feat(complete): Offer - as a path option

clap_complete/src/engine/custom.rs

@@ -167,6 +167,7 @@ where
 pub struct PathCompleter {
     current_dir: Option<std::path::PathBuf>,
     filter: Option<Box<dyn Fn(&std::path::Path) -> bool + Send + Sync>>,
+    stdio: bool,
 }
 
 impl PathCompleter {
@@ -175,6 +176,7 @@ impl PathCompleter {
         Self {
             filter: None,
             current_dir: None,
+            stdio: false,
         }
     }
 
@@ -188,6 +190,12 @@ impl PathCompleter {
         Self::any().filter(|p| p.is_dir())
     }
 
+    /// Include stdio (`-`)
+    pub fn stdio(mut self) -> Self {
+        self.stdio = true;
+        self
+    }
+
     /// Select which paths should be completed
     pub fn filter(
         mut self,
@@ -218,7 +226,11 @@ impl ValueCompleter for PathCompleter {
             current_dir_actual = std::env::current_dir().ok();
             current_dir_actual.as_deref()
         });
-        complete_path(current, current_dir, filter)
+        let mut candidates = complete_path(current, current_dir, filter);
+        if self.stdio && current.is_empty() {
+            candidates.push(CompletionCandidate::new("-").help(Some("stdio".into())));
+        }
+        candidates
     }
 }
 

clap_complete/tests/testsuite/engine.rs

@@ -592,7 +592,9 @@ fn suggest_value_path_file() {
                 .long("input")
                 .short('i')
                 .add(ArgValueCompleter::new(
-                    PathCompleter::file().current_dir(testdir_path.to_owned()),
+                    PathCompleter::file()
+                        .stdio()
+                        .current_dir(testdir_path.to_owned()),
                 )),
         )
         .args_conflicts_with_subcommands(true);
@@ -604,6 +606,7 @@ a_file
 b_file
 c_dir/
 d_dir/
+-	stdio
 "#]],
     );