scope_cli/cli/

resolve.rs

//! One resolver for every command that takes a token symbol
//! (docs/design/2026-10-15-token-disambiguation-design.md).
//!
//! Steps: `--token` → an address → a saved binding (checked against a CEX
//! venue's coin list) → the candidates → 0 stops, 1 is used, more go to
//! the picker → the save question. It never chooses silently.

use crate::cli::output::Output;
use crate::note;
use scope::error::{Result, ScopeError};
use scope::market::assets::chain_for_network;
use scope::tokens::{TokenAliases, TokenInfo};
use std::path::Path;

/// One token a symbol could mean.
#[derive(Debug, Clone, PartialEq)]
pub struct Candidate {
    pub symbol: String,
    pub name: String,
    /// The chain, or the venue's network name for a CEX candidate.
    pub chain: String,
    /// The contract; `None` for a native coin or an unknown contract.
    pub address: Option<String>,
    pub price_usd: Option<f64>,
    pub liquidity_usd: Option<f64>,
}

/// Where the command reads its market data.
#[derive(Debug, Clone, PartialEq, Eq)]
pub enum VenueKind {
    Dex,
    /// A CEX venue, by id.
    Cex(String),
}

/// What the command knows before the lookup.
#[derive(Debug, Clone)]
pub struct ResolveContext {
    /// The chain filter, when the user set one.
    pub chain: Option<String>,
    pub venue: VenueKind,
    /// `--token <contract>`.
    pub token_flag: Option<String>,
    /// `--yes`: no save question; an ambiguous symbol stops.
    pub yes: bool,
    /// `--save`: save the choice without a question.
    pub save: bool,
}

/// How the token was chosen.
#[derive(Debug, Clone, Copy, PartialEq, Eq)]
pub enum Source {
    Flag,
    Address,
    Binding,
    Single,
    Picked {
        saved: bool,
    },
    /// A CEX venue that does not list contracts: the symbol is used as is.
    Unchecked,
}

/// The token a command uses.
#[derive(Debug, Clone, PartialEq)]
pub struct Resolved {
    pub symbol: String,
    pub name: String,
    pub chain: String,
    pub address: Option<String>,
    pub source: Source,
}

/// Where candidates come from: a DEX search or a venue's coin list.
#[async_trait::async_trait]
pub trait CandidateSource: Send + Sync {
    async fn candidates(&self, symbol: &str, chain: Option<&str>) -> Result<Vec<Candidate>>;
    /// What was searched, for a "not found" error.
    fn searched(&self, chain: Option<&str>) -> String;
    /// False for a CEX venue without a coin list: its symbols cannot be
    /// checked against contracts.
    fn lists_contracts(&self) -> bool {
        true
    }
}

/// Asks the user to choose.
#[async_trait::async_trait]
pub trait Picker: Send + Sync {
    /// The index of the chosen candidate.
    async fn pick(&self, input: &str, candidates: &[Candidate]) -> Result<usize>;
    /// The answer to a yes/no question.
    async fn confirm(&self, question: &str) -> Result<bool>;
}

/// The saved bindings.
pub trait BindingStore: Send {
    fn get(&self, symbol: &str, chain: Option<&str>) -> Option<TokenInfo>;
    /// Every saved binding for `symbol`, on any chain.
    fn all(&self, symbol: &str) -> Vec<TokenInfo>;
    fn save(&mut self, candidate: &Candidate, venue: Option<&str>) -> Result<()>;
}

/// One line for a candidate in lists and errors: chain, contract, name.
pub fn candidate_line(c: &Candidate) -> String {
    format!(
        "{} {} {}",
        c.chain,
        c.address.as_deref().unwrap_or("native"),
        c.name
    )
}

/// Two contracts are the same token: EVM hex compares without case.
fn same_contract(a: &str, b: &str) -> bool {
    if a.starts_with("0x") && b.starts_with("0x") {
        a.eq_ignore_ascii_case(b)
    } else {
        a == b
    }
}

/// A DexScreener search result as a candidate. An empty address (the CEX
/// ticker fallback) is a token without a contract.
pub(crate) fn dex_candidate(r: &scope::chains::dex::TokenSearchResult) -> Candidate {
    Candidate {
        symbol: r.symbol.clone(),
        name: r.name.clone(),
        chain: r.chain.clone(),
        address: (!r.address.is_empty()).then(|| r.address.clone()),
        price_usd: r.price_usd,
        liquidity_usd: Some(r.liquidity_usd),
    }
}

/// The venue's networks for `symbol`, one candidate each.
pub(crate) fn venue_candidates_from(
    symbol: &str,
    assets: &[scope::market::assets::AssetInfo],
) -> Vec<Candidate> {
    assets
        .iter()
        .filter(|a| a.symbol.eq_ignore_ascii_case(symbol))
        .flat_map(|a| {
            a.networks.iter().map(|n| Candidate {
                symbol: a.symbol.clone(),
                name: a.symbol.clone(),
                chain: n.network.clone(),
                address: n.contract.clone(),
                price_usd: None,
                liquidity_usd: None,
            })
        })
        .collect()
}

/// Candidates from a DexScreener search, with the CEX ticker fallback when
/// `fallback` (its transport) is set and the search finds nothing.
pub struct DexCandidates<'a> {
    pub dex: &'a dyn scope::chains::DexDataSource,
    pub out: &'a Output,
    pub fallback: Option<std::sync::Arc<dyn scope::http::HttpClient>>,
}

#[async_trait::async_trait]
impl CandidateSource for DexCandidates<'_> {
    async fn candidates(&self, symbol: &str, chain: Option<&str>) -> Result<Vec<Candidate>> {
        let mut found = self.dex.search_tokens(symbol, chain).await?;
        // A set chain is a guarantee: never offer a token from another one.
        if let Some(chain) = chain {
            found.retain(|r| chain_for_network(&r.chain) == chain_for_network(chain));
        }
        if found.is_empty()
            && let Some(http) = &self.fallback
            && let Some(f) = crate::cli::token_pick::cex_fallback(
                symbol,
                chain.unwrap_or("ethereum"),
                None,
                http.clone(),
                self.out,
            )
            .await
        {
            found.push(f);
        }
        Ok(found.iter().map(dex_candidate).collect())
    }

    fn searched(&self, chain: Option<&str>) -> String {
        format!(
            "DexScreener on {}{}",
            chain.unwrap_or("all chains"),
            if self.fallback.is_some() {
                " and the CEX ticker fallback"
            } else {
                ""
            }
        )
    }
}

/// Candidates from a CEX venue's coin list (the `assets` capability).
pub struct VenueCandidates<'a> {
    pub client: &'a scope::market::ExchangeClient,
}

