polyjose 0.1.1

//! The JWT Claims Set (RFC 7519 §4): typed registered claims, every other
//! claim kept as a [`Value`] (ADR 0027 §1).

use core::fmt;

use crate::error::{Error, Result};
use crate::json::{Object, Value, parse};
use zeroize::Zeroizing;

use super::NumericDate;

/// The seven registered claim names of RFC 7519 §4.1, in the order they
/// are serialized and checked for presence (ADR 0027 §1, §9 J4).
pub(crate) const REGISTERED_CLAIMS: [&str; 7] = ["iss", "sub", "aud", "exp", "nbf", "iat", "jti"];

/// The `aud` claim (RFC 7519 §4.1.3), in the form it was received, so it
/// re-serializes unchanged.
///
/// "In the general case, the "aud" value is an array of case-sensitive
/// strings", and with one audience it "MAY be a single case-sensitive
/// string" (RFC 7519 §4.1.3).
///
/// `Debug` prints the form and one `"<redacted>"` per value, never a
/// value, like [`Value`]'s strings (see [`Claims`#debug]).
///
/// ```
/// use polyjose::jwt::Audience;
///
/// let aud = Audience::Many(vec!["alice@example.com".into(), "api".into()]);
/// assert_eq!(format!("{aud:?}"), r#"Many(["<redacted>", "<redacted>"])"#);
/// ```
#[derive(Clone, PartialEq, Eq)]
pub enum Audience {
    /// A single string.
    One(String),
    /// An array of strings, in order. It may be empty, which matches no
    /// audience (ADR 0027 §4).
    Many(Vec<String>),
}

impl Audience {
    /// The audience values, whatever the form: one for
    /// [`One`](Audience::One), the array for [`Many`](Audience::Many).
    ///
    /// ```
    /// use polyjose::jwt::Audience;
    ///
    /// assert_eq!(Audience::One("api".into()).values(), ["api"]);
    /// assert!(Audience::Many(vec![]).values().is_empty());
    /// ```
    pub fn values(&self) -> &[String] {
        match self {
            Audience::One(aud) => core::slice::from_ref(aud),
            Audience::Many(auds) => auds,
        }
    }
}

/// A JWT Claims Set (RFC 7519 §4).
///
/// The registered claims of RFC 7519 §4.1 are typed fields; every other
/// claim, public or private (RFC 7519 §4.2–§4.3), is kept as a
/// [`Value`] in insertion order and reached with [`get`](Claims::get) and
/// [`insert`](Claims::insert). Validation ignores claims it does not
/// understand (RFC 7519 §4).
///
/// ```
/// use polyjose::json::Value;
/// use polyjose::jwt::{Audience, Claims, NumericDate};
///
/// let mut claims = Claims::new();
/// claims.iss = Some("joe".into());
/// claims.aud = Some(Audience::One("https://api.example".into()));
/// claims.exp = NumericDate::from_secs(1300819380);
/// claims.insert("http://example.com/is_root", Value::Bool(true))?;
/// assert_eq!(
///     claims.get("http://example.com/is_root"),
///     Some(&Value::Bool(true))
/// );
///
/// // Registered claims live in their typed fields.
/// assert!(claims.insert("exp", Value::Null).is_err());
/// # Ok::<(), polyjose::Error>(())
/// ```
///
/// # Debug
///
/// `Debug` is polyjose's own and never prints a claim string, so a logged
/// Claims Set (or the [`VerifiedJwt`](super::VerifiedJwt) or
/// [`VerifiedNestedJwt`](super::VerifiedNestedJwt) holding it) cannot leak
/// a claim (workspace secrets rule, ADR 0049 §4). A nested JWT is
/// encrypted because its claims are confidential (RFC 7519 §11.2), and a
/// `sub` is often personal data. It follows [`Value`]'s redacting `Debug`:
///
/// - `iss`, `sub` and `jti` print as `Some("<redacted>")` or `None`,
///   whatever their content or length (RFC 7519 §4.1.1, §4.1.2, §4.1.7).
/// - `aud` prints its form, [`One`](Audience::One) or
///   [`Many`](Audience::Many), with one `"<redacted>"` per value, so the
///   number of audiences shows and no value does (RFC 7519 §4.1.3).
/// - `exp`, `nbf` and `iat` print in full: a NumericDate is a time, not a
///   secret, and is what a reader needs to diagnose an expiry
///   (RFC 7519 §4.1.4–§4.1.6).
/// - The other claims print through [`Object`]'s `Debug`: claim names,
///   `null`, booleans, numbers and structure show, and every string
///   prints as `String("<redacted>")` (see [`Value`#debug]).
///
/// ```
/// use polyjose::jwt::{Audience, Claims};
///
/// let mut claims = Claims::new();
/// claims.sub = Some("alice@example.com".into());
/// claims.aud = Some(Audience::One("https://api.example".into()));
/// claims.insert("email", "alice@example.com")?;
/// assert_eq!(
///     format!("{claims:?}"),
///     concat!(
///         r#"Claims { iss: None, sub: Some("<redacted>"), aud: Some(One("<redacted>")), "#,
///         r#"exp: None, nbf: None, iat: None, jti: None, other: {"email": String("<redacted>")} }"#,
///     )
/// );
/// # Ok::<(), polyjose::Error>(())
/// ```
#[derive(Clone, PartialEq, Default)]
#[non_exhaustive]
pub struct Claims {
    /// `iss`, the issuer: a case-sensitive StringOrURI (RFC 7519 §4.1.1).
    pub iss: Option<String>,
    /// `sub`, the subject: a case-sensitive StringOrURI (RFC 7519 §4.1.2).
    pub sub: Option<String>,
    /// `aud`, the audience (RFC 7519 §4.1.3).
    pub aud: Option<Audience>,
    /// `exp`, the expiration time (RFC 7519 §4.1.4).
    pub exp: Option<NumericDate>,
    /// `nbf`, the not-before time (RFC 7519 §4.1.5).
    pub nbf: Option<NumericDate>,
    /// `iat`, the issued-at time (RFC 7519 §4.1.6).
    pub iat: Option<NumericDate>,
    /// `jti`, the JWT ID: a case-sensitive string (RFC 7519 §4.1.7).
    pub jti: Option<String>,
    /// Every other claim (RFC 7519 §4.2–§4.3), in insertion order. Never
    /// holds a registered name, so serializing cannot duplicate one.
    other: Object,
}

impl Claims {
    /// An empty Claims Set: no registered and no other claims.
    pub fn new() -> Self {
        Self::default()
    }

