAX_CHARS {
        return false;
    }
    if sentence.trim_end().ends_with('?') {
        return false;
    }
    let plain = outside_code(strip_filler(sentence)).to_lowercase();
    let first = plain
        .split(|c: char| !c.is_alphanumeric() && c != '\'')
        .next()
        .unwrap_or("");
    if QUESTION_OPENINGS.contains(&first) || first == "you" {
        return false;
    }
    let bare = plain.trim_end_matches(|c: char| !c.is_alphanumeric());
    if ANYWHERE.iter().any(|p| plain.contains(p))
        || ENDINGS.iter().any(|p| bare.ends_with(p))
        || COMMA_LEADS
            .iter()
            .any(|p| plain.trim_start().starts_with(p))
    {
        return true;
    }
    plain.split([',', ';']).any(clause_leads)
}

/// The words saved for a stated choice: the sentence with its filler
/// taken off, capitalized. "Remember that X" saves X as a lesson.
fn saved_words(sentence: &str) -> Stated {
    let s = strip_filler(sentence).trim();
    let lower = s.to_lowercase();
    let (kind, body) = match lower.strip_prefix("remember that ") {
        Some(_) => ("lesson", &s["remember that ".len()..]),
        None => ("preference", s),
    };
    let mut chars = body.trim().chars();
    let text = match chars.next() {
        Some(f) => f.to_uppercase().collect::<String>() + chars.as_str(),
        None => String::new(),
    };
    Stated { kind, text }
}

/// The standing choice a prompt states, if it states one: first-person or
/// imperative phrasing such as "from now on", "always", "never", "going
/// forward" or "remember that", outside code and quotes, in a sentence of
/// at most [`STATED_MAX_CHARS`] characters. A question, pasted output and
/// a quoted rule state nothing.
#[must_use]
pub fn stated_preference(prompt: &str) -> Option<Stated> {
    if pasted_or_quoted(prompt) {
        return None;
    }
    sentences(prompt)
        .into_iter()
        .find(|s| states_a_rule(s))
        .map(|s| saved_words(&s))
        .filter(|s| s.text.split_whitespace().count() >= 2)
}

/// Whether `LJOS_UNATTENDED` says no person is at this session: `1`,
/// `true`, `yes` or `on`. An overnight runner or a script driving an agent
/// sets it, and its prompts are then nobody's stated choice.
#[must_use]
pub fn unattended() -> bool {
    std::env::var("LJOS_UNATTENDED").is_ok_and(|v| {
        matches!(
            v.trim().to_ascii_lowercase().as_str(),
            "1" | "true" | "yes" | "on"
        )
    })
}

/// The thread a Codex rollout file is for, from a name such as
/// `rollout-2026-10-11T09-30-00-<uuid>.jsonl`, or `None` for any other
/// name.
fn rollout_thread(path: &str) -> Option<String> {
    let name = path.rsplit(['/', '\\']).next()?;
    let rest = name.strip_prefix("rollout-")?;
    let stem = &rest[..rest.find(".jsonl")?];
    // The stamp is `YYYY-MM-DDTHH-MM-SS-`, twenty characters.
    let id = stem.get(20..56)?;
    let tail = &stem[56..];
    let uuid_shape = id.char_indices().all(|(i, c)| {
        if matches!(i, 8 | 13 | 18 | 23) {
            c == '-'
        } else {
            c.is_ascii_hexdigit()
        }
    });
    (uuid_shape && (tail.is_empty() || tail.starts_with('_'))).then(|| id.to_ascii_lowercase())
}

/// Why a prompt event does not carry the person's words, or `None` when
/// it does. A prompt event is not always typed by a person: Codex fires it
/// inside a subagent, with the brief the parent agent wrote as `prompt`.
/// A spawned agent's payload names it with `agent_id`, as Claude Code's
/// does inside a subagent, and Codex's own review thread names a rollout
/// file for a thread other than the session's. [`unattended`] covers a
/// session with nobody there at all.
#[must_use]
pub fn not_the_person(input: &str) -> Option<&'static str> {
    if unattended() {
        return Some("LJOS_UNATTENDED is set");
    }
    let v: Value = serde_json::from_str(input.trim()).ok()?;
    let named = |key: &str| {
        v.get(key)
            .and_then(Value::as_str)
            .is_some_and(|s| !s.trim().is_empty())
    };
    if named("agent_id") || named("agentId") {
        return Some("a subagent's brief");
    }
    let session = v
        .get("session_id")
        .and_then(Value::as_str)
        .map(|s| s.trim().to_ascii_lowercase())
        .filter(|s| !s.is_empty());
    let thread = v
        .get("transcript_path")
        .and_then(Value::as_str)
        .and_then(rollout_thread);
    match (session, thread) {
        (Some(session), Some(thread)) if session != thread => Some("another thread's prompt"),
        _ => None,
    }
}

