Support for MSC3758: exact_event_match push condition (#14964)

This specifies to search for an exact value match, instead of
string globbing. It only works across non-compound JSON values
(null, boolean, integer, and strings).

2 files changed, 137 insertions, 15 deletions

diff --git a/rust/src/push/evaluator.rs b/rust/src/push/evaluator.rs
index ec7a8c4453..dd6b4343ec 100644
--- a/rust/src/push/evaluator.rs
+++ b/rust/src/push/evaluator.rs
@@ -22,8 +22,8 @@ use regex::Regex;
 
 use super::{
     utils::{get_glob_matcher, get_localpart_from_id, GlobMatchType},
-    Action, Condition, EventMatchCondition, FilteredPushRules, KnownCondition,
-    RelatedEventMatchCondition,
+    Action, Condition, EventMatchCondition, ExactEventMatchCondition, FilteredPushRules,
+    KnownCondition, RelatedEventMatchCondition, SimpleJsonValue,
 };
 
 lazy_static! {
@@ -61,9 +61,9 @@ impl RoomVersionFeatures {
 /// Allows running a set of push rules against a particular event.
 #[pyclass]
 pub struct PushRuleEvaluator {
-    /// A mapping of "flattened" keys to string values in the event, e.g.
+    /// A mapping of "flattened" keys to simple JSON values in the event, e.g.
     /// includes things like "type" and "content.msgtype".
-    flattened_keys: BTreeMap<String, String>,
+    flattened_keys: BTreeMap<String, SimpleJsonValue>,
 
     /// The "content.body", if any.
     body: String,
@@ -87,7 +87,7 @@ pub struct PushRuleEvaluator {
 
     /// The related events, indexed by relation type. Flattened in the same manner as
     /// `flattened_keys`.
-    related_events_flattened: BTreeMap<String, BTreeMap<String, String>>,
+    related_events_flattened: BTreeMap<String, BTreeMap<String, SimpleJsonValue>>,
 
     /// If msc3664, push rules for related events, is enabled.
     related_event_match_enabled: bool,
@@ -98,6 +98,9 @@ pub struct PushRuleEvaluator {
     /// If MSC3931 (room version feature flags) is enabled. Usually controlled by the same
     /// flag as MSC1767 (extensible events core).
     msc3931_enabled: bool,
+
+    /// If MSC3758 (exact_event_match push rule condition) is enabled.
+    msc3758_exact_event_match: bool,
 }
 
 #[pymethods]
@@ -106,22 +109,23 @@ impl PushRuleEvaluator {
     #[allow(clippy::too_many_arguments)]
     #[new]
     pub fn py_new(
-        flattened_keys: BTreeMap<String, String>,
+        flattened_keys: BTreeMap<String, SimpleJsonValue>,
         has_mentions: bool,
         user_mentions: BTreeSet<String>,
         room_mention: bool,
         room_member_count: u64,
         sender_power_level: Option<i64>,
         notification_power_levels: BTreeMap<String, i64>,
-        related_events_flattened: BTreeMap<String, BTreeMap<String, String>>,
+        related_events_flattened: BTreeMap<String, BTreeMap<String, SimpleJsonValue>>,
         related_event_match_enabled: bool,
         room_version_feature_flags: Vec<String>,
         msc3931_enabled: bool,
+        msc3758_exact_event_match: bool,
     ) -> Result<Self, Error> {
-        let body = flattened_keys
-            .get("content.body")
-            .cloned()
-            .unwrap_or_default();
+        let body = match flattened_keys.get("content.body") {
+            Some(SimpleJsonValue::Str(s)) => s.clone(),
+            _ => String::new(),
+        };
 
         Ok(PushRuleEvaluator {
             flattened_keys,
@@ -136,6 +140,7 @@ impl PushRuleEvaluator {
             related_event_match_enabled,
             room_version_feature_flags,
             msc3931_enabled,
+            msc3758_exact_event_match,
         })
     }
 
