feat(completions): Dynamic fish completions

clap_complete/src/dynamic/shells/fish.rs

@@ -0,0 +1,38 @@
+/// Fish completions
+#[derive(Copy, Clone, PartialEq, Eq, Debug)]
+pub struct Fish;
+
+impl crate::dynamic::Completer for Fish {
+    fn file_name(&self, name: &str) -> String {
+        format!("{name}.fish")
+    }
+    fn write_registration(
+        &self,
+        _name: &str,
+        bin: &str,
+        completer: &str,
+        buf: &mut dyn std::io::Write,
+    ) -> Result<(), std::io::Error> {
+        let bin = shlex::quote(bin);
+        let completer = shlex::quote(completer);
+        writeln!(
+            buf,
+            r#"complete -x -c {bin} -a "("'{completer}'" complete --shell fish -- (commandline --current-process --tokenize --cut-at-cursor) (commandline --current-token))""#
+        )
+    }
+    fn write_complete(
+        &self,
+        cmd: &mut clap::Command,
+        args: Vec<std::ffi::OsString>,
+        current_dir: Option<&std::path::Path>,
+        buf: &mut dyn std::io::Write,
+    ) -> Result<(), std::io::Error> {
+        let index = args.len() - 1;
+        let completions = crate::dynamic::complete(cmd, args, index, current_dir)?;
+
+        for completion in completions {
+            writeln!(buf, "{}", completion.to_string_lossy())?;
+        }
+        Ok(())
+    }
+}

clap_complete/src/dynamic/shells/mod.rs

@@ -1,9 +1,11 @@
 //! Shell support
 
 mod bash;
+mod fish;
 mod shell;
 
 pub use bash::*;
+pub use fish::*;
 pub use shell::*;
 
 use std::ffi::OsString;

clap_complete/src/dynamic/shells/shell.rs

@@ -10,6 +10,8 @@ use clap::ValueEnum;
 pub enum Shell {
     /// Bourne Again SHell (bash)
     Bash,
+    /// Friendly Interactive SHell (fish)
+    Fish,
 }
 
 impl Display for Shell {
@@ -37,12 +39,13 @@ impl FromStr for Shell {
 // Hand-rolled so it can work even when `derive` feature is disabled
 impl ValueEnum for Shell {
     fn value_variants<'a>() -> &'a [Self] {
-        &[Shell::Bash]
+        &[Shell::Bash, Shell::Fish]
     }
 
     fn to_possible_value<'a>(&self) -> Option<PossibleValue> {
         Some(match self {
             Shell::Bash => PossibleValue::new("bash"),
+            Shell::Fish => PossibleValue::new("fish"),
         })
     }
 }
@@ -51,6 +54,7 @@ impl Shell {
     fn completer(&self) -> &dyn crate::dynamic::Completer {
         match self {
             Self::Bash => &super::Bash,
+            Self::Fish => &super::Fish,
         }
     }
 }

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

@@ -0,0 +1 @@
+complete -x -c exhaustive -a "("'exhaustive'" complete --shell fish -- (commandline --current-process --tokenize --cut-at-cursor) (commandline --current-token))"

clap_complete/tests/snapshots/home/dynamic/exhaustive/fish/fish/config.fish

@@ -0,0 +1,7 @@
+set -U fish_greeting ""
+set -U fish_autosuggestion_enabled 0
+function fish_title
+end
+function fish_prompt
+    printf '%% '
+end;

clap_complete/tests/snapshots/home/static/exhaustive/bash/.bashrc

@@ -236,7 +236,7 @@ _exhaustive() {
             fi
             case "${prev}" in
                 --shell)
-                    COMPREPLY=($(compgen -W "bash" -- "${cur}"))
+                    COMPREPLY=($(compgen -W "bash fish" -- "${cur}"))
                     return 0
                     ;;
                 --register)

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

@@ -104,7 +104,7 @@ 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	}"
+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/home/static/exhaustive/zsh/zsh/_exhaustive

@@ -309,7 +309,7 @@ _arguments "${_arguments_options[@]}" \
 ;;
 (complete)
 _arguments "${_arguments_options[@]}" \
-'--shell=[Specify shell to complete for]:SHELL:(bash)' \
+'--shell=[Specify shell to complete for]:SHELL:(bash fish)' \
 '--register=[Path to write completion-registration to]:REGISTER:_files' \
 '--global[everywhere]' \
 '-h[Print help (see more with '\''--help'\'')]' \

clap_complete/tests/snapshots/register_dynamic.fish

@@ -0,0 +1 @@
+complete -x -c my-app -a 'my-app'" complete --shell fish -- (commandline --current-process --tokenize --cut-at-cursor) (commandline --current-token)"

clap_complete/tests/testsuite/fish.rs

@@ -143,3 +143,28 @@ alias   help  (Print this message or the help of the given subcommand(s))  last
     let actual = runtime.complete(input, &term).unwrap();
     snapbox::assert_eq(expected, actual);
 }
+
+#[cfg(all(unix, feature = "unstable-dynamic"))]
+#[test]
+fn register_dynamic() {
+    common::register_example("dynamic", "exhaustive", completest::Shell::Fish);
+}
+
+#[test]
+#[cfg(all(unix, feature = "unstable-dynamic"))]
+fn complete_dynamic() {
+    if !common::has_command("fish") {
+        return;
+    }
+
+    let term = completest::Term::new();
+    let mut runtime = common::load_runtime("dynamic", "exhaustive", completest::Shell::Fish);
+
+    let input = "exhaustive \t";
+    let expected = r#"% exhaustive
+action    help  pacman  -h          --global
+alias     hint  quote   -V          --help
+complete  last  value   --generate  --version"#;
+    let actual = runtime.complete(input, &term).unwrap();
+    snapbox::assert_eq(expected, actual);
+}