refactor: address clippy warnings

clap_complete/src/shells/bash.rs

@@ -59,7 +59,7 @@ impl Generator for Bash {
 complete -F _{name} -o bashdefault -o default {name}
 ",
                 name = bin_name,
-                cmd = bin_name.replace("-", "__"),
+                cmd = bin_name.replace('-', "__"),
                 name_opts = all_options_for_path(app, bin_name),
                 name_opts_details = option_details_for_path(app, bin_name),
                 subcmds = all_subcommands(app),
@@ -88,7 +88,7 @@ fn all_subcommands(app: &App) -> String {
                 cmd+=\"__{fn_name}\"
                 ;;",
             name = sc,
-            fn_name = sc.replace("-", "__")
+            fn_name = sc.replace('-', "__")
         )
     }));
 
@@ -101,7 +101,7 @@ fn subcommand_details(app: &App) -> String {
     let mut subcmd_dets = vec![String::new()];
     let mut scs = utils::all_subcommands(app)
         .iter()
-        .map(|x| x.1.replace(" ", "__"))
+        .map(|x| x.1.replace(' ', "__"))
         .collect::<Vec<_>>();
 
     scs.sort();
@@ -122,7 +122,7 @@ fn subcommand_details(app: &App) -> String {
             COMPREPLY=( $(compgen -W \"${{opts}}\" -- \"${{cur}}\") )
             return 0
             ;;",
-            subcmd = sc.replace("-", "__"),
+            subcmd = sc.replace('-', "__"),
             sc_opts = all_options_for_path(app, &*sc),
             level = sc.split("__").map(|_| 1).sum::<u64>(),
             opts_details = option_details_for_path(app, &*sc)

clap_complete/src/shells/elvish.rs

@@ -54,7 +54,7 @@ set edit:completion:arg-completer[{bin_name}] = [@words]{{
 
 // Escape string inside single quotes
 fn escape_string(string: &str) -> String {
-    string.replace("'", "''")
+    string.replace('\'', "''")
 }
 
 fn get_tooltip<T: ToString>(help: Option<&str>, data: T) -> String {

clap_complete/src/shells/fish.rs

@@ -26,7 +26,7 @@ impl Generator for Fish {
 
 // Escape string inside single quotes
 fn escape_string(string: &str) -> String {
-    string.replace("\\", "\\\\").replace("'", "\\'")
+    string.replace('\\', "\\\\").replace('\'', "\\'")
 }
 
 fn gen_fish_inner(root_command: &str, parent_commands: &[&str], app: &App, buffer: &mut String) {

clap_complete/src/shells/powershell.rs

@@ -58,7 +58,7 @@ Register-ArgumentCompleter -Native -CommandName '{bin_name}' -ScriptBlock {{
 
 // Escape string inside single quotes
 fn escape_string(string: &str) -> String {
-    string.replace("'", "''")
+    string.replace('\'', "''")
 }
 
 fn get_tooltip<T: ToString>(help: Option<&str>, data: T) -> String {

clap_complete/src/shells/zsh.rs

@@ -92,7 +92,7 @@ _{bin_name_underscore}_commands() {{
     local commands; commands=({subcommands_and_args})
     _describe -t commands '{bin_name} commands' commands \"$@\"
 }}",
-        bin_name_underscore = name.replace(" ", "__"),
+        bin_name_underscore = name.replace(' ', "__"),
         bin_name = name,
         subcommands_and_args = subcommands_of(p)
     );
@@ -114,7 +114,7 @@ _{bin_name_underscore}_commands() {{
     local commands; commands=({subcommands_and_args})
     _describe -t commands '{bin_name} commands' commands \"$@\"
 }}",
-            bin_name_underscore = bin_name.replace(" ", "__"),
+            bin_name_underscore = bin_name.replace(' ', "__"),
             bin_name = bin_name,
             subcommands_and_args =
                 subcommands_of(parser_of(p, bin_name).expect(INTERNAL_ERROR_MSG))
@@ -259,7 +259,7 @@ fn get_subcommands_of(parent: &App) -> String {
     ;;
 esac",
         name = parent.get_name(),
-        name_hyphen = parent.get_bin_name().unwrap().replace(" ", "-"),
+        name_hyphen = parent.get_bin_name().unwrap().replace(' ', "-"),
         subcommands = all_subcommands.join("\n"),
         pos = parent.get_positionals().count() + 1
     )
@@ -328,7 +328,7 @@ fn get_args_of(parent: &App, p_global: Option<&App>) -> String {
     if parent.has_subcommands() {
         let subcommand_bin_name = format!(
             "\":: :_{name}_commands\" \\",
-            name = parent.get_bin_name().as_ref().unwrap().replace(" ", "__")
+            name = parent.get_bin_name().as_ref().unwrap().replace(' ', "__")
         );
         segments.push(subcommand_bin_name);
 
