Use bool::then to simplify some code

crates/ruma-api-macros/src/api/parse.rs

@@ -49,15 +49,15 @@ impl Parse for Api {
             None
         };
 
-        // TODO: Use `bool::then` when MSRV >= 1.50
-        let error_ty = if input.peek(kw::error) {
+        let error_ty = input
+            .peek(kw::error)
+            .then(|| {
                 let _: kw::error = input.parse()?;
                 let _: Token![:] = input.parse()?;
 
-            Some(input.parse()?)
-        } else {
-            None
-        };
+                input.parse()
+            })
+            .transpose()?;
 
         if let Some(req) = &request {
             let newtype_body_field = req.newtype_body_field();

crates/ruma-api-macros/src/api/request/incoming.rs

@@ -144,14 +144,14 @@ impl Request {
             (TokenStream::new(), TokenStream::new())
         };
 
-        let extract_body = if self.has_body_fields() || self.newtype_body_field().is_some() {
-            let body_lifetimes = if self.has_body_lifetimes() {
+        let extract_body =
+            (self.has_body_fields() || self.newtype_body_field().is_some()).then(|| {
+                let body_lifetimes = self.has_body_lifetimes().then(|| {
                     // duplicate the anonymous lifetime as many times as needed
-                let lifetimes = std::iter::repeat(quote! { '_ }).take(self.lifetimes.body.len());
+                    let lifetimes =
+                        std::iter::repeat(quote! { '_ }).take(self.lifetimes.body.len());
                     quote! { < #( #lifetimes, )* > }
-            } else {
-                TokenStream::new()
-            };
+                });
 
                 quote! {
                     let request_body: <
@@ -171,9 +171,7 @@ impl Request {
                         })?
                     };
                 }
-        } else {
-            TokenStream::new()
-        };
+            });
 
         let (parse_body, body_vars) = if let Some(field) = self.newtype_body_field() {
             let field_name = field.ident.as_ref().expect("expected field to have an identifier");
@@ -194,8 +192,8 @@ impl Request {
             self.vars(RequestFieldKind::Body, quote!(request_body))
         };
 
-        let non_auth_impls = metadata.authentication.iter().map(|auth| {
-            if auth.value == "None" {
+        let non_auth_impls = metadata.authentication.iter().filter_map(|auth| {
+            (auth.value == "None").then(|| {
                 let attrs = &auth.attrs;
                 quote! {
                     #( #attrs )*
@@ -203,9 +201,7 @@ impl Request {
                     #[cfg(feature = "server")]
                     impl #ruma_api::IncomingNonAuthRequest for #incoming_request_type {}
                 }
-            } else {
-                TokenStream::new()
-            }
+            })
         });
 
         quote! {

crates/ruma-api-macros/src/api/request/outgoing.rs

@@ -183,8 +183,8 @@ impl Request {
             quote! { <T as ::std::default::Default>::default() }
         };
 
-        let non_auth_impls = metadata.authentication.iter().map(|auth| {
-            if auth.value == "None" {
+        let non_auth_impls = metadata.authentication.iter().filter_map(|auth| {
+            (auth.value == "None").then(|| {
                 let attrs = &auth.attrs;
                 quote! {
                     #( #attrs )*
@@ -192,9 +192,7 @@ impl Request {
                     #[cfg(feature = "client")]
                     impl #lifetimes #ruma_api::OutgoingNonAuthRequest for Request #lifetimes {}
                 }
-            } else {
-                TokenStream::new()
-            }
+            })
         });
 
         quote! {

crates/ruma-api-macros/src/api/response/incoming.rs

@@ -9,16 +9,14 @@ impl Response {
         let ruma_serde = quote! { #ruma_api::exports::ruma_serde };
         let serde_json = quote! { #ruma_api::exports::serde_json };
 
