fix(engine,parser): do not create an Aura token whose host is undefined (#7302)

crates/engine/src/game/effects/add_target_replacement.rs

@@ -954,7 +954,7 @@ mod tests {
             sacrifice_at: None,
             source_id: ObjectId(50),
             controller: PlayerId(1),
-            attach_to: None,
+            attach_to: crate::types::proposed_event::TokenHostRequest::NotRequested,
         };
         let proposed = ProposedEvent::CreateToken {
             owner: PlayerId(1),
@@ -1048,7 +1048,7 @@ mod tests {
             sacrifice_at: None,
             source_id: ObjectId(70),
             controller: PlayerId(1),
-            attach_to: None,
+            attach_to: crate::types::proposed_event::TokenHostRequest::NotRequested,
         };
         let proposed = ProposedEvent::CreateToken {
             owner: PlayerId(1),
@@ -1132,7 +1132,7 @@ mod tests {
             sacrifice_at: None,
             source_id: ObjectId(60),
             controller: PlayerId(0),
-            attach_to: None,
+            attach_to: crate::types::proposed_event::TokenHostRequest::NotRequested,
         };
         let proposed = ProposedEvent::CreateToken {
             owner: PlayerId(0),

crates/engine/src/game/effects/amass.rs

@@ -204,7 +204,7 @@ fn create_army_token(
         enter_with_counters: vec![],
         tapped: false,
         enters_attacking: false,
-        attach_to: None,
+        attach_to: crate::types::proposed_event::TokenHostRequest::NotRequested,
         sacrifice_at: None,
         source_id: ability.source_id,
         controller: ability.controller,
@@ -383,7 +383,7 @@ mod tests {
                 enter_with_counters: Vec::new(),
                 tapped: false,
                 enters_attacking: false,
-                attach_to: None,
+                attach_to: crate::types::proposed_event::TokenHostRequest::NotRequested,
                 sacrifice_at: None,
                 source_id: ObjectId(0),
                 controller: P0,

crates/engine/src/game/effects/attach.rs

@@ -685,7 +685,7 @@ pub(crate) enum AttachmentAuthority<'a> {
 /// Player hosts are Auras-only (see [`attach_to_player`]); a copy exception that
 /// adds or removes the `Aura` subtype (CR 205.1a) changes the answer, so this
 /// reads the authority rather than the stored object.
-fn authority_is_aura(
+pub(crate) fn authority_is_aura(
     state: &GameState,
     attachment_id: ObjectId,
     authority: AttachmentAuthority<'_>,

crates/engine/src/game/engine_debug.rs

@@ -540,7 +540,7 @@ pub fn apply_debug_action(
                 sacrifice_at: None,
                 source_id: ObjectId(0),
                 controller: owner,
-                attach_to: None,
+                attach_to: crate::types::proposed_event::TokenHostRequest::NotRequested,
             };
             let proposed = ProposedEvent::CreateToken {
                 owner,

crates/engine/src/game/engine_replacement.rs

@@ -4458,7 +4458,7 @@ mod tests {
             sacrifice_at: None,
             source_id: ObjectId(1),
             controller: PlayerId(0),
-            attach_to: None,
+            attach_to: crate::types::proposed_event::TokenHostRequest::NotRequested,
         };
 
         let battlefield_before = state.battlefield.clone();
@@ -4583,7 +4583,7 @@ mod tests {
             sacrifice_at: None,
             source_id: replacement_source,
             controller: PlayerId(0),
-            attach_to: None,
+            attach_to: crate::types::proposed_event::TokenHostRequest::NotRequested,
         };
         let battlefield_before = state.battlefield.clone();
 
@@ -4741,7 +4741,7 @@ mod tests {
             sacrifice_at: None,
             source_id: replacement_source,
             controller: PlayerId(0),
-            attach_to: None,
+            attach_to: crate::types::proposed_event::TokenHostRequest::NotRequested,
         };
         let battlefield_before = state.battlefield.clone();
 
@@ -4916,7 +4916,7 @@ mod tests {
             sacrifice_at: None,
             source_id: replacement_source,
             controller: PlayerId(0),
-            attach_to: None,
+            attach_to: crate::types::proposed_event::TokenHostRequest::NotRequested,
         };
         let battlefield_before = state.battlefield.clone();
 
