feat(complete): Complete value_parser possible values

clap_complete/src/dynamic.rs

@@ -438,7 +438,7 @@ complete OPTIONS -F _clap_complete_NAME EXECUTABLES
         let mut values = Vec::new();
         debug!("complete_arg_value: arg={:?}, value={:?}", arg, value);
 
-        if let Some(possible_values) = arg.get_possible_values() {
+        if let Some(possible_values) = crate::generator::utils::possible_values(arg) {
             if let Ok(value) = value {
                 values.extend(possible_values.into_iter().filter_map(|p| {
                     let name = p.get_name();

clap_complete/src/generator/utils.rs

@@ -126,6 +126,19 @@ pub fn flags<'help>(p: &Command<'help>) -> Vec<Arg<'help>> {
         .collect()
 }
 
+/// Get the possible values for completion
+pub fn possible_values<'help>(a: &Arg<'help>) -> Option<Vec<clap::PossibleValue<'help>>> {
+    if let Some(pvs) = a.get_possible_values() {
+        // Check old first in case the user explicitly set possible values and the derive inferred
+        // a `ValueParser` with some.
+        Some(pvs.iter().map(|pv| pv.clone()).collect())
+    } else if let Some(pvs) = a.get_value_parser().possible_values() {
+        Some(pvs.collect())
+    } else {
+        None
+    }
+}
+
 #[cfg(test)]
 mod tests {
     use super::*;

clap_complete/src/shells/bash.rs

@@ -174,7 +174,7 @@ fn option_details_for_path(cmd: &Command, path: &str) -> String {
 fn vals_for(o: &Arg) -> String {
     debug!("vals_for: o={}", o.get_id());
 
-    if let Some(vals) = o.get_possible_values() {
+    if let Some(vals) = crate::generator::utils::possible_values(o) {
         format!(
             "$(compgen -W \"{}\" -- \"${{cur}}\")",
             vals.iter()

clap_complete/src/shells/fish.rs

@@ -152,7 +152,7 @@ fn value_completion(option: &Arg) -> String {
         return "".to_string();
     }
 
-    if let Some(data) = option.get_possible_values() {
+    if let Some(data) = crate::generator::utils::possible_values(option) {
         // We return the possible values with their own empty description e.g. {a\t,b\t}
         // this makes sure that a and b don't get the description of the option or argument
         format!(

clap_complete/src/shells/zsh.rs

@@ -359,7 +359,7 @@ fn get_args_of(parent: &Command, p_global: Option<&Command>) -> String {
 
 // Uses either `possible_vals` or `value_hint` to give hints about possible argument values
 fn value_completion(arg: &Arg) -> Option<String> {
-    if let Some(values) = &arg.get_possible_values() {
+    if let Some(values) = crate::generator::utils::possible_values(arg) {
         if values
             .iter()
             .any(|value| !value.is_hide_set() && value.get_help().is_some())

clap_complete_fig/src/fig.rs

@@ -350,7 +350,7 @@ fn gen_args(arg: &Arg, indent: usize) -> String {
         ));
     }
 
-    if let Some(data) = arg.get_possible_values() {
+    if let Some(data) = generator::utils::possible_values(arg) {
         buffer.push_str(&format!(
             "{:indent$}suggestions: [\n",
             "",

src/builder/arg.rs

@@ -4633,7 +4633,7 @@ impl<'help> Arg<'help> {
 
     /// Get the list of the possible values for this argument, if any
     #[inline]
-    pub fn get_possible_values(&self) -> Option<&[PossibleValue]> {
+    pub fn get_possible_values(&self) -> Option<&[PossibleValue<'help>]> {
         if self.possible_vals.is_empty() {
             None
         } else {