chore: use variables in Rust format strings

Change this:

    format!("{}", foo)

into this:

    format!("{foo}")

Support for this feature was added in Rust 1.58 (see
https://github.com/rust-lang/rust/releases/tag/1.58.0) and in 1.67
clippy suggests about this. Because the new style seems to be where
the Rust ecosystem is going, I think Subplot should follow to avoid
being needlessly different from most other projects.

Sponsored-by: author

17 files changed, 61 insertions, 85 deletions

diff --git a/build.rs b/build.rs
index 857452b..2276f93 100644
--- a/build.rs
+++ b/build.rs
@@ -127,15 +127,11 @@ fn write_out_resource_file<'a>(paths: impl Iterator<Item = &'a Path>) -> Result<
 /// to contain `BUILTIN_{var}` to either the env value, or `{def}` if not
 /// provided.
 fn adopt_env_var(var: &str, def: &str) {
-    println!("cargo:rerun-if-env-changed=SUBPLOT_{var}", var = var);
-    if let Ok(value) = std::env::var(format!("SUBPLOT_{var}", var = var)) {
-        println!(
-            "cargo:rustc-env=BUILTIN_{var}={value}",
-            var = var,
-            value = value
-        );
+    println!("cargo:rerun-if-env-changed=SUBPLOT_{var}");
+    if let Ok(value) = std::env::var(format!("SUBPLOT_{var}")) {
+        println!("cargo:rustc-env=BUILTIN_{var}={value}",);
     } else {
-        println!("cargo:rustc-env=BUILTIN_{var}={def}", var = var, def = def);
+        println!("cargo:rustc-env=BUILTIN_{var}={def}");
     }
 }
 
diff --git a/examples/seq/seq-extras.rs b/examples/seq/seq-extras.rs
index 79863fc..b2185fb 100644
--- a/examples/seq/seq-extras.rs
+++ b/examples/seq/seq-extras.rs
@@ -26,8 +26,7 @@ fn count_lines_in_stdout(context: &Runcmd, count: usize) {
         // step error.  This will be reported as the reason the
         // scenario fails.
         throw!(format!(
-            "Incorrect number of lines, got {} expected {}",
-            stdout_count, count
+            "Incorrect number of lines, got {stdout_count} expected {count}",
         ));
     }
 }
@@ -57,8 +56,7 @@ fn stderr_contains_two_things(context: &ScenarioContext, what: &str, other: &str
 
     if !stderr_has_both {
         throw!(format!(
-            "Stderr does not contain both of {:?} and {:?}",
-            what, other
+            "Stderr does not contain both of {what:?} and {other:?}",
         ))
     }
 }
diff --git a/src/bin/cli/mod.rs b/src/bin/cli/mod.rs
index 4e15efb..dacf9b6 100644
--- a/src/bin/cli/mod.rs
+++ b/src/bin/cli/mod.rs
@@ -97,7 +97,7 @@ impl TryFrom<&mut Document> for Metadata {
 
 impl Metadata {
     fn write_list(v: &[String], prefix: &str) {
-        v.iter().for_each(|entry| println!("{}: {}", prefix, entry))
+        v.iter().for_each(|entry| println!("{prefix}: {entry}"))
     }
 
