fix: strip end-of-line whitespace from wait-for needles (codeplain-tty)

The transcript is rendered per line with trailing whitespace stripped, so a
needle quoting a prompt verbatim — 'Master password: ' — could never match as
written; every such wait burned its full timeout and stacked past the script
budget. Deterministically reproduced from the cli-password-manager failure in
the pty-with-codeplain-tty benchmark run (17 of the render's conformance
failures were 120-second timeouts): the generated tests drove the CLI through
codeplain-tty exactly as instructed, and hung only on the trailing space in
'wait-for "Master password: "'.

The broker now strips end-of-line whitespace from wait-for and
wait-until-absent needles before matching; a needle that is empty after the
normalization is a usage error.

Author: gorandodig

render_machine/tty_broker.py

@@ -239,9 +239,12 @@ def _text_arg(args: dict, key: str = "text") -> str:
         return value
 
     def _wait(self, args: dict, present: bool) -> dict:
-        text = self._text_arg(args)
+        # The transcript is rendered per line with trailing whitespace stripped, so a
+        # needle quoting a prompt verbatim — "Master password: " — could never match as
+        # written. End-of-line whitespace is stripped from the needle to compensate.
+        text = "\n".join(part.rstrip() for part in self._text_arg(args).split("\n"))
         if not text:
-            raise ValueError("the text to wait for must not be empty")
+            raise ValueError("the text to wait for must not be empty or whitespace-only")
         timeout = args.get("timeout", DEFAULT_WAIT_SECONDS)
         if not isinstance(timeout, (int, float)) or isinstance(timeout, bool) or timeout <= 0:
             raise ValueError("'timeout' must be a positive number of seconds")

tests/test_tty_broker.py

@@ -128,6 +128,35 @@ def appear_later():
     assert response["ok"] is True
 
 
+def test_wait_for_matches_a_prompt_despite_trailing_whitespace(broker):
+    """The transcript is rendered per line with trailing whitespace stripped, so a
+    needle quoting a prompt verbatim — 'Master password: ' — could never match as
+    written. The broker strips end-of-line whitespace from the needle to compensate."""
+    instance, process = broker
+    process.transcript = "Master password:"
+    response = command(instance, "wait-for", {"text": "Master password: ", "timeout": 2})
+    assert response["ok"] is True
+
+
+def test_wait_until_absent_applies_the_same_needle_normalization(broker):
+    instance, process = broker
+    process.transcript = "spinner"
+
+    def clear_later():
+        time.sleep(0.2)
+        process.transcript = "done"
+
+    threading.Thread(target=clear_later, daemon=True).start()
+    response = command(instance, "wait-until-absent", {"text": "spinner ", "timeout": 5})
+    assert response["ok"] is True
+
+
+def test_a_whitespace_only_wait_needle_is_a_usage_error(broker):
+    instance, _ = broker
+    response = command(instance, "wait-for", {"text": "   ", "timeout": 2})
+    assert response["error"] == tty_protocol.ERROR_INVALID_REQUEST
+
+
 def test_wait_for_times_out_with_the_timeout_error(broker):
     instance, _ = broker
     response = command(instance, "wait-for", {"text": "never", "timeout": 0.2})