    /// Parses a JWT Claims Set from the JWS payload octets (RFC 7519 §7.2
    /// step 10), directly, without a second base64url decoding (reported
    /// erratum 8225; ADR 0027 §1).
    ///
    /// The octets are parsed with polyjose's own JSON and its default
    /// [`Limits`](crate::json::Limits) (ADR 0016), which reject duplicate
    /// member names (RFC 7519 §4, RFC 7493 §2.3). Then:
    ///
    /// - `iss`, `sub` and `jti` must be strings (RFC 7519 §4.1.1, §4.1.2,
    ///   §4.1.7);
    /// - `aud` must be a string or an array of strings, and keeps the form
    ///   it was received in (RFC 7519 §4.1.3);
    /// - `exp`, `nbf` and `iat` must be NumericDates (RFC 7519 §2,
    ///   §4.1.4–§4.1.6; ADR 0027 §2, see [`NumericDate`]);
    /// - every other member is kept as a [`Value`], in order (RFC 7519
    ///   §4.2–§4.3).
    ///
    /// The registered claims are checked in the order `iss, sub, aud, exp,
    /// nbf, iat, jti`, whatever their order in the input, so the first
    /// wrong one in that order decides the error (ADR 0027 §9 J3).
    ///
    /// **Secrets** (ADR 0049 §4): the payload may be secret, so no
    /// unwiped copy of it is made. The parser borrows `bytes`, every string
    /// it builds is wiped on drop, and every error path drops them that way.
    /// On success the buffers of the `iss`, `sub`, `aud` and `jti` strings
    /// are moved, not copied, into their `String` fields, which are not
    /// wiped on drop; the other claims stay [`Value`]s.
    ///
    /// ```
    /// use polyjose::{json::Value, jwt::Claims, Error};
    ///
    /// // RFC 7519 §3.1, line breaks included.
    /// let claims = Claims::from_json(
    ///     b"{\"iss\":\"joe\",\r\n \"exp\":1300819380,\r\n \"http://example.com/is_root\":true}",
    /// )?;
    /// assert_eq!(claims.iss.as_deref(), Some("joe"));
    /// assert_eq!(claims.exp.and_then(|d| d.as_secs()), Some(1300819380));
    /// assert_eq!(claims.get("http://example.com/is_root"), Some(&Value::Bool(true)));
    ///
    /// // A NumericDate is a number (RFC 7519 §4.1.4).
    /// assert_eq!(Claims::from_json(br#"{"exp":"1300819380"}"#), Err(Error::InvalidClaim("exp")));
    /// // Duplicate claim names are rejected (RFC 7519 §4).
    /// assert!(matches!(Claims::from_json(br#"{"exp":1,"exp":2}"#), Err(Error::InvalidJson(_))));
    /// # Ok::<(), polyjose::Error>(())
    /// ```
    ///
    /// # Errors
    ///
    /// [`Error::InvalidJson`] if the octets are not UTF-8, not one JSON
    /// object, or repeat a member name (RFC 7519 §4, §7.2 step 10);
    /// [`Error::InvalidClaim`]`(name)` if a registered claim has the wrong
    /// type, `null` included (ADR 0027 §1–§2). Neither echoes a claim
    /// value.
    pub fn from_json(bytes: &[u8]) -> Result<Self> {
        let object = parse(bytes)?.into_object().ok_or(NOT_AN_OBJECT)?;

        // Split the members, moving them, into the registered slots and
        // the other claims. The parser has rejected duplicate names, so no
        // slot is filled twice and the other names are unique.
        let mut slots: [Option<Value>; 7] = Default::default();
        let mut other = Vec::with_capacity(object.len());
        for (name, value) in object {
            match REGISTERED_CLAIMS
                .iter()
                .zip(slots.iter_mut())
                .find(|(claim, _)| **claim == name.as_str())
            {
                Some((_, slot)) => *slot = Some(value),
                None => other.push((name, value)),
            }
        }
        let [iss, sub, aud, exp, nbf, iat, jti] = slots;

        // Every check runs before any string leaves its wiping buffer.
        let iss = string_claim(iss, "iss")?;
        let sub = string_claim(sub, "sub")?;
        let aud = audience_claim(aud)?;
        let exp = date_claim(exp.as_ref(), "exp")?;
        let nbf = date_claim(nbf.as_ref(), "nbf")?;
        let iat = date_claim(iat.as_ref(), "iat")?;
        let jti = string_claim(jti, "jti")?;

        Ok(Claims {
            iss: iss.map(unwrap_string),
            sub: sub.map(unwrap_string),
            aud: aud.map(|aud| match aud {
                ParsedAudience::One(one) => Audience::One(unwrap_string(one)),
                ParsedAudience::Many(many) => {
                    Audience::Many(many.into_iter().map(unwrap_string).collect())
                }
            }),
            exp,
            nbf,
            iat,
            jti: jti.map(unwrap_string),
            other: Object::from_unique_members(other),
        })
    }

    /// Serializes the Claims Set as compact JSON (RFC 7519 §7.1 step 1):
    /// the registered claims in the order `iss, sub, aud, exp, nbf, iat,
    /// jti`, then the other claims in insertion order (ADR 0027 §1).
    ///
    /// An [`Audience::One`] is written as a string and an
    /// [`Audience::Many`] as an array (RFC 7519 §4.1.3), so a parsed `aud`
    /// re-serializes in the form it was received. An integral
    /// [`NumericDate`] is written without a fraction
    /// ([`NumericDate::to_json_value`]). Strings and numbers use the
    /// crate's canonical JSON writer ([`Value::to_json`]), so the output is
    /// deterministic and [`from_json`](Claims::from_json) of it gives an
    /// equal Claims Set.
    ///
    /// ```
    /// use polyjose::json::Value;
    /// use polyjose::jwt::{Audience, Claims, NumericDate};
    ///
    /// let mut claims = Claims::new();
    /// claims.insert("http://example.com/is_root", Value::Bool(true))?;
    /// claims.exp = NumericDate::from_secs(1300819380);
    /// claims.aud = Some(Audience::Many(vec!["a".into(), "b".into()]));
    /// claims.iss = Some("joe".into());
    /// assert_eq!(
    ///     claims.to_json(),
    ///     r#"{"iss":"joe","aud":["a","b"],"exp":1300819380,"http://example.com/is_root":true}"#
    /// );
    /// # Ok::<(), polyjose::Error>(())
    /// ```
    ///
    /// **Secrets:** like [`Value::to_json`], the output is allocated once
    /// at its exact size and the members are staged in wiping buffers, but
    /// the returned `String` is the caller's to wipe if the claims are
    /// secret (ADR 0049 §4).
    pub fn to_json(&self) -> String {
        /// A member name, in a wiping buffer like every `Object` name.
        fn name(name: &str) -> Zeroizing<String> {
            Zeroizing::new(name.to_owned())
        }