     pub fn write_out(&self) {
@@ -107,7 +107,7 @@ impl Metadata {
         let templates: Vec<String> = self.impls.keys().map(String::from).collect();
         Self::write_list(&templates, "templates");
         for (template, filenames) in self.impls.iter() {
-            Self::write_list(filenames, &format!("functions[{}]", template));
+            Self::write_list(filenames, &format!("functions[{template}]"));
         }
         Self::write_list(&self.bibliographies, "bibliography");
         Self::write_list(&self.files, "file");
@@ -139,7 +139,7 @@ impl FromStr for OutputFormat {
         match s.to_ascii_lowercase().as_ref() {
             "plain" => Ok(OutputFormat::Plain),
             "json" => Ok(OutputFormat::Json),
-            _ => Err(format!("Unknown output format: `{}`", s)),
+            _ => Err(format!("Unknown output format: `{s}`")),
         }
     }
 }
diff --git a/src/bin/subplot.rs b/src/bin/subplot.rs
index b86c613..7f51b5c 100644
--- a/src/bin/subplot.rs
+++ b/src/bin/subplot.rs
@@ -88,7 +88,7 @@ fn long_version() -> Result<String> {
     writeln!(ret, "{}", render_testament!(VERSION))?;
     writeln!(ret, "Crate version: {}", env!("CARGO_PKG_VERSION"))?;
     if let Some(branch) = VERSION.branch_name {
-        writeln!(ret, "Built from branch: {}", branch)?;
+        writeln!(ret, "Built from branch: {branch}")?;
     } else {
         writeln!(ret, "Branch information is missing.")?;
     }
diff --git a/src/bindings.rs b/src/bindings.rs
index 98379c9..2738aa1 100644
--- a/src/bindings.rs
+++ b/src/bindings.rs
@@ -176,7 +176,7 @@ impl Binding {
         case_sensitive: bool,
         mut types: HashMap<String, CaptureType>,
     ) -> Result<Binding, SubplotError> {
-        let regex = RegexBuilder::new(&format!("^{}$", pattern))
+        let regex = RegexBuilder::new(&format!("^{pattern}$"))
             .case_insensitive(!case_sensitive)
             .build()
             .map_err(|err| SubplotError::Regex(pattern.to_string(), err))?;
@@ -541,12 +541,12 @@ fn from_hashmap(parsed: &ParsedBinding) -> Result<Binding, SubplotError> {
     let then: i32 = parsed.then.is_some().into();
 
     if given + when + then == 0 {
-        let msg = format!("{:?}", parsed);
+        let msg = format!("{parsed:?}");
         return Err(SubplotError::BindingWithoutKnownKeyword(msg));
     }
 
     if given + when + then > 1 {
-        let msg = format!("{:?}", parsed);
+        let msg = format!("{parsed:?}");
         return Err(SubplotError::BindingHasManyKeywords(msg));
     }
 
@@ -557,7 +557,7 @@ fn from_hashmap(parsed: &ParsedBinding) -> Result<Binding, SubplotError> {
     } else if parsed.then.is_some() {
         (StepKind::Then, parsed.then.as_ref().unwrap())
     } else {
-        let msg = format!("{:?}", parsed);
+        let msg = format!("{parsed:?}");
         return Err(SubplotError::BindingWithoutKnownKeyword(msg));
     };
 
@@ -641,7 +641,7 @@ mod test_bindings {
 ";
         let mut bindings = Bindings::new();
         bindings.add_from_yaml(yaml).unwrap();
-        println!("test: {:?}", bindings);
+        println!("test: {bindings:?}");
         assert!(bindings.has(StepKind::Given, "I am Tomjon"));
         assert!(bindings.has(StepKind::When, "I declare myself king"));
         assert!(bindings.has(StepKind::Then, "there is applause"));
diff --git a/src/md/typeset.rs b/src/md/typeset.rs
index f63206a..aa6528d 100644
--- a/src/md/typeset.rs
+++ b/src/md/typeset.rs
@@ -14,7 +14,7 @@ use pandoc_ast::Target;
 
 /// Typeset an error as a Pandoc AST Block element.
 pub fn error(err: SubplotError) -> Block {
-    let msg = format!("ERROR: {}", err);
+    let msg = format!("ERROR: {err}");
     Block::Para(error_msg(&msg))
 }
 
