Update intentional mentions (MSC3952) to depend on `exact_event_property_contains` (MSC3966). (#15051)

This replaces the specific `is_user_mention` push rule condition
used in MSC3952 with the generic `exact_event_property_contains`
push rule condition from MSC3966.

11 files changed, 73 insertions, 94 deletions

diff --git a/changelog.d/15051.misc b/changelog.d/15051.misc
new file mode 100644
index 0000000000..fabfe77d35
--- /dev/null
+++ b/changelog.d/15051.misc
@@ -0,0 +1 @@
+Update [MSC3952](https://github.com/matrix-org/matrix-spec-proposals/pull/3952) support based on changes to the MSC.
diff --git a/rust/benches/evaluator.rs b/rust/benches/evaluator.rs
index 9a871f5693..7c987d4948 100644
--- a/rust/benches/evaluator.rs
+++ b/rust/benches/evaluator.rs
@@ -44,7 +44,6 @@ fn bench_match_exact(b: &mut Bencher) {
     let eval = PushRuleEvaluator::py_new(
         flattened_keys,
         false,
-        BTreeSet::new(),
         10,
         Some(0),
         Default::default(),
@@ -92,7 +91,6 @@ fn bench_match_word(b: &mut Bencher) {
     let eval = PushRuleEvaluator::py_new(
         flattened_keys,
         false,
-        BTreeSet::new(),
         10,
         Some(0),
         Default::default(),
@@ -140,7 +138,6 @@ fn bench_match_word_miss(b: &mut Bencher) {
     let eval = PushRuleEvaluator::py_new(
         flattened_keys,
         false,
-        BTreeSet::new(),
         10,
         Some(0),
         Default::default(),
@@ -188,7 +185,6 @@ fn bench_eval_message(b: &mut Bencher) {
     let eval = PushRuleEvaluator::py_new(
         flattened_keys,
         false,
-        BTreeSet::new(),
         10,
         Some(0),
         Default::default(),
diff --git a/rust/src/push/base_rules.rs b/rust/src/push/base_rules.rs
index 62de51d915..3d72a4a4c3 100644
--- a/rust/src/push/base_rules.rs
+++ b/rust/src/push/base_rules.rs
@@ -21,13 +21,13 @@ use lazy_static::lazy_static;
 use serde_json::Value;
 
 use super::KnownCondition;
-use crate::push::PushRule;
 use crate::push::RelatedEventMatchTypeCondition;
 use crate::push::SetTweak;
 use crate::push::TweakValue;
 use crate::push::{Action, ExactEventMatchCondition, SimpleJsonValue};
 use crate::push::{Condition, EventMatchTypeCondition};
 use crate::push::{EventMatchCondition, EventMatchPatternType};
+use crate::push::{ExactEventMatchTypeCondition, PushRule};
 
 const HIGHLIGHT_ACTION: Action = Action::SetTweak(SetTweak {
     set_tweak: Cow::Borrowed("highlight"),
@@ -144,7 +144,12 @@ pub const BASE_APPEND_OVERRIDE_RULES: &[PushRule] = &[
     PushRule {
         rule_id: Cow::Borrowed(".org.matrix.msc3952.is_user_mention"),
         priority_class: 5,
-        conditions: Cow::Borrowed(&[Condition::Known(KnownCondition::IsUserMention)]),
+        conditions: Cow::Borrowed(&[Condition::Known(
+            KnownCondition::ExactEventPropertyContainsType(ExactEventMatchTypeCondition {
+                key: Cow::Borrowed("content.org.matrix.msc3952.mentions.user_ids"),
+                value_type: Cow::Borrowed(&EventMatchPatternType::UserId),
+            }),
+        )]),
         actions: Cow::Borrowed(&[Action::Notify, HIGHLIGHT_ACTION, SOUND_ACTION]),
         default: true,
         default_enabled: true,
diff --git a/rust/src/push/evaluator.rs b/rust/src/push/evaluator.rs
index a65c645caf..55846627cc 100644
--- a/rust/src/push/evaluator.rs
+++ b/rust/src/push/evaluator.rs
@@ -13,7 +13,7 @@
 // limitations under the License.
 