        let mut members = Vec::with_capacity(REGISTERED_CLAIMS.len() + self.other.len());
        let strings = [("iss", &self.iss), ("sub", &self.sub)];
        for (claim, value) in strings {
            if let Some(value) = value {
                members.push((name(claim), Value::from(value.as_str())));
            }
        }
        if let Some(aud) = &self.aud {
            let value = match aud {
                Audience::One(one) => Value::from(one.as_str()),
                Audience::Many(many) => {
                    Value::Array(many.iter().map(|a| Value::from(a.as_str())).collect())
                }
            };
            members.push((name("aud"), value));
        }
        let dates = [("exp", &self.exp), ("nbf", &self.nbf), ("iat", &self.iat)];
        for (claim, date) in dates {
            if let Some(date) = date {
                members.push((name(claim), date.to_json_value()));
            }
        }
        if let Some(jti) = &self.jti {
            members.push((name("jti"), Value::from(jti.as_str())));
        }
        // `other` never holds a registered name (`insert` refuses one and
        // `from_json` routes them to the typed fields), and its own names
        // are unique, so every name is unique.
        members.extend(self.other.clone());
        Object::from_unique_members(members).to_json()
    }

    /// The claim `name` if it is not a registered claim (RFC 7519
    /// §4.2–§4.3). A registered name returns `None`: read its typed field.
    pub fn get(&self, name: &str) -> Option<&Value> {
        if registered(name).is_some() {
            return None;
        }
        self.other.get(name)
    }

    /// Sets the public or private claim `name` (RFC 7519 §4.2–§4.3),
    /// returning its previous value. A new name is appended.
    ///
    /// # Errors
    ///
    /// [`Error::InvalidClaim`]`(name)` if `name` is a registered claim
    /// (RFC 7519 §4.1): set its typed field instead, so a Claims Set can
    /// never hold the same name twice (RFC 7519 §4).
    pub fn insert(
        &mut self,
        name: impl Into<String>,
        value: impl Into<Value>,
    ) -> Result<Option<Value>> {
        let name = name.into();
        if let Some(registered) = registered(&name) {
            return Err(Error::InvalidClaim(registered));
        }
        Ok(self.other.insert(name, value))
    }

    /// Every claim that is not a registered one (RFC 7519 §4.2–§4.3), in
    /// insertion order.
    pub fn other_claims(&self) -> &Object {
        &self.other
    }
}

/// The registered claim name equal to `name`, as a `'static` string for
/// error details.
fn registered(name: &str) -> Option<&'static str> {
    REGISTERED_CLAIMS.into_iter().find(|claim| *claim == name)
}

/// A Claims Set payload that parsed as JSON but is not an object
/// (RFC 7519 §7.2 step 10: the octets must be "a UTF-8-encoded
/// representation of a completely valid JSON object").
const NOT_AN_OBJECT: Error = Error::InvalidJson("JWT Claims Set is not a JSON object");

/// An `aud` claim that has passed its type check, its strings still in
/// their wiping buffers.
enum ParsedAudience {
    One(Zeroizing<String>),
    Many(Vec<Zeroizing<String>>),
}

/// The StringOrURI or string claim `claim` (RFC 7519 §4.1.1, §4.1.2,
/// §4.1.7): absent, or a JSON string.
///
/// # Errors
///
/// [`Error::InvalidClaim`]`(claim)` for any other JSON type, `null`
/// included (ADR 0027 §1).
fn string_claim(value: Option<Value>, claim: &'static str) -> Result<Option<Zeroizing<String>>> {
    match value {
        None => Ok(None),
        Some(Value::String(s)) => Ok(Some(s)),
        Some(_) => Err(Error::InvalidClaim(claim)),
    }
}

/// The `aud` claim (RFC 7519 §4.1.3): absent, a string, or an array of
/// strings, possibly empty (ADR 0027 §4).
///
/// # Errors
///
/// [`Error::InvalidClaim`]`("aud")` for any other JSON type, `null`
/// included, or an array with an element that is not a string
/// (ADR 0027 §4).
fn audience_claim(value: Option<Value>) -> Result<Option<ParsedAudience>> {
    match value {
        None => Ok(None),
        Some(Value::String(one)) => Ok(Some(ParsedAudience::One(one))),
        Some(Value::Array(items)) => items
            .into_iter()
            .map(|item| match item {
                Value::String(s) => Ok(s),
                _ => Err(Error::InvalidClaim("aud")),
            })
            .collect::<Result<Vec<_>>>()
            .map(|many| Some(ParsedAudience::Many(many))),
        Some(_) => Err(Error::InvalidClaim("aud")),
    }
}

/// The NumericDate claim `claim` (RFC 7519 §2, §4.1.4–§4.1.6): absent, or
/// a value [`NumericDate::from_json`] accepts (ADR 0027 §2).
///
/// # Errors
///
/// [`Error::InvalidClaim`]`(claim)` as [`NumericDate::from_json`] returns
/// it.
fn date_claim(value: Option<&Value>, claim: &'static str) -> Result<Option<NumericDate>> {
    value
        .map(|value| NumericDate::from_json(value, claim))
        .transpose()
}

/// What `Debug` prints instead of a claim string: the placeholder
/// [`Value`]'s `Debug` prints for a string.
const REDACTED: &str = "<redacted>";

/// Redacting: the form and one placeholder per value (see
/// [`Claims`#debug]).
impl fmt::Debug for Audience {
    fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
        match self {
            Audience::One(_) => f.debug_tuple("One").field(&REDACTED).finish(),
            Audience::Many(auds) => f.debug_tuple("Many").field(&RedactedStrings(auds)).finish(),
        }
    }
}

