Use variable names directly in the format strings (#7906)

# Description

Lint: `clippy::uninlined_format_args`

More readable in most situations.
(May be slightly confusing for modifier format strings
https://doc.rust-lang.org/std/fmt/index.html#formatting-parameters)

Alternative to #7865

# User-Facing Changes

None intended

# Tests + Formatting

(Ran `cargo +stable clippy --fix --workspace -- -A clippy::all -D
clippy::uninlined_format_args` to achieve this. Depends on Rust `1.67`)

crates/nu-cli/src/completions/completer.rs

@@ -104,7 +104,7 @@ impl NuCompleter {
                     return Some(result);
                 }
             }
-            Err(err) => println!("failed to eval completer block: {}", err),
+            Err(err) => println!("failed to eval completer block: {err}"),
         }
 
         None

crates/nu-cli/src/completions/directory_completions.rs

@@ -119,7 +119,7 @@ pub fn directory_completion(
                             let mut file_name = entry.file_name().to_string_lossy().into_owned();
                             if matches(&partial, &file_name, options) {
                                 let mut path = if prepend_base_dir(original_input, &base_dir_name) {
-                                    format!("{}{}", base_dir_name, file_name)
+                                    format!("{base_dir_name}{file_name}")
                                 } else {
                                     file_name.to_string()
                                 };
@@ -135,7 +135,7 @@ pub fn directory_completion(
                                     || path.contains(' ')
                                     || path.contains('#')
                                 {
-                                    path = format!("`{}`", path);
+                                    path = format!("`{path}`");
                                 }
 
                                 Some((span, path))

crates/nu-cli/src/completions/dotnu_completions.rs

@@ -58,7 +58,7 @@ impl Completer for DotNuCompletion {
             };
 
         // Check if the base_dir is a folder
-        if base_dir != format!(".{}", SEP) {
+        if base_dir != format!(".{SEP}") {
             // Add the base dir into the directories to be searched
             search_dirs.push(base_dir.clone());
 

crates/nu-cli/src/completions/file_completions.rs

@@ -124,7 +124,7 @@ pub fn file_path_completion(
                     let mut file_name = entry.file_name().to_string_lossy().into_owned();
                     if matches(&partial, &file_name, options) {
                         let mut path = if prepend_base_dir(original_input, &base_dir_name) {
-                            format!("{}{}", base_dir_name, file_name)
+                            format!("{base_dir_name}{file_name}")
                         } else {
                             file_name.to_string()
                         };
@@ -142,7 +142,7 @@ pub fn file_path_completion(
                             || path.contains('(')
                             || path.contains(')')
                         {
-                            path = format!("`{}`", path);
+                            path = format!("`{path}`");
                         }
 
                         Some((span, path))
@@ -170,7 +170,7 @@ pub fn matches(partial: &str, from: &str, options: &CompletionOptions) -> bool {
 
 /// Returns whether the base_dir should be prepended to the file path
 pub fn prepend_base_dir(input: &str, base_dir: &str) -> bool {
-    if base_dir == format!(".{}", SEP) {
+    if base_dir == format!(".{SEP}") {
         // if the current base_dir path is the local folder we only add a "./" prefix if the user
         // input already includes a local folder prefix.
         let manually_entered = {

crates/nu-cli/src/eval_file.rs

@@ -81,7 +81,7 @@ pub fn evaluate_file(
         report_error(
             &working_set,
             &ShellError::FileNotFoundCustom(
-                format!("The file path '{}' does not have a parent", file_path_str),
+                format!("The file path '{file_path_str}' does not have a parent"),
                 Span::unknown(),
             ),
         );
@@ -193,6 +193,6 @@ fn print_or_exit(pipeline_data: PipelineData, engine_state: &mut EngineState, co
         }
 
         let out = item.into_string("\n", config) + "\n";
-        let _ = stdout_write_all_and_flush(out).map_err(|err| eprintln!("{}", err));
+        let _ = stdout_write_all_and_flush(out).map_err(|err| eprintln!("{err}"));
     }
 }

crates/nu-cli/src/menus/description_menu.rs

@@ -411,10 +411,10 @@ impl DescriptionMenu {
                             RESET
                         )
                     } else {
-                        format!("  {}\r\n", example)
+                        format!("  {example}\r\n")
                     }
                 } else {
-                    format!("  {}\r\n", example)
+                    format!("  {example}\r\n")
                 }
             })
             .collect();
@@ -429,7 +429,7 @@ impl DescriptionMenu {
                 examples,
             )
         } else {
-            format!("\r\n\r\nExamples:\r\n{}", examples,)
+            format!("\r\n\r\nExamples:\r\n{examples}",)
         }
     }
 }