#[async_trait::async_trait]
impl CandidateSource for VenueCandidates<'_> {
    async fn candidates(&self, symbol: &str, _chain: Option<&str>) -> Result<Vec<Candidate>> {
        match self.client.fetch_assets().await {
            Some(assets) => Ok(venue_candidates_from(symbol, &assets?)),
            // No `assets` capability: the venue symbol is all that is known.
            None => Ok(vec![Candidate {
                symbol: symbol.to_uppercase(),
                name: symbol.to_uppercase(),
                chain: String::new(),
                address: None,
                price_usd: None,
                liquidity_usd: None,
            }]),
        }
    }

    fn searched(&self, _chain: Option<&str>) -> String {
        format!("the {} coin list", self.client.venue_id())
    }

    fn lists_contracts(&self) -> bool {
        self.client.lists_assets()
    }
}

impl BindingStore for TokenAliases {
    fn get(&self, symbol: &str, chain: Option<&str>) -> Option<TokenInfo> {
        TokenAliases::get(self, symbol, chain).cloned()
    }

    fn all(&self, symbol: &str) -> Vec<TokenInfo> {
        let mut chains = self.get_chains_for_alias(symbol);
        chains.sort_unstable();
        chains
            .into_iter()
            .filter_map(|c| TokenAliases::get(self, symbol, Some(c)).cloned())
            .collect()
    }

    fn save(&mut self, c: &Candidate, venue: Option<&str>) -> Result<()> {
        let address = c.address.as_deref().unwrap_or("");
        self.add_binding(&c.symbol, &c.chain, address, &c.name, venue);
        TokenAliases::save(self)
    }
}

/// Asks on the terminal: the numbered token list, then yes/no.
pub struct TerminalPicker<'a> {
    pub out: &'a Output,
}

#[async_trait::async_trait]
impl Picker for TerminalPicker<'_> {
    async fn pick(&self, _input: &str, cs: &[Candidate]) -> Result<usize> {
        let table = crate::cli::token_pick::candidate_table(cs);
        let mut input = crate::cli::prompt::stdin();
        crate::cli::prompt::pick(&mut input, self.out, &table, "token", cs.len())
    }

    async fn confirm(&self, question: &str) -> Result<bool> {
        confirm_from(&mut crate::cli::prompt::stdin(), self.out, question)
    }
}

/// Asks `question` and reads the answer from `reader`: yes for `y` or
/// `yes` in any case, no for anything else.
fn confirm_from(reader: &mut impl std::io::BufRead, out: &Output, question: &str) -> Result<bool> {
    let answer = crate::cli::prompt::ask(reader, out, question)?;
    Ok(matches!(
        answer.trim().to_ascii_lowercase().as_str(),
        "y" | "yes"
    ))
}

/// Asks in the TUI: puts the question in the pane's ask slot and waits for
/// the list's answer.
pub struct TuiPicker {
    pub asker: crate::cli::output::Asker,
}

impl TuiPicker {
    /// Asks the TUI `prompt` with `options` in its list; `None` on cancel.
    pub(crate) async fn ask(&self, prompt: String, options: Vec<String>) -> Option<usize> {
        let (reply, answer) = tokio::sync::oneshot::channel();
        let mut ask = Some(crate::cli::output::Ask {
            prompt,
            options,
            reply,
        });
        // One question at a time: wait until the slot is free. The lock
        // is held only inside the block, never across an await.
        while ask.is_some() {
            let placed = {
                let mut slot = self.asker.lock().unwrap_or_else(|e| e.into_inner());
                if slot.is_none() {
                    *slot = ask.take();
                    true
                } else {
                    false
                }
            };
            if !placed {
                // A pause, not a yield: a yield wakes the TUI's task at
                // once, and it would spin until the open question is
                // answered.
                tokio::time::sleep(std::time::Duration::from_millis(20)).await;
            }
        }
        answer.await.ok().flatten()
    }
}

#[async_trait::async_trait]
impl Picker for TuiPicker {
    async fn pick(&self, input: &str, cs: &[Candidate]) -> Result<usize> {
        let prompt = format!("'{input}' matches more than one token. Choose one:");
        self.ask(prompt, cs.iter().map(candidate_line).collect())
            .await
            .ok_or_else(|| {
                ScopeError::Other(format!("Choosing a token for '{input}' was cancelled."))
            })
    }

    async fn confirm(&self, question: &str) -> Result<bool> {
        // The list is the answer: the terminal's "[y/N]: " does not apply.
        let prompt = question
            .trim_end_matches([' ', ':'])
            .trim_end_matches("[y/N]")
            .trim_end()
            .to_string();
        let options = vec!["No".to_string(), "Yes".to_string()];
        Ok(self.ask(prompt, options).await == Some(1))
    }
}

/// Never asks: a choice is an error that lists the candidates.
pub struct NoTerminalPicker;

#[async_trait::async_trait]
impl Picker for NoTerminalPicker {
    async fn pick(&self, input: &str, cs: &[Candidate]) -> Result<usize> {
        Err(ScopeError::AmbiguousToken {
            input: input.to_string(),
            candidates: cs.iter().map(candidate_line).collect(),
        })
    }

    async fn confirm(&self, _question: &str) -> Result<bool> {
        Ok(false)
    }
}

/// The picker for this run: never for JSON output; the TUI's list when
/// the TUI pane shows the output; no prompt in a server or without a
/// terminal; else the terminal.
pub fn picker_for<'a>(out: &'a Output, json: bool) -> Box<dyn Picker + 'a> {
    use std::io::IsTerminal as _;
    if json {
        return Box::new(NoTerminalPicker);
    }
    if let Some(asker) = out.asker() {
        return Box::new(TuiPicker { asker });
    }
    let terminal = std::io::stdin().is_terminal() && std::io::stdout().is_terminal();
    if !out.prompts_allowed() || !terminal {
        Box::new(NoTerminalPicker)
    } else {
        Box::new(TerminalPicker { out })
    }
}

/// [`resolve_logged`] with the log in the scope state folder.
pub async fn resolve(
    input: &str,
    ctx: &ResolveContext,
    source: &dyn CandidateSource,
    picker: &dyn Picker,
    store: &mut dyn BindingStore,
    out: &Output,
) -> Result<Resolved> {
    let log = scope::paths::state_dir().join("resolutions.jsonl");
    resolve_logged(input, ctx, source, picker, store, out, &log).await
}

