A couple of autocomplete improvements (#1024)

* fix(tui): keep file suggestions open when typing in Tab-triggered mode

Previously, pressing Tab on an empty prompt or after a space would show
file suggestions, but typing a letter would dismiss them because the
text didn't look like a path pattern. Now the editor tracks whether
autocomplete was triggered via Tab (force mode) or naturally (regular
mode), and uses the appropriate suggestion method when updating.

* fix(tui): hide autocomplete when backspacing slash command to empty

Previously, typing / showed slash command suggestions, but pressing
Backspace to delete it showed file suggestions instead of hiding all
suggestions.

packages/tui/src/autocomplete.ts

@@ -312,9 +312,9 @@ export class CombinedAutocompleteProvider implements AutocompleteProvider {
 			return pathPrefix;
 		}
 
-		// Return empty string only if we're at the beginning of the line or after a space
-		// (not after quotes or other delimiters that don't suggest file paths)
-		if (pathPrefix === "" && (text === "" || text.endsWith(" "))) {
+		// Return empty string only after a space (not for completely empty text)
+		// Empty text should not trigger file suggestions - that's for forced Tab completion
+		if (pathPrefix === "" && text.endsWith(" ")) {
 			return pathPrefix;
 		}
 

packages/tui/src/components/editor.ts

@@ -174,7 +174,7 @@ export class Editor implements Component, Focusable {
 	// Autocomplete support
 	private autocompleteProvider?: AutocompleteProvider;
 	private autocompleteList?: SelectList;
-	private isAutocompleting: boolean = false;
+	private autocompleteState: "regular" | "force" | null = null;
 	private autocompletePrefix: string = "";
 
 	// Paste tracking for large pastes
@@ -351,7 +351,7 @@ export class Editor implements Component, Focusable {
 
 		// Render each visible layout line
 		// Emit hardware cursor marker only when focused and not showing autocomplete
-		const emitCursorMarker = this.focused && !this.isAutocompleting;
+		const emitCursorMarker = this.focused && !this.autocompleteState;
 
 		for (const layoutLine of visibleLines) {
 			let displayText = layoutLine.text;
@@ -406,7 +406,7 @@ export class Editor implements Component, Focusable {
 		}
 
 		// Add autocomplete list if active
-		if (this.isAutocompleting && this.autocompleteList) {
+		if (this.autocompleteState && this.autocompleteList) {
 			const autocompleteResult = this.autocompleteList.render(contentWidth);
 			for (const line of autocompleteResult) {
 				const lineWidth = visibleWidth(line);
@@ -459,7 +459,7 @@ export class Editor implements Component, Focusable {
 		}
 
 		// Handle autocomplete mode
-		if (this.isAutocompleting && this.autocompleteList) {
+		if (this.autocompleteState && this.autocompleteList) {
 			if (kb.matches(data, "selectCancel")) {
 				this.cancelAutocomplete();
 				return;
@@ -520,7 +520,7 @@ export class Editor implements Component, Focusable {
 		}
 
 		// Tab - trigger completion
-		if (kb.matches(data, "tab") && !this.isAutocompleting) {
+		if (kb.matches(data, "tab") && !this.autocompleteState) {
 			this.handleTabCompletion();
 			return;
 		}
@@ -893,7 +893,7 @@ export class Editor implements Component, Focusable {
 		}
 
 		// Check if we should trigger or update autocomplete
-		if (!this.isAutocompleting) {
+		if (!this.autocompleteState) {
 			// Auto-trigger for "/" at the start of a line (slash commands)
 			if (char === "/" && this.isAtStartOfMessage()) {
 				this.tryTriggerAutocomplete();
@@ -1050,7 +1050,7 @@ export class Editor implements Component, Focusable {
 		}
 
 		// Update or re-trigger autocomplete after backspace
-		if (this.isAutocompleting) {
+		if (this.autocompleteState) {
 			this.updateAutocomplete();
 		} else {
 			// If autocomplete was cancelled (no matches), re-trigger if we're in a completable context
@@ -1270,7 +1270,7 @@ export class Editor implements Component, Focusable {
 		}
 
 		// Update or re-trigger autocomplete after forward delete
-		if (this.isAutocompleting) {
+		if (this.autocompleteState) {
 			this.updateAutocomplete();
 		} else {
 			const currentLine = this.state.lines[this.state.cursorLine] || "";
@@ -1735,7 +1735,7 @@ export class Editor implements Component, Focusable {
 		if (suggestions && suggestions.items.length > 0) {
 			this.autocompletePrefix = suggestions.prefix;
 			this.autocompleteList = new SelectList(suggestions.items, 5, this.theme.selectList);
-			this.isAutocompleting = true;
+			this.autocompleteState = "regular";
 		} else {
 			this.cancelAutocomplete();
 		}
@@ -1751,7 +1751,7 @@ export class Editor implements Component, Focusable {
 		if (this.isInSlashCommandContext(beforeCursor) && !beforeCursor.trimStart().includes(" ")) {
 			this.handleSlashCommandCompletion();
 		} else {
-			this.forceFileAutocomplete();
+			this.forceFileAutocomplete(true);
 		}
 	}
 
@@ -1764,7 +1764,7 @@ https://github.com/EsotericSoftware/spine-runtimes/actions/runs/19536643416/job/
 17 this job fails with https://github.com/EsotericSoftware/spine-runtimes/actions/runs/19
 536643416/job/55932288317 havea  look at .gi
 	 */
-	private forceFileAutocomplete(): void {
+	private forceFileAutocomplete(explicitTab: boolean = false): void {
 		if (!this.autocompleteProvider) return;
 
 		// Check if provider supports force file suggestions via runtime check
@@ -1784,7 +1784,7 @@ https://github.com/EsotericSoftware/spine-runtimes/actions/runs/19536643416/job/
 
 		if (suggestions && suggestions.items.length > 0) {
 			// If there's exactly one suggestion, apply it immediately
-			if (suggestions.items.length === 1) {
+			if (explicitTab && suggestions.items.length === 1) {
 				const item = suggestions.items[0]!;
 				this.pushUndoSnapshot();
 				this.lastAction = null;
@@ -1804,31 +1804,35 @@ https://github.com/EsotericSoftware/spine-runtimes/actions/runs/19536643416/job/
 
 			this.autocompletePrefix = suggestions.prefix;
 			this.autocompleteList = new SelectList(suggestions.items, 5, this.theme.selectList);
-			this.isAutocompleting = true;
+			this.autocompleteState = "force";
 		} else {
 			this.cancelAutocomplete();
 		}
 	}
 
 	private cancelAutocomplete(): void {
-		this.isAutocompleting = false;
+		this.autocompleteState = null;
 		this.autocompleteList = undefined;
 		this.autocompletePrefix = "";
 	}
 
 	public isShowingAutocomplete(): boolean {
-		return this.isAutocompleting;
+		return this.autocompleteState !== null;
 	}
 
 	private updateAutocomplete(): void {
-		if (!this.isAutocompleting || !this.autocompleteProvider) return;
+		if (!this.autocompleteState || !this.autocompleteProvider) return;
+
+		if (this.autocompleteState === "force") {
+			this.forceFileAutocomplete();
+			return;
+		}
 
 		const suggestions = this.autocompleteProvider.getSuggestions(
 			this.state.lines,
 			this.state.cursorLine,
 			this.state.cursorCol,
 		);
-
 		if (suggestions && suggestions.items.length > 0) {
 			this.autocompletePrefix = suggestions.prefix;
 			// Always create new SelectList to ensure update

packages/tui/test/editor.test.ts

@@ -13,6 +13,26 @@ function createTestTUI(cols = 80, rows = 24): TUI {
 	return new TUI(new VirtualTerminal(cols, rows));
 }
 
+/** Standard applyCompletion that replaces prefix with item.value */
+function applyCompletion(
+	lines: string[],
+	cursorLine: number,
+	cursorCol: number,
+	item: { value: string },
+	prefix: string,
+): { lines: string[]; cursorLine: number; cursorCol: number } {
+	const line = lines[cursorLine] || "";
+	const before = line.slice(0, cursorCol - prefix.length);
+	const after = line.slice(cursorCol);
+	const newLines = [...lines];
+	newLines[cursorLine] = before + item.value + after;
+	return {
+		lines: newLines,
+		cursorLine,
+		cursorCol: cursorCol - prefix.length + item.value.length,
+	};
+}
+
 describe("Editor component", () => {
 	describe("Prompt history navigation", () => {
 		it("does nothing on Up arrow when history is empty", () => {
@@ -1728,18 +1748,7 @@ describe("Editor component", () => {
 					}
 					return null;
 				},
-				applyCompletion: (lines, cursorLine, cursorCol, item, prefix) => {
-					const line = lines[cursorLine] || "";
-					const before = line.slice(0, cursorCol - prefix.length);
-					const after = line.slice(cursorCol);
-					const newLines = [...lines];
-					newLines[cursorLine] = before + item.value + after;
-					return {
-						lines: newLines,
-						cursorLine,
-						cursorCol: cursorCol - prefix.length + item.value.length,
-					};
-				},
+				applyCompletion,
 			};
 
 			editor.setAutocompleteProvider(mockProvider);
@@ -1785,18 +1794,7 @@ describe("Editor component", () => {
 					}
 					return null;
 				},
-				applyCompletion: (lines, cursorLine, cursorCol, item, prefix) => {
-					const line = lines[cursorLine] || "";
-					const before = line.slice(0, cursorCol - prefix.length);
-					const after = line.slice(cursorCol);
-					const newLines = [...lines];
-					newLines[cursorLine] = before + item.value + after;
-					return {
-						lines: newLines,
-						cursorLine,
-						cursorCol: cursorCol - prefix.length + item.value.length,
-					};
-				},
+				applyCompletion,
 			};
 
