From 6829a5a012c792ce0b93d9439e804f826602ebd0 Mon Sep 17 00:00:00 2001
From: Alpha Diop <90140491+alphajoop@users.noreply.github.com>
Date: Wed, 16 Apr 2025 23:25:08 +0000
Subject: [PATCH] fix(text-buffer): correct word deletion logic for trailing
 spaces (Ctrl+Backspace)    (#131)

## Description
This fix resolves a bug where Ctrl+Backspace (hex 0x17) deletes the
entire line when the cursor is positioned after a trailing space.

## Problem
When the user has a line like "I want you to refactor my view " (with a
space at the end) and the cursor is after that space, Ctrl+Backspace
deletes the entire line instead of just removing the word "view".

## Solution
- Added a check to detect if the cursor is after spaces
- Modified the logic to delete only one space at a time in this case
- Added a unit test to verify this behavior

## Tests
All tests pass, including the new test that verifies the corrected
behavior.

---------

Signed-off-by: Alpha Diop <alphakhoss@gmail.com>
Co-authored-by: Thibault Sottiaux <tibo@openai.com>
---
 codex-cli/src/text-buffer.ts             | 26 +++++++++++++++++-------
 codex-cli/tests/text-buffer-word.test.ts |  9 ++++++++
 2 files changed, 28 insertions(+), 7 deletions(-)

diff --git a/codex-cli/src/text-buffer.ts b/codex-cli/src/text-buffer.ts
index 43cb6c4e2..d7ce15306 100644
--- a/codex-cli/src/text-buffer.ts
+++ b/codex-cli/src/text-buffer.ts
@@ -443,17 +443,29 @@ export default class TextBuffer {
     const line = this.line(this.cursorRow);
     const arr = toCodePoints(line);
 
-    // Step 1 – skip over any separators sitting *immediately* to the left of
-    // the caret so that consecutive deletions wipe runs of whitespace first
-    // then words.
+    // If the cursor is just after a space (or several spaces), we only delete the separators
+    // then, on the next call, the previous word. We should never delete the entire line.
     let start = this.cursorCol;
-    while (start > 0 && !isWordChar(arr[start - 1])) {
-      start--;
+    let onlySpaces = true;
+    for (let i = 0; i < start; i++) {
+      if (isWordChar(arr[i])) {
+        onlySpaces = false;
+        break;
+      }
     }
 
-    // Step 2 – now skip the word characters themselves.
-    while (start > 0 && isWordChar(arr[start - 1])) {
+    // If the line contains only spaces up to the cursor, delete just one space
+    if (onlySpaces && start > 0) {
       start--;
+    } else {
+      // Step 1 – skip over any separators sitting *immediately* to the left of the caret
+      while (start > 0 && !isWordChar(arr[start - 1])) {
+        start--;
+      }
+      // Step 2 – skip the word characters themselves
+      while (start > 0 && isWordChar(arr[start - 1])) {
+        start--;
+      }
     }
 
     this.lines[this.cursorRow] =
diff --git a/codex-cli/tests/text-buffer-word.test.ts b/codex-cli/tests/text-buffer-word.test.ts
index 4ea767945..f02ac045c 100644
--- a/codex-cli/tests/text-buffer-word.test.ts
+++ b/codex-cli/tests/text-buffer-word.test.ts
@@ -84,6 +84,15 @@ describe("TextBuffer – word‑wise navigation & deletion", () => {
     expect(col).toBe(11);
   });
 
+  test("deleteWordLeft after trailing space only deletes the last word, not the whole line", () => {
+    const tb = new TextBuffer("I want you to refactor my view ");
+    tb.move("end"); // Place caret after the space
+    tb.deleteWordLeft();
+    expect(tb.getText()).toBe("I want you to refactor my ");
+    const [, col] = tb.getCursor();
+    expect(col).toBe("I want you to refactor my ".length);
+  });
+
   test("deleteWordLeft removes the previous word and positions the caret correctly", () => {
     const tb = new TextBuffer("hello world");