@@ -82,7 +82,7 @@ fn step(
     let step = ScenarioStep::new_from_str(text, prevkind);
     if step.is_err() {
         return (
-            error_msg(&format!("Could not parse step: {}", text)),
+            error_msg(&format!("Could not parse step: {text}")),
             prevkind,
         );
     }
@@ -91,9 +91,9 @@ fn step(
     let m = match bindings.find("", &step) {
         Ok(m) => m,
         Err(e) => {
-            let w = Warning::UnknownBinding(format!("{}", e));
+            let w = Warning::UnknownBinding(format!("{e}"));
             warnings.push(w.clone());
-            return (error_msg(&format!("{}", w)), prevkind);
+            return (error_msg(&format!("{w}")), prevkind);
         }
     };
 
@@ -163,7 +163,7 @@ pub fn pikchr_to_block(pikchr: &str, class: Option<&str>, warnings: &mut Warning
     match PikchrMarkup::new(pikchr, class).as_svg() {
         Ok(svg) => typeset_svg(svg),
         Err(err) => {
-            warnings.push(Warning::Pikchr(format!("{}", err)));
+            warnings.push(Warning::Pikchr(format!("{err}")));
             error(err)
         }
     }
@@ -176,7 +176,7 @@ pub fn dot_to_block(dot: &str, warnings: &mut Warnings) -> Block {
     match DotMarkup::new(dot).as_svg() {
         Ok(svg) => typeset_svg(svg),
         Err(err) => {
-            warnings.push(Warning::Dot(format!("{}", err)));
+            warnings.push(Warning::Dot(format!("{err}")));
             error(err)
         }
     }
@@ -189,7 +189,7 @@ pub fn plantuml_to_block(markup: &str, warnings: &mut Warnings) -> Block {
     match PlantumlMarkup::new(markup).as_svg() {
         Ok(svg) => typeset_svg(svg),
         Err(err) => {
-            warnings.push(Warning::Plantuml(format!("{}", err)));
+            warnings.push(Warning::Plantuml(format!("{err}")));
             error(err)
         }
     }
@@ -225,5 +225,5 @@ fn typeset_svg(svg: Svg) -> Block {
 // referencing external files.
 fn svg_as_data_url(svg: Svg) -> String {
     let svg = base64::encode(svg.data());
-    format!("data:image/svg+xml;base64,{}", svg)
+    format!("data:image/svg+xml;base64,{svg}")
 }
diff --git a/src/md/visitor/embedded.rs b/src/md/visitor/embedded.rs
index 840d9ed..68a4118 100644
--- a/src/md/visitor/embedded.rs
+++ b/src/md/visitor/embedded.rs
@@ -19,7 +19,7 @@ impl MutVisitor for EmbeddedFiles {
                             _ => unreachable!(),
                         };
                         let contents = if add_newline {
-                            format!("{}\n", contents)
+                            format!("{contents}\n")
                         } else {
                             contents.clone()
                         };
diff --git a/src/steps.rs b/src/steps.rs
index ccbc588..b0a15e9 100644
--- a/src/steps.rs
+++ b/src/steps.rs
@@ -109,7 +109,7 @@ impl fmt::Display for StepKind {
             StepKind::When => "when",
             StepKind::Then => "then",
         };
-        write!(f, "{}", s)
+        write!(f, "{s}")
     }
 }
 
diff --git a/subplotlib-derive/src/lib.rs b/subplotlib-derive/src/lib.rs
index 7aef0dc..584d730 100644
--- a/subplotlib-derive/src/lib.rs
+++ b/subplotlib-derive/src/lib.rs
@@ -403,10 +403,7 @@ fn process_step(mut input: ItemFn) -> proc_macro2::TokenStream {
         for context in outer_ctx.into_iter().chain(contexts.iter()) {
             write!(contextattrs, "\n    #[context({:?})]", ty_as_path(context)?).unwrap();
         }
-        let func_args: Vec<_> = fields
-            .iter()
-            .map(|(ident, _)| format!("{}", ident))
-            .collect();
+        let func_args: Vec<_> = fields.iter().map(|(ident, _)| format!("{ident}")).collect();
         let func_args = func_args.join(", ");
         format!(
             r#"
@@ -424,9 +421,6 @@ fn process_step(mut input: ItemFn) -> proc_macro2::TokenStream {
     }}
     ```
     "#,
-            stepname = stepname,
-            contextattrs = contextattrs,
-            func_args = func_args,
         )
     };
     let ret = quote! {
diff --git a/subplotlib/helpers/subplotlib_impl.rs b/subplotlib/helpers/subplotlib_impl.rs
index fac54ab..768337a 100644
--- a/subplotlib/helpers/subplotlib_impl.rs
+++ b/subplotlib/helpers/subplotlib_impl.rs
@@ -36,7 +36,7 @@ fn remember_target(context: &mut Context, somename: &str) {
     if let Some(file) = context.files.get(somename) {
         context.this_file = Some(file.clone());
     } else {
-        throw!(format!("Unknown file {}", somename));
+        throw!(format!("Unknown file {somename}"));
     }
 }
 