-        let extract_response_headers = if self.has_header_fields() {
+        let extract_response_headers = self.has_header_fields().then(|| {
             quote! {
                 let mut headers = response.headers().clone();
             }
-        } else {
-            TokenStream::new()
-        };
+        });
 
         let typed_response_body_decl =
-            if self.has_body_fields() || self.newtype_body_field().is_some() {
+            (self.has_body_fields() || self.newtype_body_field().is_some()).then(|| {
                 quote! {
                     let response_body: <
                         ResponseBody
@@ -37,9 +35,7 @@ impl Response {
                         })?
                     };
                 }
-            } else {
-                TokenStream::new()
-            };
+            });
 
         let response_init_fields = {
             let mut fields = vec![];

crates/ruma-api-macros/src/util.rs

@@ -12,12 +12,12 @@ pub(crate) fn unique_lifetimes_to_tokens<'a, I: IntoIterator<Item = &'a Lifetime
     lifetimes: I,
 ) -> TokenStream {
     let lifetimes = lifetimes.into_iter().collect::<BTreeSet<_>>();
-    if lifetimes.is_empty() {
-        TokenStream::new()
-    } else {
+    (!lifetimes.is_empty())
+        .then(|| {
             let lifetimes = quote! { #( #lifetimes ),* };
             quote! { < #lifetimes > }
-    }
+        })
+        .unwrap_or_default()
 }
 
 pub(crate) fn is_valid_endpoint_path(string: &str) -> bool {

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

@@ -395,11 +395,11 @@ fn expand_from_into(
 }
 
 fn expand_eq_ord_event(input: &DeriveInput, fields: &[Field]) -> Option<TokenStream> {
-    if fields.iter().flat_map(|f| f.ident.as_ref()).any(|f| f == "event_id") {
+    fields.iter().flat_map(|f| f.ident.as_ref()).any(|f| f == "event_id").then(|| {
         let ident = &input.ident;
         let (impl_gen, ty_gen, where_clause) = input.generics.split_for_impl();
 
-        Some(quote! {
+        quote! {
             #[automatically_derived]
             impl #impl_gen ::std::cmp::PartialEq for #ident #ty_gen #where_clause {
                 /// This checks if two `EventId`s are equal.
@@ -426,10 +426,8 @@ fn expand_eq_ord_event(input: &DeriveInput, fields: &[Field]) -> Option<TokenStr
                     self.event_id.cmp(&other.event_id)
                 }
             }
-        })
-    } else {
-        None
         }
+    })
 }
 
 /// CamelCase's a field ident like "foo_bar" to "FooBar".

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

@@ -275,9 +275,7 @@ pub fn expand_event_content(
 
     Ok(quote! {
         #event_content
-
         #event_content_derive
-
         #redacted
     })
 }

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

@@ -235,15 +235,14 @@ fn expand_conversion_impl(
             let ident_variants = variants.iter().map(|v| v.match_arm(&ident));
             let self_variants = variants.iter().map(|v| v.ctor(quote!(Self)));
 
-            let redaction = if let (EventKind::Message, EventKindVariation::Full) = (kind, var) {
+            let redaction =
+                (*kind == EventKind::Message && *var == EventKindVariation::Full).then(|| {
                     quote! {
                         #ident::RoomRedaction(event) => Self::RoomRedaction(
                             #ruma_events::room::redaction::SyncRedactionEvent::from(event),
                         ),
                     }
-            } else {
-                TokenStream::new()
-            };
+                });
 
             Some(quote! {
                 impl From<#ident> for #sync {
@@ -274,15 +273,14 @@ fn expand_conversion_impl(
             let self_variants = variants.iter().map(|v| v.match_arm(quote!(Self)));
             let full_variants = variants.iter().map(|v| v.ctor(&full));
 
-            let redaction = if let (EventKind::Message, EventKindVariation::Sync) = (kind, var) {
+            let redaction =
+                (*kind == EventKind::Message && *var == EventKindVariation::Sync).then(|| {
                     quote! {
                         Self::RoomRedaction(event) => {
                             #full::RoomRedaction(event.into_full_event(room_id))
                         },
                     }
-            } else {
-                TokenStream::new()
-            };
+                });
 