/// Resolves `input`, then appends one line to `log` (the RCA trail). A
/// log failure is a warning.
pub async fn resolve_logged(
    input: &str,
    ctx: &ResolveContext,
    source: &dyn CandidateSource,
    picker: &dyn Picker,
    store: &mut dyn BindingStore,
    out: &Output,
    log: &Path,
) -> Result<Resolved> {
    let mut seen = Vec::new();
    let result = steps(input, ctx, source, picker, store, out, &mut seen).await;
    if let Err(e) = write_log(log, input, ctx, &seen, &result) {
        tracing::warn!("cannot write {}: {e}", log.display());
    }
    result
}

async fn steps(
    input: &str,
    ctx: &ResolveContext,
    source: &dyn CandidateSource,
    picker: &dyn Picker,
    store: &mut dyn BindingStore,
    out: &Output,
    seen: &mut Vec<Candidate>,
) -> Result<Resolved> {
    let symbol = input.trim().to_uppercase();
    // With no chain set, an address names its chain where its format
    // does, for `--token` as for a positional address (#108).
    let direct = |address: &str, source: Source| Resolved {
        symbol: symbol.clone(),
        name: symbol.clone(),
        chain: ctx.chain.clone().unwrap_or_else(|| {
            scope::chains::infer_chain_from_address(address)
                .unwrap_or_default()
                .to_string()
        }),
        address: Some(address.to_string()),
        source,
    };
    // 1. --token, 2. an address
    if let Some(flag) = &ctx.token_flag {
        return Ok(direct(flag, Source::Flag));
    }
    if TokenAliases::is_address(input.trim()) {
        return Ok(direct(input.trim(), Source::Address));
    }
    // 3. a saved binding, checked against a CEX venue's coin list. With
    // no chain and bindings on several chains, they are the choice.
    let saved = match ctx.chain.as_deref() {
        None => {
            let all = store.all(&symbol);
            if all.len() > 1 {
                let options: Vec<Candidate> = all.iter().map(binding_candidate).collect();
                *seen = options.clone();
                if ctx.yes {
                    return Err(ScopeError::AmbiguousToken {
                        input: input.to_string(),
                        candidates: options.iter().map(candidate_line).collect(),
                    });
                }
                Some(all[picker.pick(input, &options).await?].clone())
            } else {
                all.into_iter().next()
            }
        }
        Some(chain) => store.get(&symbol, Some(chain)),
    };
    if let Some(saved) = saved {
        if let VenueKind::Cex(venue) = &ctx.venue {
            check_binding(&symbol, &saved, venue, source, out, seen).await?;
        }
        note!(
            out,
            "Using your saved {symbol}: {} {}",
            saved.chain,
            binding_label(&saved)
        );
        let address = binding_contract(&saved).map(str::to_string);
        return Ok(Resolved {
            symbol,
            name: saved.name,
            chain: saved.chain,
            address,
            source: Source::Binding,
        });
    }
    // A venue without a coin list: nothing to choose from or check.
    if !source.lists_contracts() {
        return Ok(Resolved {
            symbol: symbol.clone(),
            name: symbol,
            chain: ctx.chain.clone().unwrap_or_default(),
            address: None,
            source: Source::Unchecked,
        });
    }
    // 4. the candidates: exact symbols, or the exact contract when the
    // input is one that is not in a known address format
    let candidates: Vec<Candidate> = source
        .candidates(&symbol, ctx.chain.as_deref())
        .await?
        .into_iter()
        .filter(|c| {
            c.symbol.eq_ignore_ascii_case(&symbol)
                || c.address
                    .as_deref()
                    .is_some_and(|a| a.eq_ignore_ascii_case(input.trim()))
        })
        .collect();
    *seen = candidates.clone();
    // 5. none, one, or a choice
    let chosen = match candidates.len() {
        0 => {
            return Err(ScopeError::TokenNotFound {
                input: input.to_string(),
                searched: source.searched(ctx.chain.as_deref()),
            });
        }
        1 => {
            note!(out, "Using {}", candidate_line(&candidates[0]));
            if ctx.save {
                save_choice(store, &candidates[0], &ctx.venue, &symbol, out);
            }
            return Ok(resolved_from(&candidates[0], Source::Single));
        }
        _ if ctx.yes => {
            return Err(ScopeError::AmbiguousToken {
                input: input.to_string(),
                candidates: candidates.iter().map(candidate_line).collect(),
            });
        }
        _ => &candidates[picker.pick(input, &candidates).await?],
    };
    // 6. the save question
    let chain = chain_for_network(&chosen.chain);
    let contract = chosen.address.as_deref().unwrap_or(NATIVE_COIN);
    let save = ctx.save
        || picker
            .confirm(&format!(
                "Save so {symbol} always means {contract} on {chain}? [y/N]: "
            ))
            .await?;
    let saved = save && save_choice(store, chosen, &ctx.venue, &symbol, out);
    Ok(resolved_from(chosen, Source::Picked { saved }))
}

/// Saves `chosen` under its scope chain name. A failure is a note: the
/// token is already chosen, so the command goes on.
fn save_choice(
    store: &mut dyn BindingStore,
    chosen: &Candidate,
    venue: &VenueKind,
    symbol: &str,
    out: &Output,
) -> bool {
    let mut binding = chosen.clone();
    binding.chain = chain_for_network(&chosen.chain);
    let venue = match venue {
        VenueKind::Cex(v) => Some(v.as_str()),
        VenueKind::Dex => None,
    };
    match store.save(&binding, venue) {
        Ok(()) => {
            note!(
                out,
                "Saved: {symbol} means {} on {}.",
                binding.address.as_deref().unwrap_or(NATIVE_COIN),
                binding.chain
            );
            true
        }
        Err(e) => {
            note!(out, "{symbol}: your choice was not saved ({e}).");
            false
        }
    }
}

/// A saved binding's contract. A native coin (a CEX pick with no
/// contract) is saved with an empty address and has none (#108).
fn binding_contract(t: &TokenInfo) -> Option<&str> {
    (!t.address.is_empty()).then_some(t.address.as_str())
}

/// A saved binding's contract for a message, or "its native coin".
fn binding_label(t: &TokenInfo) -> &str {
    binding_contract(t).unwrap_or(NATIVE_COIN)
}

/// How a message names a token with no contract.
const NATIVE_COIN: &str = "its native coin";

/// A saved binding as a candidate, for a choice between bindings.
fn binding_candidate(t: &TokenInfo) -> Candidate {
    Candidate {
        symbol: t.symbol.clone(),
        name: t.name.clone(),
        chain: t.chain.clone(),
        address: binding_contract(t).map(str::to_string),
        price_usd: None,
        liquidity_usd: None,
    }
}

