Commit 406de94b authored by Raito Bezarius's avatar Raito Bezarius
Browse files

nixos/test-driver: add `timeout` option for `wait_for_console_text` 

Previously, `wait_for_console_text` would block indefinitely until there were lines
shown in the buffer.

This is highly annoying when testing for things that can just hang for some reasons.

This introduces a classical timeout mechanism via non-blocking get on the Queue.
parent f7947266

nixos/lib/test-driver/test_driver/machine.py

+17 −4
Original line number Diff line number Diff line
@@ -855,17 +855,30 @@ class Machine: 
        with self.nested(f"waiting for {regex} to appear on screen"):

            retry(screen_matches)



    def wait_for_console_text(self, regex: str) -> None:

    def wait_for_console_text(self, regex: str, timeout: float | None = None) -> None:

        """

            Wait for the provided regex to appear on console.

            For each reads,



            If timeout is None, timeout is infinite.



            `timeout` is in seconds.

        """

        with self.nested(f"waiting for {regex} to appear on console"):

            # Buffer the console output, this is needed

            # to match multiline regexes.

            console = io.StringIO()

            start = time.time()

            while True:

                try:

                    console.write(self.last_lines.get())

                    # This will return as soon as possible and

                    # sleep 1 second.

                    console.write(self.last_lines.get(block=False))

                except queue.Empty:

                    self.sleep(1)

                    continue

                    time.sleep(1)

                    if timeout is not None and time.time() - start >= timeout:

                        # If we reached here, we didn't honor our timeout constraint.

                        raise Exception(f"`wait_for_console_text` did not match `{regex}` after {timeout} seconds")

                console.seek(0)

                matches = re.search(regex, console.read())

                if matches is not None: