fix: (fish-completion) Correct value enum help text

Resolves #5101

- The completion of value enums now displays accurate help text
- This fix encloses help text in single quotes
- Comma in help text is not escaped
- This is because the the help text is now treated as literal
- No variable expansion or command substitution in help text

clap_complete/src/shells/fish.rs

@@ -168,10 +168,12 @@ fn value_completion(option: &Arg) -> String {
                 .filter_map(|value| if value.is_hide_set() {
                     None
                 } else {
+                    // The help text after \t is wrapped in '' to make sure that the it is taken literally
+                    // and there is no command substitution or variable expansion resulting in unexpected errors
                     Some(format!(
-                        "{}\t{}",
+                        "{}\t'{}'",
                         escape_string(value.get_name(), true).as_str(),
-                        escape_string(&value.get_help().unwrap_or_default().to_string(), true)
+                        escape_string(&value.get_help().unwrap_or_default().to_string(), false)
                     ))
                 })
                 .collect::<Vec<_>>()

clap_complete/tests/snapshots/home/static/exhaustive/fish/fish/completions/exhaustive.fish

@@ -1,4 +1,4 @@
-complete -c exhaustive -n "__fish_use_subcommand" -l generate -d 'generate' -r -f -a "{bash	,elvish	,fish	,powershell	,zsh	}"
+complete -c exhaustive -n "__fish_use_subcommand" -l generate -d 'generate' -r -f -a "{bash	'',elvish	'',fish	'',powershell	'',zsh	''}"
 complete -c exhaustive -n "__fish_use_subcommand" -l global -d 'everywhere'
 complete -c exhaustive -n "__fish_use_subcommand" -s h -l help -d 'Print help'
 complete -c exhaustive -n "__fish_use_subcommand" -s V -l version -d 'Print version'
@@ -12,7 +12,7 @@ complete -c exhaustive -n "__fish_use_subcommand" -f -a "hint"
 complete -c exhaustive -n "__fish_use_subcommand" -f -a "complete" -d 'Register shell completions for this program'
 complete -c exhaustive -n "__fish_use_subcommand" -f -a "help" -d 'Print this message or the help of the given subcommand(s)'
 complete -c exhaustive -n "__fish_seen_subcommand_from action" -l set -d 'value' -r
-complete -c exhaustive -n "__fish_seen_subcommand_from action" -l choice -d 'enum' -r -f -a "{first	,second	}"
+complete -c exhaustive -n "__fish_seen_subcommand_from action" -l choice -d 'enum' -r -f -a "{first	'',second	''}"
 complete -c exhaustive -n "__fish_seen_subcommand_from action" -l set-true -d 'bool'
 complete -c exhaustive -n "__fish_seen_subcommand_from action" -l count -d 'number'
 complete -c exhaustive -n "__fish_seen_subcommand_from action" -l global -d 'everywhere'
@@ -95,7 +95,7 @@ complete -c exhaustive -n "__fish_seen_subcommand_from alias" -s f -s F -l flag
 complete -c exhaustive -n "__fish_seen_subcommand_from alias" -l global -d 'everywhere'
 complete -c exhaustive -n "__fish_seen_subcommand_from alias" -s h -l help -d 'Print help'
 complete -c exhaustive -n "__fish_seen_subcommand_from alias" -s V -l version -d 'Print version'
-complete -c exhaustive -n "__fish_seen_subcommand_from hint" -l choice -r -f -a "{bash	,fish	,zsh	}"
+complete -c exhaustive -n "__fish_seen_subcommand_from hint" -l choice -r -f -a "{bash	'',fish	'',zsh	''}"
 complete -c exhaustive -n "__fish_seen_subcommand_from hint" -l unknown -r
 complete -c exhaustive -n "__fish_seen_subcommand_from hint" -l other -r -f
 complete -c exhaustive -n "__fish_seen_subcommand_from hint" -s p -l path -r -F
@@ -111,7 +111,7 @@ complete -c exhaustive -n "__fish_seen_subcommand_from hint" -l email -r -f
 complete -c exhaustive -n "__fish_seen_subcommand_from hint" -l global -d 'everywhere'
 complete -c exhaustive -n "__fish_seen_subcommand_from hint" -s h -l help -d 'Print help'
 complete -c exhaustive -n "__fish_seen_subcommand_from hint" -s V -l version -d 'Print version'
-complete -c exhaustive -n "__fish_seen_subcommand_from complete" -l shell -d 'Specify shell to complete for' -r -f -a "{bash	,fish	}"
+complete -c exhaustive -n "__fish_seen_subcommand_from complete" -l shell -d 'Specify shell to complete for' -r -f -a "{bash	'',fish	''}"
 complete -c exhaustive -n "__fish_seen_subcommand_from complete" -l register -d 'Path to write completion-registration to' -r -F
 complete -c exhaustive -n "__fish_seen_subcommand_from complete" -l global -d 'everywhere'
 complete -c exhaustive -n "__fish_seen_subcommand_from complete" -s h -l help -d 'Print help (see more with \'--help\')'

