matrix tests: Add minimal help test for no-args and with -h.

zulip/integrations/matrix/test_matrix.py

@@ -0,0 +1,35 @@
+from unittest import TestCase
+from subprocess import Popen, PIPE
+import os
+
+script_file = "matrix_bridge.py"
+script_dir = os.path.dirname(__file__)
+script = os.path.join(script_dir, script_file)
+
+
+class MatrixBridgeTests(TestCase):
+    def test_no_args(self):
+        # type: () -> None
+        popen = Popen(["python", script], stdin=PIPE, stdout=PIPE, universal_newlines=True)
+        output_lines = popen.communicate()[0].strip().split("\n")
+        expected_lines = [
+            "Options required: -c or --config to run, OR --write-sample-config.",
+            "usage: {} [-h]".format(script_file)
+        ]
+        for expected, output in zip(expected_lines, output_lines):
+            self.assertIn(expected, output)
+
+    def test_help_usage_and_description(self):
+        # type: () -> None
+        popen = Popen(["python", script] + ["-h"], stdin=PIPE, stdout=PIPE, universal_newlines=True)
+        output_lines = popen.communicate()[0].strip().split("\n")
+        usage = "usage: {} [-h]".format(script_file)
+        description = "Script to bridge"
+        self.assertIn(usage, output_lines[0])
+        blank_lines = [num for num, line in enumerate(output_lines) if line == '']
+        # There should be blank lines in the output
+        self.assertTrue(blank_lines)
+        # There should be finite output
+        self.assertTrue(len(output_lines) > blank_lines[0])
+        # Minimal description should be in the first line of the 2nd "paragraph"
+        self.assertIn(description, output_lines[blank_lines[0] + 1])