@@ -406,20 +406,20 @@ fn value_completion(arg: &Arg) -> Option<String> {
 /// Escape help string inside single quotes and brackets
 fn escape_help(string: &str) -> String {
     string
-        .replace("\\", "\\\\")
-        .replace("'", "'\\''")
-        .replace("[", "\\[")
-        .replace("]", "\\]")
+        .replace('\\', "\\\\")
+        .replace('\'', "'\\''")
+        .replace('[', "\\[")
+        .replace(']', "\\]")
 }
 
 /// Escape value string inside single quotes and parentheses
 fn escape_value(string: &str) -> String {
     string
-        .replace("\\", "\\\\")
-        .replace("'", "'\\''")
-        .replace("(", "\\(")
-        .replace(")", "\\)")
-        .replace(" ", "\\ ")
+        .replace('\\', "\\\\")
+        .replace('\'', "'\\''")
+        .replace('(', "\\(")
+        .replace(')', "\\)")
+        .replace(' ', "\\ ")
 }
 
 fn write_opts_of(p: &App, p_global: Option<&App>) -> String {
@@ -631,9 +631,9 @@ fn write_positionals_of(p: &App) -> String {
             help = arg
                 .get_help()
                 .map_or("".to_owned(), |v| " -- ".to_owned() + v)
-                .replace("[", "\\[")
-                .replace("]", "\\]")
-                .replace(":", "\\:"),
+                .replace('[', "\\[")
+                .replace(']', "\\]")
+                .replace(':', "\\:"),
             value_completion = value_completion(arg).unwrap_or_else(|| "".to_string())
         );
 

clap_complete_fig/src/fig.rs

@@ -38,7 +38,7 @@ impl Generator for Fig {
 
 // Escape string inside double quotes
 fn escape_string(string: &str) -> String {
-    string.replace("\\", "\\\\").replace("\"", "\\\"")
+    string.replace('\\', "\\\\").replace('\"', "\\\"")
 }
 
 fn gen_fig_inner(

clap_derive/src/attrs.rs

@@ -879,8 +879,8 @@ impl Name {
                     Camel => s.to_lower_camel_case(),
                     ScreamingSnake => s.to_shouty_snake_case(),
                     Snake => s.to_snake_case(),
-                    Lower => s.to_snake_case().replace("_", ""),
-                    Upper => s.to_shouty_snake_case().replace("_", ""),
+                    Lower => s.to_snake_case().replace('_', ""),
+                    Upper => s.to_shouty_snake_case().replace('_', ""),
                     Verbatim => s,
                 };
                 quote_spanned!(ident.span()=> #s)

clap_derive/src/parse.rs

@@ -252,8 +252,8 @@ fn raw_method_suggestion(ts: ParseBuffer) -> String {
     fn to_string<T: ToTokens>(val: &T) -> String {
         val.to_token_stream()
             .to_string()
-            .replace(" ", "")
-            .replace(",", ", ")
+            .replace(' ', "")
+            .replace(',', ", ")
     }
 
     if let Ok((name, exprs)) = do_parse() {

clap_derive/src/utils/doc_comments.rs

@@ -78,7 +78,7 @@ fn split_paragraphs(lines: &[&str]) -> Vec<String> {
         let len = slice
             .iter()
             .position(|s| is_blank(s))
-            .unwrap_or_else(|| slice.len());
+            .unwrap_or(slice.len());
 
         last_line += start + len;
 

examples/tutorial_derive/04_04_custom.rs

@@ -72,10 +72,13 @@ fn main() {
 
     // Check for usage of -c
     if let Some(config) = cli.config.as_deref() {
+        // todo: remove `#[allow(clippy::or_fun_call)]` lint when MSRV is bumped.
+        #[allow(clippy::or_fun_call)]
         let input = cli
             .input_file
             .as_deref()
-            .or_else(|| cli.spec_in.as_deref())
+            // 'or' is preferred to 'or_else' here since `Option::as_deref` is 'const'
+            .or(cli.spec_in.as_deref())
             .unwrap_or_else(|| {
                 let mut app = Cli::into_app();
                 app.error(