feat: Refactor Vim/Helix keybindings with shared helper functions

Factor out the repl-eval and repl-stop event dispatching code into
replEval() and replStop() helper functions that are shared between
Vim and Helix keybindings.

This refactoring:
- Reduces code duplication between Vim :w/:q and Helix :w/:q commands
- Makes the keybinding handlers more maintainable
- Properly implements Helix commands using the commands.of() API
- Ensures consistent behavior across both keybinding modes

The Helix keybindings now properly integrate with the REPL using the
same event dispatch mechanism as Vim, dispatching custom repl-evaluate
and repl-stop events with fallbacks to keyboard events.

🤖 Generated with [Claude Code](https://claude.com/claude-code)

Co-Authored-By: Claude <noreply@anthropic.com>

packages/codemirror/keybindings.mjs

@@ -6,7 +6,7 @@ import { emacs } from '@replit/codemirror-emacs';
 import { vim, Vim } from '@replit/codemirror-vim';
 // import { vim } from './vim_test.mjs';
 import { vscodeKeymap } from '@replit/codemirror-vscode-keymap';
-import { helix } from 'codemirror-helix';
+import { helix, commands } from 'codemirror-helix';
 import { logger } from '@strudel/core';
 
 const vscodePlugin = ViewPlugin.fromClass(
@@ -21,69 +21,8 @@ const vscodePlugin = ViewPlugin.fromClass(
 );
 const vscodeExtension = (options) => [vscodePlugin].concat(options ?? []);
 