/// Checks `saved` against a CEX venue's coin list: a different contract,
/// or the symbol listed only on other networks, stops. A venue without a
/// list, or a failed fetch, gives a note.
async fn check_binding(
    symbol: &str,
    saved: &TokenInfo,
    venue: &str,
    source: &dyn CandidateSource,
    out: &Output,
    seen: &mut Vec<Candidate>,
) -> Result<()> {
    if !source.lists_contracts() {
        note!(
            out,
            "{symbol}: {venue} does not list contracts, so your saved token cannot be checked."
        );
        return Ok(());
    }
    let listed = match source.candidates(symbol, None).await {
        Ok(listed) => listed,
        Err(e) => {
            note!(
                out,
                "{symbol}: {venue} could not be checked ({e}); using your saved token."
            );
            return Ok(());
        }
    };
    *seen = listed.clone();
    if listed.is_empty() {
        return Ok(());
    }
    let mismatch = |venue_contract: String| ScopeError::TokenMismatch {
        symbol: symbol.to_string(),
        chain: saved.chain.clone(),
        saved: binding_label(saved).to_string(),
        venue_contract,
        venue: venue.to_string(),
    };
    match listed
        .iter()
        .find(|c| chain_for_network(&c.chain) == saved.chain)
    {
        Some(c) => match (&c.address, binding_contract(saved)) {
            (Some(contract), Some(saved)) if !same_contract(contract, saved) => {
                Err(mismatch(contract.clone()))
            }
            // A saved native coin that the venue lists as a contract.
            (Some(contract), None) => Err(mismatch(contract.clone())),
            _ => Ok(()),
        },
        None => {
            let networks: Vec<&str> = listed.iter().map(|c| c.chain.as_str()).collect();
            Err(mismatch(format!(
                "no {symbol} on {} (it lists {})",
                saved.chain,
                networks.join(", ")
            )))
        }
    }
}

fn resolved_from(c: &Candidate, source: Source) -> Resolved {
    Resolved {
        symbol: c.symbol.to_uppercase(),
        name: c.name.clone(),
        chain: chain_for_network(&c.chain),
        address: c.address.clone(),
        source,
    }
}

fn write_log(
    log: &Path,
    input: &str,
    ctx: &ResolveContext,
    seen: &[Candidate],
    result: &Result<Resolved>,
) -> std::io::Result<()> {
    use std::io::Write as _;
    if let Some(dir) = log.parent() {
        std::fs::create_dir_all(dir)?;
    }
    let venue = match &ctx.venue {
        VenueKind::Dex => "dex".to_string(),
        VenueKind::Cex(v) => v.clone(),
    };
    let mut line = serde_json::json!({
        "at": chrono::Utc::now().to_rfc3339(),
        "input": input,
        "chain": ctx.chain,
        "venue": venue,
        "candidates": seen.iter().map(candidate_line).collect::<Vec<_>>(),
    });
    match result {
        Ok(r) => {
            line["chosen"] = serde_json::json!(r.address);
            line["source"] = serde_json::json!(match r.source {
                Source::Flag => "flag",
                Source::Address => "address",
                Source::Binding => "binding",
                Source::Single => "single",
                Source::Picked { .. } => "picked",
                Source::Unchecked => "unchecked",
            });
            line["saved"] = serde_json::json!(matches!(r.source, Source::Picked { saved: true }));
        }
        Err(e) => line["error"] = serde_json::json!(e.to_string()),
    }
    let mut f = std::fs::OpenOptions::new()
        .create(true)
        .append(true)
        .open(log)?;
    writeln!(f, "{line}")
}

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

    fn c(chain: &str, address: &str) -> Candidate {
        Candidate {
            symbol: "USDN".into(),
            name: "USDN".into(),
            chain: chain.into(),
            address: Some(address.into()),
            price_usd: None,
            liquidity_usd: None,
        }
    }

    struct Fake(std::result::Result<Vec<Candidate>, String>);
    #[async_trait::async_trait]
    impl CandidateSource for Fake {
        async fn candidates(&self, _s: &str, _c: Option<&str>) -> Result<Vec<Candidate>> {
            match &self.0 {
                Ok(v) => Ok(v.clone()),
                Err(e) => Err(ScopeError::Network(e.clone())),
            }
        }
        fn searched(&self, _c: Option<&str>) -> String {
            "the fake source".into()
        }
    }

    /// Answers with `pick` and `confirm`, and records what it was asked.
    struct Scripted {
        pick: Option<usize>,
        confirm: bool,
        asked: Mutex<Vec<String>>,
    }
    impl Scripted {
        fn new(pick: Option<usize>, confirm: bool) -> Self {
            Self {
                pick,
                confirm,
                asked: Mutex::new(Vec::new()),
            }
        }
        fn asked(&self) -> Vec<String> {
            self.asked.lock().unwrap().clone()
        }
    }
    #[async_trait::async_trait]
    impl Picker for Scripted {
        async fn pick(&self, input: &str, cs: &[Candidate]) -> Result<usize> {
            self.asked
                .lock()
                .unwrap()
                .push(format!("pick {input} {}", cs.len()));
            self.pick.ok_or_else(|| ScopeError::AmbiguousToken {
                input: input.into(),
                candidates: cs.iter().map(candidate_line).collect(),
            })
        }
        async fn confirm(&self, q: &str) -> Result<bool> {
            self.asked.lock().unwrap().push(format!("confirm {q}"));
            Ok(self.confirm)
        }
    }

    #[derive(Default)]
    struct Store(Vec<TokenInfo>);
    impl BindingStore for Store {
        fn get(&self, s: &str, chain: Option<&str>) -> Option<TokenInfo> {
            self.0
                .iter()
                .find(|t| t.symbol.eq_ignore_ascii_case(s) && chain.is_none_or(|ch| t.chain == ch))
                .cloned()
        }
        fn all(&self, s: &str) -> Vec<TokenInfo> {
            self.0
                .iter()
                .filter(|t| t.symbol.eq_ignore_ascii_case(s))
                .cloned()
                .collect()
        }
        fn save(&mut self, c: &Candidate, venue: Option<&str>) -> Result<()> {
            self.0
                .push(binding(&c.chain, c.address.as_deref().unwrap_or(""), venue));
            Ok(())
        }
    }

    fn binding(chain: &str, address: &str, venue: Option<&str>) -> TokenInfo {
        TokenInfo {
            address: address.into(),
            symbol: "USDN".into(),
            name: "USDN".into(),
            chain: chain.into(),
            last_used: None,
            venue: venue.map(str::to_string),
        }
    }

    fn ctx(venue: VenueKind) -> ResolveContext {
        ResolveContext {
            chain: Some("ethereum".into()),
            venue,
            token_flag: None,
            yes: false,
            save: false,
        }
    }

    fn cex() -> VenueKind {
        VenueKind::Cex("weex".into())
    }

    fn out() -> Output {
        Output::capture().0
    }

    #[tokio::test]
    async fn test_the_token_flag_wins_over_everything() {
        let mut store = Store(vec![binding("ethereum", "0xSAVED", None)]);
        let mut cx = ctx(VenueKind::Dex);
        cx.token_flag = Some("0xFLAG".into());
        let picker = Scripted::new(None, false);
        let r = resolve("USDN", &cx, &Fake(Ok(vec![])), &picker, &mut store, &out())
            .await
            .unwrap();
        assert_eq!(r.address.as_deref(), Some("0xFLAG"));
        assert!(matches!(r.source, Source::Flag));
        assert!(picker.asked().is_empty());
    }