crates/nu-cli/src/menus/menu_completions.rs

@@ -154,7 +154,7 @@ fn convert_to_suggestions(
             .flat_map(|val| convert_to_suggestions(val, line, pos, only_buffer_difference))
             .collect(),
         _ => vec![Suggestion {
-            value: format!("Not a record: {:?}", value),
+            value: format!("Not a record: {value:?}"),
             description: None,
             extra: None,
             span: reedline::Span {

crates/nu-cli/src/prompt.rs

@@ -91,7 +91,7 @@ impl NushellPrompt {
     }
 
     fn default_wrapped_custom_string(&self, str: String) -> String {
-        format!("({})", str)
+        format!("({str})")
     }
 }
 

crates/nu-cli/src/prompt_update.rs

@@ -106,8 +106,7 @@ pub(crate) fn update_prompt<'prompt>(
     let left_prompt_string = if config.shell_integration {
         if let Some(prompt_string) = left_prompt_string {
             Some(format!(
-                "{}{}{}",
-                PRE_PROMPT_MARKER, prompt_string, POST_PROMPT_MARKER
+                "{PRE_PROMPT_MARKER}{prompt_string}{POST_PROMPT_MARKER}"
             ))
         } else {
             left_prompt_string

crates/nu-cli/src/reedline_config.rs

@@ -683,7 +683,7 @@ fn add_parsed_keybinding(
                 .filter(|num| matches!(num, 1..=20))
                 .ok_or(ShellError::UnsupportedConfigValue(
                     "(f1|f2|...|f20)".to_string(),
-                    format!("unknown function key: {}", c),
+                    format!("unknown function key: {c}"),
                     keybinding.keycode.span()?,
                 ))?;
             KeyCode::F(fn_num)

crates/nu-cli/src/repl.rs

@@ -125,7 +125,7 @@ pub fn evaluate_repl(
     if show_banner {
         let banner = get_banner(engine_state, stack);
         if use_ansi {
-            println!("{}", banner);
+            println!("{banner}");
         } else {
             println!("{}", nu_utils::strip_ansi_string_likely(banner));
         }
@@ -143,7 +143,7 @@ pub fn evaluate_repl(
             engine_state,
             stack,
             s.item.as_bytes(),
-            &format!("entry #{}", entry_num),
+            &format!("entry #{entry_num}"),
             PipelineData::empty(),
         );
         engine_state.merge_env(stack, get_guaranteed_cwd(engine_state, stack))?;
@@ -470,7 +470,7 @@ pub fn evaluate_repl(
                         engine_state,
                         stack,
                         s.as_bytes(),
-                        &format!("entry #{}", entry_num),
+                        &format!("entry #{entry_num}"),
                         PipelineData::empty(),
                     );
                 }
@@ -528,7 +528,7 @@ pub fn evaluate_repl(
                         // ESC]0;stringBEL -- Set icon name and window title to string
                         // ESC]1;stringBEL -- Set icon name to string
                         // ESC]2;stringBEL -- Set window title to string
-                        run_ansi_sequence(&format!("\x1b]2;{}\x07", maybe_abbrev_path))?;
+                        run_ansi_sequence(&format!("\x1b]2;{maybe_abbrev_path}\x07"))?;
                     }
                     run_ansi_sequence(RESET_APPLICATION_MODE)?;
                 }
@@ -568,7 +568,7 @@ pub fn evaluate_repl(
             Err(err) => {
                 let message = err.to_string();
                 if !message.contains("duration") {
-                    eprintln!("Error: {:?}", err);
+                    eprintln!("Error: {err:?}");
                     // TODO: Identify possible error cases where a hard failure is preferable
                     // Ignoring and reporting could hide bigger problems
                     // e.g. https://github.com/nushell/nushell/issues/6452

crates/nu-cli/src/util.rs

@@ -44,7 +44,7 @@ fn gather_env_vars(
         report_error(
             &working_set,
             &ShellError::GenericError(
-                format!("Environment variable was not captured: {}", env_str),
+                format!("Environment variable was not captured: {env_str}"),
                 "".to_string(),
                 None,
                 Some(msg.into()),
@@ -80,8 +80,7 @@ fn gather_env_vars(
                     "".to_string(),
                     None,
                     Some(format!(
-                        "Retrieving current directory failed: {:?} not a valid utf-8 path",
-                        init_cwd
+                        "Retrieving current directory failed: {init_cwd:?} not a valid utf-8 path"
                     )),
                     Vec::new(),
                 ),