-// Map Vim :w to trigger the same action as evaluation. We dispatch a custom
+function replEval(view) {
-// event 'repl-evaluate' that the editor listens for, and also simulate
-// Ctrl+Enter/Alt+Enter as a fallback. We log to the Strudel logger so it
-// appears in the Console panel.
   try {
-  if (Vim && typeof Vim.defineEx === 'function') {
-    // Map gc to toggle line comments by dispatching a custom event that our
-    // CodeMirror integration listens to. This avoids depending on Vim's
-    // internal actions and works with current selections/visual mode.
-    try {
-      Vim.defineAction('strudelToggleComment', (cm) => {
-        const view = cm?.view || cm;
-        try {
-          const ev = new CustomEvent('repl-toggle-comment', { detail: { source: 'vim', view }, cancelable: true });
-          document.dispatchEvent(ev);
-        } catch (e) {
-          console.error('strudelToggleComment dispatch failed', e);
-        }
-      });
-      Vim.mapCommand('gc', 'action', 'strudelToggleComment', {}, { context: 'normal' });
-      Vim.mapCommand('gc', 'action', 'strudelToggleComment', {}, { context: 'visual' });
-    } catch (e) {
-      console.error('Vim gc mapping failed', e);
-    }
-
-    // :q to pause/stop
-    Vim.defineEx('quit', 'q', (cm) => {
-      try {
-        const view = cm?.view || cm;
-        // First try dispatching our custom stop event, then fallback to Alt+.
-        let handled = false;
-        try {
-          const ev = new CustomEvent('repl-stop', { detail: { source: 'vim', view }, cancelable: true });
-          handled = document.dispatchEvent(ev) === false;
-        } catch (e) {
-          console.error('Error dispatching repl-stop event', e);
-        }
-        if (!handled) {
-          const altDot = new KeyboardEvent('keydown', {
-            key: '.',
-            code: 'Period',
-            altKey: true,
-            bubbles: true,
-            cancelable: true,
-          });
-          view?.dom?.dispatchEvent?.(altDot);
-        }
-      } catch (e) {
-        console.error('Error dispatching :q stop event', e);
-      }
-    });
-
-    // :w to evaluate
-    Vim.defineEx('write', 'w', (cm) => {
-      const view = cm?.view || cm; // CM6 Vim passes either an object with view or the view itself
-      try {
-        view?.focus?.();
-        // Let the app know this came from Vim :w
-        try {
-          logger('[vim] :w — evaluating code');
-        } catch (e) {
-          console.error('Error logging Vim :w evaluation', e);
-        }
     // Dispatch a dedicated evaluate event first
     let handled = false;
     try {
@@ -116,6 +55,79 @@ try {
       });
       view?.dom?.dispatchEvent?.(altEnter);
     }
+  } catch (e) {
+    console.error('Error dispatching repl evaluation event', e);
+  }
+}
+
+function replStop(view) {
+  try {
+    // First try dispatching our custom stop event, then fallback to Alt+.
+    let handled = false;
+    try {
+      const ev = new CustomEvent('repl-stop', { detail: { source: 'vim', view }, cancelable: true });
+      handled = document.dispatchEvent(ev) === false;
+    } catch (e) {
+      console.error('Error dispatching repl-stop event', e);
+    }
+    if (!handled) {
+      const altDot = new KeyboardEvent('keydown', {
+        key: '.',
+        code: 'Period',
+        altKey: true,
+        bubbles: true,
+        cancelable: true,
+      });
+      view?.dom?.dispatchEvent?.(altDot);
+    }
+  } catch (e) {
+    console.error('Error dispatching repl stop event', e);
+  }
+}
+
+// Map Vim :w to trigger the same action as evaluation. We dispatch a custom
+// event 'repl-evaluate' that the editor listens for, and also simulate
+// Ctrl+Enter/Alt+Enter as a fallback. We log to the Strudel logger so it
+// appears in the Console panel.
+try {
+  if (Vim && typeof Vim.defineEx === 'function') {
+    // Map gc to toggle line comments by dispatching a custom event that our
+    // CodeMirror integration listens to. This avoids depending on Vim's
+    // internal actions and works with current selections/visual mode.
+    try {
+      Vim.defineAction('strudelToggleComment', (cm) => {
+        const view = cm?.view || cm;
+        try {
+          const ev = new CustomEvent('repl-toggle-comment', { detail: { source: 'vim', view }, cancelable: true });
+          document.dispatchEvent(ev);
+        } catch (e) {
+          console.error('strudelToggleComment dispatch failed', e);
+        }
+      });
+      Vim.mapCommand('gc', 'action', 'strudelToggleComment', {}, { context: 'normal' });
+      Vim.mapCommand('gc', 'action', 'strudelToggleComment', {}, { context: 'visual' });
+    } catch (e) {
+      console.error('Vim gc mapping failed', e);
+    }
+
+    // :q to pause/stop
+    Vim.defineEx('quit', 'q', (cm) => {
+      const view = cm?.view || cm;
+      replStop(view);
+    });
+
+    // :w to evaluate
+    Vim.defineEx('write', 'w', (cm) => {
+      const view = cm?.view || cm; // CM6 Vim passes either an object with view or the view itself
+      try {
+        view?.focus?.();
+        // Let the app know this came from Vim :w
+        try {
+          logger('[vim] :w — evaluating code');
+        } catch (e) {
+          console.error('Error logging Vim :w evaluation', e);
+        }
+        replEval(view);
       } catch (e) {
         console.error('Error dispatching :w evaluation event', e);
       }
@@ -125,12 +137,49 @@ try {
   console.error('Vim ex command setup failed (defineEx missing or Vim unavailable)', e);
 }
 
+// Map Helix :w to trigger the same action as evaluation. We dispatch a custom
+// event 'repl-evaluate' that the editor listens for, and also simulate
+// Ctrl+Enter/Alt+Enter as a fallback. We log to the Strudel logger so it
+// appears in the Console panel.
+const helixCommands = commands.of([
+  {
+    // :w to evaluate
+    name: 'write',
+    aliases: ['w'],
+    help: 'Repl-eval',
+    handler(view, args) {
+      try {
+        view?.focus?.(); // Let the app know this came from Helix :w
+        logger('[helix] :w — evaluating code');
+        replEval(view);
+      } catch (e) {
+        console.error('Error dispatching helix :w evaluation event', e);
+      }
+    },
+  },
+  {
+    // :q to pause/stop
+    name: 'quit',
+    aliases: ['q'],
+    help: 'Repl-stop',
+    handler(view, args) {
+      try {
+        view?.focus?.(); // Let the app know this came from Helix :q
+        logger('[helix] :q — stopping repl');
+        replStop(view);
+      } catch (e) {
+        console.error('Error dispatching helix :q stop event', e);
+      }
+    },
+  },
+]);
+
 const keymaps = {
   vim,
   emacs,
-  helix,
   codemirror: () => keymap.of(defaultKeymap),
   vscode: vscodeExtension,
+  helix: () => [helix(), helixCommands],
 };
 
 export function keybindings(name) {