fix(contest): expect "rendered_cmd" but not "cmd" in assert_complete()

When extracting the completion candidates from the Bash output, we
expect "rendered_cmd" rather than "cmd".  Note that "rendered_cmd"
(i.e., the text representation of the command line by Bash) can be
different from "cmd" (i.e., the command input by the user) when "cmd"
contains TABs or control characters.

Author: akinomyoga

test/t/conftest.py

@@ -755,12 +755,16 @@ def assert_complete(
         bash.send(cmd + "\t")
         # Sleep a bit if requested, to avoid `.*` matching too early
         time.sleep(kwargs.get("sleep_after_tab", 0))
-        bash.expect_exact(kwargs.get("rendered_cmd", cmd))
+        rendered_cmd = kwargs.get("rendered_cmd", cmd)
+        bash.expect_exact(rendered_cmd)
         bash.send(MAGIC_MARK)
         got = bash.expect(
             [
                 # 0: multiple lines, result in .before
-                r"\r\n" + re.escape(PS1 + cmd) + ".*" + re.escape(MAGIC_MARK),
+                r"\r\n"
+                + re.escape(PS1 + rendered_cmd)
+                + ".*"
+                + re.escape(MAGIC_MARK),
                 # 1: no completion
                 r"^" + re.escape(MAGIC_MARK),
                 # 2: on same line, result in .match