/// The redacting `Debug` of a list of strings: one placeholder each.
struct RedactedStrings<'a>(&'a [String]);

impl fmt::Debug for RedactedStrings<'_> {
    fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
        f.debug_list()
            .entries(self.0.iter().map(|_| REDACTED))
            .finish()
    }
}

/// Redacting: `iss`, `sub`, `jti` and `aud` print placeholders, the
/// NumericDates print, other claims print through [`Object`]'s redacting
/// `Debug` (see [`Claims`#debug]).
impl fmt::Debug for Claims {
    fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
        /// `Some("<redacted>")` for a present string claim, else `None`.
        fn redacted(claim: &Option<String>) -> Option<&'static str> {
            claim.as_ref().map(|_| REDACTED)
        }
        f.debug_struct("Claims")
            .field("iss", &redacted(&self.iss))
            .field("sub", &redacted(&self.sub))
            .field("aud", &self.aud)
            .field("exp", &self.exp)
            .field("nbf", &self.nbf)
            .field("iat", &self.iat)
            .field("jti", &redacted(&self.jti))
            .field("other", &self.other)
            .finish()
    }
}

/// Moves the string out of its wiping buffer without copying it: the
/// buffer becomes the returned `String`'s, and the empty `Zeroizing` left
/// behind has nothing to wipe.
fn unwrap_string(mut s: Zeroizing<String>) -> String {
    core::mem::take(&mut *s)
}

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

    #[test]
    fn registered_names_are_refused_by_insert_and_hidden_from_get() {
        let mut claims = Claims::new();
        for name in REGISTERED_CLAIMS {
            assert_eq!(
                claims.insert(name, Value::Null),
                Err(Error::InvalidClaim(name))
            );
            assert_eq!(claims.get(name), None);
        }
        claims.exp = NumericDate::from_secs(1);
        assert_eq!(claims.get("exp"), None);
        assert!(claims.other_claims().is_empty());
    }

    #[test]
    fn other_claims_keep_insertion_order_and_replace_in_place() {
        let mut claims = Claims::new();
        assert_eq!(claims.insert("b", Value::from("1")), Ok(None));
        assert_eq!(claims.insert("a", Value::Bool(true)), Ok(None));
        assert_eq!(claims.insert("b", Value::Null), Ok(Some(Value::from("1"))));
        let names: Vec<&str> = claims.other_claims().iter().map(|(n, _)| n).collect();
        assert_eq!(names, ["b", "a"]);
        assert_eq!(claims.get("b"), Some(&Value::Null));
        assert_eq!(claims.get("missing"), None);
        // Close to a registered name is not one.
        assert_eq!(claims.insert("EXP", Value::Null), Ok(None));
    }

    #[test]
    fn audience_values() {
        assert_eq!(Audience::One("a".into()).values(), ["a"]);
        assert_eq!(
            Audience::Many(vec!["a".into(), "b".into()]).values(),
            ["a", "b"]
        );
        assert!(Audience::Many(Vec::new()).values().is_empty());
    }

    #[test]
    fn new_is_empty() {
        let claims = Claims::new();
        assert_eq!(claims, Claims::default());
        assert!(claims.iss.is_none() && claims.exp.is_none() && claims.aud.is_none());
    }

    /// The payload segment of the RFC 7519 §3.1 example JWT.
    const RFC7519_3_1_PAYLOAD_B64: &str = "eyJpc3MiOiJqb2UiLA0KICJleHAiOjEzMDA4MTkzODAsDQogImh0dHA6Ly9leGFtcGxlLmNvbS9pc19yb290Ijp0cnVlfQ";

    /// The RFC 7519 §3.1 JWT Claims Set octets, CRLF and leading spaces
    /// included.
    const RFC7519_3_1_CLAIMS: &[u8] =
        b"{\"iss\":\"joe\",\r\n \"exp\":1300819380,\r\n \"http://example.com/is_root\":true}";

    fn claims(json: &str) -> Result<Claims> {
        Claims::from_json(json.as_bytes())
    }

    fn is_invalid_json<T>(result: &Result<T>) -> bool {
        matches!(result, Err(Error::InvalidJson(_)))
    }

    #[test]
    fn rfc7519_section_3_1_claims_parse() {
        let octets = crate::util::b64url_decode(RFC7519_3_1_PAYLOAD_B64).unwrap();
        assert_eq!(octets, RFC7519_3_1_CLAIMS);

        let c = Claims::from_json(RFC7519_3_1_CLAIMS).unwrap();
        assert_eq!(c.iss.as_deref(), Some("joe"));
        assert_eq!(c.exp.and_then(|d| d.as_secs()), Some(1_300_819_380));
        assert_eq!(
            c.get("http://example.com/is_root"),
            Some(&Value::Bool(true))
        );
        assert!(c.sub.is_none() && c.aud.is_none() && c.jti.is_none());
        assert!(c.nbf.is_none() && c.iat.is_none());
        assert_eq!(c.other_claims().len(), 1);
    }

    #[test]
    fn iss_sub_jti_must_be_strings() {
        // RFC 7519 §4.1.1, §4.1.2, §4.1.7; ADR 0027 §1: `null` included.
        for (json, name) in [
            (r#"{"iss":1}"#, "iss"),
            (r#"{"sub":null}"#, "sub"),
            (r#"{"jti":[]}"#, "jti"),
            (r#"{"iss":true}"#, "iss"),
            (r#"{"sub":{}}"#, "sub"),
            (r#"{"jti":1.5}"#, "jti"),
            (r#"{"iss":["joe"]}"#, "iss"),
        ] {
            assert_eq!(claims(json), Err(Error::InvalidClaim(name)), "{json}");
        }
        let c = claims(r#"{"jti":"j","sub":"s","iss":"i"}"#).unwrap();
        assert_eq!(c.iss.as_deref(), Some("i"));
        assert_eq!(c.sub.as_deref(), Some("s"));
        assert_eq!(c.jti.as_deref(), Some("j"));
        // An empty string is a string (RFC 7519 §2 StringOrURI).
        assert_eq!(claims(r#"{"iss":""}"#).unwrap().iss.as_deref(), Some(""));
        // Escapes are unescaped; values are not normalized (RFC 7519 §7.3).
        let c = claims(r#"{"sub":"Joe"}"#).unwrap();
        assert_eq!(c.sub.as_deref(), Some("Joe"));
    }

