feat(fish): add vimode segment support

Author: rightaditya

src/config/config.go

@@ -211,7 +211,7 @@ func (cfg *Config) Features(env runtime.Environment) shell.Features {
 				}
 			}
 
-			if segment.Type == VIMODE && slices.Contains([]string{shell.ZSH, shell.PWSH}, env.Shell()) {
+			if segment.Type == VIMODE && slices.Contains([]string{shell.ZSH, shell.PWSH, shell.FISH}, env.Shell()) {
 				log.Debug("vi mode tracking enabled")
 				feats |= shell.VIMode
 			}

src/config/config_test.go

@@ -212,6 +212,11 @@ func TestFeaturesVIMode(t *testing.T) {
 			Shell:         shell.PWSH,
 			ExpectedFeats: shell.VIMode,
 		},
+		{
+			Case:          "fish enables vi mode tracking",
+			Shell:         shell.FISH,
+			ExpectedFeats: shell.VIMode,
+		},
 		{
 			Case:          "bash does not enable vi mode tracking",
 			Shell:         shell.BASH,

src/segments/vimode.go

@@ -27,15 +27,15 @@ func (v *VIMode) Enabled() bool {
 
 func mapVIModeKeymap(keymap string) string {
 	switch keymap {
-	case "main", "viins", "emacs":
+	case "main", "viins", "emacs", "insert":
 		return "insert"
-	case "vicmd":
+	case "vicmd", "default":
 		return "normal"
 	case "visual":
 		return "visual"
-	case "viopp":
+	case "viopp", "operator", "f", "F", "t", "T":
 		return "viopp"
-	case "replace":
+	case "replace", "replace_one":
 		return "replace"
 	default:
 		return keymap

src/segments/vimode_test.go

@@ -20,10 +20,18 @@ func TestVIMode(t *testing.T) {
 		{Case: "main keymap maps to insert", Env: "main", ExpectedMode: "insert", ExpectedKeymap: "main", ExpectedEnabled: true},
 		{Case: "viins keymap maps to insert", Env: "viins", ExpectedMode: "insert", ExpectedKeymap: "viins", ExpectedEnabled: true},
 		{Case: "emacs keymap maps to insert", Env: "emacs", ExpectedMode: "insert", ExpectedKeymap: "emacs", ExpectedEnabled: true},
+		{Case: "insert keymap maps is preserved", Env: "insert", ExpectedMode: "insert", ExpectedKeymap: "insert", ExpectedEnabled: true},
 		{Case: "vicmd keymap maps to normal", Env: "vicmd", ExpectedMode: "normal", ExpectedKeymap: "vicmd", ExpectedEnabled: true},
+		{Case: "default keymap maps to normal", Env: "default", ExpectedMode: "normal", ExpectedKeymap: "default", ExpectedEnabled: true},
 		{Case: "visual keymap is preserved", Env: "visual", ExpectedMode: "visual", ExpectedKeymap: "visual", ExpectedEnabled: true},
 		{Case: "viopp keymap is preserved", Env: "viopp", ExpectedMode: "viopp", ExpectedKeymap: "viopp", ExpectedEnabled: true},
+		{Case: "operator keymap maps to viopp", Env: "operator", ExpectedMode: "viopp", ExpectedKeymap: "operator", ExpectedEnabled: true},
+		{Case: "f keymap maps to viopp", Env: "f", ExpectedMode: "viopp", ExpectedKeymap: "f", ExpectedEnabled: true},
+		{Case: "F keymap maps to viopp", Env: "F", ExpectedMode: "viopp", ExpectedKeymap: "F", ExpectedEnabled: true},
+		{Case: "t keymap maps to viopp", Env: "t", ExpectedMode: "viopp", ExpectedKeymap: "t", ExpectedEnabled: true},
+		{Case: "T keymap maps to viopp", Env: "T", ExpectedMode: "viopp", ExpectedKeymap: "T", ExpectedEnabled: true},
 		{Case: "replace keymap is preserved", Env: "replace", ExpectedMode: "replace", ExpectedKeymap: "replace", ExpectedEnabled: true},
+		{Case: "replace_one keymap maps to replace", Env: "replace_one", ExpectedMode: "replace", ExpectedKeymap: "replace_one", ExpectedEnabled: true},
 		{Case: "unknown keymap falls through", Env: "custom", ExpectedMode: "custom", ExpectedKeymap: "custom", ExpectedEnabled: true},
 		{Case: "empty env disables segment", Env: "", ExpectedEnabled: false},
 	}

src/shell/fish.go

@@ -29,7 +29,9 @@ func (f Features) Fish() Code {
 		return unixUpgrade
 	case Notice:
 		return unixNotice
-	case RPrompt, PoshGit, Azure, LineError, Jobs, Async, KeyHandlers, VIMode:
+	case VIMode:
+		return "_omp_enable_vimode"
+	case RPrompt, PoshGit, Azure, LineError, Jobs, Async, KeyHandlers:
 		fallthrough
 	default:
 		return ""

src/shell/fish_test.go

@@ -19,7 +19,8 @@ set --global _omp_ftcs_marks 1
 set --global _omp_prompt_mark 1
 set --global _omp_cursor_positioning 1
 set --global _omp_enable_streaming 1
-set --global _omp_transient_rprompt 1`
+set --global _omp_transient_rprompt 1
+_omp_enable_vimode`
 
 	assert.Equal(t, want, got)
 }

src/shell/scripts/omp.fish

@@ -666,6 +666,25 @@ function enable_poshtooltips
     bind \x7f _omp_backspace_key_handler -M insert
 end
 
+function _omp_export_bind_mode
+    if not contains -- "$fish_key_bindings" fish_vi_key_bindings fish_hybrid_key_bindings
+        set --export --global POSH_VI_MODE "emacs"
+    else
+        set --export --global POSH_VI_MODE "$fish_bind_mode"
+    end
+end
+
+function _omp_enable_vimode
+    _omp_export_bind_mode
+    # fish calls `fish_mode_prompt` when the bind mode is changed. if it
+    # produces no output, fish will then call `fish_prompt` so there's no need
+    # to repaint as long as `fish_mode_prompt` outputs nothing
+    function fish_mode_prompt
+        _omp_export_bind_mode
+        set --global _omp_new_prompt 1
+    end
+end
+
 # transient prompt
 
 function _omp_enter_key_handler

website/docs/segments/system/vimode.mdx

@@ -7,12 +7,14 @@ sidebar_label: Vi mode
 ## What
 
 Display the current Vi mode (insert / normal / visual …) in the prompt. Useful
-when using ZSH [keymaps][zsh-vi-mode] via `bindkey -v` or PowerShell PSReadLine
-`-EditMode Vi` so you can tell at a glance which mode you are in.
+when using ZSH [keymaps][zsh-vi-mode] via `bindkey -v`, PowerShell PSReadLine
+`-EditMode Vi`, or fish [`fish_key_bindings`][fish-key-bindings] so you can
+tell at a glance which mode you are in.
 
 In ZSH, adding this segment automatically registers a `zle-keymap-select` hook.
 In PowerShell, it registers a PSReadLine [Vi mode change handler][pwsh-vi-mode].
-Both re-render the prompt every time the active mode changes.
+In fish, it overrides [`fish_mode_prompt`][fish-mode-prompt].
+All three re-render the prompt every time the active mode changes.
 
 :::caution PowerShell cursor indicator
 
@@ -22,6 +24,13 @@ segment in the prompt instead.
 
 :::
 
+:::caution `fish_mode_prompt`
+
+Make sure nothing else in your fish config overrides `fish_mode_prompt`, as
+this will interfere with this segment's functionality.
+
+:::
+
 ## Sample Configuration
 
 import Config from "@site/src/components/Config.js";
@@ -57,3 +66,5 @@ import Config from "@site/src/components/Config.js";
 [zsh-vi-mode]: https://zsh.sourceforge.io/Doc/Release/Zsh-Line-Editor.html#Keymaps
 [zsh-keymap]: https://zsh.sourceforge.io/Doc/Release/Zsh-Line-Editor.html#index-KEYMAP
 [pwsh-vi-mode]: https://learn.microsoft.com/en-us/powershell/module/psreadline/set-psreadlineoption#-vimodechangehandler
+[fish-key-bindings]: https://fishshell.com/docs/current/language.html#envvar-fish_key_bindings
+[fish-mode-prompt]: https://fishshell.com/docs/current/cmds/fish_mode_prompt.html