/// How long a prompt counts as the latest one for [`said_in_latest_prompt`].
pub const LATEST_PROMPT_SECS: u64 = 3600;

/// The longest prompt kept for [`said_in_latest_prompt`].
const LATEST_PROMPT_CHARS: usize = 8000;

fn latest_prompt_path() -> std::path::PathBuf {
    runtime_dir().join("latest-prompt")
}

/// Keep the person's prompt, so an agent's `ljos remember` of their words
/// can be told from the agent's own lesson. The file sits in the login's
/// runtime directory, readable by its owner only, and each prompt
/// replaces it. Off when [`capture_mode`] is off.
pub fn note_latest_prompt(prompt: &str) {
    if capture_mode() == CaptureMode::Off || pasted_or_quoted(prompt) {
        return;
    }
    let path = latest_prompt_path();
    if let Some(dir) = path.parent() {
        let _ = std::fs::create_dir_all(dir);
    }
    let text: String = prompt.chars().take(LATEST_PROMPT_CHARS).collect();
    use std::io::Write as _;
    use std::os::unix::fs::OpenOptionsExt as _;
    if let Ok(mut f) = std::fs::OpenOptions::new()
        .write(true)
        .create(true)
        .truncate(true)
        .mode(0o600)
        .open(&path)
    {
        let _ = f.write_all(text.as_bytes());
    }
}

/// Lowercase words and nothing else, for comparing a sentence with a
/// prompt whatever their spacing and punctuation.
fn words_only(text: &str) -> String {
    text.split(|c: char| !c.is_alphanumeric() && c != '\'')
        .filter(|w| !w.is_empty())
        .map(str::to_lowercase)
        .collect::<Vec<_>>()
        .join(" ")
}

/// Whether `text` is the person's words: it appears in the prompt they
/// sent last, within [`LATEST_PROMPT_SECS`]. Four words or more, so "use
/// bun" alone is not taken as a quote.
#[must_use]
pub fn said_in_latest_prompt(text: &str) -> bool {
    let want = words_only(text);
    if want.split(' ').count() < 4 {
        return false;
    }
    let path = latest_prompt_path();
    let fresh = std::fs::metadata(&path)
        .and_then(|m| m.modified())
        .ok()
        .and_then(|t| t.elapsed().ok())
        .is_some_and(|age| age.as_secs() <= LATEST_PROMPT_SECS);
    if !fresh {
        return false;
    }
    let Ok(prompt) = std::fs::read_to_string(&path) else {
        return false;
    };
    format!(" {} ", words_only(&prompt)).contains(&format!(" {want} "))
}

/// The session key that keeps one stated choice from being saved twice.
fn capture_key(text: &str) -> String {
    use std::hash::{Hash, Hasher};
    let mut h = std::collections::hash_map::DefaultHasher::new();
    words_only(text).hash(&mut h);
    format!("capture:{:016x}", h.finish())
}

/// How long the prompt hook waits for the pack to take a stated choice.
/// Runners cut a hook off at 10 to 20 s, and the search behind it needs
/// its own share.
pub const CAPTURE_BUDGET_MS: u64 = 3000;

/// Write a stated choice as the person's own claim: origin user, standing,
/// tagged `via:prompt`. The atom the pack answered with.
fn save(stated: &Stated) -> Option<Value> {
    with_pack_timeout(CAPTURE_BUDGET_MS, || {
        let client = pack().ok()?;
        let workspace = client.workspace();
        let mut atom = atom_body(stated.kind, &stated.text, &workspace);
        add_entities(&mut atom, ["via:prompt".to_string()]);
        stamp_horizon(&mut atom, stated.kind, &stated.text, Some(false));
        admit::stamp_origin(&mut atom, admit::ORIGIN_USER);
        let posted = admit::post_kept(&client, &atom).ok()?;
        admit::satisfy_text(&stated.text);
        Some(posted)
    })
}