 use std::borrow::Cow;
-use std::collections::{BTreeMap, BTreeSet};
+use std::collections::BTreeMap;
 
 use crate::push::{EventMatchPatternType, JsonValue};
 use anyhow::{Context, Error};
@@ -72,8 +72,6 @@ pub struct PushRuleEvaluator {
 
     /// True if the event has a mentions property and MSC3952 support is enabled.
     has_mentions: bool,
-    /// The user mentions that were part of the message.
-    user_mentions: BTreeSet<String>,
 
     /// The number of users in the room.
     room_member_count: u64,
@@ -114,7 +112,6 @@ impl PushRuleEvaluator {
     pub fn py_new(
         flattened_keys: BTreeMap<String, JsonValue>,
         has_mentions: bool,
-        user_mentions: BTreeSet<String>,
         room_member_count: u64,
         sender_power_level: Option<i64>,
         notification_power_levels: BTreeMap<String, i64>,
@@ -134,7 +131,6 @@ impl PushRuleEvaluator {
             flattened_keys,
             body,
             has_mentions,
-            user_mentions,
             room_member_count,
             notification_power_levels,
             sender_power_level,
@@ -310,15 +306,30 @@ impl PushRuleEvaluator {
                     Some(Cow::Borrowed(pattern)),
                 )?
             }
-            KnownCondition::ExactEventPropertyContains(exact_event_match) => {
-                self.match_exact_event_property_contains(exact_event_match)?
-            }
-            KnownCondition::IsUserMention => {
-                if let Some(uid) = user_id {
-                    self.user_mentions.contains(uid)
+            KnownCondition::ExactEventPropertyContains(exact_event_match) => self
+                .match_exact_event_property_contains(
+                    exact_event_match.key.clone(),
+                    exact_event_match.value.clone(),
+                )?,
+            KnownCondition::ExactEventPropertyContainsType(exact_event_match) => {
+                // The `pattern_type` can either be "user_id" or "user_localpart",
+                // either way if we don't have a `user_id` then the condition can't
+                // match.
+                let user_id = if let Some(user_id) = user_id {
+                    user_id
                 } else {
-                    false
-                }
+                    return Ok(false);
+                };
+
+                let pattern = match &*exact_event_match.value_type {
+                    EventMatchPatternType::UserId => user_id,
+                    EventMatchPatternType::UserLocalpart => get_localpart_from_id(user_id)?,
+                };
+
+                self.match_exact_event_property_contains(
+                    exact_event_match.key.clone(),
+                    Cow::Borrowed(&SimpleJsonValue::Str(pattern.to_string())),
+                )?
             }
             KnownCondition::ContainsDisplayName => {
                 if let Some(dn) = display_name {
@@ -456,24 +467,21 @@ impl PushRuleEvaluator {
     /// Evaluates a `exact_event_property_contains` condition. (MSC3758)
     fn match_exact_event_property_contains(
         &self,
-        exact_event_match: &ExactEventMatchCondition,
+        key: Cow<str>,
+        value: Cow<SimpleJsonValue>,
     ) -> Result<bool, Error> {
         // First check if the feature is enabled.
         if !self.msc3966_exact_event_property_contains {
             return Ok(false);
         }
 
-        let value = &exact_event_match.value;
-
-        let haystack = if let Some(JsonValue::Array(haystack)) =
-            self.flattened_keys.get(&*exact_event_match.key)
-        {
+        let haystack = if let Some(JsonValue::Array(haystack)) = self.flattened_keys.get(&*key) {
             haystack
         } else {
             return Ok(false);
         };
 