diff --git a/subplotlib/src/scenario.rs b/subplotlib/src/scenario.rs
index 7a78ae5..8c734b9 100644
--- a/subplotlib/src/scenario.rs
+++ b/subplotlib/src/scenario.rs
@@ -174,9 +174,9 @@ impl DebuggedContext {
         C: Debug,
     {
         let body = if alternate {
-            format!("{:#?}", obj)
+            format!("{obj:#?}")
         } else {
-            format!("{:?}", obj)
+            format!("{obj:?}")
         };
         self.body.push(body);
     }
diff --git a/subplotlib/src/step.rs b/subplotlib/src/step.rs
index 7a70e23..12b4ddf 100644
--- a/subplotlib/src/step.rs
+++ b/subplotlib/src/step.rs
@@ -57,11 +57,11 @@ impl ScenarioStep {
     /// a formatted string then we won't be able to render it sadly.
     fn render_panic(name: &str, err: Box<dyn Any + Send>) -> String {
         if let Some(msg) = err.downcast_ref::<&str>() {
-            format!("step {} panic'd: {}", name, msg)
+            format!("step {name} panic'd: {msg}")
         } else if let Some(msg) = err.downcast_ref::<String>() {
-            format!("step {} panic'd: {}", name, msg)
+            format!("step {name} panic'd: {msg}")
         } else {
-            format!("step {} panic'd", name)
+            format!("step {name} panic'd")
         }
     }
 
diff --git a/subplotlib/src/steplibrary/datadir.rs b/subplotlib/src/steplibrary/datadir.rs
index 5a344df..5060f63 100644
--- a/subplotlib/src/steplibrary/datadir.rs
+++ b/subplotlib/src/steplibrary/datadir.rs
@@ -150,8 +150,7 @@ pub fn datadir_has_enough_space(datadir: &Datadir, bytes: u64) {
     let available = fs2::available_space(datadir.base_path())?;
     if available < bytes {
         throw!(format!(
-            "Available space check failed, wanted {} bytes, but only {} were available",
-            bytes, available
+            "Available space check failed, wanted {bytes} bytes, but only {available} were available",
         ));
     }
 }
diff --git a/subplotlib/src/steplibrary/files.rs b/subplotlib/src/steplibrary/files.rs
index 8abe546..c60358f 100644
--- a/subplotlib/src/steplibrary/files.rs
+++ b/subplotlib/src/steplibrary/files.rs
@@ -90,7 +90,7 @@ pub fn touch_with_timestamp(context: &Datadir, filename: &Path, mtime: &str) {
     let fd = format_description!(
         "[year]-[month]-[day] [hour]:[minute]:[second] [offset_hour]:[offset_minute]"
     );
-    let full_time = format!("{} +00:00", mtime);
+    let full_time = format!("{mtime} +00:00");
     let ts = OffsetDateTime::parse(&full_time, &fd)?;
     let (secs, nanos) = (ts.unix_timestamp(), 0);
     let mtime = FileTime::from_unix_time(secs, nanos);
diff --git a/subplotlib/src/steplibrary/runcmd.rs b/subplotlib/src/steplibrary/runcmd.rs
index 6692441..99605a3 100644
--- a/subplotlib/src/steplibrary/runcmd.rs
+++ b/subplotlib/src/steplibrary/runcmd.rs
@@ -353,7 +353,7 @@ pub fn exit_code_is(context: &Runcmd, exit: i32) {
 #[step]
 pub fn exit_code_is_not(context: &Runcmd, exit: i32) {
     if context.exitcode.is_none() || context.exitcode == Some(exit) {
-        throw!(format!("Expected exit code to not equal {}", exit));
+        throw!(format!("Expected exit code to not equal {exit}"));
     }
 }
 