/// On a prompt that states a standing choice, save it (or nudge, per
/// [`capture_mode`]) and return the one line the note carries and the
/// keys to mark seen when the note is delivered. The saved atom's id is
/// marked seen at once, so the same prompt's note does not repeat it.
#[must_use]
pub fn capture_stated(call: &HookCall) -> Option<(String, Vec<String>)> {
    if call.event != "UserPromptSubmit" {
        return None;
    }
    let mode = capture_mode();
    if mode == CaptureMode::Off {
        return None;
    }
    let stated = stated_preference(&call.cue)?;
    let key = capture_key(&stated.text);
    let session = call.session.as_deref();
    if seen_ids(session).contains(&key) {
        return None;
    }
    let verb = if stated.kind == "lesson" {
        "remember"
    } else {
        "prefer"
    };
    if mode == CaptureMode::Nudge {
        return Some((
            format!(
                "This prompt states a standing choice. Write it in the person's words with `ljos {verb} \"{}\"` so the hook raises it next time.",
                stated.text.replace('"', "'")
            ),
            vec![key],
        ));
    }
    let Some(posted) = save(&stated) else {
        return Some((
            format!(
                "This prompt states a standing choice and the pack did not take it. Write it with `ljos {verb} \"{}\"`.",
                stated.text.replace('"', "'")
            ),
            vec![key],
        ));
    };
    let id = posted["id"].as_str().unwrap_or("").to_string();
    let mut now = vec![key.clone()];
    if !id.is_empty() {
        now.push(id.clone());
    }
    // The correction hook would file the same words as a proposal and say
    // so; the person's words are already saved.
    if let Some(cue) = super::correction_cue(&call.cue) {
        now.push(format!("correction:{cue}"));
        now.push(format!("correction-stored:{cue}"));
    }
    mark_seen(session, &now);
    let what = if stated.kind == "lesson" {
        "lesson"
    } else {
        "preference"
    };
    let undo = if id.is_empty() {
        String::new()
    } else {
        format!(" `ljos forget {id}` takes it back.")
    };
    Some((
        format!(
            "Saved the person's {what} in their words, standing from now: \"{}\".{undo}",
            stated.text
        ),
        vec![key],
    ))
}

#[cfg(test)]
mod tests {
    use super::*;

    const SAVES: &[&str] = &[
        "From now on always use bun, never yarn, in this repo",
        "Always run cargo fmt before committing.",
        "Never push directly to main.",
        "Going forward, write commit messages in the imperative mood.",
        "Please always use pnpm for installs.",
        "Remember that the staging database is read-only on Fridays.",
        "Use bun, never yarn.",
        "From now on, run the linter before every push.",
        "Don't ever commit the .env file.",
        "Never use force push on shared branches.",
        "ok, from now on use tabs in Go files",
        "We always squash merge pull requests here.",
        "Always ask before running a database migration.",
        "In future, put new tests next to the code they cover.",
        "Stop using unwrap in library code.",
        "I prefer small commits with one change each.",
        "Henceforth all scripts use bash strict mode.",
        "Remember to bump the version in Cargo.toml before tagging.",
        "Never deploy on a Friday afternoon.",
        "Keep it short, and from now on skip the summary at the end.",
        "Always write `set -euo pipefail` at the top of shell scripts.",
        "Make sure you always run the tests first.",
        "We never edit an applied migration.",
        "Thanks. From now on use uv instead of pip.",
        "Use rg instead of grep going forward.",
        "Always prefer rtrash over rm.",
        "Never commit secrets to the repo.",
        "Please never run npm install in this project.",
        "From here on, write docs one sentence per line.",
        "Also, always pin action versions by SHA.",
    ];

    const SAVES_NOTHING: &[&str] = &[
        "Why do you always use yarn?",
        "Should we always run the full suite?",
        "Does this ever fail on CI?",
        "Fix the failing test in parser.rs",
        "You never listen to me",
        "It always fails on the second run",
        "Never mind, that was my mistake.",
        "```\nalways_on = true\nnever_retry = false\n```",
        "> Never push directly to main\nwhat does this rule mean",
        "The doc says \"always use bun, never yarn, for this repo\" but is that right",
        "error: always-run hook failed\nwarning: never-again flag set\nerror: exit 1",
        "This could break in the future.",
        "Run the tests and tell me what fails",
        "I always forget how this works, can you explain it",
        "Never seen this error before, what is it",
        "Always the same problem with this build",
        "What's the best way to always keep the cache warm?",
        "Add a flag `--always-retry` to the CLI",
        "Rename never_called to unused in lib.rs",
        "Can you remember that function we wrote yesterday?",
        "It never worked on macOS anyway",
        "Remember when the build broke last week",
        "Is it true that git never forgets a commit",
        "Please look at the failing job",
        "Traceback (most recent call last):\n  File \"a.py\", line 3\nerror: always broken\nwarning: never set",
        "Always?",
        "never",
        "The upstream README says to always use yarn",
        "Explain why we never got the webhook",
        "Going forward is the only option for the migration",
    ];

