chore: Release trueskill-tt version 0.8.0

Reject malformed games at the Game entry point, which does not pass
through History's ingestion chokepoint.

Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_011hcFjNDmHXZF8URGLku5zZ

CHANGELOG.md

@@ -2,12 +2,51 @@
 
 All notable changes to this project will be documented in this file.
 
+## 0.8.0 - 2026-09-08
+
+### Breaking Changes
+
+- feat!: make a short fit an error and raise the default iteration cap
+- feat!: validate mu, sigma and beta on HistoryBuilder
+- feat!: add History::register and History::rating, and reject config conflicts across batches
+- fix!: reject non-finite weights at ingestion
+- fix!: reject malformed games at the Game boundary too
+
+### Bug Fixes
+
+- fix: reject malformed events at the ingestion boundary
+
+### Documentation
+
+- docs: record the rayon opt-in deviation in spec section 6
+- docs: state what the joint's cost actually scales in
+
+### Features
+
+- feat: add EventBuilder::members for per-member configuration
+
+### Other (unconventional)
+
+- Merge branch 'fix/ingestion-shape'
+- Merge branch 'feat/convergence-strictness'
+- Merge branch 'fix/non-finite-weights'
+- Merge branch 'test/close-coverage-gaps'
+- Merge branch 'fix/game-boundary'
+
+### Testing
+
+- test: cover non-finite results and color-group disjointness
+
 ## 0.7.0 - 2026-09-08
 
 ### Features
 
 - feat: factorise the joint once with History::joint
 
+### Miscellaneous Tasks
+
+- chore: Release trueskill-tt version 0.7.0
+
 ### Other (unconventional)
 
 - Merge branch 'feat/joint-handle'

Cargo.toml

@@ -1,6 +1,6 @@
 [package]
 name = "trueskill-tt"
-version = "0.7.0"
+version = "0.8.0"
 edition = "2024"
 rust-version = "1.85"
 description = "TrueSkill Through Time: Bayesian skill rating that tracks how skill evolves over time, via Gaussian message passing"

src/game.rs

@@ -431,6 +431,29 @@ impl<'a, T: Time, D: Drift<T>> Game<'a, T, D> {
 }
 
 impl<T: Time, D: Drift<T>> Game<'_, T, D> {
+    /// Reject the team shapes inference cannot represent.
+    ///
+    /// `run_chain` builds one diff link per adjacent pair of teams, so fewer
+    /// than two teams leaves it indexing `links[1..]` on an empty vector — a
+    /// panic, in release, from safe API. An empty team is the quiet half: it
+    /// contributes no performance, so a malformed game returns a finite,
+    /// plausible-looking posterior for whoever it was matched against.
+    ///
+    /// `History` validates the same two things at its own ingestion
+    /// chokepoint. `Game` is a separate public entry point that does not pass
+    /// through it, so it needs its own check rather than inheriting one.
+    fn validate_teams(teams: &[&[Rating<T, D>]]) -> Result<(), crate::InferenceError> {
+        if teams.len() < 2 {
+            return Err(crate::InferenceError::NotEnoughTeams { got: teams.len() });
+        }
+        for (team, members) in teams.iter().enumerate() {
+            if members.is_empty() {
+                return Err(crate::InferenceError::EmptyTeam { team });
+            }
+        }
+        Ok(())
+    }
+
     /// # Errors
     ///
     /// - `InvalidParameter` if `options.convergence` is out of range — an
@@ -442,12 +465,15 @@ impl<T: Time, D: Drift<T>> Game<'_, T, D> {
     /// - `TieWithoutDrawProbability` if the outcome ties two teams while
     ///   `p_draw` is zero: the truncation margin is then zero and the two-sided
     ///   tie update evaluates `0/0`.
+    /// - `NotEnoughTeams` for fewer than two teams, and `EmptyTeam` for a team
+    ///   with no members.
     pub fn ranked(
         teams: &[&[Rating<T, D>]],
         outcome: crate::Outcome,
         options: &GameOptions,
     ) -> Result<OwnedGame<T, D>, crate::InferenceError> {
         options.convergence.validate()?;
+        Self::validate_teams(teams)?;
         if !(0.0..1.0).contains(&options.p_draw) {
             return Err(crate::InferenceError::InvalidProbability {
                 value: options.p_draw,
@@ -499,12 +525,15 @@ impl<T: Time, D: Drift<T>> Game<'_, T, D> {
     ///   or is NaN, or if `options.convergence` is out of range.
     /// - `MismatchedShape` if the outcome's score count differs from `teams.len()`.
     /// - `WrongOutcomeKind` if `outcome` is not `Outcome::Scored`.
+    /// - `NotEnoughTeams` for fewer than two teams, `EmptyTeam` for a team with
+    ///   no members, and `InvalidParameter` for a non-finite score.
     pub fn scored(
         teams: &[&[Rating<T, D>]],
         outcome: crate::Outcome,
         options: &GameOptions,
     ) -> Result<OwnedGame<T, D>, crate::InferenceError> {
         options.convergence.validate()?;
+        Self::validate_teams(teams)?;
         if options.score_sigma <= 0.0 || options.score_sigma.is_nan() {
             return Err(crate::InferenceError::InvalidParameter {
                 name: "score_sigma",
@@ -526,6 +555,16 @@ impl<T: Time, D: Drift<T>> Game<'_, T, D> {
                 got: "Outcome::Ranked",
             })?
             .to_vec();
+        // A non-finite score poisons the chain rather than failing it. Ranks
+        // need no equivalent: they are `u32`.
+        for value in &scores {
+            if !value.is_finite() {
+                return Err(crate::InferenceError::InvalidParameter {
+                    name: "score",
+                    value: *value,
+                });
+            }
+        }
         let teams_owned: Vec<Vec<Rating<T, D>>> = teams.iter().map(|t| t.to_vec()).collect();
         let weights: Vec<Vec<f64>> = teams.iter().map(|t| vec![1.0; t.len()]).collect();
         Ok(OwnedGame::new_scored(