    #[test]
    fn aud_is_a_string_or_an_array_of_strings_in_its_received_form() {
        // RFC 7519 §4.1.3; ADR 0027 §1, §4.
        let aud = |json: &str| claims(json).map(|c| c.aud);
        assert_eq!(aud(r#"{"aud":"a"}"#), Ok(Some(Audience::One("a".into()))));
        assert_eq!(
            aud(r#"{"aud":["b","a"]}"#),
            Ok(Some(Audience::Many(vec!["b".into(), "a".into()])))
        );
        assert_eq!(
            aud(r#"{"aud":["a"]}"#),
            Ok(Some(Audience::Many(vec!["a".into()])))
        );
        assert_eq!(aud(r#"{"aud":[]}"#), Ok(Some(Audience::Many(Vec::new()))));
        for json in [
            r#"{"aud":["a",1]}"#,
            r#"{"aud":{}}"#,
            r#"{"aud":null}"#,
            r#"{"aud":1}"#,
            r#"{"aud":true}"#,
            r#"{"aud":[null]}"#,
            r#"{"aud":[["a"]]}"#,
            r#"{"aud":["a",{"b":"c"}]}"#,
        ] {
            assert_eq!(aud(json), Err(Error::InvalidClaim("aud")), "{json}");
        }
    }

    #[test]
    fn exp_nbf_iat_are_numeric_dates() {
        // RFC 7519 §2, §4.1.4–§4.1.6; ADR 0027 §2 through NumericDate::from_json.
        for name in ["exp", "nbf", "iat"] {
            let date = |value: &str| {
                claims(&format!(r#"{{"{name}":{value}}}"#)).map(|c| match name {
                    "exp" => c.exp,
                    "nbf" => c.nbf,
                    _ => c.iat,
                })
            };
            for bad in [
                r#""1300819380""#,
                "9007199254740992",
                "-9007199254740992",
                "null",
                "true",
                "[]",
                "{}",
            ] {
                assert_eq!(date(bad), Err(Error::InvalidClaim(name)), "{name}: {bad}");
            }
            for (good, secs) in [
                ("1300819380.25", 1_300_819_380.25),
                ("-5", -5.0),
                ("0", 0.0),
                ("9007199254740991", 9_007_199_254_740_991.0),
                ("1e3", 1000.0),
            ] {
                let got = date(good).unwrap().map(|d| d.as_f64());
                assert_eq!(got, Some(secs), "{name}: {good}");
            }
        }
    }

    #[test]
    fn registered_claim_errors_follow_the_registered_order() {
        // Deterministic whatever the member order: the order of
        // REGISTERED_CLAIMS (ADR 0027 §9 J3–J4).
        assert_eq!(
            claims(r#"{"jti":1,"exp":"x","sub":1}"#),
            Err(Error::InvalidClaim("sub"))
        );
        assert_eq!(
            claims(r#"{"jti":1,"iat":"x","aud":[1]}"#),
            Err(Error::InvalidClaim("aud"))
        );
        assert_eq!(
            claims(r#"{"jti":1,"iat":"x"}"#),
            Err(Error::InvalidClaim("iat"))
        );
    }

    #[test]
    fn json_level_problems_are_invalid_json() {
        // RFC 7519 §4 (duplicates rejected), §7.2 step 10; ADR 0027 §1.
        let inputs: [&[u8]; 17] = [
            br#"{"exp":1,"exp":2}"#,
            br#"{"exp":1,"exp":2}"#,
            br#"{"iss":"a","iss":"a"}"#,
            br#"{"x":1,"x":2}"#,
            br#"{"x":{"a":1,"a":2}}"#,
            b"{\"iss\":\"\xff\"}",
            b"\xef\xbb\xbf{}",
            b"[]",
            br#"[{"iss":"joe"}]"#,
            br#""joe""#,
            b"1300819380",
            b"null",
            b"true",
            br#"{"iss":"joe"}x"#,
            b"{} {}",
            b"",
            b"{",
        ];
        for input in inputs {
            assert!(
                is_invalid_json(&Claims::from_json(input)),
                "{:?}",
                String::from_utf8_lossy(input)
            );
        }
        // JSON problems are found before claim types.
        assert!(is_invalid_json(&claims(r#"{"iss":1,"iss":2}"#)));
    }

    #[test]
    fn other_claims_are_kept_as_values_in_order() {
        // RFC 7519 §4.2–§4.3; ADR 0027 §1.
        let c = claims(
            r#"{"z":{"nested":[1,{"deep":"v"}]},"iss":"joe","a":[true,null],"m":"s","n":-1.5}"#,
        )
        .unwrap();
        let names: Vec<&str> = c.other_claims().iter().map(|(n, _)| n).collect();
        assert_eq!(names, ["z", "a", "m", "n"]);
        assert_eq!(c.iss.as_deref(), Some("joe"));
        let deep = c
            .get("z")
            .and_then(|z| z.get("nested"))
            .and_then(Value::as_array)
            .and_then(|items| items.get(1))
            .and_then(|o| o.get("deep"))
            .and_then(Value::as_str);
        assert_eq!(deep, Some("v"));
        assert_eq!(
            c.get("a"),
            Some(&Value::Array(vec![Value::Bool(true), Value::Null]))
        );
        assert_eq!(c.get("m").and_then(Value::as_str), Some("s"));
        assert_eq!(c.get("n").and_then(Value::as_f64), Some(-1.5));
        // Registered names stay in the typed fields.
        for name in REGISTERED_CLAIMS {
            assert_eq!(c.get(name), None);
        }
        // Names that only resemble registered ones are other claims.
        let c = claims(r#"{"EXP":"x","iss ":1}"#).unwrap();
        assert!(c.exp.is_none() && c.iss.is_none());
        assert_eq!(c.get("EXP").and_then(Value::as_str), Some("x"));
        assert_eq!(c.get("iss ").and_then(Value::as_i64), Some(1));
        // The empty object is an empty Claims Set.
        assert_eq!(claims("{}"), Ok(Claims::new()));
        assert_eq!(claims(" \r\n{ }\t"), Ok(Claims::new()));
    }

    #[test]
    fn rfc7519_section_3_1_claims_serialize_compactly() {
        // RFC 7519 §7.1 step 1; ADR 0027 §1.
        let c = Claims::from_json(RFC7519_3_1_CLAIMS).unwrap();
        assert_eq!(
            c.to_json(),
            r#"{"iss":"joe","exp":1300819380,"http://example.com/is_root":true}"#
        );
    }

