zshrs 0.12.18

//! Port of `_set_command` from `Completion/Base/Utility/_set_command`.
//!
//! Full upstream body (31 lines verbatim):
//! ```text
//! sh: 1  #autoload
//! sh: 5  local command
//! sh: 6  command="$words[1]"
//! sh: 7  [[ -z "$command" ]] && return
//! sh: 9  if (( $+builtins[$command] + $+functions[$command] )); then
//! sh:10    _comp_command1="$command"
//! sh:11    _comp_command="$_comp_command1"
//! sh:12  elif [[ "$command[1]" = '=' ]]; then
//! sh:13    eval _comp_command2\=$command
//! sh:14    _comp_command1="$command[2,-1]"
//! sh:15    _comp_command="$_comp_command2"
//! sh:16  elif [[ "$command" = ..#/* ]]; then
//! sh:17    _comp_command1="${PWD}/$command"
//! sh:18    _comp_command2="${command:t}"
//! sh:19    _comp_command="$_comp_command2"
//! sh:20  elif [[ "$command" = */* ]]; then
//! sh:21    _comp_command1="$command"
//! sh:22    _comp_command2="${command:t}"
//! sh:23    _comp_command="$_comp_command2"
//! sh:24  else
//! sh:25    _comp_command1="$command"
//! sh:26    _comp_command2="$commands[$command]"
//! sh:27    _comp_command="$_comp_command1"
//! sh:28  fi
//! ```
//!
//! Reads `$words[1]`, classifies the command (builtin/function vs
//! `=cmd` vs absolute path vs basename), and publishes the three
//! `_comp_command{,1,2}` params for downstream consumers.

use crate::ported::params::{getaparam, getsparam, setsparam};

/// `_set_command` — classify `$words[1]` and publish
/// `_comp_command`, `_comp_command1`, `_comp_command2`. Returns 0
/// on success, 1 when `$words[1]` is empty.
pub fn _set_command() -> i32 {
    let words = getaparam("words").unwrap_or_default();
    // sh:6
    let command = words.first().cloned().unwrap_or_default();
    // sh:7
    if command.is_empty() {
        return 1;
    }

    // sh:9 — builtin OR function lookup (we approximate: check the
    //   shfunc table; builtins are also enumerable but we keep it
    //   simple, falling through to the path-classify branches when
    //   not a known function).
    let is_function = crate::ported::utils::getshfunc(&command).is_some();
    let is_builtin = is_known_builtin(&command);
    if is_function || is_builtin {
        // sh:10-11
        let _ = setsparam("_comp_command1", &command);
        let _ = setsparam("_comp_command", &command);
        return 0;
    }

    // sh:12  `=cmd` — expand to full path via the `commands` assoc
    if command.starts_with('=') {
        let bare = &command[1..];
        let commands = getaparam("commands").unwrap_or_default();
        // commands is a flat array of key/value pairs in our port —
        //   look up `bare` linearly.
        let resolved: String = commands
            .chunks(2)
            .find(|kv| kv.first().map(|k| k == bare).unwrap_or(false))
            .and_then(|kv| kv.get(1).cloned())
            .unwrap_or_default();
        let _ = setsparam("_comp_command2", &resolved);
        let _ = setsparam("_comp_command1", bare);
        let _ = setsparam("_comp_command", &resolved);
        return 0;
    }

    // sh:16 — `..*/...` relative path
    if let Some(stripped) = command.strip_prefix("..") {
        if stripped.starts_with('/') {
            let pwd = getsparam("PWD").unwrap_or_default();
            let _ = setsparam("_comp_command1", &format!("{}/{}", pwd, command));
            let tail = basename(&command);
            let _ = setsparam("_comp_command2", &tail);
            let _ = setsparam("_comp_command", &tail);
            return 0;
        }
    }

    // sh:20 — `*/*` containing slash
    if command.contains('/') {
        let _ = setsparam("_comp_command1", &command);
        let tail = basename(&command);
        let _ = setsparam("_comp_command2", &tail);
        let _ = setsparam("_comp_command", &tail);
        return 0;
    }

    // sh:24-27 — bare name, lookup in $commands
    let commands = getaparam("commands").unwrap_or_default();
    let cmd2: String = commands
        .chunks(2)
        .find(|kv| kv.first().map(|k| k == &command).unwrap_or(false))
        .and_then(|kv| kv.get(1).cloned())
        .unwrap_or_default();
    let _ = setsparam("_comp_command1", &command);
    let _ = setsparam("_comp_command2", &cmd2);
    let _ = setsparam("_comp_command", &command);
    0
}

/// sh:12's `$+builtins[$command]` test — consult the LIVE builtin table.
/// The previous port used a hardcoded ~34-name allowlist that misclassified
/// every builtin outside it (`print`, `typeset`, `zle`, `setopt`, `zstyle`,
/// `compadd`, `zmodload`, `whence`, `getopts`, …) as non-builtins, so
/// `_set_command` failed to recognise them as the command word. Bug #657.
fn is_known_builtin(name: &str) -> bool {
    crate::ported::builtin::createbuiltintable().contains_key(name)
}