@@ -422,7 +422,7 @@ fn check_matches(runcmd: &Runcmd, which: Stream, how: MatchKind, against: &str)
 #[step]
 pub fn stdout_is(runcmd: &Runcmd, text: &str) {
     if !check_matches(runcmd, Stream::Stdout, MatchKind::Exact, text)? {
-        throw!(format!("stdout is not {:?}", text));
+        throw!(format!("stdout is not {text:?}"));
     }
 }
 
@@ -435,7 +435,7 @@ pub fn stdout_is(runcmd: &Runcmd, text: &str) {
 #[step]
 pub fn stdout_isnt(runcmd: &Runcmd, text: &str) {
     if check_matches(runcmd, Stream::Stdout, MatchKind::Exact, text)? {
-        throw!(format!("stdout is exactly {:?}", text));
+        throw!(format!("stdout is exactly {text:?}"));
     }
 }
 
@@ -448,7 +448,7 @@ pub fn stdout_isnt(runcmd: &Runcmd, text: &str) {
 #[step]
 pub fn stderr_is(runcmd: &Runcmd, text: &str) {
     if !check_matches(runcmd, Stream::Stderr, MatchKind::Exact, text)? {
-        throw!(format!("stderr is not {:?}", text));
+        throw!(format!("stderr is not {text:?}"));
     }
 }
 
@@ -461,7 +461,7 @@ pub fn stderr_is(runcmd: &Runcmd, text: &str) {
 #[step]
 pub fn stderr_isnt(runcmd: &Runcmd, text: &str) {
     if check_matches(runcmd, Stream::Stderr, MatchKind::Exact, text)? {
-        throw!(format!("stderr is exactly {:?}", text));
+        throw!(format!("stderr is exactly {text:?}"));
     }
 }
 
@@ -474,7 +474,7 @@ pub fn stderr_isnt(runcmd: &Runcmd, text: &str) {
 #[step]
 pub fn stdout_contains(runcmd: &Runcmd, text: &str) {
     if !check_matches(runcmd, Stream::Stdout, MatchKind::Contains, text)? {
-        throw!(format!("stdout does not contain {:?}", text));
+        throw!(format!("stdout does not contain {text:?}"));
     }
 }
 
@@ -487,7 +487,7 @@ pub fn stdout_contains(runcmd: &Runcmd, text: &str) {
 #[step]
 pub fn stdout_doesnt_contain(runcmd: &Runcmd, text: &str) {
     if check_matches(runcmd, Stream::Stdout, MatchKind::Contains, text)? {
-        throw!(format!("stdout contains {:?}", text));
+        throw!(format!("stdout contains {text:?}"));
     }
 }
 
@@ -500,7 +500,7 @@ pub fn stdout_doesnt_contain(runcmd: &Runcmd, text: &str) {
 #[step]
 pub fn stderr_contains(runcmd: &Runcmd, text: &str) {
     if !check_matches(runcmd, Stream::Stderr, MatchKind::Contains, text)? {
-        throw!(format!("stderr does not contain {:?}", text));
+        throw!(format!("stderr does not contain {text:?}"));
     }
 }
 
