fix: formatting in src/ and tests/ directories

Author: hamirmahal

src/book/mod.rs

@@ -508,9 +508,7 @@ fn determine_preprocessors(config: &Config) -> Result<Vec<Box<dyn Preprocessor>>
 
             if let Some(after) = table.get("after") {
                 let after = after.as_array().ok_or_else(|| {
-                    Error::msg(format!(
-                        "Expected preprocessor.{name}.after to be an array"
-                    ))
+                    Error::msg(format!("Expected preprocessor.{name}.after to be an array"))
                 })?;
                 for before in after {
                     let before = before.as_str().ok_or_else(|| {

src/renderer/html_handlebars/hbs_renderer.rs

@@ -856,9 +856,7 @@ fn fix_code_blocks(html: &str) -> String {
             let classes = &caps[2].replace(',', " ");
             let after = &caps[3];
 
-            format!(
-                r#"<code{before}class="{classes}"{after}>"#
-            )
+            format!(r#"<code{before}class="{classes}"{after}>"#)
         })
         .into_owned()
 }
@@ -916,8 +914,7 @@ fn add_playground_pre(
                             // we need to inject our own main
                             let (attrs, code) = partition_source(code);
 
-                            format!("# #![allow(unused)]\n{attrs}#fn main() {{\n{code}#}}")
-                                .into()
+                            format!("# #![allow(unused)]\n{attrs}#fn main() {{\n{code}#}}").into()
                         };
                         content
                     }

tests/alternative_backends.rs

@@ -121,9 +121,7 @@ fn dummy_book_with_backend(
         .unwrap();
 
     if backend_is_optional {
-        config
-            .set(format!("output.{name}.optional"), true)
-            .unwrap();
+        config.set(format!("output.{name}.optional"), true).unwrap();
     }
 
     let md = MDBook::init(temp.path())