@@ -5070,7 +5070,7 @@ mod tests {
             sacrifice_at: None,
             source_id: jinnie_source,
             controller: PlayerId(0),
-            attach_to: None,
+            attach_to: crate::types::proposed_event::TokenHostRequest::NotRequested,
         };
         let applied = state
             .post_replacement_token_choice_applied
@@ -5207,7 +5207,7 @@ mod tests {
             sacrifice_at: None,
             source_id: jinnie_source,
             controller: PlayerId(0),
-            attach_to: None,
+            attach_to: crate::types::proposed_event::TokenHostRequest::NotRequested,
         };
         let battlefield_before = state.battlefield.clone();
 

crates/engine/src/game/replacement.rs

@@ -14430,7 +14430,7 @@ mod tests {
             sacrifice_at: None,
             source_id: ObjectId(999),
             controller: owner_controller,
-            attach_to: None,
+            attach_to: crate::types::proposed_event::TokenHostRequest::NotRequested,
         }
     }
 
@@ -17708,7 +17708,7 @@ mod tests {
             sacrifice_at: None,
             source_id: ObjectId(0),
             controller: PlayerId(0),
-            attach_to: None,
+            attach_to: crate::types::proposed_event::TokenHostRequest::NotRequested,
         };
         let repl = ReplacementDefinition::new(ReplacementEvent::CreateToken)
             .token_owner_scope(ControllerRef::You)
@@ -17735,7 +17735,7 @@ mod tests {
             sacrifice_at: None,
             source_id: chatterfang,
             controller: PlayerId(0),
-            attach_to: None,
+            attach_to: crate::types::proposed_event::TokenHostRequest::NotRequested,
         };
         let proposed = ProposedEvent::CreateToken {
             owner: PlayerId(0),
@@ -17807,7 +17807,7 @@ mod tests {
                 sacrifice_at: None,
                 source_id: ObjectId(0),
                 controller: PlayerId(0),
-                attach_to: None,
+                attach_to: crate::types::proposed_event::TokenHostRequest::NotRequested,
             }
         }
 
@@ -17941,7 +17941,7 @@ mod tests {
             sacrifice_at: None,
             source_id: ObjectId(0),
             controller: PlayerId(0),
-            attach_to: None,
+            attach_to: crate::types::proposed_event::TokenHostRequest::NotRequested,
         };
 
         let proposed = ProposedEvent::CreateToken {
@@ -18269,7 +18269,7 @@ mod tests {
             sacrifice_at: None,
             source_id: ObjectId(0),
             controller: PlayerId(0),
-            attach_to: None,
+            attach_to: crate::types::proposed_event::TokenHostRequest::NotRequested,
         }
     }
 
@@ -18496,7 +18496,7 @@ mod tests {
             sacrifice_at: None,
             source_id: ObjectId(0),
             controller: PlayerId(1),
-            attach_to: None,
+            attach_to: crate::types::proposed_event::TokenHostRequest::NotRequested,
         };
 
         let proposed = ProposedEvent::CreateToken {
@@ -19024,7 +19024,7 @@ mod tests {
                 sacrifice_at: None,
                 source_id: ObjectId(0),
                 controller: PlayerId(0),
-                attach_to: None,
+                attach_to: crate::types::proposed_event::TokenHostRequest::NotRequested,
             }
         }
 
@@ -19142,7 +19142,7 @@ mod tests {
                 sacrifice_at: None,
                 source_id: ObjectId(0),
                 controller: PlayerId(0),
-                attach_to: None,
+                attach_to: crate::types::proposed_event::TokenHostRequest::NotRequested,
             }
         }
 
@@ -19322,7 +19322,7 @@ mod tests {
                 sacrifice_at: None,
                 source_id: ObjectId(0),
                 controller: PlayerId(0),
-                attach_to: None,
+                attach_to: crate::types::proposed_event::TokenHostRequest::NotRequested,
             }),
             copy: None,
             enter_tapped: EtbTapState::Unspecified,

crates/engine/src/game/stack.rs

@@ -9007,7 +9007,7 @@ mod tests {
                 sacrifice_at: None,
                 source_id: ObjectId(1),
                 controller: PlayerId(0),
-                attach_to: None,
+                attach_to: crate::types::proposed_event::TokenHostRequest::NotRequested,
             };
             // Bare spec passes.
             assert!(super::super::effects::token::spec_emits_only_etb_pair(
@@ -9033,7 +9033,9 @@ mod tests {
             ));
 
             let mut attached = base.clone();
-            attached.attach_to = Some(crate::game::game_object::AttachTarget::Object(ObjectId(2)));
+            attached.attach_to = crate::types::proposed_event::TokenHostRequest::Bound(
+                crate::game::game_object::AttachTarget::Object(ObjectId(2)),
+            );
             assert!(!super::super::effects::token::spec_emits_only_etb_pair(
                 &attached
             ));

crates/engine/src/parser/oracle_effect/token.rs

@@ -453,21 +453,51 @@ fn tracked_set_count_is_type_restricted(qty: &QuantityRef) -> bool {
         .any(|type_filter| !matches!(type_filter, TypeFilter::Card))
 }
 