/// `${command:t}` — basename.
fn basename(s: &str) -> String {
    s.rsplit('/').next().unwrap_or("").to_string()
}

#[cfg(test)]
mod tests {
    use super::*;
    use crate::ported::params::setaparam;

    #[test]
    fn empty_words_returns_one() {
        let _g = crate::test_util::global_state_lock();
        setaparam("words", Vec::new());
        assert_eq!(_set_command(), 1);
    }

    #[test]
    fn slash_path_uses_basename() {
        // sh:20-23
        let _g = crate::test_util::global_state_lock();
        setaparam("words", vec!["/usr/bin/ls".to_string()]);
        let _ = _set_command();
        assert_eq!(getsparam("_comp_command1").as_deref(), Some("/usr/bin/ls"));
        assert_eq!(getsparam("_comp_command2").as_deref(), Some("ls"));
        assert_eq!(getsparam("_comp_command").as_deref(), Some("ls"));
    }

    #[test]
    fn known_builtin_takes_builtin_branch() {
        // sh:9-11
        let _g = crate::test_util::global_state_lock();
        setaparam("words", vec!["cd".to_string()]);
        let _ = _set_command();
        assert_eq!(getsparam("_comp_command1").as_deref(), Some("cd"));
        assert_eq!(getsparam("_comp_command").as_deref(), Some("cd"));
    }

    // ========================================================
    // is_known_builtin — recognition matrix
    // ========================================================

    #[test]
    fn known_builtins_include_navigation_and_io() {
        for name in ["cd", "echo", "pwd", "printf", "read"] {
            assert!(
                is_known_builtin(name),
                "expected {} to register as builtin",
                name
            );
        }
    }

    #[test]
    fn known_builtins_include_set_and_unset_family() {
        for name in ["set", "unset", "export", "alias", "unalias"] {
            assert!(is_known_builtin(name), "{} missing from builtin set", name);
        }
    }

    #[test]
    fn known_builtins_include_control_flow() {
        for name in ["return", "break", "continue", "trap"] {
            assert!(is_known_builtin(name), "{} missing from builtin set", name);
        }
    }

    #[test]
    fn known_builtins_include_test_aliases() {
        // Both `test` and the bracketed form `[` are listed.
        assert!(is_known_builtin("test"));
        assert!(is_known_builtin("["));
    }

    #[test]
    fn known_builtins_includes_source_and_dot_alias() {
        // `source` and `.` are both registered as builtin per sh:9.
        assert!(is_known_builtin("source"));
        assert!(is_known_builtin("."));
    }

    #[test]
    fn unknown_command_is_not_a_builtin() {
        assert!(!is_known_builtin("ls"));
        assert!(!is_known_builtin("grep"));
        assert!(!is_known_builtin(""));
        assert!(!is_known_builtin("foo-bar-baz"));
    }

    #[test]
    fn builtin_name_is_case_sensitive() {
        // POSIX builtin lookup is case-sensitive — uppercase aliases
        // are NOT auto-recognized.
        assert!(!is_known_builtin("CD"));
        assert!(!is_known_builtin("Echo"));
    }

    // ========================================================
    // basename — `${command:t}` analog
    // ========================================================

    #[test]
    fn basename_strips_leading_directory_components() {
        assert_eq!(basename("/usr/bin/ls"), "ls");
        assert_eq!(basename("foo/bar/baz"), "baz");
    }

    #[test]
    fn basename_passes_through_when_no_slash() {
        assert_eq!(basename("plain"), "plain");
    }

    #[test]
    fn basename_empty_input_returns_empty() {
        assert_eq!(basename(""), "");
    }

    #[test]
    fn basename_trailing_slash_yields_empty_string() {
        // rsplit('/').next() on `"foo/"` returns the empty tail.
        assert_eq!(basename("foo/"), "");
    }

    #[test]
    fn basename_handles_root_only() {
        assert_eq!(basename("/"), "");
    }

    // ========================================================
    // _set_command — control-flow branches
    // ========================================================

    #[test]
    fn relative_dotdot_path_uses_pwd_prefix_and_basename() {
        // sh:16-19  command begins with `../`
        let _g = crate::test_util::global_state_lock();
        let _ = crate::ported::params::setsparam("PWD", "/here");
        setaparam("words", vec!["../tools/runme".to_string()]);
        let _ = _set_command();
        assert_eq!(
            getsparam("_comp_command1").as_deref(),
            Some("/here/../tools/runme")
        );
        assert_eq!(getsparam("_comp_command2").as_deref(), Some("runme"));
        assert_eq!(getsparam("_comp_command").as_deref(), Some("runme"));
    }
}