@@ -252,6 +257,9 @@ impl PushRuleEvaluator {
             KnownCondition::EventMatch(event_match) => {
                 self.match_event_match(event_match, user_id)?
             }
+            KnownCondition::ExactEventMatch(exact_event_match) => {
+                self.match_exact_event_match(exact_event_match)?
+            }
             KnownCondition::RelatedEventMatch(event_match) => {
                 self.match_related_event_match(event_match, user_id)?
             }
@@ -337,7 +345,9 @@ impl PushRuleEvaluator {
             return Ok(false);
         };
 
-        let haystack = if let Some(haystack) = self.flattened_keys.get(&*event_match.key) {
+        let haystack = if let Some(SimpleJsonValue::Str(haystack)) =
+            self.flattened_keys.get(&*event_match.key)
+        {
             haystack
         } else {
             return Ok(false);
@@ -355,6 +365,27 @@ impl PushRuleEvaluator {
         compiled_pattern.is_match(haystack)
     }
 
+    /// Evaluates a `exact_event_match` condition. (MSC3758)
+    fn match_exact_event_match(
+        &self,
+        exact_event_match: &ExactEventMatchCondition,
+    ) -> Result<bool, Error> {
+        // First check if the feature is enabled.
+        if !self.msc3758_exact_event_match {
+            return Ok(false);
+        }
+
+        let value = &exact_event_match.value;
+
+        let haystack = if let Some(haystack) = self.flattened_keys.get(&*exact_event_match.key) {
+            haystack
+        } else {
+            return Ok(false);
+        };
+
+        Ok(haystack == &**value)
+    }
+
     /// Evaluates a `related_event_match` condition. (MSC3664)
     fn match_related_event_match(
         &self,
@@ -410,7 +441,7 @@ impl PushRuleEvaluator {
             return Ok(false);
         };
 
-        let haystack = if let Some(haystack) = event.get(&**key) {
+        let haystack = if let Some(SimpleJsonValue::Str(haystack)) = event.get(&**key) {
             haystack
         } else {
             return Ok(false);
@@ -455,7 +486,10 @@ impl PushRuleEvaluator {
 #[test]
 fn push_rule_evaluator() {
     let mut flattened_keys = BTreeMap::new();
-    flattened_keys.insert("content.body".to_string(), "foo bar bob hello".to_string());
+    flattened_keys.insert(
+        "content.body".to_string(),
+        SimpleJsonValue::Str("foo bar bob hello".to_string()),
+    );
     let evaluator = PushRuleEvaluator::py_new(
         flattened_keys,
         false,
@@ -468,6 +502,7 @@ fn push_rule_evaluator() {
         true,
         vec![],
         true,
+        true,
     )
     .unwrap();
 
@@ -482,7 +517,10 @@ fn test_requires_room_version_supports_condition() {
     use crate::push::{PushRule, PushRules};
 
     let mut flattened_keys = BTreeMap::new();
-    flattened_keys.insert("content.body".to_string(), "foo bar bob hello".to_string());
+    flattened_keys.insert(
+        "content.body".to_string(),
+        SimpleJsonValue::Str("foo bar bob hello".to_string()),
+    );
     let flags = vec![RoomVersionFeatures::ExtensibleEvents.as_str().to_string()];
     let evaluator = PushRuleEvaluator::py_new(
         flattened_keys,
@@ -496,6 +534,7 @@ fn test_requires_room_version_supports_condition() {
         false,
         flags,
         true,
+        true,
     )
     .unwrap();
 
diff --git a/rust/src/push/mod.rs b/rust/src/push/mod.rs
index 3c4f876cab..79e519fe11 100644
--- a/rust/src/push/mod.rs
+++ b/rust/src/push/mod.rs
@@ -56,7 +56,9 @@ use std::collections::{BTreeMap, HashMap, HashSet};
 
 use anyhow::{Context, Error};
 use log::warn;
+use pyo3::exceptions::PyTypeError;
 use pyo3::prelude::*;
+use pyo3::types::{PyBool, PyLong, PyString};
 use pythonize::{depythonize, pythonize};
 use serde::de::Error as _;
 use serde::{Deserialize, Serialize};
@@ -248,6 +250,36 @@ impl<'de> Deserialize<'de> for Action {
     }
 }
 
+/// A simple JSON values (string, int, boolean, or null).
+#[derive(Serialize, Deserialize, Debug, Clone, PartialEq, Eq)]
+#[serde(untagged)]
+pub enum SimpleJsonValue {
+    Str(String),
+    Int(i64),
+    Bool(bool),
+    Null,
+}
+
+impl<'source> FromPyObject<'source> for SimpleJsonValue {
+    fn extract(ob: &'source PyAny) -> PyResult<Self> {
+        if let Ok(s) = <PyString as pyo3::PyTryFrom>::try_from(ob) {
+            Ok(SimpleJsonValue::Str(s.to_string()))
+        // A bool *is* an int, ensure we try bool first.
+        } else if let Ok(b) = <PyBool as pyo3::PyTryFrom>::try_from(ob) {
+            Ok(SimpleJsonValue::Bool(b.extract()?))
+        } else if let Ok(i) = <PyLong as pyo3::PyTryFrom>::try_from(ob) {
+            Ok(SimpleJsonValue::Int(i.extract()?))
+        } else if ob.is_none() {
+            Ok(SimpleJsonValue::Null)
+        } else {
+            Err(PyTypeError::new_err(format!(
+                "Can't convert from {} to SimpleJsonValue",
+                ob.get_type().name()?
+            )))
+        }
+    }
+}
+
 /// A condition used in push rules to match against an event.
 ///
 /// We need this split as `serde` doesn't give us the ability to have a
@@ -267,6 +299,8 @@ pub enum Condition {
 #[serde(tag = "kind")]
 pub enum KnownCondition {
     EventMatch(EventMatchCondition),
+    #[serde(rename = "com.beeper.msc3758.exact_event_match")]
+    ExactEventMatch(ExactEventMatchCondition),
     #[serde(rename = "im.nheko.msc3664.related_event_match")]
     RelatedEventMatch(RelatedEventMatchCondition),
     #[serde(rename = "org.matrix.msc3952.is_user_mention")]
@@ -309,6 +343,13 @@ pub struct EventMatchCondition {
     pub pattern_type: Option<Cow<'static, str>>,
 }
 
+/// The body of a [`Condition::ExactEventMatch`]
+#[derive(Serialize, Deserialize, Debug, Clone)]
+pub struct ExactEventMatchCondition {
+    pub key: Cow<'static, str>,
+    pub value: Cow<'static, SimpleJsonValue>,
+}
+
 /// The body of a [`Condition::RelatedEventMatch`]
 #[derive(Serialize, Deserialize, Debug, Clone)]
 pub struct RelatedEventMatchCondition {
@@ -543,6 +584,48 @@ fn test_deserialize_unstable_msc3931_condition() {
 }
 
 #[test]
+fn test_deserialize_unstable_msc3758_condition() {
+    // A string condition should work.
+    let json =
+        r#"{"kind":"com.beeper.msc3758.exact_event_match","key":"content.value","value":"foo"}"#;
+
+    let condition: Condition = serde_json::from_str(json).unwrap();
+    assert!(matches!(
+        condition,
+        Condition::Known(KnownCondition::ExactEventMatch(_))
+    ));
+
+    // A boolean condition should work.
+    let json =
+        r#"{"kind":"com.beeper.msc3758.exact_event_match","key":"content.value","value":true}"#;
+
+    let condition: Condition = serde_json::from_str(json).unwrap();
+    assert!(matches!(
+        condition,
+        Condition::Known(KnownCondition::ExactEventMatch(_))
+    ));
+
+    // An integer condition should work.
+    let json = r#"{"kind":"com.beeper.msc3758.exact_event_match","key":"content.value","value":1}"#;
+
+    let condition: Condition = serde_json::from_str(json).unwrap();
+    assert!(matches!(
+        condition,
+        Condition::Known(KnownCondition::ExactEventMatch(_))
+    ));
+
+    // A null condition should work
+    let json =
+        r#"{"kind":"com.beeper.msc3758.exact_event_match","key":"content.value","value":null}"#;
+
+    let condition: Condition = serde_json::from_str(json).unwrap();
+    assert!(matches!(
+        condition,
+        Condition::Known(KnownCondition::ExactEventMatch(_))
+    ));
+}
+
+#[test]
 fn test_deserialize_unstable_msc3952_user_condition() {
     let json = r#"{"kind":"org.matrix.msc3952.is_user_mention"}"#;