@@ -513,7 +513,7 @@ pub fn stderr_contains(runcmd: &Runcmd, text: &str) {
 #[step]
 pub fn stderr_doesnt_contain(runcmd: &Runcmd, text: &str) {
     if check_matches(runcmd, Stream::Stderr, MatchKind::Contains, text)? {
-        throw!(format!("stderr contains {:?}", text));
+        throw!(format!("stderr contains {text:?}"));
     }
 }
 
@@ -527,7 +527,7 @@ pub fn stderr_doesnt_contain(runcmd: &Runcmd, text: &str) {
 #[step]
 pub fn stdout_matches_regex(runcmd: &Runcmd, regex: &str) {
     if !check_matches(runcmd, Stream::Stdout, MatchKind::Regex, regex)? {
-        throw!(format!("stdout does not match {:?}", regex));
+        throw!(format!("stdout does not match {regex:?}"));
     }
 }
 
@@ -541,7 +541,7 @@ pub fn stdout_matches_regex(runcmd: &Runcmd, regex: &str) {
 #[step]
 pub fn stdout_doesnt_match_regex(runcmd: &Runcmd, regex: &str) {
     if check_matches(runcmd, Stream::Stdout, MatchKind::Regex, regex)? {
-        throw!(format!("stdout matches {:?}", regex));
+        throw!(format!("stdout matches {regex:?}"));
     }
 }
 
@@ -555,7 +555,7 @@ pub fn stdout_doesnt_match_regex(runcmd: &Runcmd, regex: &str) {
 #[step]
 pub fn stderr_matches_regex(runcmd: &Runcmd, regex: &str) {
     if !check_matches(runcmd, Stream::Stderr, MatchKind::Regex, regex)? {
-        throw!(format!("stderr does not match {:?}", regex));
+        throw!(format!("stderr does not match {regex:?}"));
     }
 }
 
@@ -569,6 +569,6 @@ pub fn stderr_matches_regex(runcmd: &Runcmd, regex: &str) {
 #[step]
 pub fn stderr_doesnt_match_regex(runcmd: &Runcmd, regex: &str) {
     if check_matches(runcmd, Stream::Stderr, MatchKind::Regex, regex)? {
-        throw!(format!("stderr matches {:?}", regex));
+        throw!(format!("stderr matches {regex:?}"));
     }
 }
diff --git a/subplotlib/subplot-rust-support.rs b/subplotlib/subplot-rust-support.rs
index 4763eff..95dc3f5 100644
--- a/subplotlib/subplot-rust-support.rs
+++ b/subplotlib/subplot-rust-support.rs
@@ -61,8 +61,6 @@ set -eu
 exec '{target_path}/{bin_name}' --resources '{src_dir}/share' "$@"
 "#,
                     target_path = target_path.display(),
-                    bin_name = bin_name,
-                    src_dir = src_dir,
                 ),
             )?;
             {
@@ -92,21 +90,21 @@ fn uninstall_subplot(context: &mut SubplotContext) {
 #[step]
 #[context(Runcmd)]
 fn scenario_was_run(context: &ScenarioContext, name: &str) {
-    let text = format!("\nscenario: {}\n", name);
+    let text = format!("\nscenario: {name}\n");
     runcmd::stdout_contains::call(context, &text)?;
 }
 
 #[step]
 #[context(Runcmd)]
 fn scenario_was_not_run(context: &ScenarioContext, name: &str) {
-    let text = format!("\nscenario: {}\n", name);
+    let text = format!("\nscenario: {name}\n");
     runcmd::stdout_doesnt_contain::call(context, &text)?;
 }
 
 #[step]
 #[context(Runcmd)]
 fn step_was_run(context: &ScenarioContext, keyword: &str, name: &str) {
-    let text = format!("\n  step: {} {}\n", keyword, name);
+    let text = format!("\n  step: {keyword} {name}\n");
     runcmd::stdout_contains::call(context, &text)?;
 }
 
