Make use of implicit format string arguments

examples/rondpoint/src/lib.rs

@@ -179,7 +179,7 @@ impl Stringifier {
         value.to_string()
     }
     fn well_known_string(&self, value: String) -> String {
-        format!("uniffi 💚 {}!", value)
+        format!("uniffi 💚 {value}!")
     }
 }
 

fixtures/coverall/src/lib.rs

@@ -159,15 +159,15 @@ impl Coveralls {
     }
 
     fn fallible_panic(&self, message: String) -> Result<()> {
-        panic!("{}", message);
+        panic!("{message}");
     }
 
     fn get_name(&self) -> String {
         self.name.clone()
     }
 
     fn panicing_new(message: String) -> Self {
-        panic!("{}", message);
+        panic!("{message}");
     }
 
     fn maybe_throw(&self, should_throw: bool) -> Result<bool> {
@@ -201,7 +201,7 @@ impl Coveralls {
     }
 
     fn panic(&self, message: String) {
-        panic!("{}", message);
+        panic!("{message}");
     }
 
     fn strong_count(self: Arc<Self>) -> u64 {
@@ -221,7 +221,7 @@ impl Coveralls {
     }
 
     fn take_other_panic(self: Arc<Self>, message: String) {
-        panic!("{}", message);
+        panic!("{message}");
     }
 
     fn clone_me(&self) -> Arc<Self> {
@@ -235,7 +235,7 @@ impl Coveralls {
     }
 
     fn get_status(&self, status: String) -> String {
-        format!("status: {}", status)
+        format!("status: {status}")
     }
 
     fn get_dict(&self, key: String, value: u64) -> HashMap<String, u64> {

fixtures/reexport-scaffolding-macro/src/lib.rs

@@ -21,7 +21,7 @@ mod tests {
         let output = std::io::BufReader::new(child.stdout.take().unwrap());
         let artifacts = Message::parse_stream(output)
             .filter_map(|message| match message {
-                Err(e) => panic!("{}", e),
+                Err(e) => panic!("{e}"),
                 Ok(Message::CompilerArtifact(artifact)) => {
                     if artifact.target.name == "reexport_scaffolding_macro"
                         && artifact.target.kind.iter().any(|item| item == "cdylib")
@@ -39,7 +39,7 @@ mod tests {
         }
         let artifact = match artifacts.len() {
             1 => &artifacts[0],
-            n => panic!("Found {} artfiacts from cargo build", n),
+            n => panic!("Found {n} artfiacts from cargo build"),
         };
         let cdylib_files: Vec<_> = artifact
             .filenames

uniffi/src/ffi/rustcalls.rs

@@ -190,7 +190,7 @@ mod test {
     fn function(a: u8) -> i8 {
         match a {
             0 => 100,
-            x => panic!("Unexpected value: {}", x),
+            x => panic!("Unexpected value: {x}"),
         }
     }
 
@@ -240,7 +240,7 @@ mod test {
         match a {
             0 => Ok(100),
             1 => Err(TestError("Error".to_owned())),
-            x => panic!("Unexpected value: {}", x),
+            x => panic!("Unexpected value: {x}"),
         }
     }
 

uniffi/src/lib.rs

@@ -220,11 +220,10 @@ pub unsafe trait FfiConverter: Sized {
 /// helper function to instead return an explicit error, to help with debugging.
 pub fn check_remaining(buf: &[u8], num_bytes: usize) -> Result<()> {
     if buf.remaining() < num_bytes {
-        bail!(format!(
-            "not enough bytes remaining in buffer ({} < {})",
+        bail!(
+            "not enough bytes remaining in buffer ({} < {num_bytes})",
             buf.remaining(),
-            num_bytes
-        ));
+        );
     }
     Ok(())
 }
@@ -640,7 +639,7 @@ where
 {
     match err.downcast::<ErrConverter::RustType>() {
         Ok(actual_error) => ErrConverter::lower(actual_error),
-        Err(ohno) => panic!("Failed to convert arg '{}': {}", arg_name, ohno),
+        Err(ohno) => panic!("Failed to convert arg '{arg_name}': {ohno}"),
     }
 }
 

uniffi/src/panichook.rs

@@ -20,7 +20,7 @@ pub fn ensure_setup() {
                 // in the future.
                 ("<unknown>", 0)
             };
-            log::error!("### Rust `panic!` hit at file '{}', line {}", file, line);
+            log::error!("### Rust `panic!` hit at file '{file}', line {line}");
             #[cfg(all(feature = "log_backtraces", not(target_os = "android")))]
             {
                 log::error!("  Complete stack trace:\n{:?}", backtrace::Backtrace::new());