 			editor.setAutocompleteProvider(mockProvider);
@@ -1840,18 +1838,7 @@ describe("Editor component", () => {
 					}
 					return null;
 				},
-				applyCompletion: (lines, cursorLine, cursorCol, item, prefix) => {
-					const line = lines[cursorLine] || "";
-					const before = line.slice(0, cursorCol - prefix.length);
-					const after = line.slice(cursorCol);
-					const newLines = [...lines];
-					newLines[cursorLine] = before + item.value + after;
-					return {
-						lines: newLines,
-						cursorLine,
-						cursorCol: cursorCol - prefix.length + item.value.length,
-					};
-				},
+				applyCompletion,
 			};
 
 			editor.setAutocompleteProvider(mockProvider);
@@ -1872,5 +1859,110 @@ describe("Editor component", () => {
 			assert.strictEqual(editor.getText(), "src/");
 			assert.strictEqual(editor.isShowingAutocomplete(), false);
 		});
+
+		it("keeps suggestions open when typing in force mode (Tab-triggered)", () => {
+			const editor = new Editor(createTestTUI(), defaultEditorTheme);
+
+			// Mock provider with both getSuggestions and getForceFileSuggestions
+			// getSuggestions only returns results for path-like patterns
+			// getForceFileSuggestions always extracts prefix and filters
+			const allFiles = [
+				{ value: "readme.md", label: "readme.md" },
+				{ value: "package.json", label: "package.json" },
+				{ value: "src/", label: "src/" },
+				{ value: "dist/", label: "dist/" },
+			];
+
+			const mockProvider: AutocompleteProvider & {
+				getForceFileSuggestions: (
+					lines: string[],
+					cursorLine: number,
+					cursorCol: number,
+				) => { items: { value: string; label: string }[]; prefix: string } | null;
+			} = {
+				getSuggestions: (lines, _cursorLine, cursorCol) => {
+					const text = lines[0] || "";
+					const prefix = text.slice(0, cursorCol);
+					// Only return suggestions for path-like patterns (contains / or starts with .)
+					if (prefix.includes("/") || prefix.startsWith(".")) {
+						const filtered = allFiles.filter((f) => f.value.toLowerCase().startsWith(prefix.toLowerCase()));
+						if (filtered.length > 0) {
+							return { items: filtered, prefix };
+						}
+					}
+					return null;
+				},
+				getForceFileSuggestions: (lines, _cursorLine, cursorCol) => {
+					const text = lines[0] || "";
+					const prefix = text.slice(0, cursorCol);
+					// Always filter files by prefix
+					const filtered = allFiles.filter((f) => f.value.toLowerCase().startsWith(prefix.toLowerCase()));
+					if (filtered.length > 0) {
+						return { items: filtered, prefix };
+					}
+					return null;
+				},
+				applyCompletion,
+			};
+
+			editor.setAutocompleteProvider(mockProvider);
+
+			// Press Tab on empty prompt - should show all files (force mode)
+			editor.handleInput("\t");
+			assert.strictEqual(editor.isShowingAutocomplete(), true);
+
+			// Type "r" - should narrow to "readme.md" (force mode keeps suggestions open)
+			editor.handleInput("r");
+			assert.strictEqual(editor.getText(), "r");
+			assert.strictEqual(editor.isShowingAutocomplete(), true);
+
+			// Type "e" - should still show "readme.md"
+			editor.handleInput("e");
+			assert.strictEqual(editor.getText(), "re");
+			assert.strictEqual(editor.isShowingAutocomplete(), true);
+
+			// Accept with Tab
+			editor.handleInput("\t");
+			assert.strictEqual(editor.getText(), "readme.md");
+			assert.strictEqual(editor.isShowingAutocomplete(), false);
+		});
+
+		it("hides autocomplete when backspacing slash command to empty", () => {
+			const editor = new Editor(createTestTUI(), defaultEditorTheme);
+
+			// Mock provider with slash commands
+			const mockProvider: AutocompleteProvider = {
+				getSuggestions: (lines, _cursorLine, cursorCol) => {
+					const text = lines[0] || "";
+					const prefix = text.slice(0, cursorCol);
+					// Only return slash command suggestions when line starts with /
+					if (prefix.startsWith("/")) {
+						const commands = [
+							{ value: "/model", label: "model", description: "Change model" },
+							{ value: "/help", label: "help", description: "Show help" },
+						];
+						const query = prefix.slice(1); // Remove leading /
+						const filtered = commands.filter((c) => c.value.startsWith(query));
+						if (filtered.length > 0) {
+							return { items: filtered, prefix };
+						}
+					}
+					return null;
+				},
+				applyCompletion,
+			};
+
+			editor.setAutocompleteProvider(mockProvider);
+
+			// Type "/" - should show slash command suggestions
+			editor.handleInput("/");
+			assert.strictEqual(editor.getText(), "/");
+			assert.strictEqual(editor.isShowingAutocomplete(), true);
+
+			// Backspace to delete "/" - should hide autocomplete completely
+			editor.handleInput("\x7f"); // Backspace
+			assert.strictEqual(editor.getText(), "");
+			assert.strictEqual(editor.isShowingAutocomplete(), false);
+		});
 	});
 });