    #[test]
    fn registered_claims_come_first_in_the_fixed_order() {
        // ADR 0027 §1: iss, sub, aud, exp, nbf, iat, jti, then the other
        // claims in insertion order, whatever order the fields were set in.
        let mut c = Claims::new();
        c.insert("z", Value::Null).unwrap();
        c.jti = Some("j".into());
        c.iat = NumericDate::from_secs(3);
        c.insert("a", Value::from("x")).unwrap();
        c.nbf = NumericDate::from_secs(2);
        c.exp = NumericDate::from_secs(1);
        c.aud = Some(Audience::One("au".into()));
        c.sub = Some("s".into());
        c.iss = Some("i".into());
        assert_eq!(
            c.to_json(),
            r#"{"iss":"i","sub":"s","aud":"au","exp":1,"nbf":2,"iat":3,"jti":"j","z":null,"a":"x"}"#
        );
        // The same order from a parsed Claims Set whose input order differs.
        let parsed = claims(
            r#"{"m":1,"jti":"j","iat":3,"nbf":2,"exp":1,"aud":"au","sub":"s","iss":"i","b":[]}"#,
        )
        .unwrap();
        assert_eq!(
            parsed.to_json(),
            r#"{"iss":"i","sub":"s","aud":"au","exp":1,"nbf":2,"iat":3,"jti":"j","m":1,"b":[]}"#
        );
        assert_eq!(Claims::new().to_json(), "{}");
    }

    #[test]
    fn audience_keeps_its_form_and_dates_their_value() {
        // RFC 7519 §4.1.3 (form kept); ADR 0027 §1 (integral dates have no
        // fraction), §2 (fractions and negatives kept).
        let json = |c: &Claims| c.to_json();
        let mut c = Claims::new();
        c.aud = Some(Audience::One("a".into()));
        assert_eq!(json(&c), r#"{"aud":"a"}"#);
        c.aud = Some(Audience::Many(vec!["a".into()]));
        assert_eq!(json(&c), r#"{"aud":["a"]}"#);
        c.aud = Some(Audience::Many(vec!["b".into(), "a".into()]));
        assert_eq!(json(&c), r#"{"aud":["b","a"]}"#);
        c.aud = Some(Audience::Many(Vec::new()));
        assert_eq!(json(&c), r#"{"aud":[]}"#);
        for (input, output) in [
            (r#"{"exp":1e3}"#, r#"{"exp":1000}"#),
            (r#"{"exp":1300819380.0}"#, r#"{"exp":1300819380}"#),
            (r#"{"nbf":1300819380.25}"#, r#"{"nbf":1300819380.25}"#),
            (r#"{"iat":-5}"#, r#"{"iat":-5}"#),
            (r#"{"iat":-0}"#, r#"{"iat":0}"#),
            (r#"{"exp":9007199254740991}"#, r#"{"exp":9007199254740991}"#),
        ] {
            assert_eq!(json(&claims(input).unwrap()), output, "{input}");
        }
    }

    #[test]
    fn strings_are_escaped_minimally() {
        // RFC 8259 §7, through the crate's writer.
        let mut c = Claims::new();
        c.iss = Some("a\"b\\c\n\u{1}é/".into());
        c.insert("k\"ey", Value::from("v\t")).unwrap();
        assert_eq!(
            c.to_json(),
            "{\"iss\":\"a\\\"b\\\\c\\n\\u0001\u{e9}/\",\"k\\\"ey\":\"v\\t\"}"
        );
    }

    #[test]
    fn parse_of_serialize_is_the_identity() {
        // ADR 0027 §1: from_json(to_json(c)) == c.
        let mut built = Claims::new();
        built.iss = Some("https://issuer.example".into());
        built.sub = Some(String::new());
        built.aud = Some(Audience::Many(vec!["x".into(), "y".into()]));
        built.exp = NumericDate::from_f64(1_300_819_380.5);
        built.nbf = NumericDate::from_secs(-1);
        built.iat = NumericDate::from_secs(0);
        built.jti = Some("\u{1f600}\u{0}".into());
        built
            .insert("nested", Value::from(vec![Value::Null, Value::from("s")]))
            .unwrap();
        let mut table = vec![Claims::new(), built];
        for json in [
            r#"{"iss":"joe","exp":1300819380,"http://example.com/is_root":true}"#,
            r#"{"aud":"one"}"#,
            r#"{"aud":[]}"#,
            r#"{"x":{"b":[1,2.5,{"c":null}],"a":"é"},"exp":1e3,"y":false}"#,
            r#"{"jti":"😀","sub":"\"","iat":1300819380.25}"#,
        ] {
            table.push(claims(json).unwrap());
        }
        for c in table {
            let text = c.to_json();
            assert_eq!(claims(&text).as_ref(), Ok(&c), "{text}");
            // Serializing is deterministic: a second round gives the same text.
            assert_eq!(claims(&text).unwrap().to_json(), text);
        }
    }

    /// Secret text for the `Debug` tests; a leak would contain it.
    const MARKER: &str = "MARKER-f01-claim-value";

    #[test]
    fn debug_redacts_every_claim_string() {
        // Workspace secrets rule, ADR 0049 §4: `iss`, `sub`, `aud` and `jti`
        // (RFC 7519 §4.1.1–§4.1.3, §4.1.7) print redacted like `Value`'s
        // strings; NumericDates and claim names print.
        let mut c = Claims::new();
        c.iss = Some(format!("{MARKER}-iss"));
        c.sub = Some(format!("{MARKER}-sub"));
        c.aud = Some(Audience::Many(vec![
            format!("{MARKER}-aud-1"),
            format!("{MARKER}-aud-2"),
        ]));
        c.exp = NumericDate::from_secs(1300819380);
        c.nbf = NumericDate::from_secs(1300819000);
        c.jti = Some(format!("{MARKER}-jti"));
        c.insert("private", format!("{MARKER}-private")).unwrap();
        c.insert("n", Value::Bool(true)).unwrap();
        let (exp, nbf) = (format!("{:?}", c.exp), format!("{:?}", c.nbf));
        assert_eq!(
            format!("{c:?}"),
            format!(
                r#"Claims {{ iss: Some("<redacted>"), sub: Some("<redacted>"), aud: Some(Many(["<redacted>", "<redacted>"])), exp: {exp}, nbf: {nbf}, iat: None, jti: Some("<redacted>"), other: {{"private": String("<redacted>"), "n": Bool(true)}} }}"#
            )
        );
        assert!(exp.contains("1300819380"), "{exp}");
        let pretty = format!("{c:#?}");
        assert!(!pretty.contains(MARKER), "{pretty}");
        assert!(pretty.contains("    iss: Some(\n        \"<redacted>\",\n    ),"));
        assert!(pretty.contains("\"private\": String("), "{pretty}");

