🎨 Palette: Improve greeting name input handling and feedback

- Trim leading/trailing whitespace from name input
- Fallback to "World" for empty or whitespace-only names
- Show actual character count in name length validation error
- Add tests for new trimming and fallback behavior
- Document UX learnings in .Jules/palette.md

Author: google-labs-jules[bot]

project/app.py

@@ -23,8 +23,10 @@ def main(name: str = "World"):
     Args:
       name: the name to be greeted
     """
+    name = name.strip() or "World"
+
     if len(name) > 100:
-        raise UsageError("Invalid name: maximum length is 100 characters.")
+        raise UsageError(f"Invalid name: {len(name)} characters (maximum is 100).")
     if any(c < " " for c in name):
         raise UsageError("Invalid name: control characters are not allowed.")
 

tests/test_app.py

@@ -26,11 +26,25 @@ def test_greet():
     assert "Hello Jules! 👋" in result.output
 
 
+def test_greet_trimming():
+    runner = CliRunner()
+    result = runner.invoke(main, ["--name", "  Jules  "])
+    assert result.exit_code == 0
+    assert "Hello Jules! 👋" in result.output
+
+
+def test_greet_empty_fallback():
+    runner = CliRunner()
+    result = runner.invoke(main, ["--name", "   "])
+    assert result.exit_code == 0
+    assert "Hello World! 👋" in result.output
+
+
 def test_name_too_long():
     runner = CliRunner()
     result = runner.invoke(main, ["--name", "A" * 101])
     assert result.exit_code != 0
-    assert "maximum length is 100 characters" in result.output
+    assert "101 characters (maximum is 100)" in result.output
 
 
 def test_name_control_characters():