+/// CR 303.4: The printed surfaces that bind a created token to a host inside the
+/// same create-token instruction — "an Aura enters the battlefield attached to
+/// an object or player". `" attached to "` states the relation and
+/// `" and attach it to "` states the action; the resulting permanent is
+/// identical, so both feed one `attach_to` field rather than two code paths.
+///
+/// Scanned at word boundaries with a single `alt`, so the connector that occurs
+/// FIRST in the text wins regardless of which spelling it is — testing each
+/// spelling over the whole string separately would let a later "attached to"
+/// beat an earlier "and attach it to".
+fn first_token_attachment_connector(lower: &str) -> Option<&'static str> {
+    nom_primitives::scan_at_word_boundaries(lower, |input| {
+        alt((
+            value(
+                " and attach it to ",
+                tag::<_, _, OracleError<'_>>("and attach it to "),
+            ),
+            value(" attached to ", tag("attached to ")),
+        ))
+        .parse(input)
+    })
+}
+
 fn parse_token_description_with_context(
     text: &str,
     ctx: &ParseContext,
 ) -> Option<TokenDescription> {
     let text = text.trim().trim_end_matches('.');
     let lower = text.to_lowercase();
 
-    // CR 303.7: Strip "attached to [target]" suffix and capture the attachment target.
+    // CR 303.4: Strip the attachment clause and capture its target. Oracle
+    // prints the same relation two ways in a create-token instruction — as a
+    // STATE ("create a Cursed Role token attached to target creature") and as an
+    // ACTION ("create a Questing Role token and attach it to target creature").
+    // Both mean the token enters attached, in the same instruction, so both bind
+    // the same `attach_to` field; only the printed surface differs. Keying on the
+    // state form alone dropped the attachment entirely for the action form, and
+    // CR 303.4i then says a hostless Aura token is not created at all (#7302).
     let tp = TextPair::new(text, &lower);
-    let (text, attach_to) = if let Some((before, after)) = tp.split_around(" attached to ") {
-        let (target, _) = parse_target(after.original);
-        (before.original, Some(target))
-    } else {
-        (text, None)
-    };
+    let (text, attach_to) = first_token_attachment_connector(&lower)
+        .and_then(|connector| tp.split_around(connector))
+        .map_or((text, None), |(before, after)| {
+            let (target, _) = parse_target(after.original);
+            (before.original, Some(target))
+        });
 
     // CR 508.4 + CR 506.3a: Strip inline "that's tapped and attacking" /
     // "that is tapped and attacking" / "thats tapped and attacking" /
@@ -3491,3 +3521,44 @@ fn copy_token_non_saga_token_you_control_issue_3294() {
     assert!(tf.properties.contains(&FilterProp::Token));
     assert_eq!(tf.controller, Some(ControllerRef::You));
 }
+
+#[cfg(test)]
+mod token_attachment_connector_tests {
+    use super::*;
+
+    /// CR 303.4 + CR 303.4i: Oracle prints one relation two ways inside a
+    /// create-token instruction — as a STATE ("…token attached to target
+    /// creature") and as an ACTION ("…token and attach it to target creature").
+    /// Both must bind `attach_to`; the action surface used to drop it, leaving a
+    /// hostless Aura token that CR 303.4i says is not created at all
+    /// (Questing Cosplayer, #7302).
+    ///
+    /// Table-driven over both surfaces plus the counter-direction: a token line
+    /// with no attachment clause must keep `attach_to` at `None`.
+    #[test]
+    fn both_printed_attachment_surfaces_bind_the_host() {
+        let cases: &[(&str, bool)] = &[
+            (
+                "create a Questing Role token and attach it to target creature",
+                true,
+            ),
+            (
+                "create a Cursed Role token attached to target creature",
+                true,
+            ),
+            ("create a 1/1 white Soldier creature token", false),
+        ];
+        for (text, expects_host) in cases {
+            let effect = try_parse_token(&text.to_lowercase(), text, &mut ParseContext::default())
+                .unwrap_or_else(|| panic!("{text:?} must parse as a token line"));
+            let Effect::Token { attach_to, .. } = effect else {
+                panic!("{text:?} must lower to Effect::Token");
+            };
+            assert_eq!(
+                attach_to.is_some(),
+                *expects_host,
+                "{text:?} host binding mismatch, got {attach_to:?}"
+            );
+        }
+    }
+}

crates/engine/src/parser/oracle_replacement.rs

@@ -9605,7 +9605,7 @@ fn token_description_to_spec(
         controller: crate::types::player::PlayerId(0),
         // Replacement-created tokens ("instead, create a token") are not the
         // "attached to" Aura/Role class; that path flows through `Effect::Token`.
-        attach_to: None,
+        attach_to: crate::types::proposed_event::TokenHostRequest::NotRequested,
     })
 }