clap_complete/tests/snapshots/sub_subcommands.fish

@@ -11,7 +11,7 @@ complete -c my-app -n "__fish_seen_subcommand_from some_cmd; and not __fish_seen
 complete -c my-app -n "__fish_seen_subcommand_from some_cmd; and not __fish_seen_subcommand_from sub_cmd; and not __fish_seen_subcommand_from help" -s V -l version -d 'Print version'
 complete -c my-app -n "__fish_seen_subcommand_from some_cmd; and not __fish_seen_subcommand_from sub_cmd; and not __fish_seen_subcommand_from help" -f -a "sub_cmd" -d 'sub-subcommand'
 complete -c my-app -n "__fish_seen_subcommand_from some_cmd; and not __fish_seen_subcommand_from sub_cmd; and not __fish_seen_subcommand_from help" -f -a "help" -d 'Print this message or the help of the given subcommand(s)'
-complete -c my-app -n "__fish_seen_subcommand_from some_cmd; and __fish_seen_subcommand_from sub_cmd" -l config -d 'the other case to test' -r -f -a "{Lest quotes\, aren\'t escaped.	help\,with\,comma,Second to trigger display of options	}"
+complete -c my-app -n "__fish_seen_subcommand_from some_cmd; and __fish_seen_subcommand_from sub_cmd" -l config -d 'the other case to test' -r -f -a "{Lest quotes\, aren\'t escaped.	'help,with,comma',Second to trigger display of options	''}"
 complete -c my-app -n "__fish_seen_subcommand_from some_cmd; and __fish_seen_subcommand_from sub_cmd" -s h -l help -d 'Print help (see more with \'--help\')'
 complete -c my-app -n "__fish_seen_subcommand_from some_cmd; and __fish_seen_subcommand_from sub_cmd" -s V -l version -d 'Print version'
 complete -c my-app -n "__fish_seen_subcommand_from some_cmd; and __fish_seen_subcommand_from help; and not __fish_seen_subcommand_from sub_cmd; and not __fish_seen_subcommand_from help" -f -a "sub_cmd" -d 'sub-subcommand'

clap_complete/tests/snapshots/value_help.fish

@@ -0,0 +1,2 @@
+complete -c my-app -l choice -r -f -a "{bash	'bash shell (some, more, text)',fish	'fish shell',zsh	'zsh shell'}"
+complete -c my-app -s h -l help -d 'Print help (see more with \'--help\')'

clap_complete/tests/snapshots/value_help.ps1

@@ -0,0 +1,32 @@
+
+using namespace System.Management.Automation
+using namespace System.Management.Automation.Language
+
+Register-ArgumentCompleter -Native -CommandName 'my-app' -ScriptBlock {
+    param($wordToComplete, $commandAst, $cursorPosition)
+
+    $commandElements = $commandAst.CommandElements
+    $command = @(
+        'my-app'
+        for ($i = 1; $i -lt $commandElements.Count; $i++) {
+            $element = $commandElements[$i]
+            if ($element -isnot [StringConstantExpressionAst] -or
+                $element.StringConstantType -ne [StringConstantType]::BareWord -or
+                $element.Value.StartsWith('-') -or
+                $element.Value -eq $wordToComplete) {
+                break
+        }
+        $element.Value
+    }) -join ';'
+
+    $completions = @(switch ($command) {
+        'my-app' {
+            [CompletionResult]::new('--choice', 'choice', [CompletionResultType]::ParameterName, 'choice')
+			[CompletionResult]::new('--help', 'help', [CompletionResultType]::ParameterName, 'Print help')
+            break
+        }
+    })
+
+    $completions.Where{ $_.CompletionText -like "$wordToComplete*" } |
+        Sort-Object -Property ListItemText
+}

clap_complete/tests/snapshots/value_hint.fish

@@ -1,4 +1,4 @@
-complete -c my-app -l choice -r -f -a "{bash	,fish	,zsh	}"
+complete -c my-app -l choice -r -f -a "{bash	'',fish	'',zsh	''}"
 complete -c my-app -l unknown -r
 complete -c my-app -l other -r -f
 complete -c my-app -s p -l path -r -F

clap_complete/tests/testsuite/common.rs

@@ -252,6 +252,19 @@ pub fn value_hint_command(name: &'static str) -> clap::Command {
         )
 }
 
+pub fn value_help_command(name: &'static str) -> clap::Command {
+    clap::Command::new(name).arg(
+        clap::Arg::new("choice")
+            .long("choice")
+            .action(clap::ArgAction::Set)
+            .value_parser(clap::builder::PossibleValuesParser::new([
+                PossibleValue::new("bash").help("bash shell (some, more, text)"),
+                PossibleValue::new("fish").help("fish shell"),
+                PossibleValue::new("zsh").help("zsh shell"),
+            ])),
+    )
+}
+
 pub fn value_terminator_command(name: &'static str) -> clap::Command {
     clap::Command::new(name).arg(
         clap::Arg::new("arguments")

clap_complete/tests/testsuite/fish.rs

@@ -84,6 +84,18 @@ fn value_hint() {
     );
 }
 
+#[test]
+fn value_help() {
+    let name = "my-app";
+    let cmd = common::value_help_command(name);
+    common::assert_matches_path(
+        "tests/snapshots/value_help.fish",
+        clap_complete::shells::Fish,
+        cmd,
+        name,
+    )
+}
+
 #[test]
 fn value_terminator() {
     let name = "my-app";