tests: Adjust minimum wait/count timers for run_and_expect() if they are too low

If the developer pass way too low timers, we end up with most likely false-positive
situations for random tests under a high load of the system.

It would be better to fallback to the minimum default values for such a cases.

E.g.:

```
WARNING: topo: Waiting time is too small (count=1, wait=0.5), using default values (count=20, wait=3)
```

Signed-off-by: Donatas Abraitis <donatas@opensourcerouting.org>

1 files changed, 13 insertions, 5 deletions

diff --git a/tests/topotests/lib/topotest.py b/tests/topotests/lib/topotest.py
index 5a8c2e5964..dc6107bbef 100644
--- a/tests/topotests/lib/topotest.py
+++ b/tests/topotests/lib/topotest.py
@@ -396,6 +396,9 @@ def run_and_expect(func, what, count=20, wait=3):
     waiting `wait` seconds between tries. By default it tries 20 times with
     3 seconds delay between tries.
 
+    Changing default count/wait values, please change them below also for
+    `minimum_wait`, and `minimum_count`.
+
     Returns (True, func-return) on success or
     (False, func-return) on failure.
 
@@ -414,13 +417,18 @@ def run_and_expect(func, what, count=20, wait=3):
 
     # Just a safety-check to avoid running topotests with very
     # small wait/count arguments.
+    # If too low count/wait values are defined, override them
+    # with the minimum values.
+    minimum_count = 20
+    minimum_wait = 3
+    minimum_wait_time = 15  # The overall minimum seconds for the test to wait
     wait_time = wait * count
-    if wait_time < 5:
-        assert (
-            wait_time >= 5
-        ), "Waiting time is too small (count={}, wait={}), adjust timer values".format(
-            count, wait
+    if wait_time < minimum_wait_time:
+        logger.warn(
+            f"Waiting time is too small (count={count}, wait={wait}), using default values (count={minimum_count}, wait={minimum_wait})"
         )
+        count = minimum_count
+        wait = minimum_wait
 
     logger.debug(
         "'{}' polling started (interval {} secs, maximum {} tries)".format(