From 0faa00ca95f48c6c2fbda0488f06be9598abfee5 Mon Sep 17 00:00:00 2001
From: Jonas Platte <jplatte@element.io>
Date: Mon, 7 Mar 2022 15:17:28 +0100
Subject: [PATCH] macros: Move additional utility function into util module

---
 crates/ruma-macros/src/events/event_enum.rs | 24 ++-------------------
 crates/ruma-macros/src/util.rs              | 23 +++++++++++++++++++-
 2 files changed, 24 insertions(+), 23 deletions(-)

diff --git a/crates/ruma-macros/src/events/event_enum.rs b/crates/ruma-macros/src/events/event_enum.rs
index b8593e6a..c662e87a 100644
--- a/crates/ruma-macros/src/events/event_enum.rs
+++ b/crates/ruma-macros/src/events/event_enum.rs
@@ -8,6 +8,7 @@ use super::{
     event_parse::{EventEnumDecl, EventEnumEntry, EventKind, EventKindVariation},
     util::{has_prev_content_field, EVENT_FIELDS},
 };
+use crate::util::m_prefix_name_to_type_name;
 
 /// Create a content enum from `EventEnumInput`.
 pub fn expand_event_enums(input: &EventEnumDecl) -> syn::Result<TokenStream> {
@@ -574,27 +575,6 @@ fn to_event_content_path(
     }
 }
 
-/// Splits the given `event_type` string on `.` and `_` removing the `m.room.` then
-/// camel casing to give the `Event` struct name.
-fn to_camel_case(name: &LitStr) -> syn::Result<Ident> {
-    let span = name.span();
-    let name = name.value();
-
-    if &name[..2] != "m." {
-        return Err(syn::Error::new(
-            span,
-            format!("well-known matrix events have to start with `m.` found `{}`", name),
-        ));
-    }
-
-    let s: String = name[2..]
-        .split(&['.', '_'] as &[char])
-        .map(|s| s.chars().next().unwrap().to_uppercase().to_string() + &s[1..])
-        .collect();
-
-    Ok(Ident::new(&s, span))
-}
-
 fn field_return_type(
     name: &str,
     var: EventKindVariation,
@@ -657,7 +637,7 @@ impl EventEnumVariant {
 impl EventEnumEntry {
     pub(crate) fn to_variant(&self) -> syn::Result<EventEnumVariant> {
         let attrs = self.attrs.clone();
-        let ident = to_camel_case(&self.ev_type)?;
+        let ident = m_prefix_name_to_type_name(&self.ev_type)?;
         Ok(EventEnumVariant { attrs, ident })
     }
 }
diff --git a/crates/ruma-macros/src/util.rs b/crates/ruma-macros/src/util.rs
index 1d3a4bba..e7005a69 100644
--- a/crates/ruma-macros/src/util.rs
+++ b/crates/ruma-macros/src/util.rs
@@ -1,7 +1,7 @@
 use proc_macro2::TokenStream;
 use proc_macro_crate::{crate_name, FoundCrate};
 use quote::{format_ident, quote};
-use syn::Ident;
+use syn::{Ident, LitStr};
 
 pub(crate) fn import_ruma_common() -> TokenStream {
     if let Ok(FoundCrate::Name(name)) = crate_name("ruma-common") {
@@ -32,3 +32,24 @@ pub(crate) fn to_camel_case(name: &Ident) -> Ident {
         .collect();
     Ident::new(&s, span)
 }
+
+/// Splits the given string on `.` and `_` removing the `m.` then camel casing to give a Rust type
+/// name.
+pub(crate) fn m_prefix_name_to_type_name(name: &LitStr) -> syn::Result<Ident> {
+    let span = name.span();
+    let name = name.value();
+
+    if &name[..2] != "m." {
+        return Err(syn::Error::new(
+            span,
+            format!("well-known matrix events have to start with `m.` found `{}`", name),
+        ));
+    }
+
+    let s: String = name[2..]
+        .split(&['.', '_'] as &[char])
+        .map(|s| s.chars().next().unwrap().to_uppercase().to_string() + &s[1..])
+        .collect();
+
+    Ok(Ident::new(&s, span))
+}