    /// A Codex subagent's brief, Codex's review thread and an unattended
    /// run are not the person; the root thread's prompt and Claude Code's
    /// main thread are.
    #[test]
    fn a_subagent_brief_or_unattended_run_is_not_the_person() {
        let _g = crate::tests::env_guard();
        unsafe { std::env::remove_var("LJOS_UNATTENDED") };
        let root = "019a1b2c-3d4e-7f80-9a1b-2c3d4e5f6a7b";
        let other = "019a1b2c-3d4e-7f80-9a1b-ffffffffffff";
        let codex = |extra: &str, thread: &str| {
            format!(
                r#"{{"hook_event_name":"UserPromptSubmit","session_id":"{root}","turn_id":"t-1","prompt":"Always run the tests with --release","transcript_path":"/home/u/.codex/sessions/2026/10/11/rollout-2026-10-11T09-30-00-{thread}.jsonl"{extra}}}"#
            )
        };
        assert_eq!(not_the_person(&codex("", root)), None);
        assert_eq!(
            not_the_person(&codex(
                r#","agent_id":"019a-sub","agent_type":"worker""#,
                root
            )),
            Some("a subagent's brief")
        );
        assert_eq!(
            not_the_person(&codex("", other)),
            Some("another thread's prompt")
        );
        let claude_main = r#"{"hook_event_name":"UserPromptSubmit","session_id":"abc","prompt":"From now on use uv","transcript_path":"/home/u/.claude/projects/x/abc.jsonl","agent_type":"reviewer"}"#;
        assert_eq!(
            not_the_person(claude_main),
            None,
            "--agent alone is the main thread"
        );
        let claude_sub =
            claude_main.replace(r#""agent_type""#, r#""agent_id":"sub-1","agent_type""#);
        assert_eq!(not_the_person(&claude_sub), Some("a subagent's brief"));
        unsafe { std::env::set_var("LJOS_UNATTENDED", "1") };
        assert_eq!(not_the_person(claude_main), Some("LJOS_UNATTENDED is set"));
        unsafe { std::env::set_var("LJOS_UNATTENDED", "0") };
        assert_eq!(not_the_person(claude_main), None);
        unsafe { std::env::remove_var("LJOS_UNATTENDED") };
    }

    #[test]
    fn a_rollout_name_gives_its_thread() {
        let id = "019a1b2c-3d4e-7f80-9a1b-2c3d4e5f6a7b";
        assert_eq!(
            rollout_thread(&format!("/x/rollout-2026-10-11T09-30-00-{id}.jsonl")).as_deref(),
            Some(id)
        );
        assert_eq!(
            rollout_thread(&format!("rollout-2026-10-11T09-30-00-{id}_0042.jsonl")).as_deref(),
            Some(id)
        );
        assert_eq!(rollout_thread("/x/abc.jsonl"), None);
        assert_eq!(
            rollout_thread("rollout-2026-10-11T09-30-00-not-a-uuid.jsonl"),
            None
        );
    }

    #[test]
    fn thirty_stated_choices_are_read() {
        assert_eq!(SAVES.len(), 30);
        let missed: Vec<&&str> = SAVES
            .iter()
            .filter(|p| stated_preference(p).is_none())
            .collect();
        assert!(
            missed.is_empty(),
            "not read as a standing choice: {missed:#?}"
        );
    }

    #[test]
    fn thirty_other_prompts_save_nothing() {
        assert_eq!(SAVES_NOTHING.len(), 30);
        let saved: Vec<(&&str, Stated)> = SAVES_NOTHING
            .iter()
            .filter_map(|p| stated_preference(p).map(|s| (p, s)))
            .collect();
        assert!(saved.is_empty(), "read as a standing choice: {saved:#?}");
    }

    #[test]
    fn the_saved_words_are_the_persons_sentence() {
        let s = stated_preference("From now on always use bun, never yarn, in this repo").unwrap();
        assert_eq!(s.kind, "preference");
        assert_eq!(
            s.text,
            "From now on always use bun, never yarn, in this repo"
        );
        let s = stated_preference("ok, from now on use tabs in Go files").unwrap();
        assert_eq!(s.text, "From now on use tabs in Go files");
        let s = stated_preference("Thanks. From now on use uv instead of pip.").unwrap();
        assert_eq!(s.text, "From now on use uv instead of pip.");
        let s = stated_preference("Remember that the staging database is read-only on Fridays.")
            .unwrap();
        assert_eq!(s.kind, "lesson");
        assert_eq!(s.text, "The staging database is read-only on Fridays.");
    }

    #[test]
    fn the_mode_reads_ljos_capture() {
        let _g = crate::tests::env_guard();
        let prev = std::env::var_os("LJOS_CAPTURE");
        for (v, want) in [
            ("", CaptureMode::Save),
            ("save", CaptureMode::Save),
            ("nudge", CaptureMode::Nudge),
            ("off", CaptureMode::Off),
            ("bogus", CaptureMode::Save),
        ] {
            unsafe { std::env::set_var("LJOS_CAPTURE", v) };
            assert_eq!(capture_mode(), want, "{v}");
        }
        match prev {
            Some(v) => unsafe { std::env::set_var("LJOS_CAPTURE", v) },
            None => unsafe { std::env::remove_var("LJOS_CAPTURE") },
        }
    }

    #[test]
    fn words_compare_whatever_the_punctuation() {
        assert_eq!(words_only("Use bun,  never   yarn!"), "use bun never yarn");
    }
}