-        Ok(haystack.contains(&**value))
+        Ok(haystack.contains(&value))
     }
 
     /// Match the member count against an 'is' condition
@@ -510,7 +518,6 @@ fn push_rule_evaluator() {
     let evaluator = PushRuleEvaluator::py_new(
         flattened_keys,
         false,
-        BTreeSet::new(),
         10,
         Some(0),
         BTreeMap::new(),
@@ -542,7 +549,6 @@ fn test_requires_room_version_supports_condition() {
     let evaluator = PushRuleEvaluator::py_new(
         flattened_keys,
         false,
-        BTreeSet::new(),
         10,
         Some(0),
         BTreeMap::new(),
diff --git a/rust/src/push/mod.rs b/rust/src/push/mod.rs
index 97feb6efc9..6391d2ed47 100644
--- a/rust/src/push/mod.rs
+++ b/rust/src/push/mod.rs
@@ -340,8 +340,12 @@ pub enum KnownCondition {
     RelatedEventMatchType(RelatedEventMatchTypeCondition),
     #[serde(rename = "org.matrix.msc3966.exact_event_property_contains")]
     ExactEventPropertyContains(ExactEventMatchCondition),
-    #[serde(rename = "org.matrix.msc3952.is_user_mention")]
-    IsUserMention,
+    // Identical to exact_event_property_contains but gives predefined patterns. Cannot be added by users.
+    #[serde(
+        skip_deserializing,
+        rename = "org.matrix.msc3966.exact_event_property_contains"
+    )]
+    ExactEventPropertyContainsType(ExactEventMatchTypeCondition),
     ContainsDisplayName,
     RoomMemberCount {
         #[serde(skip_serializing_if = "Option::is_none")]
@@ -398,6 +402,15 @@ pub struct ExactEventMatchCondition {
     pub value: Cow<'static, SimpleJsonValue>,
 }
 
+/// The body of a [`Condition::ExactEventMatch`] that uses user_id or user_localpart as a pattern.
+#[derive(Serialize, Debug, Clone)]
+pub struct ExactEventMatchTypeCondition {
+    pub key: Cow<'static, str>,
+    // During serialization, the pattern_type property gets replaced with a
+    // pattern property of the correct value in synapse.push.clientformat.format_push_rules_for_user.
+    pub value_type: Cow<'static, EventMatchPatternType>,
+}
+
 /// The body of a [`Condition::RelatedEventMatch`]
 #[derive(Serialize, Deserialize, Debug, Clone)]
 pub struct RelatedEventMatchCondition {
@@ -740,17 +753,6 @@ fn test_deserialize_unstable_msc3758_condition() {
 }
 
 #[test]
-fn test_deserialize_unstable_msc3952_user_condition() {
-    let json = r#"{"kind":"org.matrix.msc3952.is_user_mention"}"#;
-
-    let condition: Condition = serde_json::from_str(json).unwrap();
-    assert!(matches!(
-        condition,
-        Condition::Known(KnownCondition::IsUserMention)
-    ));
-}
-
-#[test]
 fn test_deserialize_custom_condition() {
     let json = r#"{"kind":"custom_tag"}"#;
 
diff --git a/stubs/synapse/synapse_rust/push.pyi b/stubs/synapse/synapse_rust/push.pyi
index a8f0ed2435..c17796ffbd 100644
--- a/stubs/synapse/synapse_rust/push.pyi
+++ b/stubs/synapse/synapse_rust/push.pyi
@@ -12,7 +12,7 @@
 # See the License for the specific language governing permissions and
 # limitations under the License.
 