tests/game.rs

@@ -138,3 +138,115 @@ fn one_v_one_honours_convergence_options() {
     let (a_post, _) = Game::<i64, _>::one_v_one(&a, &b, Outcome::winner(0, 2), &options).unwrap();
     assert!(a_post.mu() > 25.0);
 }
+
+/// `Game` is a public entry point that does not pass through `History`'s
+/// ingestion chokepoint, so it needs its own boundary — and did not have one.
+///
+/// A one-team game panicked at `src/game.rs:317` with "range start index 1 out
+/// of range for slice of length 0", in release, from safe API. This is the
+/// same defect `tests/ingestion_shape.rs` covers for `History`; fixing that
+/// path left this one open, because they share no validation.
+mod malformed_games {
+    use super::*;
+
+    #[test]
+    fn a_one_team_ranked_game_is_an_error_not_a_panic() {
+        let a = default_rating();
+        let err = Game::<i64, _>::ranked(&[&[a]], Outcome::winner(0, 1), &GameOptions::default())
+            .unwrap_err();
+        assert!(
+            matches!(err, InferenceError::NotEnoughTeams { got: 1 }),
+            "{err:?}"
+        );
+    }
+
+    #[test]
+    fn a_one_team_scored_game_is_an_error_not_a_panic() {
+        let a = default_rating();
+        let err = Game::<i64, _>::scored(
+            &[&[a]],
+            Outcome::scores([1.0]),
+            &GameOptions {
+                score_sigma: 1.0,
+                ..GameOptions::default()
+            },
+        )
+        .unwrap_err();
+        assert!(
+            matches!(err, InferenceError::NotEnoughTeams { got: 1 }),
+            "{err:?}"
+        );
+    }
+
+    #[test]
+    fn a_zero_team_game_is_an_error() {
+        let err =
+            Game::<i64, ConstantDrift>::ranked(&[], Outcome::ranking([]), &GameOptions::default())
+                .unwrap_err();
+        assert!(
+            matches!(err, InferenceError::NotEnoughTeams { got: 0 }),
+            "{err:?}"
+        );
+    }
+
+    /// The quiet half: an empty team contributed no performance, so the game
+    /// returned a finite posterior for its opponent as though it had won one.
+    #[test]
+    fn an_empty_team_is_an_error() {
+        let a = default_rating();
+        let err =
+            Game::<i64, _>::ranked(&[&[], &[a]], Outcome::winner(0, 2), &GameOptions::default())
+                .unwrap_err();
+        assert!(
+            matches!(err, InferenceError::EmptyTeam { team: 0 }),
+            "{err:?}"
+        );
+    }
+
+    #[test]
+    fn a_non_finite_score_is_an_error() {
+        let a = default_rating();
+        for bad in [f64::NAN, f64::INFINITY, f64::NEG_INFINITY] {
+            let err = Game::<i64, _>::scored(
+                &[&[a], &[a]],
+                Outcome::scores([bad, 1.0]),
+                &GameOptions {
+                    score_sigma: 1.0,
+                    ..GameOptions::default()
+                },
+            )
+            .unwrap_err();
+            assert!(
+                matches!(err, InferenceError::InvalidParameter { name: "score", .. }),
+                "{bad}: {err:?}"
+            );
+        }
+    }
+
+    /// `free_for_all` and `one_v_one` build their teams internally, so they
+    /// must keep working — the check must not catch well-formed games.
+    #[test]
+    fn well_formed_games_are_untouched() {
+        let a = default_rating();
+        assert!(
+            Game::<i64, _>::ranked(
+                &[&[a], &[a]],
+                Outcome::winner(0, 2),
+                &GameOptions::default()
+            )
+            .is_ok()
+        );
+        assert!(
+            Game::<i64, _>::free_for_all(
+                &[&a, &a, &a],
+                Outcome::ranking([0, 1, 2]),
+                &GameOptions::default()
+            )
+            .is_ok()
+        );
+        assert!(
+            Game::<i64, _>::one_v_one(&a, &a, Outcome::winner(0, 2), &GameOptions::default())
+                .is_ok()
+        );
+    }
+}