             Some(quote! {
                 #[automatically_derived]
@@ -639,8 +637,8 @@ fn generate_redacted_fields(
     var: &EventKindVariation,
     is_event_kind: EventKindFn,
     ruma_events: &TokenStream,
-) -> TokenStream {
-    if is_event_kind(kind, var) {
+) -> Option<TokenStream> {
+    is_event_kind(kind, var).then(|| {
         let name = Ident::new(name, Span::call_site());
 
         if name == "unsigned" {
@@ -654,9 +652,7 @@ fn generate_redacted_fields(
                 #name: event.#name,
             }
         }
-    } else {
-        TokenStream::new()
-    }
+    })
 }
 
 fn generate_custom_variant(
@@ -772,7 +768,7 @@ fn accessor_methods(
         }
     };
 
-    let prev_content = if has_prev_content_field(kind, var) {
+    let prev_content = has_prev_content_field(kind, var).then(|| {
         quote! {
             /// Returns the any content enum for this events prev_content.
             pub fn prev_content(&self) -> Option<#content_enum> {
@@ -788,9 +784,7 @@ fn accessor_methods(
                 }
             }
         }
-    } else {
-        TokenStream::new()
-    };
+    });
 
     Some(quote! {
         #[automatically_derived]
@@ -956,8 +950,8 @@ fn generate_accessor(
     is_event_kind: EventKindFn,
     variants: &[EventEnumVariant],
     ruma_events: &TokenStream,
-) -> TokenStream {
-    if is_event_kind(kind, var) {
+) -> Option<TokenStream> {
+    is_event_kind(kind, var).then(|| {
         let docs = format!("Returns this event's {} field.", name);
         let ident = Ident::new(name, Span::call_site());
         let field_type = field_return_type(name, var, ruma_events);
@@ -972,9 +966,7 @@ fn generate_accessor(
                 }
             }
         }
-    } else {
-        TokenStream::new()
-    }
+    })
 }
 
 fn field_return_type(

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

@@ -747,11 +747,7 @@ impl FormattedBody {
 
         pulldown_cmark::html::push_html(&mut html_body, pulldown_cmark::Parser::new(body));
 
-        if html_body == format!("<p>{}</p>\n", body) {
-            None
-        } else {
-            Some(Self::html(html_body))
-        }
+        (html_body != format!("<p>{}</p>\n", body)).then(|| Self::html(html_body))
     }
 }
 

crates/ruma-state-res/src/event_auth.rs

@@ -341,24 +341,12 @@ pub fn valid_membership_change<E: Event>(
     )?;
 
     let sender_power = power_levels.users.get(user_sender).map_or_else(
-        || {
-            if sender_membership != MembershipState::Join {
-                None
-            } else {
-                Some(&power_levels.users_default)
-            }
-        },
+        || (sender_membership == MembershipState::Join).then(|| &power_levels.users_default),
         // If it's okay, wrap with Some(_)
         Some,
     );
     let target_power = power_levels.users.get(&target_user_id).map_or_else(
-        || {
-            if target_membership != MembershipState::Join {
-                None
-            } else {
-                Some(&power_levels.users_default)
-            }
-        },
+        || (target_membership == MembershipState::Join).then(|| &power_levels.users_default),
         // If it's okay, wrap with Some(_)
         Some,
     );

crates/ruma-state-res/src/lib.rs

@@ -450,11 +450,10 @@ impl StateResolution {
             // The key for this is (eventType + a state_key of the signed token not sender) so
             // search for it
             let current_third_party = auth_events.iter().find_map(|(_, pdu)| {
-                if pdu.kind() == EventType::RoomThirdPartyInvite {
-                    Some(pdu.clone()) // TODO no clone, auth_events is borrowed while moved
-                } else {
-                    None
-                }
+                (pdu.kind() == EventType::RoomThirdPartyInvite).then(|| {
+                    // TODO no clone, auth_events is borrowed while moved
+                    pdu.clone()
+                })
             });
 
             if auth_check(