Add a script to repeatedly run the test suite

Add a script to assist with debugging #2249 by running the test suite
repeatedly and checking the output.

test-loop.py

@@ -0,0 +1,29 @@
+import re
+import subprocess
+import sys
+
+max_iterations = 100
+for i in range(0, max_iterations):
+    print(f"Running test iteration {i+1} of {max_iterations}")
+
+    proc = subprocess.run(
+        "node_modules/.bin/gulp test",
+        shell=True,
+        stdout=subprocess.PIPE,
+        check=True,
+    )
+    stdout = proc.stdout.decode()
+
+    tests_run_match = re.search("TOTAL: ([0-9]+) SUCCESS", stdout)
+
+    if not tests_run_match:
+        print(f"Tests failed on run {i}")
+        print(stdout)
+        sys.exit(1)
+
+    expected_tests = 2439
+    tests_run = int(tests_run_match.group(1))
+    if tests_run < expected_tests:
+        print(f"Only ran {tests_run} instead of {expected_tests}")
+        print(stdout)
+        sys.exit(1)