    #[tokio::test]
    async fn test_an_address_passes_through() {
        let addr = "0xeC747DAf41A4Ca4ebE72356592F8301924132907";
        let picker = Scripted::new(None, false);
        let r = resolve(
            addr,
            &ctx(VenueKind::Dex),
            &Fake(Ok(vec![])),
            &picker,
            &mut Store::default(),
            &out(),
        )
        .await
        .unwrap();
        assert_eq!(r.address.as_deref(), Some(addr));
        assert!(matches!(r.source, Source::Address));
    }

    #[tokio::test]
    async fn test_a_saved_binding_is_used_without_a_question() {
        let mut store = Store(vec![binding("ethereum", "0xSAVED", None)]);
        let picker = Scripted::new(None, false);
        let two = Fake(Ok(vec![c("ethereum", "0xA"), c("ethereum", "0xB")]));
        let r = resolve(
            "usdn",
            &ctx(VenueKind::Dex),
            &two,
            &picker,
            &mut store,
            &out(),
        )
        .await
        .unwrap();
        assert_eq!(r.address.as_deref(), Some("0xSAVED"));
        assert!(matches!(r.source, Source::Binding));
        assert!(picker.asked().is_empty());
    }

    #[tokio::test]
    async fn test_a_binding_the_venue_contradicts_stops_with_both_contracts() {
        let mut store = Store(vec![binding("ethereum", "0xAAA", Some("weex"))]);
        let venue = Fake(Ok(vec![c("ETH", "0xBBB")]));
        let err = resolve(
            "USDN",
            &ctx(cex()),
            &venue,
            &Scripted::new(None, false),
            &mut store,
            &out(),
        )
        .await
        .unwrap_err();
        let text = err.to_string();
        assert!(matches!(err, ScopeError::TokenMismatch { .. }), "{text}");
        assert!(text.contains("0xAAA") && text.contains("0xBBB"), "{text}");
    }

    #[tokio::test]
    async fn test_a_binding_matches_a_venue_network_by_chain() {
        // Review focus 2: the venue calls it ERC20; the binding says ethereum.
        let mut store = Store(vec![binding("ethereum", "0xAAA", Some("weex"))]);
        let venue = Fake(Ok(vec![c("BEP20", "0xOTHER"), c("ERC20", "0xAAA")]));
        let r = resolve(
            "USDN",
            &ctx(cex()),
            &venue,
            &Scripted::new(None, false),
            &mut store,
            &out(),
        )
        .await
        .unwrap();
        assert_eq!(r.address.as_deref(), Some("0xAAA"));
    }

    #[tokio::test]
    async fn test_evm_contracts_compare_without_case() {
        // Review focus 3.
        let mut store = Store(vec![binding(
            "ethereum",
            "0xeC747DAf41A4Ca4ebE72356592F8301924132907",
            None,
        )]);
        let venue = Fake(Ok(vec![c(
            "ETH",
            "0xec747daf41a4ca4ebe72356592f8301924132907",
        )]));
        assert!(
            resolve(
                "USDN",
                &ctx(cex()),
                &venue,
                &Scripted::new(None, false),
                &mut store,
                &out()
            )
            .await
            .is_ok()
        );
    }

    #[tokio::test]
    async fn test_a_binding_is_used_when_the_venue_check_fails() {
        // Review focus 4: a network error must not block a saved binding.
        let (o, cap) = Output::capture();
        let mut store = Store(vec![binding("ethereum", "0xAAA", None)]);
        let venue = Fake(Err("down".into()));
        let r = resolve(
            "USDN",
            &ctx(cex()),
            &venue,
            &Scripted::new(None, false),
            &mut store,
            &o,
        )
        .await
        .unwrap();
        assert_eq!(r.address.as_deref(), Some("0xAAA"));
        assert!(cap.err().contains("could not be checked"), "{}", cap.err());
    }

    #[tokio::test]
    async fn test_no_candidates_stops_and_names_the_source() {
        let err = resolve(
            "USDN",
            &ctx(VenueKind::Dex),
            &Fake(Ok(vec![])),
            &Scripted::new(None, false),
            &mut Store::default(),
            &out(),
        )
        .await
        .unwrap_err();
        assert!(matches!(err, ScopeError::TokenNotFound { .. }));
        assert!(err.to_string().contains("the fake source"));
    }

    #[tokio::test]
    async fn test_one_candidate_is_used_without_a_question() {
        let picker = Scripted::new(None, false);
        let r = resolve(
            "USDN",
            &ctx(VenueKind::Dex),
            &Fake(Ok(vec![c("ethereum", "0xA")])),
            &picker,
            &mut Store::default(),
            &out(),
        )
        .await
        .unwrap();
        assert_eq!(r.address.as_deref(), Some("0xA"));
        assert!(matches!(r.source, Source::Single));
        assert!(picker.asked().is_empty());
    }

    #[tokio::test]
    async fn test_only_exact_symbols_are_candidates() {
        // Review focus 1: USDNX is not USDN.
        let mut other = c("ethereum", "0xX");
        other.symbol = "USDNX".into();
        let picker = Scripted::new(None, false);
        let r = resolve(
            "USDN",
            &ctx(VenueKind::Dex),
            &Fake(Ok(vec![other, c("ethereum", "0xA")])),
            &picker,
            &mut Store::default(),
            &out(),
        )
        .await
        .unwrap();
        assert_eq!(r.address.as_deref(), Some("0xA"));
        assert!(picker.asked().is_empty(), "one exact match: no question");
    }

    #[tokio::test]
    async fn test_a_pasted_contract_matches_its_candidate() {
        // An input that is a contract in no known address format still
        // means the candidate with that contract, not a symbol search miss.
        let mut t = c("ethereum", "0xTEST123");
        t.symbol = "TEST".into();
        let r = resolve(
            "0xTEST123",
            &ctx(VenueKind::Dex),
            &Fake(Ok(vec![t])),
            &Scripted::new(None, false),
            &mut Store::default(),
            &out(),
        )
        .await
        .unwrap();
        assert_eq!(r.address.as_deref(), Some("0xTEST123"));
    }

