feat(ffi): add room display name to room alias transformation

Cargo.lock

@@ -597,7 +597,7 @@ source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "05efc5cfd9110c8416e471df0e96702d58690178e206e61b7173706673c93706"
 dependencies = [
  "memchr",
- "regex-automata 0.4.7",
+ "regex-automata 0.4.8",
  "serde",
 ]
 
@@ -2965,6 +2965,7 @@ dependencies = [
  "matrix-sdk-store-encryption",
  "matrix-sdk-test",
  "once_cell",
+ "regex",
  "ruma",
  "serde",
  "serde_json",
@@ -4143,7 +4144,7 @@ dependencies = [
  "rand",
  "rand_chacha",
  "rand_xorshift",
- "regex-syntax 0.8.4",
+ "regex-syntax 0.8.5",
  "rusty-fork",
  "tempfile",
  "unarray",
@@ -4385,14 +4386,14 @@ dependencies = [
 
 [[package]]
 name = "regex"
-version = "1.10.5"
+version = "1.11.1"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "b91213439dad192326a0d7c6ee3955910425f441d7038e0d6933b0aec5c4517f"
+checksum = "b544ef1b4eac5dc2db33ea63606ae9ffcfac26c1416a2806ae0bf5f56b201191"
 dependencies = [
  "aho-corasick",
  "memchr",
- "regex-automata 0.4.7",
- "regex-syntax 0.8.4",
+ "regex-automata 0.4.8",
+ "regex-syntax 0.8.5",
 ]
 
 [[package]]
@@ -4406,13 +4407,13 @@ dependencies = [
 
 [[package]]
 name = "regex-automata"
-version = "0.4.7"
+version = "0.4.8"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "38caf58cc5ef2fed281f89292ef23f6365465ed9a41b7a7754eb4e26496c92df"
+checksum = "368758f23274712b504848e9d5a6f010445cc8b87a7cdb4d7cbee666c1288da3"
 dependencies = [
  "aho-corasick",
  "memchr",
- "regex-syntax 0.8.4",
+ "regex-syntax 0.8.5",
 ]
 
 [[package]]
@@ -4423,9 +4424,9 @@ checksum = "f162c6dd7b008981e4d40210aca20b4bd0f9b60ca9271061b07f78537722f2e1"
 
 [[package]]
 name = "regex-syntax"
-version = "0.8.4"
+version = "0.8.5"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "7a66a03ae7c801facd77a29370b4faec201768915ac14a721ba36f20bc9c209b"
+checksum = "2b15c43186be67a4fd63bee50d0303afffcef381492ebe2c5d87f324e1b8815c"
 
 [[package]]
 name = "reqwest"

bindings/matrix-sdk-ffi/src/lib.rs

@@ -16,6 +16,7 @@ mod notification;
 mod notification_settings;
 mod platform;
 mod room;
+mod room_alias;
 mod room_directory_search;
 mod room_info;
 mod room_list;
@@ -30,7 +31,6 @@ mod timeline_event_filter;
 mod tracing;
 mod utils;
 mod widget;
-mod room_alias;
 
 use async_compat::TOKIO1 as RUNTIME;
 use matrix_sdk::ruma::events::room::{

bindings/matrix-sdk-ffi/src/room_alias.rs

@@ -1,7 +1,14 @@
+use matrix_sdk::DisplayName;
 use ruma::RoomAliasId;
 
 /// Verifies the passed `String` matches the expected room alias format.
 #[matrix_sdk_ffi_macros::export]
 fn is_room_alias_format_valid(alias: String) -> bool {
     RoomAliasId::parse(alias).is_ok()
-}
+}
+
+/// Transforms a Room's display name into a valid room alias name.
+#[matrix_sdk_ffi_macros::export]
+fn room_alias_name_from_room_display_name(room_name: String) -> String {
+    DisplayName::Named(room_name).to_room_alias_name()
+}

crates/matrix-sdk-base/Cargo.toml

@@ -67,6 +67,7 @@ tokio = { workspace = true }
 thiserror = { workspace = true }
 tracing = { workspace = true }
 uniffi = { workspace = true, optional = true }
+regex = "1.11.1"
 
 [dev-dependencies]
 assert_matches = { workspace = true }

crates/matrix-sdk-base/src/rooms/mod.rs

@@ -15,6 +15,7 @@ pub use normal::{
     Room, RoomHero, RoomInfo, RoomInfoNotableUpdate, RoomInfoNotableUpdateReasons, RoomState,
     RoomStateFilter,
 };
+use regex::Regex;
 use ruma::{
     assign,
     events::{
@@ -64,6 +65,38 @@ pub enum DisplayName {
     Empty,
 }
 
+const WHITESPACE_REGEX: &str = r"\s+";
+const INVALID_SYMBOLS_REGEX: &str = r"[#,:]+";
+
+impl DisplayName {
+    /// Transforms the current display name into the name part of a
+    /// `RoomAliasId`.
+    pub fn to_room_alias_name(&self) -> String {
+        let room_name = match self {
+            Self::Named(name) => name,
+            Self::Aliased(name) => name,
+            Self::Calculated(name) => name,
+            Self::EmptyWas(name) => name,
+            Self::Empty => "",
+        };
+
+        let whitespace_regex =
+            Regex::new(WHITESPACE_REGEX).expect("`WHITESPACE_REGEX` should be valid");
+        let symbol_regex =
+            Regex::new(INVALID_SYMBOLS_REGEX).expect("`INVALID_SYMBOLS_REGEX` should be valid");
+
+        // Replace whitespaces with `-`
+        let sanitised = whitespace_regex.replace_all(room_name, "-");
+        // Remove non-ASCII characters and ASCII control characters
+        let sanitised =
+            String::from_iter(sanitised.chars().filter(|c| c.is_ascii() && !c.is_ascii_control()));
+        // Remove other problematic ASCII symbols
+        let sanitised = symbol_regex.replace_all(&sanitised, "");
+        // Lowercased
+        sanitised.to_lowercase()
+    }
+}
+
 impl fmt::Display for DisplayName {
     fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
         match self {
@@ -541,6 +574,7 @@ mod tests {
     use ruma::events::tag::{TagInfo, TagName, Tags};
 
     use super::{BaseRoomInfo, RoomNotableTags};
+    use crate::DisplayName;
 
     #[test]
     fn test_handle_notable_tags_favourite() {
@@ -571,4 +605,24 @@ mod tests {
         base_room_info.handle_notable_tags(&tags);
         assert!(base_room_info.notable_tags.contains(RoomNotableTags::LOW_PRIORITY).not());
     }
+
+    #[test]
+    fn test_room_alias_from_room_display_name_lowercases() {
+        assert_eq!("roomalias", DisplayName::Named("RoomAlias".to_owned()).to_room_alias_name());
+    }
+
+    #[test]
+    fn test_room_alias_from_room_display_name_removes_whitespace() {
+        assert_eq!("room-alias", DisplayName::Named("Room Alias".to_owned()).to_room_alias_name());
+    }
+
+    #[test]
+    fn test_room_alias_from_room_display_name_removes_non_ascii_symbols() {
+        assert_eq!("roomalias", DisplayName::Named("Room±Alias√".to_owned()).to_room_alias_name());
+    }
+
+    #[test]
+    fn test_room_alias_from_room_display_name_removes_invalid_ascii_symbols() {
+        assert_eq!("roomalias", DisplayName::Named("#Room,Alias:".to_owned()).to_room_alias_name());
+    }
 }