uniffi/src/testing.rs

@@ -102,15 +102,13 @@ pub fn ensure_compiled_cdylib(pkg_dir: &str) -> Result<Utf8PathBuf> {
             {
                 Some(cdylib) => {
                     log::warn!(
-                        "Crate produced multiple cdylibs, using the one produced by {}",
-                        pkg_dir
+                        "Crate produced multiple cdylibs, using the one produced by {pkg_dir}",
                     );
                     cdylib
                 }
                 None => {
                     bail!(
-                        "Crate produced multiple cdylibs, none of which is produced by {}",
-                        pkg_dir
+                        "Crate produced multiple cdylibs, none of which is produced by {pkg_dir}",
                     );
                 }
             }
@@ -145,7 +143,7 @@ fn run_uniffi_bindgen_test(out_dir: &str, udl_files: &[&str], test_file: &str) -
         .args(&["test", out_dir, &udl_files, test_file])
         .status()?;
     if !status.success() {
-        bail!("Error while running tests: {}", status);
+        bail!("Error while running tests: {status}");
     }
     Ok(())
 }

uniffi_bindgen/src/interface/callbacks.rs

@@ -75,7 +75,7 @@ impl CallbackInterface {
     }
 
     pub(super) fn derive_ffi_funcs(&mut self, ci_prefix: &str) {
-        self.ffi_init_callback.name = format!("ffi_{}_{}_init_callback", ci_prefix, self.name);
+        self.ffi_init_callback.name = format!("ffi_{ci_prefix}_{}_init_callback", self.name);
         self.ffi_init_callback.arguments = vec![FFIArgument {
             name: "callback_stub".to_string(),
             type_: FFIType::ForeignCallback,

uniffi_bindgen/src/interface/function.rs

@@ -92,7 +92,7 @@ impl Function {
         // The name is already set if the function is defined in a proc-macro-generated JSON file
         // rather than in UDL. Don't overwrite it in that case.
         if self.ffi_func.name.is_empty() {
-            self.ffi_func.name = format!("{}_{}", ci_prefix, self.name);
+            self.ffi_func.name = format!("{ci_prefix}_{}", self.name);
         }
 
         self.ffi_func.arguments = self.arguments.iter().map(|arg| arg.into()).collect();

uniffi_bindgen/src/interface/mod.rs

@@ -118,7 +118,7 @@ impl ComponentInterface {
         let (remaining, defns) = weedle::Definitions::parse(idl.trim()).unwrap();
         if !remaining.is_empty() {
             println!("Error parsing the IDL. Text remaining to be parsed is:");
-            println!("{}", remaining);
+            println!("{remaining}");
             bail!("parse error");
         }
         // Unconditionally add the String type, which is used by the panic handling

uniffi_bindgen/src/interface/object.rs

@@ -136,7 +136,7 @@ impl Object {
         let matches: Vec<_> = self.methods.iter().filter(|m| m.name() == name).collect();
         match matches.len() {
             1 => matches[0].clone(),
-            n => panic!("{} methods named {}", n, name),
+            n => panic!("{n} methods named {name}"),
         }
     }
 
@@ -155,7 +155,7 @@ impl Object {
     }
 
     pub fn derive_ffi_funcs(&mut self, ci_prefix: &str) -> Result<()> {
-        self.ffi_func_free.name = format!("ffi_{}_{}_object_free", ci_prefix, self.name);
+        self.ffi_func_free.name = format!("ffi_{ci_prefix}_{}_object_free", self.name);
         self.ffi_func_free.arguments = vec![FFIArgument {
             name: "ptr".to_string(),
             type_: FFIType::RustArcPtr(self.name().to_string()),
@@ -276,7 +276,7 @@ impl Constructor {
     }
 
     fn derive_ffi_func(&mut self, ci_prefix: &str, obj_name: &str) {
-        self.ffi_func.name = format!("{}_{}_{}", ci_prefix, obj_name, self.name);
+        self.ffi_func.name = format!("{ci_prefix}_{obj_name}_{}", self.name);
         self.ffi_func.arguments = self.arguments.iter().map(Into::into).collect();
         self.ffi_func.return_type = Some(FFIType::RustArcPtr(obj_name.to_string()));
     }
@@ -389,7 +389,7 @@ impl Method {
     }
 
