Improve control character detection in input validation (#102)

Author: google-labs-jules[bot]

project/app.py

@@ -25,7 +25,7 @@ def main(name: str = "World"):
     """
     if len(name) > 100:
         raise UsageError("Invalid name: maximum length is 100 characters.")
-    if any(c < " " for c in name):
+    if any(not c.isprintable() for c in name):
         raise UsageError("Invalid name: control characters are not allowed.")
 
     secho(f"Hello {name}! 👋", fg="green", bold=True)

scripts/rename.py

@@ -78,7 +78,7 @@ def main(name: str, description: str, author: str, email: str, github: str):
     ]:
         if len(value) > 100:
             raise UsageError(f"Invalid {label}: maximum length is 100 characters.")
-        if any(c < " " for c in value):
+        if any(not c.isprintable() for c in value):
             raise UsageError(f"Invalid {label}: control characters are not allowed.")
         if label != "description" and '"' in value:
             raise UsageError(f"Invalid {label}: double quotes are not allowed.")

tests/test_app.py

@@ -38,3 +38,7 @@ def test_name_control_characters():
     result = runner.invoke(main, ["--name", "Injected\x1b[31mRed\x1b[0m"])
     assert result.exit_code != 0
     assert "control characters are not allowed" in result.output
+
+    result = runner.invoke(main, ["--name", "test\x7f"])
+    assert result.exit_code != 0
+    assert "control characters are not allowed" in result.output