-from typing import Any, Collection, Dict, Mapping, Optional, Sequence, Set, Tuple, Union
+from typing import Any, Collection, Dict, Mapping, Optional, Sequence, Tuple, Union
 
 from synapse.types import JsonDict, JsonValue
 
@@ -58,7 +58,6 @@ class PushRuleEvaluator:
         self,
         flattened_keys: Mapping[str, JsonValue],
         has_mentions: bool,
-        user_mentions: Set[str],
         room_member_count: int,
         sender_power_level: Optional[int],
         notification_power_levels: Mapping[str, int],
diff --git a/synapse/config/experimental.py b/synapse/config/experimental.py
index 7c81f055b6..fc64f2bda1 100644
--- a/synapse/config/experimental.py
+++ b/synapse/config/experimental.py
@@ -179,10 +179,16 @@ class ExperimentalConfig(Config):
             "msc3873_escape_event_match_key", False
         )
 
-        # MSC3952: Intentional mentions, this depends on MSC3758.
+        # MSC3966: exact_event_property_contains push rule condition.
+        self.msc3966_exact_event_property_contains = experimental.get(
+            "msc3966_exact_event_property_contains", False
+        )
+
+        # MSC3952: Intentional mentions, this depends on MSC3758 and MSC3966.
         self.msc3952_intentional_mentions = (
             experimental.get("msc3952_intentional_mentions", False)
             and self.msc3758_exact_event_match
+            and self.msc3966_exact_event_property_contains
         )
 
         # MSC3959: Do not generate notifications for edits.
diff --git a/synapse/push/bulk_push_rule_evaluator.py b/synapse/push/bulk_push_rule_evaluator.py
index 3c4a152d6b..abcf687f05 100644
--- a/synapse/push/bulk_push_rule_evaluator.py
+++ b/synapse/push/bulk_push_rule_evaluator.py
@@ -23,7 +23,6 @@ from typing import (
     Mapping,
     Optional,
     Sequence,
-    Set,
     Tuple,
     Union,
 )
@@ -396,18 +395,10 @@ class BulkPushRuleEvaluator:
                         del notification_levels[key]
 
         # Pull out any user and room mentions.
-        mentions = event.content.get(EventContentFields.MSC3952_MENTIONS)
-        has_mentions = self._intentional_mentions_enabled and isinstance(mentions, dict)
-        user_mentions: Set[str] = set()
-        if has_mentions:
-            # mypy seems to have lost the type even though it must be a dict here.
-            assert isinstance(mentions, dict)
-            # Remove out any non-string items and convert to a set.
-            user_mentions_raw = mentions.get("user_ids")
-            if isinstance(user_mentions_raw, list):
-                user_mentions = set(
-                    filter(lambda item: isinstance(item, str), user_mentions_raw)
-                )
+        has_mentions = (
+            self._intentional_mentions_enabled
+            and EventContentFields.MSC3952_MENTIONS in event.content
+        )
 
         evaluator = PushRuleEvaluator(
             _flatten_dict(
@@ -415,7 +406,6 @@ class BulkPushRuleEvaluator:
                 msc3873_escape_event_match_key=self.hs.config.experimental.msc3873_escape_event_match_key,
             ),
             has_mentions,
-            user_mentions,
             room_member_count,
             sender_power_level,
             notification_levels,
diff --git a/synapse/push/clientformat.py b/synapse/push/clientformat.py
index bb76c169c6..222afbdcc8 100644
--- a/synapse/push/clientformat.py
+++ b/synapse/push/clientformat.py
@@ -41,11 +41,12 @@ def format_push_rules_for_user(
 
         rulearray.append(template_rule)
 
-        pattern_type = template_rule.pop("pattern_type", None)
-        if pattern_type == "user_id":
-            template_rule["pattern"] = user.to_string()
-        elif pattern_type == "user_localpart":
-            template_rule["pattern"] = user.localpart
+        for type_key in ("pattern", "value"):
+            type_value = template_rule.pop(f"{type_key}_type", None)
+            if type_value == "user_id":
+                template_rule[type_key] = user.to_string()
+            elif type_value == "user_localpart":
+                template_rule[type_key] = user.localpart
 