    #[tokio::test]
    async fn test_two_candidates_ask_then_save_on_yes() {
        let mut store = Store::default();
        let picker = Scripted::new(Some(1), true);
        let r = resolve(
            "USDN",
            &ctx(cex()),
            &Fake(Ok(vec![c("ETH", "0xA"), c("BSC", "0xB")])),
            &picker,
            &mut store,
            &out(),
        )
        .await
        .unwrap();
        assert_eq!(r.address.as_deref(), Some("0xB"));
        assert!(matches!(r.source, Source::Picked { saved: true }));
        assert_eq!(store.0.len(), 1);
        assert_eq!(store.0[0].chain, "bsc", "saved under the scope chain name");
        assert_eq!(store.0[0].venue.as_deref(), Some("weex"));
        let asked = picker.asked();
        assert!(asked[1].contains("always means 0xB on bsc"), "{asked:?}");
    }

    #[tokio::test]
    async fn test_no_saves_nothing_and_the_save_flag_skips_the_question() {
        let two = || Fake(Ok(vec![c("ethereum", "0xA"), c("bsc", "0xB")]));
        let mut store = Store::default();
        let picker = Scripted::new(Some(0), false);
        resolve(
            "USDN",
            &ctx(VenueKind::Dex),
            &two(),
            &picker,
            &mut store,
            &out(),
        )
        .await
        .unwrap();
        assert!(store.0.is_empty());

        // --save answers yes without a question.
        let mut cx = ctx(VenueKind::Dex);
        cx.save = true;
        let picker = Scripted::new(Some(0), false);
        resolve("USDN", &cx, &two(), &picker, &mut store, &out())
            .await
            .unwrap();
        assert_eq!(store.0.len(), 1);
        assert!(!picker.asked().iter().any(|a| a.starts_with("confirm")));
    }

    #[tokio::test]
    async fn test_yes_with_an_ambiguous_symbol_stops_with_the_candidates() {
        // Jon, 2026-10-15: --yes never picks the first match.
        let mut cx = ctx(VenueKind::Dex);
        cx.yes = true;
        let err = resolve(
            "USDN",
            &cx,
            &Fake(Ok(vec![c("ethereum", "0xA"), c("bsc", "0xB")])),
            &Scripted::new(Some(0), true),
            &mut Store::default(),
            &out(),
        )
        .await
        .unwrap_err();
        let text = err.to_string();
        assert!(matches!(err, ScopeError::AmbiguousToken { .. }), "{text}");
        assert!(
            text.contains("ethereum 0xA") && text.contains("bsc 0xB"),
            "{text}"
        );
    }

    #[tokio::test]
    async fn test_no_terminal_picker_lists_every_candidate_and_the_hint() {
        let err = NoTerminalPicker
            .pick("USDN", &[c("ethereum", "0xA"), c("bsc", "0xB")])
            .await
            .unwrap_err();
        let text = err.to_string();
        assert!(
            text.contains("ethereum 0xA") && text.contains("bsc 0xB"),
            "{text}"
        );
        assert!(text.contains("--token"), "{text}");
        assert!(!NoTerminalPicker.confirm("save?").await.unwrap());
    }

    #[tokio::test]
    async fn test_pane_commands_never_use_the_terminal_picker() {
        // Review focus 5: in the TUI pane a prompt would read the TUI's
        // stdin and hang.
        let (o, _cap) = Output::capture_merged();
        assert!(o.is_tui());
        let p = picker_for(&o, false);
        let r = p
            .pick("USDN", &[c("ethereum", "0xA"), c("bsc", "0xB")])
            .await;
        assert!(matches!(r, Err(ScopeError::AmbiguousToken { .. })));
    }

    #[tokio::test]
    async fn test_a_server_output_never_prompts() {
        // scope web passes stdio output; a request must not wait on stdin.
        let o = Output::stdio().without_prompts();
        let p = picker_for(&o, false);
        let r = p
            .pick("USDN", &[c("ethereum", "0xA"), c("bsc", "0xB")])
            .await;
        assert!(matches!(r, Err(ScopeError::AmbiguousToken { .. })));
    }

    #[tokio::test]
    async fn test_picker_for_json_never_prompts() {
        // A JSON run must not wait for stdin.
        let (o, _cap) = Output::capture();
        let p = picker_for(&o, true);
        let r = p
            .pick("USDN", &[c("ethereum", "0xA"), c("bsc", "0xB")])
            .await;
        assert!(matches!(r, Err(ScopeError::AmbiguousToken { .. })));
    }

    #[test]
    fn test_venue_candidates_are_one_per_network() {
        use scope::market::assets::{AssetInfo, AssetNetwork};
        let assets = vec![
            AssetInfo {
                symbol: "USDN".into(),
                networks: vec![
                    AssetNetwork {
                        network: "ETH".into(),
                        contract: Some("0xA".into()),
                    },
                    AssetNetwork {
                        network: "BSC".into(),
                        contract: Some("0xB".into()),
                    },
                ],
            },
            AssetInfo {
                symbol: "BTC".into(),
                networks: vec![],
            },
        ];
        let cs = venue_candidates_from("usdn", &assets);
        assert_eq!(cs.len(), 2);
        assert_eq!(cs[0].address.as_deref(), Some("0xA"));
        assert_eq!(cs[0].chain, "ETH", "the venue's name; resolve maps it");
    }

    #[test]
    fn test_dex_results_become_candidates_with_liquidity() {
        let r = scope::chains::dex::TokenSearchResult {
            address: "0xA".into(),
            symbol: "USDN".into(),
            name: "USDN".into(),
            chain: "ethereum".into(),
            price_usd: None,
            volume_24h: 0.0,
            liquidity_usd: 5.0,
            market_cap: None,
        };
        assert_eq!(dex_candidate(&r).liquidity_usd, Some(5.0));
        // The CEX ticker fallback has no address: no contract.
        let mut f = r.clone();
        f.address = String::new();
        assert_eq!(dex_candidate(&f).address, None);
    }

