feat: add undo action and fix hotkeys rendering (#438)

* Fix prompt action undo and hotkeys rendering

* Fix prompt action test typechecks

* Simplify undo and hotkeys PR

* Fix editor formatting

packages/coding-agent/src/config/keybindings.ts

@@ -264,10 +264,7 @@ export class KeybindingsManager {
 	 * Get display string for an action.
 	 */
 	getDisplayString(action: AppAction): string {
-		const keys = this.getKeys(action);
-		if (keys.length === 0) return "";
-		if (keys.length === 1) return keys[0]!;
-		return keys.join("/");
+		return formatKeyHints(this.getKeys(action));
 	}
 
 	/**

packages/coding-agent/src/modes/controllers/command-controller.ts

@@ -24,6 +24,7 @@ import { DynamicBorder } from "../../modes/components/dynamic-border";
 import { PythonExecutionComponent } from "../../modes/components/python-execution";
 import { getMarkdownTheme, getSymbolTheme, theme } from "../../modes/theme/theme";
 import type { InteractiveModeContext } from "../../modes/types";
+import { buildHotkeysMarkdown } from "../../modes/utils/hotkeys-markdown";
 import type { AsyncJobSnapshotItem } from "../../session/agent-session";
 import type { AuthStorage } from "../../session/auth-storage";
 import { outputMeta } from "../../tools/output-meta";
@@ -509,52 +510,13 @@ export class CommandController {
 		const sttKey = this.ctx.keybindings.getDisplayString("toggleSTT") || "Alt+H";
 		const copyLineKey = this.ctx.keybindings.getDisplayString("copyLine") || "Alt+Shift+L";
 		const copyPromptKey = this.ctx.keybindings.getDisplayString("copyPrompt") || "Alt+Shift+C";
-		const hotkeys = `
-		**Navigation**
-		| Key | Action |
-		|-----|--------|
-		| \`Arrow keys\` | Move cursor / browse history (Up when empty) |
-		| \`Option+Left/Right\` | Move by word |
-		| \`Ctrl+A\` / \`Home\` / \`Cmd+Left\` | Start of line |
-		| \`Ctrl+E\` / \`End\` / \`Cmd+Right\` | End of line |
-		
-		**Editing**
-		| Key | Action |
-		|-----|--------|
-		| \`Enter\` | Send message |
-		| \`Shift+Enter\` / \`Alt+Enter\` | New line |
-		| \`Ctrl+W\` / \`Option+Backspace\` | Delete word backwards |
-		| \`Ctrl+U\` | Delete to start of line |
-		| \`Ctrl+K\` | Delete to end of line |
-		| \`${copyLineKey}\` | Copy current line |
-		| \`${copyPromptKey}\` | Copy whole prompt |
-		
-		**Other**
-		| Key | Action |
-		|-----|--------|
-		| \`Tab\` | Path completion / accept autocomplete |
-		| \`Escape\` | Cancel autocomplete / abort streaming |
-		| \`Ctrl+C\` | Clear editor (first) / exit (second) |
-		| \`Ctrl+D\` | Exit (when editor is empty) |
-		| \`Ctrl+Z\` | Suspend to background |
-		| \`Shift+Tab\` | Cycle thinking level |
-		| \`Ctrl+P\` | Cycle role models (slow/default/smol) |
-		| \`Shift+Ctrl+P\` | Cycle role models (temporary) |
-		| \`Alt+P\` | Select model (temporary) |
-		| \`Ctrl+L\` | Select model (set roles) |
-		| \`${planModeKey}\` | Toggle plan mode |
-		| \`Ctrl+R\` | Search prompt history |
-		| \`${expandToolsKey}\` | Toggle tool output expansion |
-		| \`Ctrl+T\` | Toggle todo list expansion |
-		| \`Ctrl+G\` | Edit message in external editor |
-		| \`${sttKey}\` | Toggle speech-to-text recording |
-		| \`#\` | Open prompt actions |
-		| \`/\` | Slash commands |
-		| \`!\` | Run bash command |
-		| \`!!\` | Run bash command (excluded from context) |
-		| \`$\` | Run Python in shared kernel |
-		| \`$$\` | Run Python (excluded from context) |
-		`;
+		const hotkeys = buildHotkeysMarkdown({
+			expandToolsKey,
+			planModeKey,
+			sttKey,
+			copyLineKey,
+			copyPromptKey,
+		});
 		this.ctx.chatContainer.addChild(new Spacer(1));
 		this.ctx.chatContainer.addChild(new DynamicBorder());
 		this.ctx.chatContainer.addChild(new Text(theme.bold(theme.fg("accent", "Keyboard Shortcuts")), 1, 0));

packages/coding-agent/src/modes/controllers/input-controller.ts

@@ -535,6 +535,7 @@ export class InputController {
 			keybindings: this.ctx.keybindings,
 			copyCurrentLine: () => this.handleCopyCurrentLine(),
 			copyPrompt: () => this.handleCopyPrompt(),
+			undo: prefix => this.ctx.editor.undoPastTransientText(prefix),
 			moveCursorToMessageEnd: () => this.ctx.editor.moveToMessageEnd(),
 			moveCursorToMessageStart: () => this.ctx.editor.moveToMessageStart(),
 			moveCursorToLineStart: () => this.ctx.editor.moveToLineStart(),