         template_rule["enabled"] = enabled
 
diff --git a/tests/push/test_bulk_push_rule_evaluator.py b/tests/push/test_bulk_push_rule_evaluator.py
index 1458076a90..73fecfd4ad 100644
--- a/tests/push/test_bulk_push_rule_evaluator.py
+++ b/tests/push/test_bulk_push_rule_evaluator.py
@@ -233,6 +233,7 @@ class TestBulkPushRuleEvaluator(HomeserverTestCase):
             "experimental_features": {
                 "msc3758_exact_event_match": True,
                 "msc3952_intentional_mentions": True,
+                "msc3966_exact_event_property_contains": True,
             }
         }
     )
@@ -336,6 +337,7 @@ class TestBulkPushRuleEvaluator(HomeserverTestCase):
             "experimental_features": {
                 "msc3758_exact_event_match": True,
                 "msc3952_intentional_mentions": True,
+                "msc3966_exact_event_property_contains": True,
             }
         }
     )
diff --git a/tests/push/test_push_rule_evaluator.py b/tests/push/test_push_rule_evaluator.py
index 1d30e3c3e4..d4a4bc4d93 100644
--- a/tests/push/test_push_rule_evaluator.py
+++ b/tests/push/test_push_rule_evaluator.py
@@ -12,7 +12,7 @@
 # See the License for the specific language governing permissions and
 # limitations under the License.
 
-from typing import Any, Dict, List, Optional, Set, Union, cast
+from typing import Any, Dict, List, Optional, Union, cast
 
 import frozendict
 
@@ -147,8 +147,6 @@ class PushRuleEvaluatorTestCase(unittest.TestCase):
         self,
         content: JsonMapping,
         *,
-        has_mentions: bool = False,
-        user_mentions: Optional[Set[str]] = None,
         related_events: Optional[JsonDict] = None,
     ) -> PushRuleEvaluator:
         event = FrozenEvent(
@@ -167,8 +165,7 @@ class PushRuleEvaluatorTestCase(unittest.TestCase):
         power_levels: Dict[str, Union[int, Dict[str, int]]] = {}
         return PushRuleEvaluator(
             _flatten_dict(event),
-            has_mentions,
-            user_mentions or set(),
+            False,
             room_member_count,
             sender_power_level,
             cast(Dict[str, int], power_levels.get("notifications", {})),
@@ -204,32 +201,6 @@ class PushRuleEvaluatorTestCase(unittest.TestCase):
         # A display name with spaces should work fine.
         self.assertTrue(evaluator.matches(condition, "@user:test", "foo bar"))
 
-    def test_user_mentions(self) -> None:
-        """Check for user mentions."""
-        condition = {"kind": "org.matrix.msc3952.is_user_mention"}
-
-        # No mentions shouldn't match.
-        evaluator = self._get_evaluator({}, has_mentions=True)
-        self.assertFalse(evaluator.matches(condition, "@user:test", None))
-
-        # An empty set shouldn't match
-        evaluator = self._get_evaluator({}, has_mentions=True, user_mentions=set())
-        self.assertFalse(evaluator.matches(condition, "@user:test", None))
-
-        # The Matrix ID appearing anywhere in the mentions list should match
-        evaluator = self._get_evaluator(
-            {}, has_mentions=True, user_mentions={"@user:test"}
-        )
-        self.assertTrue(evaluator.matches(condition, "@user:test", None))
-
-        evaluator = self._get_evaluator(
-            {}, has_mentions=True, user_mentions={"@another:test", "@user:test"}
-        )
-        self.assertTrue(evaluator.matches(condition, "@user:test", None))
-
-        # Note that invalid data is tested at tests.push.test_bulk_push_rule_evaluator.TestBulkPushRuleEvaluator.test_mentions
-        # since the BulkPushRuleEvaluator is what handles data sanitisation.
-
     def _assert_matches(
         self, condition: JsonDict, content: JsonMapping, msg: Optional[str] = None
     ) -> None: