events: Generate redact method for content enums

… and remove redacted content structs non-room events

crates/ruma-events-macros/src/event_content.rs

@@ -129,7 +129,8 @@ pub fn expand_event_content(
     let content_derives =
         content_attr.iter().flat_map(|args| args.get_event_kinds()).collect::<Vec<_>>();
 
-    let redacted = if needs_redacted(&content_attr) {
+    // We only generate redacted content structs for state and message events
+    let redacted = if needs_redacted(&content_attr, &content_derives) {
         let doc = format!("The payload for a redacted `{}`", ident);
         let redacted_ident = format_ident!("Redacted{}", ident);
         let kept_redacted_fields = if let syn::Data::Struct(syn::DataStruct {
@@ -358,9 +359,10 @@ fn generate_event_content_impl(
     }
 }
 
-fn needs_redacted(input: &[MetaAttrs]) -> bool {
+fn needs_redacted(input: &[MetaAttrs], content_derives: &[&EventKind]) -> bool {
     // `is_custom` means that the content struct does not need a generated
     // redacted struct also. If no `custom_redacted` attrs are found the content
     // needs a redacted struct generated.
     !input.iter().any(|a| a.is_custom())
+        && content_derives.iter().any(|e| e.is_message() || e.is_state())
 }

crates/ruma-events-macros/src/event_enum.rs

@@ -364,16 +364,18 @@ fn expand_content_enum(
     variants: &[EventEnumVariant],
     ruma_events: &TokenStream,
 ) -> TokenStream {
+    let ruma_identifiers = quote! { #ruma_events::exports::ruma_identifiers };
     let serde = quote! { #ruma_events::exports::serde };
     let serde_json = quote! { #ruma_events::exports::serde_json };
 
     let ident = kind.to_content_enum();
+
     let event_type_str = events;
 
     let content: Vec<_> =
-        events.iter().map(|ev| to_event_content_path(kind, ev, ruma_events)).collect();
+        events.iter().map(|ev| to_event_content_path(kind, ev, None, ruma_events)).collect();
 
-    let variant_decls = variants.iter().map(|v| v.decl());
+    let variant_decls = variants.iter().map(|v| v.decl()).collect::<Vec<_>>();
 
     let content_enum = quote! {
         #( #attrs )*
@@ -394,7 +396,7 @@ fn expand_content_enum(
         let attrs = &v.attrs;
         quote! { #(#attrs)* }
     });
-    let variant_arms = variants.iter().map(|v| v.match_arm(quote!(Self)));
+    let variant_arms = variants.iter().map(|v| v.match_arm(quote!(Self))).collect::<Vec<_>>();
     let variant_ctors = variants.iter().map(|v| v.ctor(quote!(Self)));
 
     let event_content_impl = quote! {
@@ -430,12 +432,65 @@ fn expand_content_enum(
 
     let marker_trait_impls = marker_traits(kind, ruma_events);
 
+    let redacted_content_enum = if kind.is_state() || kind.is_message() {
+        let redacted_ident = kind.to_redacted_content_enum();
+        let redaction_variants = variants.iter().map(|v| v.ctor(&redacted_ident));
+        let redacted_content: Vec<_> = events
+            .iter()
+            .map(|ev| to_event_content_path(kind, ev, Some("Redacted"), ruma_events))
+            .collect();
+
+        quote! {
+            #( #attrs )*
+            #[derive(Clone, Debug, #serde::Serialize)]
+            #[serde(untagged)]
+            #[allow(clippy::large_enum_variant)]
+            pub enum #redacted_ident {
+                #(
+                    #[doc = #event_type_str]
+                    #variant_decls(#redacted_content),
+                )*
+                /// Content of a redacted event not defined by the Matrix specification.
+                Custom(#ruma_events::custom::RedactedCustomEventContent),
+            }
+
+            impl #ruma_events::RedactContent for #ident {
+                type Redacted = #redacted_ident;
+
+                /// Redacts `Self` given a `RoomVersionId`.
+                fn redact(
+                    self,
+                    version: &#ruma_identifiers::RoomVersionId,
+                ) -> #redacted_ident {
+                    match self {
+                        #(
+                            #variant_arms(content) => {
+                                #redaction_variants(
+                                    #ruma_events::RedactContent::redact(content, version)
+                                )
+                            },
+                        )*
+                        Self::Custom(content) => {
+                            #redacted_ident::Custom(
+                                #ruma_events::RedactContent::redact(content, version)
+                            )
+                        },
+                    }
+                }
+            }
+        }
+    } else {
+        TokenStream::new()
+    };
+
     quote! {
         #content_enum
 
         #event_content_impl
 
         #marker_trait_impls
+
+        #redacted_content_enum
     }
 }
 
@@ -859,6 +914,7 @@ fn to_event_path(name: &LitStr, struct_name: &Ident, ruma_events: &TokenStream)
 fn to_event_content_path(
     kind: &EventKind,
     name: &LitStr,
+    prefix: Option<&str>,
     ruma_events: &TokenStream,
 ) -> TokenStream {
     let span = name.span();
@@ -876,8 +932,10 @@ fn to_event_content_path(
         .collect();
 
     let content_str = match kind {
-        EventKind::ToDevice => format_ident!("{}ToDeviceEventContent", event),
-        _ => format_ident!("{}EventContent", event),
+        EventKind::ToDevice => {
+            format_ident!("{}{}ToDeviceEventContent", prefix.unwrap_or(""), event)
+        }
+        _ => format_ident!("{}{}EventContent", prefix.unwrap_or(""), event),
     };
 
     let path = path.iter().map(|s| Ident::new(s, span));

crates/ruma-events-macros/src/event_parse.rs

@@ -3,7 +3,7 @@
 use std::fmt;
 
 use proc_macro2::Span;
-use quote::format_ident;
+use quote::{format_ident, IdentFragment};
 use syn::{
     braced,
     parse::{self, Parse, ParseStream},
@@ -88,6 +88,26 @@ impl fmt::Display for EventKind {
     }
 }
 
+impl IdentFragment for EventKind {
+    fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
+        fmt::Display::fmt(self, f)
+    }
+
+    fn span(&self) -> Option<Span> {
+        Some(Span::call_site())
+    }
+}
+
+impl IdentFragment for EventKindVariation {
+    fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
+        fmt::Display::fmt(self, f)
+    }
+
+    fn span(&self) -> Option<Span> {
+        Some(Span::call_site())
+    }
+}
+
 impl EventKind {
     pub fn is_state(&self) -> bool {
         matches!(self, Self::State)
@@ -112,9 +132,7 @@ impl EventKind {
             | (Self::State, V::Redacted)
             | (Self::Message, V::RedactedSync)
             | (Self::State, V::RedactedSync)
-            | (Self::State, V::RedactedStripped) => {
-                Some(Ident::new(&format!("{}{}", var, self), Span::call_site()))
-            }
+            | (Self::State, V::RedactedStripped) => Some(format_ident!("{}{}", var, self)),
             _ => None,
         }
     }
@@ -125,7 +143,12 @@ impl EventKind {
 
     /// `Any[kind]EventContent`
     pub fn to_content_enum(&self) -> Ident {
-        Ident::new(&format!("Any{}Content", self), Span::call_site())
+        format_ident!("Any{}Content", self)
+    }
+
+    /// `AnyRedacted[kind]EventContent`
+    pub fn to_redacted_content_enum(&self) -> Ident {
+        format_ident!("AnyRedacted{}Content", self)
     }
 }
 

crates/ruma-events/src/lib.rs

@@ -82,8 +82,8 @@
 //!     }
 //! });
 //!
-//! // The downside of this event is we cannot use it with event enums, but could be deserialized
-//! // from a `Raw<_>` that has failed to deserialize.
+//! // The downside of this event is we cannot use it with event enums,
+//! // but could be deserialized from a `Raw<_>` that has failed to deserialize.
 //! matches::assert_matches!(
 //!     serde_json::from_value::<SyncMessageEvent<ReactionEventContent>>(json),
 //!     Ok(SyncMessageEvent {

crates/ruma-events/src/room/redaction.rs

@@ -5,10 +5,7 @@ use ruma_events_macros::{Event, EventContent};
 use ruma_identifiers::{EventId, RoomId, UserId};
 use serde::{Deserialize, Serialize};
 
