matrix tests: Add test for sample config generation.

zulip/integrations/matrix/test_matrix.py

@@ -2,12 +2,40 @@ from unittest import TestCase
 from subprocess import Popen, PIPE
 import os
 
+import shutil
+
+from contextlib import contextmanager
+from tempfile import mkdtemp
+
 script_file = "matrix_bridge.py"
 script_dir = os.path.dirname(__file__)
 script = os.path.join(script_dir, script_file)
 
-from typing import List
+from typing import List, Iterator
 
+sample_config_path = "matrix_test.conf"
+
+sample_config_text = """[matrix]
+host = https://matrix.org
+username = username
+password = password
+room_id = #zulip:matrix.org
+
+[zulip]
+email = glitch-bot@chat.zulip.org
+api_key = aPiKeY
+site = https://chat.zulip.org
+stream = test here
+topic = matrix
+
+"""
+
+@contextmanager
+def new_temp_dir():
+    # type: () -> Iterator[str]
+    path = mkdtemp()
+    yield path
+    shutil.rmtree(path)
 
 class MatrixBridgeTests(TestCase):
     def output_from_script(self, options):
@@ -38,3 +66,13 @@ class MatrixBridgeTests(TestCase):
         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])
+
+    def test_write_sample_config(self):
+        # type: () -> None
+        with new_temp_dir() as tempdir:
+            path = os.path.join(tempdir, sample_config_path)
+            output_lines = self.output_from_script(["--write-sample-config", path])
+            self.assertEqual(output_lines, ["Wrote sample configuration to '{}'".format(path)])
+
+            with open(path) as sample_file:
+                self.assertEqual(sample_file.read(), sample_config_text)