Support vicmd_symbol in fish-shell (#254)

src/init.rs

@@ -255,11 +255,18 @@ export STARSHIP_SHELL="zsh"
 
 const FISH_INIT: &str = r##"
 function fish_prompt
+    switch "$fish_key_bindings"
+        case fish_hybrid_key_bindings fish_vi_key_bindings
+            set keymap "$fish_bind_mode"
+        case '*'
+            set keymap insert
+    end
     set -l exit_code $status
     # Account for changes in variable name between v2.7 and v3.0
     set -l CMD_DURATION "$CMD_DURATION$cmd_duration"
     set -l starship_duration (math --scale=0 "$CMD_DURATION / 1000")
-    ## STARSHIP ## prompt --status=$exit_code --cmd-duration=$starship_duration --jobs=(count (jobs -p))
+    ## STARSHIP ## prompt --status=$exit_code --keymap=$keymap --cmd-duration=$starship_duration --jobs=(count (jobs -p))
 end
+function fish_mode_prompt; end
 export STARSHIP_SHELL="fish"
 "##;

src/main.rs

@@ -48,8 +48,8 @@ fn main() {
         .short("k")
         .long("keymap")
         .value_name("KEYMAP")
-        // zsh only
-        .help("The keymap of zsh")
+        // fish/zsh only
+        .help("The keymap of fish/zsh")
         .takes_value(true);
 
     let jobs_arg = Arg::with_name("jobs")

src/modules/character.rs

@@ -13,6 +13,12 @@ pub fn module<'a>(context: &'a Context) -> Option<Module<'a>> {
     const SUCCESS_CHAR: &str = "❯";
     const FAILURE_CHAR: &str = "✖";
     const VICMD_CHAR: &str = "❮";
+    enum ShellEditMode {
+        Normal,
+        Insert,
+    };
+    const ASSUMED_MODE: ShellEditMode = ShellEditMode::Insert;
+    // TODO: extend config to more modes
 
     let color_success = Color::Green.bold();
     let color_failure = Color::Red.bold();
@@ -25,16 +31,28 @@ pub fn module<'a>(context: &'a Context) -> Option<Module<'a>> {
         .config_value_bool("use_symbol_for_status")
         .unwrap_or(false);
     let exit_success = arguments.value_of("status_code").unwrap_or("0") == "0";
+    let shell = std::env::var("STARSHIP_SHELL").unwrap_or_default();
     let keymap = arguments.value_of("keymap").unwrap_or("viins");
 
+    // Match shell "keymap" names to normalized vi modes
+    // NOTE: in vi mode, fish reports normal mode as "default".
+    // Unfortunately, this is also the name of the non-vi default mode.
+    // We do some environment detection in src/init.rs to translate.
+    // The result: in non-vi fish, keymap is always reported as "insert"
+    let mode = match (shell.as_str(), keymap) {
+        ("fish", "default") | ("zsh", "vicmd") => ShellEditMode::Normal,
+        _ => ASSUMED_MODE,
+    };
+
     /* If an error symbol is set in the config, use symbols to indicate
     success/failure, in addition to color */
     let symbol = if use_symbol && !exit_success {
         module.new_segment("error_symbol", FAILURE_CHAR)
-    } else if keymap == "vicmd" {
-        module.new_segment("vicmd_symbol", VICMD_CHAR)
     } else {
-        module.new_segment("symbol", SUCCESS_CHAR)
+        match mode {
+            ShellEditMode::Normal => module.new_segment("vicmd_symbol", VICMD_CHAR),
+            ShellEditMode::Insert => module.new_segment("symbol", SUCCESS_CHAR),
+        }
     };
 
     if exit_success {