     pub fn derive_ffi_func(&mut self, ci_prefix: &str, obj_prefix: &str) -> Result<()> {
-        self.ffi_func.name = format!("{}_{}_{}", ci_prefix, obj_prefix, self.name);
+        self.ffi_func.name = format!("{ci_prefix}_{obj_prefix}_{}", self.name);
         self.ffi_func.arguments = self.full_arguments().iter().map(Into::into).collect();
         self.ffi_func.return_type = self.return_type.as_ref().map(Into::into);
         Ok(())

uniffi_bindgen/src/interface/types/mod.rs

@@ -97,11 +97,11 @@ impl Type {
             // cases like a record named `SequenceRecord` interfering with `sequence<Record>`.
             // However, types that support importing all end up with the same prefix of "Type", so
             // that the import handling code knows how to find the remote reference.
-            Type::Object(nm) => format!("Type{}", nm),
-            Type::Error(nm) => format!("Type{}", nm),
-            Type::Enum(nm) => format!("Type{}", nm),
-            Type::Record(nm) => format!("Type{}", nm),
-            Type::CallbackInterface(nm) => format!("CallbackInterface{}", nm),
+            Type::Object(nm) => format!("Type{nm}"),
+            Type::Error(nm) => format!("Type{nm}"),
+            Type::Enum(nm) => format!("Type{nm}"),
+            Type::Record(nm) => format!("Type{nm}"),
+            Type::CallbackInterface(nm) => format!("CallbackInterface{nm}"),
             Type::Timestamp => "Timestamp".into(),
             Type::Duration => "Duration".into(),
             // Recursive types.
@@ -117,7 +117,7 @@ impl Type {
                 v.canonical_name().to_upper_camel_case()
             ),
             // A type that exists externally.
-            Type::External { name, .. } | Type::Custom { name, .. } => format!("Type{}", name),
+            Type::External { name, .. } | Type::Custom { name, .. } => format!("Type{name}"),
         }
     }
 
@@ -217,14 +217,13 @@ impl TypeUniverse {
     pub fn add_type_definition(&mut self, name: &str, type_: Type) -> Result<()> {
         if resolve_builtin_type(name).is_some() {
             bail!(
-                "please don't shadow builtin types ({}, {})",
-                name,
-                type_.canonical_name()
+                "please don't shadow builtin types ({name}, {})",
+                type_.canonical_name(),
             );
         }
         let type_ = self.add_known_type(type_)?;
         match self.type_definitions.entry(name.to_string()) {
-            Entry::Occupied(_) => bail!("Conflicting type definition for \"{}\"", name),
+            Entry::Occupied(_) => bail!("Conflicting type definition for \"{name}\""),
             Entry::Vacant(e) => {
                 e.insert(type_);
                 Ok(())

uniffi_bindgen/src/lib.rs

@@ -201,9 +201,9 @@ fn load_bindings_config_toml<BC: BindingGeneratorConfig>(
     }
 
     let contents = fs::read_to_string(&config_path)
-        .with_context(|| format!("Failed to read config file from {}", config_path))?;
+        .with_context(|| format!("Failed to read config file from {config_path}"))?;
     let full_config = toml::Value::from_str(&contents)
-        .with_context(|| format!("Failed to parse config file {}", config_path))?;
+        .with_context(|| format!("Failed to parse config file {config_path}"))?;
 
     Ok(full_config
         .get("bindings")
@@ -286,7 +286,7 @@ pub fn generate_component_scaffolding(
         config_file_override,
     );
     let file_stem = udl_file.file_stem().context("not a file")?;
-    let filename = format!("{}.uniffi.rs", file_stem);
+    let filename = format!("{file_stem}.uniffi.rs");
     let out_dir = get_out_dir(udl_file, out_dir_override)?.join(filename);
     let mut f = File::create(&out_dir)?;
     write!(f, "{}", RustScaffolding::new(&component)).context("Failed to write output file")?;
@@ -418,9 +418,9 @@ fn get_config(
     match config_file {
         Some(path) => {
             let contents = fs::read_to_string(&path)
-                .with_context(|| format!("Failed to read config file from {}", &path))?;
+                .with_context(|| format!("Failed to read config file from {path}"))?;
             let loaded_config: Config = toml::de::from_str(&contents)
-                .with_context(|| format!("Failed to generate config from file {}", &path))?;
+                .with_context(|| format!("Failed to generate config from file {path}"))?;
             Ok(loaded_config.merge_with(&default_config))
         }
         None => Ok(default_config),
@@ -443,7 +443,7 @@ fn get_out_dir(udl_file: &Utf8Path, out_dir_override: Option<&Utf8Path>) -> Resu
 