    #[test]
    fn test_the_alias_file_is_a_binding_store() {
        // This writes the test process's one tokens.yaml, which other
        // tests read (a saved choice for their symbol settles an ambiguity
        // they expect), so it saves a symbol no other test uses.
        let symbol = "BINDING_STORE_TEST";
        let mut aliases = TokenAliases::default();
        let store: &mut dyn BindingStore = &mut aliases;
        let candidate = Candidate {
            symbol: symbol.into(),
            ..c("bsc", "0xB")
        };
        store.save(&candidate, Some("weex")).unwrap();
        let got = store.get(symbol, Some("bsc")).unwrap();
        assert_eq!(
            (got.address.as_str(), got.venue.as_deref()),
            ("0xB", Some("weex"))
        );
        let on_disk = TokenAliases::load().get(symbol, Some("bsc")).cloned();
        aliases.remove(symbol, None);
        let _ = TokenAliases::save(&aliases);
        assert_eq!(on_disk.map(|t| t.address).as_deref(), Some("0xB"));
    }

    #[tokio::test]
    async fn test_save_flag_saves_a_single_candidate_too() {
        // Review I2: --save must save even when there was nothing to pick.
        let mut store = Store::default();
        let mut cx = ctx(VenueKind::Dex);
        cx.save = true;
        resolve(
            "USDN",
            &cx,
            &Fake(Ok(vec![c("ethereum", "0xA")])),
            &Scripted::new(None, false),
            &mut store,
            &out(),
        )
        .await
        .unwrap();
        assert_eq!(store.0.len(), 1);
    }

    #[tokio::test]
    async fn test_bindings_on_several_chains_are_a_choice_without_a_chain() {
        // Review I3: no chain set, USDN saved on bsc and solana: ask, never
        // pick one by map order.
        let mut store = Store(vec![
            binding("bsc", "0xB", None),
            binding("solana", "So1", None),
        ]);
        let mut cx = ctx(VenueKind::Dex);
        cx.chain = None;
        let picker = Scripted::new(Some(1), true);
        let r = resolve("USDN", &cx, &Fake(Ok(vec![])), &picker, &mut store, &out())
            .await
            .unwrap();
        assert_eq!(r.address.as_deref(), Some("So1"));
        assert!(
            picker.asked().iter().any(|a| a.starts_with("pick USDN 2")),
            "{:?}",
            picker.asked()
        );
        assert_eq!(store.0.len(), 2, "no new binding: both are saved already");
    }

    #[tokio::test]
    async fn test_a_binding_hit_says_which_token() {
        let (o, cap) = Output::capture();
        let mut store = Store(vec![binding("ethereum", "0xSAVED", None)]);
        resolve(
            "USDN",
            &ctx(VenueKind::Dex),
            &Fake(Ok(vec![])),
            &Scripted::new(None, false),
            &mut store,
            &o,
        )
        .await
        .unwrap();
        assert!(cap.err().contains("0xSAVED"), "{}", cap.err());
    }

    #[tokio::test]
    async fn test_a_venue_without_the_bindings_chain_stops() {
        // Review I4: the venue lists USDN, but not on the saved chain.
        let mut store = Store(vec![binding("ethereum", "0xAAA", None)]);
        let venue = Fake(Ok(vec![c("TRC20", "TXYZ")]));
        let err = resolve(
            "USDN",
            &ctx(cex()),
            &venue,
            &Scripted::new(None, false),
            &mut store,
            &out(),
        )
        .await
        .unwrap_err();
        assert!(matches!(err, ScopeError::TokenMismatch { .. }), "{err}");
        assert!(err.to_string().contains("TRC20"), "{err}");
    }

    #[tokio::test]
    async fn test_a_token_flag_with_no_chain_takes_the_address_chain() {
        // #108 1: `--token <address>` infers the chain, as a positional
        // address does.
        let ctx = |token: &str| ResolveContext {
            chain: None,
            token_flag: Some(token.into()),
            ..ctx(VenueKind::Dex)
        };
        for (token, chain) in [
            ("0xA0b86991c6218b36c1d19D4a2e9Eb0cE3606eB48", "ethereum"),
            ("TR7NHqjeKQxGTCi8q8ZY4pL8otSzgjLj6t", "tron"),
        ] {
            let r = resolve(
                "USDC",
                &ctx(token),
                &Fake(Ok(vec![])),
                &Scripted::new(None, false),
                &mut Store::default(),
                &out(),
            )
            .await
            .unwrap();
            assert_eq!(r.chain, chain, "{token}");
        }
        // A chain the user set still wins.
        let r = resolve(
            "USDC",
            &ResolveContext {
                chain: Some("base".into()),
                ..ctx("0xA0b86991c6218b36c1d19D4a2e9Eb0cE3606eB48")
            },
            &Fake(Ok(vec![])),
            &Scripted::new(None, false),
            &mut Store::default(),
            &out(),
        )
        .await
        .unwrap();
        assert_eq!(r.chain, "base");
    }

    #[tokio::test]
    async fn test_a_saved_native_coin_has_no_contract_and_says_so() {
        // #108 2: a native-coin binding is saved with an empty address.
        let native = |chain: &str| Candidate {
            address: None,
            ..c(chain, "")
        };
        let (o, cap) = Output::capture();
        let mut store = Store(vec![binding("ethereum", "", Some("weex"))]);
        let r = resolve(
            "USDN",
            &ctx(cex()),
            &Fake(Ok(vec![native("ETH")])),
            &Scripted::new(None, false),
            &mut store,
            &o,
        )
        .await
        .unwrap();
        assert_eq!(r.address, None, "no empty contract");
        assert!(
            cap.err().contains("ethereum its native coin"),
            "{}",
            cap.err()
        );

        // The venue now lists a contract on that chain: a mismatch that
        // names the native coin, never an empty contract.
        let mut store = Store(vec![binding("ethereum", "", Some("weex"))]);
        let err = resolve(
            "USDN",
            &ctx(cex()),
            &Fake(Ok(vec![c("ETH", "0xAAA")])),
            &Scripted::new(None, false),
            &mut store,
            &out(),
        )
        .await
        .unwrap_err();
        assert!(matches!(err, ScopeError::TokenMismatch { .. }), "{err}");
        assert!(err.to_string().contains("its native coin"), "{err}");
        assert!(!err.to_string().contains("is , "), "{err}");
    }

    #[test]
    fn test_the_terminal_confirm_takes_y_and_yes_in_any_case() {
        // #108 4.
        for (answer, yes) in [
            ("y\n", true),
            ("yes\n", true),
            ("Y\n", true),
            (" YES \n", true),
            ("\n", false),
            ("n\n", false),
            ("yep\n", false),
            ("", false),
        ] {
            let mut reader = std::io::Cursor::new(answer.as_bytes());
            assert_eq!(
                confirm_from(&mut reader, &out(), "Save? [y/N]: ").unwrap(),
                yes,
                "{answer:?}"
            );
        }
    }