-use crate::{
-    MessageEventContent, RedactedMessageEventContent, RedactedStateEventContent, RoomEventContent,
-    Unsigned,
-};
+use crate::{RedactedStateEventContent, Unsigned};
 
 /// Redaction event.
 #[derive(Clone, Debug, Event)]
@@ -59,17 +56,11 @@ pub struct SyncRedactionEvent {
 
 /// A redaction of an event.
 #[derive(Clone, Debug, Deserialize, Serialize, EventContent)]
-#[ruma_event(type = "m.room.redaction")]
+#[ruma_event(type = "m.room.redaction", kind = Message)]
 pub struct RedactionEventContent {
     /// The reason for the redaction, if any.
     #[serde(skip_serializing_if = "Option::is_none")]
     pub reason: Option<String>,
 }
 
-impl RoomEventContent for RedactionEventContent {}
-
-impl MessageEventContent for RedactionEventContent {}
-
-impl RedactedMessageEventContent for RedactedRedactionEventContent {}
-
 impl RedactedStateEventContent for RedactedRedactionEventContent {}

crates/ruma-events/tests/redacted.rs

@@ -9,13 +9,17 @@ use ruma_events::{
         message::RedactedMessageEventContent,
         redaction::{RedactionEventContent, SyncRedactionEvent},
     },
-    AnyMessageEvent, AnyRedactedMessageEvent, AnyRedactedSyncMessageEvent,
-    AnyRedactedSyncStateEvent, AnyRoomEvent, AnySyncRoomEvent, Redact, RedactedMessageEvent,
-    RedactedSyncMessageEvent, RedactedSyncStateEvent, RedactedUnsigned, Unsigned,
+    AnyMessageEvent, AnyMessageEventContent, AnyRedactedMessageEvent,
+    AnyRedactedMessageEventContent, AnyRedactedStateEventContent, AnyRedactedSyncMessageEvent,
+    AnyRedactedSyncStateEvent, AnyRoomEvent, AnyStateEventContent, AnySyncRoomEvent, EventContent,
+    Redact, RedactContent, RedactedMessageEvent, RedactedSyncMessageEvent, RedactedSyncStateEvent,
+    RedactedUnsigned, Unsigned,
 };
 use ruma_identifiers::{event_id, room_id, user_id, RoomVersionId};
 use ruma_serde::Raw;
-use serde_json::{from_value as from_json_value, json, to_value as to_json_value};
+use serde_json::{
+    from_value as from_json_value, json, to_value as to_json_value, value::to_raw_value,
+};
 
 fn unsigned() -> RedactedUnsigned {
     let mut unsigned = RedactedUnsigned::default();
@@ -332,3 +336,39 @@ fn redact_method_properly_redacts() {
             && origin_server_ts == MilliSecondsSinceUnixEpoch(uint!(1))
     );
 }
+
+#[test]
+fn redact_message_content() {
+    let json = json!({
+        "body": "test",
+        "msgtype": "m.audio",
+        "url": "mxc://example.com/AuDi0",
+    });
+
+    let content =
+        AnyMessageEventContent::from_parts("m.room.message", to_raw_value(&json).unwrap()).unwrap();
+
+    assert_matches!(
+        content.redact(&RoomVersionId::Version6),
+        AnyRedactedMessageEventContent::RoomMessage(RedactedMessageEventContent)
+    );
+}
+
+#[test]
+fn redact_state_content() {
+    let json = json!({
+        "creator": "@carl:example.com",
+        "m.federate": true,
+        "room_version": "4"
+    });
+
+    let content =
+        AnyStateEventContent::from_parts("m.room.create", to_raw_value(&json).unwrap()).unwrap();
+
+    assert_matches!(
+        content.redact(&RoomVersionId::Version6),
+        AnyRedactedStateEventContent::RoomCreate(RedactedCreateEventContent {
+            creator
+        }) if creator == user_id!("@carl:example.com")
+    );
+}