        // Absent claims print as `None`.
        assert_eq!(
            format!("{:?}", Claims::new()),
            "Claims { iss: None, sub: None, aud: None, exp: None, nbf: None, iat: None, jti: None, other: {} }"
        );

        // Parsed claims too, whatever the claim strings hold.
        let parsed = claims(&format!(
            r#"{{"iss":"{MARKER}","sub":"{MARKER}","aud":"{MARKER}","jti":"{MARKER}","exp":1300819380,"secret":"{MARKER}","list":["{MARKER}"],"obj":{{"k":"{MARKER}"}}}}"#
        ))
        .unwrap();
        for debug in [format!("{parsed:?}"), format!("{parsed:#?}")] {
            assert!(!debug.contains(MARKER), "{debug}");
            for shown in ["1300819380", "\"secret\"", "\"list\"", "\"k\"", "One("] {
                assert!(debug.contains(shown), "{shown} missing from {debug}");
            }
        }
        // Nothing of the input's layout (RFC 7519 §3.1 CRLF and spaces)
        // survives into the parsed value.
        let debug = format!("{:?}", Claims::from_json(RFC7519_3_1_CLAIMS).unwrap());
        assert!(!debug.contains('\r') && !debug.contains("\\r"), "{debug}");
    }

    #[test]
    fn audience_debug_prints_its_form_and_count_but_no_value() {
        // RFC 7519 §4.1.3: the form shows; each value is a placeholder.
        let one = Audience::One(MARKER.into());
        assert_eq!(format!("{one:?}"), r#"One("<redacted>")"#);
        assert_eq!(format!("{one:#?}"), "One(\n    \"<redacted>\",\n)");
        assert_eq!(format!("{:?}", Audience::Many(vec![])), "Many([])");
        let many = Audience::Many(vec![MARKER.into(), String::new(), MARKER.repeat(9)]);
        assert_eq!(
            format!("{many:?}"),
            r#"Many(["<redacted>", "<redacted>", "<redacted>"])"#
        );
        assert!(!format!("{many:#?}").contains(MARKER));
        // The placeholder is the same whatever the length: no length leaks.
        assert_eq!(
            format!("{:?}", Audience::One(String::new())),
            format!("{one:?}")
        );
    }

    #[test]
    fn errors_never_echo_claim_values() {
        // Error::InvalidClaim names the claim, never its value; the
        // parser's InvalidJson details are fixed strings (ADR 0007).
        let inputs = [
            r#"{"iss":424242}"#,
            r#"{"sub":["SENTINEL"]}"#,
            r#"{"jti":{"SENTINEL":"SENTINEL"}}"#,
            r#"{"aud":["SENTINEL",424242]}"#,
            r#"{"aud":{"SENTINEL":1}}"#,
            r#"{"exp":"SENTINEL"}"#,
            r#"{"nbf":9007199254740993424242}"#,
            r#"{"iat":["SENTINEL"]}"#,
            r#"{"SENTINEL":1,"SENTINEL":2}"#,
            r#"["SENTINEL"]"#,
            r#""SENTINEL""#,
            r#"{"iss":"SENTINEL"}SENTINEL"#,
        ];
        for input in inputs {
            let err = claims(input).unwrap_err();
            assert!(
                matches!(err, Error::InvalidClaim(_) | Error::InvalidJson(_)),
                "{input}: {err:?}"
            );
            for text in [format!("{err}"), format!("{err:?}")] {
                assert!(
                    !text.contains("SENTINEL") && !text.contains("424242"),
                    "{input}: {text}"
                );
            }
        }
    }

    // ---- tester probes (T03 verification) ----

    #[test]
    fn probe_escaped_duplicate_names_are_invalid_json() {
        // RFC 7519 §4 / RFC 7493 §2.3: names compare after unescaping.
        for input in [
            r#"{"exp":1,"exp":2}"#,
            r#"{"exp":1,"exp":2}"#,
            r#"{"exp":1,"exp":2}"#,
            r#"{"iss":"a","iss":"b"}"#,
            r#"{"a\/b":1,"a/b":2}"#,
            r#"{"😀":1,"😀":2}"#,
        ] {
            assert!(is_invalid_json(&claims(input)), "{input}");
        }
        // Escaped registered name is the registered claim, not a private one.
        let c = claims(r#"{"iss":"joe"}"#).unwrap();
        assert_eq!(c.iss.as_deref(), Some("joe"));
        assert!(c.other_claims().is_empty());
        assert_eq!(claims(r#"{"exp":"x"}"#), Err(Error::InvalidClaim("exp")));
    }

    #[test]
    fn probe_rfc_payload_variants() {
        // Leading/trailing JSON whitespace around the object is allowed.
        let padded = b" \r\n\t{\"iss\":\"joe\",\r\n \"exp\":1300819380,\r\n \"http://example.com/is_root\":true} \r\n";
        let c = Claims::from_json(padded).unwrap();
        assert_eq!(c.iss.as_deref(), Some("joe"));
        assert_eq!(
            c.to_json(),
            r#"{"iss":"joe","exp":1300819380,"http://example.com/is_root":true}"#
        );
    }

    #[test]
    fn probe_number_edge_forms() {
        let exp = |v: &str| claims(&format!(r#"{{"exp":{v}}}"#)).map(|c| c.exp);
        for (v, want) in [
            ("-0", 0.0),
            ("1E3", 1000.0),
            ("1.0", 1.0),
            ("0.1", 0.1),
            ("1300819380.25", 1_300_819_380.25),
            ("9007199254740991", 9_007_199_254_740_991.0),
            ("-9007199254740991", -9_007_199_254_740_991.0),
            ("9007199254740991.0", 9_007_199_254_740_991.0),
        ] {
            let got = exp(v).unwrap_or_else(|e| panic!("{v}: {e:?}")).unwrap();
            assert_eq!(got.as_f64(), want, "{v}");
        }
        for v in [
            "9007199254740992",
            "-9007199254740992",
            "9007199254740993",
            "9007199254740992.0",
            "1e17",
        ] {
            assert_eq!(exp(v), Err(Error::InvalidClaim("exp")), "{v}");
        }
        // Not representable as a finite number at all: a JSON-level error.
        assert!(is_invalid_json(&exp("1e400")), "1e400");
        assert!(is_invalid_json(&exp("-1e400")), "-1e400");
        // JSON grammar violations.
        for v in ["+1", "01", ".5", "1.", "NaN", "Infinity", "0x10"] {
            assert!(is_invalid_json(&exp(v)), "{v}");
        }
    }