 fn parse_udl(udl_file: &Utf8Path) -> Result<ComponentInterface> {
     let udl = fs::read_to_string(udl_file)
-        .with_context(|| format!("Failed to read UDL from {}", &udl_file))?;
+        .with_context(|| format!("Failed to read UDL from {udl_file}"))?;
     ComponentInterface::from_webidl(&udl).context("Failed to parse UDL")
 }
 
@@ -478,9 +478,7 @@ fn rebuild_metadata(crate_root: &Utf8Path) -> anyhow::Result<()> {
                 .to_string_lossy();
             ensure!(
                 filename.ends_with(".json"),
-                "all files in `{}` must have `.json` file endings, found `{}`",
-                metadata_dir,
-                filename,
+                "all files in `{metadata_dir}` must have `.json` file endings, found `{filename}`",
             );
 
             fs::remove_file(path)?;

uniffi_bindgen/src/macro_metadata.rs

@@ -37,11 +37,7 @@ pub(crate) fn add_macro_metadata(
             .map_err(|_| anyhow!("non-utf8 file names are not supported"))?;
 
         let file_basename = file_name.strip_suffix(".json").ok_or_else(|| {
-            anyhow!(
-                "expected only JSON files in `{}`, found `{}`",
-                metadata_dir,
-                file_name
-            )
+            anyhow!("expected only JSON files in `{metadata_dir}`, found `{file_name}`")
         })?;
 
         let mut segments = match file_basename.strip_prefix("mod.") {

uniffi_build/src/lib.rs

@@ -24,7 +24,7 @@ use std::env;
 pub fn generate_scaffolding(udl_file: impl AsRef<Utf8Path>) -> Result<()> {
     let udl_file = udl_file.as_ref();
 
-    println!("cargo:rerun-if-changed={}", udl_file);
+    println!("cargo:rerun-if-changed={udl_file}");
     // The UNIFFI_TESTS_DISABLE_EXTENSIONS variable disables some bindings, but it is evaluated
     // at *build* time, so we need to rebuild when it changes.
     println!("cargo:rerun-if-env-changed=UNIFFI_TESTS_DISABLE_EXTENSIONS");

uniffi_macros/src/export/metadata/function.rs

@@ -20,7 +20,7 @@ pub(super) fn gen_fn_metadata(item: syn::ItemFn, mod_path: &[String]) -> syn::Re
     ));
 
     let tracked_file = write_json_metadata(&path, &meta)
-        .map_err(|e| syn::Error::new(Span::call_site(), format!("failed to write file: {}", e)))?;
+        .map_err(|e| syn::Error::new(Span::call_site(), format!("failed to write file: {e}")))?;
 
     Ok(ExportItem::Function {
         item,

uniffi_macros/src/export/scaffolding.rs

@@ -49,7 +49,7 @@ fn gen_fn_scaffolding(
             }
             FnArg::Typed(pat_ty) => {
                 let ty = &pat_ty.ty;
-                let name = format_ident!("arg{}", i);
+                let name = format_ident!("arg{i}");
 
                 params.push(quote! { #name: <#ty as ::uniffi::FfiConverter>::FfiType });
 
@@ -58,7 +58,7 @@ fn gen_fn_scaffolding(
                         format!("Failed to convert arg '{}': {{}}", i.ident)
                     }
                     _ => {
-                        format!("Failed to convert arg #{}: {{}}", i)
+                        format!("Failed to convert arg #{i}: {{}}")
                     }
                 };
                 args.push(quote! {

uniffi_macros/src/util.rs

@@ -38,7 +38,7 @@ pub fn mod_path() -> syn::Result<Vec<String>> {
         let cargo_toml_bytes =
             fs::read(Path::new(&manifest_dir).join("Cargo.toml")).map_err(|e| e.to_string())?;
         let cargo_toml = toml::from_slice::<CargoToml>(&cargo_toml_bytes)
-            .map_err(|e| format!("Failed to parse `Cargo.toml`: {}", e))?;
+            .map_err(|e| format!("Failed to parse `Cargo.toml`: {e}"))?;
 
         let lib_crate_name = cargo_toml
             .lib