@@ -119,10 +117,7 @@ fn step_was_run_and_then(
     keyword2: &str,
     name2: &str,
 ) {
-    let text = format!(
-        "\n  step: {} {}\n  step: {} {}",
-        keyword1, name1, keyword2, name2
-    );
+    let text = format!("\n  step: {keyword1} {name1}\n  step: {keyword2} {name2}");
     runcmd::stdout_contains::call(context, &text)?;
 }
 
@@ -135,17 +130,14 @@ fn cleanup_was_run(
     keyword2: &str,
     name2: &str,
 ) {
-    let text = format!(
-        "\n  cleanup: {} {}\n  cleanup: {} {}\n",
-        keyword1, name1, keyword2, name2
-    );
+    let text = format!("\n  cleanup: {keyword1} {name1}\n  cleanup: {keyword2} {name2}\n");
     runcmd::stdout_contains::call(context, &text)?;
 }
 
 #[step]
 #[context(Runcmd)]
 fn cleanup_was_not_run(context: &ScenarioContext, keyword: &str, name: &str) {
-    let text = format!("\n  cleanup: {} {}\n", keyword, name);
+    let text = format!("\n  cleanup: {keyword} {name}\n");
     runcmd::stdout_doesnt_contain::call(context, &text)?;
 }
 
@@ -162,7 +154,7 @@ fn end_of_file(context: &Datadir, filename: &str, nbytes: usize) -> Vec<u8> {
 fn file_ends_in_zero_newlines(context: &Datadir, filename: &str) {
     let b = end_of_file(context, filename, 1)?;
     if b[0] == b'\n' {
-        throw!(format!("File {} ends in unexpected newline", filename));
+        throw!(format!("File {filename} ends in unexpected newline"));
     }
 }
 
@@ -171,8 +163,7 @@ fn file_ends_in_one_newline(context: &Datadir, filename: &str) {
     let b = end_of_file(context, filename, 2)?;
     if !(b[0] != b'\n' && b[1] == b'\n') {
         throw!(format!(
-            "File {} does not end in exactly one newline",
-            filename
+            "File {filename} does not end in exactly one newline",
         ));
     }
 }
@@ -182,8 +173,7 @@ fn file_ends_in_two_newlines(context: &Datadir, filename: &str) {
     let b = end_of_file(context, filename, 2)?;
     if b[0] != b'\n' || b[1] != b'\n' {
         throw!(format!(
-            "File {} does not end in exactly two newlines",
-            filename
+            "File {filename} does not end in exactly two newlines",
         ));
     }
 }
@@ -209,12 +199,11 @@ fn json_output_matches_file(context: &ScenarioContext, filename: &str) {
     let output: serde_json::Value = serde_json::from_str(&output)?;
     let fcontent: serde_json::Value = serde_json::from_str(&fcontent)?;
     println!("########");
-    println!("Output:\n{:#}", output);
-    println!("File:\n{:#}", fcontent);
+    println!("Output:\n{output:#}");
+    println!("File:\n{fcontent:#}");
     println!("########");
     assert_eq!(
         output, fcontent,
-        "Command output does not match the content of {}",
-        filename
+        "Command output does not match the content of {filename}",
     );
 }
diff --git a/tests/bindings-ubm.rs b/tests/bindings-ubm.rs
index dc3be19..0ee59e5 100644
--- a/tests/bindings-ubm.rs
+++ b/tests/bindings-ubm.rs
@@ -16,7 +16,7 @@ fn bindings_microbenchmark() {
 
     let mut texts = vec![];
     for i in 0..N {
-        texts.push(format!("step {}", i));
+        texts.push(format!("step {i}"));
     }
     let texted = time.elapsed().unwrap();
 
@@ -24,7 +24,7 @@ fn bindings_microbenchmark() {
     for t in texts.iter() {
         re.push((
             t,
-            RegexBuilder::new(&format!("^{}$", t))
+            RegexBuilder::new(&format!("^{t}$"))
                 .case_insensitive(false)
                 .build()
                 .unwrap(),