    #[test]
    fn probe_integral_dates_serialize_without_fraction_and_round_trip() {
        for (input, out) in [
            (r#"{"exp":1E3}"#, r#"{"exp":1000}"#),
            (r#"{"exp":1.0}"#, r#"{"exp":1}"#),
            (r#"{"exp":1300819380.25}"#, r#"{"exp":1300819380.25}"#),
            (r#"{"nbf":0.1}"#, r#"{"nbf":0.1}"#),
            (r#"{"iat":-5}"#, r#"{"iat":-5}"#),
            (
                r#"{"exp":9007199254740991,"nbf":-9007199254740991}"#,
                r#"{"exp":9007199254740991,"nbf":-9007199254740991}"#,
            ),
        ] {
            let c = claims(input).unwrap();
            let json = c.to_json();
            assert_eq!(json, out, "{input}");
            assert!(!json.contains(".0"), "{json}");
            assert_eq!(Claims::from_json(json.as_bytes()).as_ref(), Ok(&c));
        }
        // -0 serializes without a sign or fraction.
        let c = claims(r#"{"exp":-0}"#).unwrap();
        assert_eq!(c.to_json(), r#"{"exp":0}"#);
        assert_eq!(Claims::from_json(c.to_json().as_bytes()), Ok(c));
    }

    #[test]
    fn probe_first_wrong_registered_claim_wins_in_every_input_order() {
        // Wrong: sub, aud, exp, nbf, iat, jti (iss fine). Permute all input orders.
        let bad: [(&str, &str); 6] = [
            ("sub", "1"),
            ("aud", "{}"),
            ("exp", r#""x""#),
            ("nbf", "null"),
            ("iat", "[]"),
            ("jti", "true"),
        ];
        let order = ["iss", "sub", "aud", "exp", "nbf", "iat", "jti"];
        // For each suffix of the registered order, rotate and reverse input order.
        for start in 0..bad.len() {
            let mut members: Vec<(&str, &str)> = bad[start..].to_vec();
            let expect = members[0].0;
            assert!(order.contains(&expect));
            for rot in 0..members.len() {
                members.rotate_left(1);
                let body = members
                    .iter()
                    .map(|(k, v)| format!(r#""{k}":{v}"#))
                    .collect::<Vec<_>>()
                    .join(",");
                let json = format!("{{{body}}}");
                assert_eq!(
                    claims(&json),
                    Err(Error::InvalidClaim(expect)),
                    "{rot} {json}"
                );
                let mut rev = members.clone();
                rev.reverse();
                let body = rev
                    .iter()
                    .map(|(k, v)| format!(r#""{k}":{v}"#))
                    .collect::<Vec<_>>()
                    .join(",");
                assert_eq!(
                    claims(&format!("{{{body}}}")),
                    Err(Error::InvalidClaim(expect))
                );
            }
        }
    }

    #[test]
    fn probe_no_value_in_any_error_or_debug_with_marker() {
        const M: &str = "ZQMARKERQZ";
        let inputs = [
            format!(r#"{{"iss":["{M}"]}}"#),
            format!(r#"{{"sub":{{"{M}":"{M}"}}}}"#),
            format!(r#"{{"aud":["{M}",1]}}"#),
            format!(r#"{{"exp":"{M}"}}"#),
            format!(r#"{{"{M}":1,"{M}":2}}"#),
            format!(r#"{{"{M}":"{M}"}}x"#),
            format!(r#"["{M}"]"#),
            format!(r#"{{"jti":"{M}","exp":"{M}"}}"#),
            format!("{{\"{M}\":\"\u{ff}\"}}"),
        ];
        for input in inputs {
            let mut bytes = input.into_bytes();
            if let Some(i) = bytes.windows(2).position(|w| w == [0xc3, 0xbf]) {
                bytes[i] = 0xff; // invalid UTF-8 variant
                bytes.remove(i + 1);
            }
            let err = Claims::from_json(&bytes).unwrap_err();
            for t in [format!("{err}"), format!("{err:?}")] {
                assert!(!t.contains(M), "{t}");
            }
        }
        // Debug of parsed claims redacts private string values and names none of the marker in `other`.
        let c = claims(&format!(r#"{{"p":"{M}","q":[{{"r":"{M}"}}]}}"#)).unwrap();
        assert!(!format!("{c:?}").contains(M), "{c:?}");
    }

    #[test]
    fn probe_nested_and_private_claims_roundtrip_in_order() {
        let c = claims(r#"{"z":{"b":[1,{"c":null}],"a":"x"},"iss":"i","m":[],"a":0.5}"#).unwrap();
        let names: Vec<&str> = c.other_claims().iter().map(|(n, _)| n).collect();
        assert_eq!(names, ["z", "m", "a"]);
        let json = c.to_json();
        assert_eq!(
            json,
            r#"{"iss":"i","z":{"b":[1,{"c":null}],"a":"x"},"m":[],"a":0.5}"#
        );
        assert_eq!(Claims::from_json(json.as_bytes()), Ok(c));
    }

    mod probe_props {
        use super::*;
        use proptest::prelude::*;

        proptest! {
            #![proptest_config(ProptestConfig::with_cases(1000))]

            #[test]
            fn from_json_never_panics_on_arbitrary_bytes(
                bytes in proptest::collection::vec(any::<u8>(), 0..256)
            ) {
                if let Ok(c) = Claims::from_json(&bytes) {
                    prop_assert_eq!(Claims::from_json(c.to_json().as_bytes()), Ok(c));
                }
            }

            #[test]
            fn from_json_never_panics_on_json_shaped_input(
                s in r#"[{}\[\]",:a-z0-9.eE+\- \\u]{0,64}"#
            ) {
                let _ = Claims::from_json(s.as_bytes());
                let wrapped = format!(r#"{{"exp":{s},"aud":{s},"iss":{s}}}"#);
                let _ = Claims::from_json(wrapped.as_bytes());
            }
        }
    }
}