packages/coding-agent/src/modes/prompt-action-autocomplete.ts

@@ -12,12 +12,12 @@ interface PromptActionDefinition {
 	label: string;
 	description: string;
 	keywords: string[];
-	execute: () => void;
+	execute: (prefix: string) => void;
 }
 
 interface PromptActionAutocompleteItem extends AutocompleteItem {
 	actionId: string;
-	execute: () => void;
+	execute: (prefix: string) => void;
 }
 
 interface PromptActionAutocompleteOptions {
@@ -26,6 +26,7 @@ interface PromptActionAutocompleteOptions {
 	keybindings: KeybindingsManager;
 	copyCurrentLine: () => void;
 	copyPrompt: () => void;
+	undo: (prefix: string) => void;
 	moveCursorToMessageEnd: () => void;
 	moveCursorToMessageStart: () => void;
 	moveCursorToLineStart: () => void;
@@ -141,6 +142,14 @@ export class PromptActionAutocompleteProvider implements AutocompleteProvider {
 		onApplied?: () => void;
 	} {
 		if (prefix.startsWith("#") && isPromptActionItem(item)) {
+			if (item.actionId === "undo") {
+				return {
+					lines,
+					cursorLine,
+					cursorCol,
+					onApplied: () => item.execute(prefix),
+				};
+			}
 			const currentLine = lines[cursorLine] || "";
 			const beforePrefix = currentLine.slice(0, cursorCol - prefix.length);
 			const afterCursor = currentLine.slice(cursorCol);
@@ -150,7 +159,7 @@ export class PromptActionAutocompleteProvider implements AutocompleteProvider {
 				lines: newLines,
 				cursorLine,
 				cursorCol: beforePrefix.length,
-				onApplied: item.execute,
+				onApplied: () => item.execute(prefix),
 			};
 		}
 
@@ -181,6 +190,13 @@ export function createPromptActionAutocompleteProvider(
 			keywords: ["copy", "prompt", "clipboard", "message"],
 			execute: options.copyPrompt,
 		},
+		{
+			id: "undo",
+			label: "Undo",
+			description: formatKeyHints(editorKeybindings.getKeys("undo")),
+			keywords: ["undo", "revert", "edit", "history"],
+			execute: options.undo,
+		},
 		{
 			id: "cursor-message-end",
 			label: "Move cursor to end of message",

packages/coding-agent/src/modes/utils/hotkeys-markdown.ts

@@ -0,0 +1,57 @@
+export interface HotkeysMarkdownBindings {
+	expandToolsKey: string;
+	planModeKey: string;
+	sttKey: string;
+	copyLineKey: string;
+	copyPromptKey: string;
+}
+
+export function buildHotkeysMarkdown(bindings: HotkeysMarkdownBindings): string {
+	const { expandToolsKey, planModeKey, sttKey, copyLineKey, copyPromptKey } = bindings;
+	return [
+		"**Navigation**",
+		"| Key | Action |",
+		"|-----|--------|",
+		"| `Arrow keys` | Move cursor / browse history (Up when empty) |",
+		"| `Option+Left/Right` | Move by word |",
+		"| `Ctrl+A` / `Home` / `Cmd+Left` | Start of line |",
+		"| `Ctrl+E` / `End` / `Cmd+Right` | End of line |",
+		"",
+		"**Editing**",
+		"| Key | Action |",
+		"|-----|--------|",
+		"| `Enter` | Send message |",
+		"| `Shift+Enter` / `Alt+Enter` | New line |",
+		"| `Ctrl+W` / `Option+Backspace` | Delete word backwards |",
+		"| `Ctrl+U` | Delete to start of line |",
+		"| `Ctrl+K` | Delete to end of line |",
+		`| \`${copyLineKey}\` | Copy current line |`,
+		`| \`${copyPromptKey}\` | Copy whole prompt |`,
+		"",
+		"**Other**",
+		"| Key | Action |",
+		"|-----|--------|",
+		"| `Tab` | Path completion / accept autocomplete |",
+		"| `Escape` | Cancel autocomplete / abort streaming |",
+		"| `Ctrl+C` | Clear editor (first) / exit (second) |",
+		"| `Ctrl+D` | Exit (when editor is empty) |",
+		"| `Ctrl+Z` | Suspend to background |",
+		"| `Shift+Tab` | Cycle thinking level |",
+		"| `Ctrl+P` | Cycle role models (slow/default/smol) |",
+		"| `Shift+Ctrl+P` | Cycle role models (temporary) |",
+		"| `Alt+P` | Select model (temporary) |",
+		"| `Ctrl+L` | Select model (set roles) |",
+		`| \`${planModeKey}\` | Toggle plan mode |`,
+		"| `Ctrl+R` | Search prompt history |",
+		`| \`${expandToolsKey}\` | Toggle tool output expansion |`,
+		"| `Ctrl+T` | Toggle todo list expansion |",
+		"| `Ctrl+G` | Edit message in external editor |",
+		`| \`${sttKey}\` | Toggle speech-to-text recording |`,
+		"| `#` | Open prompt actions |",
+		"| `/` | Slash commands |",
+		"| `!` | Run bash command |",
+		"| `!!` | Run bash command (excluded from context) |",
+		"| `$` | Run Python in shared kernel |",
+		"| `$$` | Run Python (excluded from context) |",
+	].join("\n");
+}