    /// A CEX venue that does not list contracts (no `assets`).
    struct Unlisted;
    #[async_trait::async_trait]
    impl CandidateSource for Unlisted {
        async fn candidates(&self, _s: &str, _c: Option<&str>) -> Result<Vec<Candidate>> {
            Ok(vec![])
        }
        fn searched(&self, _c: Option<&str>) -> String {
            "nothing".into()
        }
        fn lists_contracts(&self) -> bool {
            false
        }
    }

    #[tokio::test]
    async fn test_a_venue_that_lists_no_contracts_is_not_checked_and_says_so() {
        // Review I5: no false "Using … native" line; a binding gets the
        // spec's "cannot be checked" note.
        let (o, cap) = Output::capture();
        let r = resolve(
            "USDC",
            &ctx(cex()),
            &Unlisted,
            &Scripted::new(None, false),
            &mut Store::default(),
            &o,
        )
        .await
        .unwrap();
        assert!(matches!(r.source, Source::Unchecked));
        assert!(!cap.err().contains("native"), "{}", cap.err());
        let (o, cap) = Output::capture();
        let mut store = Store(vec![binding("ethereum", "0xAAA", None)]);
        resolve(
            "USDN",
            &ctx(cex()),
            &Unlisted,
            &Scripted::new(None, false),
            &mut store,
            &o,
        )
        .await
        .unwrap();
        assert!(cap.err().contains("cannot be checked"), "{}", cap.err());
    }

    /// A store whose save always fails.
    struct ReadOnly;
    impl BindingStore for ReadOnly {
        fn get(&self, _s: &str, _c: Option<&str>) -> Option<TokenInfo> {
            None
        }
        fn all(&self, _s: &str) -> Vec<TokenInfo> {
            Vec::new()
        }
        fn save(&mut self, _c: &Candidate, _v: Option<&str>) -> Result<()> {
            Err(ScopeError::Other("read-only".into()))
        }
    }

    #[tokio::test]
    async fn test_a_failed_save_warns_and_keeps_the_choice() {
        // Review I7: the token was chosen; a save failure must not fail
        // the command.
        let (o, cap) = Output::capture();
        let r = resolve(
            "USDN",
            &ctx(VenueKind::Dex),
            &Fake(Ok(vec![c("ethereum", "0xA"), c("bsc", "0xB")])),
            &Scripted::new(Some(0), true),
            &mut ReadOnly,
            &o,
        )
        .await
        .unwrap();
        assert_eq!(r.address.as_deref(), Some("0xA"));
        assert!(matches!(r.source, Source::Picked { saved: false }));
        assert!(cap.err().contains("not saved"), "{}", cap.err());
    }

    /// Answers the next question in `asker` with `answer`.
    fn answer(asker: &crate::cli::output::Asker, answer: Option<usize>) {
        let asker = asker.clone();
        tokio::spawn(async move {
            loop {
                let ask = asker.lock().unwrap().take();
                if let Some(ask) = ask {
                    let _ = ask.reply.send(answer);
                    return;
                }
                tokio::task::yield_now().await;
            }
        });
    }

    #[tokio::test]
    async fn test_the_tui_picker_asks_through_the_slot() {
        let asker = crate::cli::output::Asker::default();
        let p = TuiPicker {
            asker: asker.clone(),
        };
        answer(&asker, Some(1));
        let cs = [c("ethereum", "0xA"), c("bsc", "0xB")];
        assert_eq!(p.pick("USDN", &cs).await.unwrap(), 1);
        answer(&asker, Some(1));
        assert!(
            p.confirm("Save so …? [y/N]: ").await.unwrap(),
            "option 1 is Yes"
        );
    }

    #[tokio::test]
    async fn test_the_save_list_title_has_no_terminal_hint() {
        let asker = crate::cli::output::Asker::default();
        let p = TuiPicker {
            asker: asker.clone(),
        };
        let slot = asker.clone();
        let title = tokio::spawn(async move {
            loop {
                let ask = slot.lock().unwrap().take();
                if let Some(ask) = ask {
                    let _ = ask.reply.send(Some(0));
                    return ask.prompt;
                }
                tokio::task::yield_now().await;
            }
        });
        assert!(!p.confirm("Save so X? [y/N]: ").await.unwrap());
        assert_eq!(title.await.unwrap(), "Save so X?");
    }

    #[tokio::test]
    async fn test_escape_on_the_choice_is_a_cancel() {
        let asker = crate::cli::output::Asker::default();
        let p = TuiPicker {
            asker: asker.clone(),
        };
        answer(&asker, None);
        let cs = [c("ethereum", "0xA"), c("bsc", "0xB")];
        let err = p.pick("USDN", &cs).await.unwrap_err();
        assert!(err.to_string().contains("cancelled"), "{err}");
        answer(&asker, None);
        assert!(
            !p.confirm("Save?").await.unwrap(),
            "Esc on the save question is No"
        );
    }

    #[tokio::test]
    async fn test_a_pane_output_with_an_asker_gets_the_tui_picker() {
        let (o, _cap) = Output::capture_merged();
        let asker = crate::cli::output::Asker::default();
        let o = o.with_asker(asker.clone());
        let cs = [c("ethereum", "0xA"), c("bsc", "0xB")];
        let p = picker_for(&o, false);
        answer(&asker, Some(0));
        assert_eq!(p.pick("USDN", &cs).await.unwrap(), 0);
        // JSON still never asks.
        let p = picker_for(&o, true);
        assert!(p.pick("USDN", &cs).await.is_err());
    }

    #[tokio::test]
    async fn test_each_resolution_writes_one_log_line() {
        let dir = tempfile::tempdir().unwrap();
        let log = dir.path().join("resolutions.jsonl");
        let picker = Scripted::new(None, false);
        resolve_logged(
            "USDN",
            &ctx(VenueKind::Dex),
            &Fake(Ok(vec![c("ethereum", "0xA")])),
            &picker,
            &mut Store::default(),
            &out(),
            &log,
        )
        .await
        .unwrap();
        let _ = resolve_logged(
            "NOPE",
            &ctx(VenueKind::Dex),
            &Fake(Ok(vec![])),
            &picker,
            &mut Store::default(),
            &out(),
            &log,
        )
        .await;
        let lines: Vec<serde_json::Value> = std::fs::read_to_string(&log)
            .unwrap()
            .lines()
            .map(|l| serde_json::from_str(l).unwrap())
            .collect();
        assert_eq!(lines.len(), 2);
        assert_eq!(lines[0]["source"], "single");
        assert_eq!(lines[0]["chosen"], "0xA");
        assert!(lines[1]["error"].as_str().unwrap().contains("NOPE"));
    }
}