Emit dots on travis to avoid timeout (#867)

The current method of running a background sleep until travis is
finished is causing integration test runs to pass even when they should
be failing.

Instead, update the code to emit dots itself.

1 files changed, 49 insertions, 0 deletions

diff --git a/tests/integration_tests/util.py b/tests/integration_tests/util.py
new file mode 100644
index 00000000..3ef12358
--- /dev/null
+++ b/tests/integration_tests/util.py
@@ -0,0 +1,49 @@
+import logging
+import multiprocessing
+import os
+import time
+from contextlib import contextmanager
+
+log = logging.getLogger('integration_testing')
+
+
+def verify_ordered_items_in_text(to_verify: list, text: str):
+    """Assert all items in list appear in order in text.
+
+    Examples:
+      verify_ordered_items_in_text(['a', '1'], 'ab1')  # passes
+      verify_ordered_items_in_text(['1', 'a'], 'ab1')  # raises AssertionError
+    """
+    index = 0
+    for item in to_verify:
+        index = text[index:].find(item)
+        assert index > -1, "Expected item not found: '{}'".format(item)
+
+
+@contextmanager
+def emit_dots_on_travis():
+    """emit a dot every 60 seconds if running on Travis.
+
+    Travis will kill jobs that don't emit output for a certain amount of time.
+    This context manager spins up a background process which will emit a dot to
+    stdout every 60 seconds to avoid being killed.
+
+    It should be wrapped selectively around operations that are known to take a
+    long time.
+    """
+    if os.environ.get('TRAVIS') != "true":
+        # If we aren't on Travis, don't do anything.
+        yield
+        return
+
+    def emit_dots():
+        while True:
+            log.info(".")
+            time.sleep(60)
+
+    dot_process = multiprocessing.Process(target=emit_dots)
+    dot_process.start()
+    try:
+        yield
+    finally:
+        dot_process.terminate()