Start adding testing utilities

4 files changed, 48 insertions, 26 deletions

diff --git a/docs/source/reference/hazwaz.rst b/docs/source/reference/hazwaz.rst
index 32a91d1..fd849c2 100644
--- a/docs/source/reference/hazwaz.rst
+++ b/docs/source/reference/hazwaz.rst
@@ -14,3 +14,4 @@ Submodules
 
    hazwaz.command
    hazwaz.mixins
+   hazwaz.unittest
diff --git a/docs/source/reference/hazwaz.unittest.rst b/docs/source/reference/hazwaz.unittest.rst
new file mode 100644
index 0000000..8c09131
--- /dev/null
+++ b/docs/source/reference/hazwaz.unittest.rst
@@ -0,0 +1,7 @@
+hazwaz.unittest module
+======================
+
+.. automodule:: hazwaz.unittest
+   :members:
+   :undoc-members:
+   :show-inheritance:
diff --git a/hazwaz/unittest.py b/hazwaz/unittest.py
new file mode 100644
index 0000000..2b28cdc
--- /dev/null
+++ b/hazwaz/unittest.py
@@ -0,0 +1,29 @@
+import contextlib
+import io
+import sys
+import unittest
+
+
+class HazwazTestCase(unittest.TestCase):
+    def run_with_argv(self, cmd, argv: list[str]) -> dict[str, io.StringIO]:
+        """
+        Run a command with a list of command line options.
+
+        :param argv: the full command line except for the program name,
+                     as a list of strings; e.g. ``["subcommand",
+                     "--help"]`` or ``["subcommand", "--option",
+                     "value"]``.
+
+        :return: stdout and stderr resulting from the command.
+        """
+        stream = {
+            'stdout': io.StringIO(),
+            'stderr': io.StringIO(),
+        }
+        old_argv = sys.argv
+        sys.argv = argv
+        with contextlib.redirect_stdout(stream['stdout']):
+            with contextlib.redirect_stderr(stream['stderr']):
+                cmd.run()
+        sys.argv = old_argv
+        return stream
diff --git a/tests/test_command.py b/tests/test_command.py
index cbb7aad..96b36de 100644
--- a/tests/test_command.py
+++ b/tests/test_command.py
@@ -1,10 +1,8 @@
-import contextlib
-import io
 import logging
-import sys
 import unittest
 
 import hazwaz
+import hazwaz.unittest
 
 
 class MySubCommand(hazwaz.Command):
@@ -76,20 +74,7 @@ class MyCommandWithNoVerbose(hazwaz.MainCommand):
         )
 
 
-class testCommand(unittest.TestCase):
-    def _run_with_argv(self, cmd, argv):
-        stream = {
-            'stdout': io.StringIO(),
-            'stderr': io.StringIO(),
-        }
-        old_argv = sys.argv
-        sys.argv = argv
-        with contextlib.redirect_stdout(stream['stdout']):
-            with contextlib.redirect_stderr(stream['stderr']):
-                cmd.run()
-        sys.argv = old_argv
-        return stream
-
+class testCommand(hazwaz.unittest.HazwazTestCase):
     def test_description(self):
         cmd = MyCommand()
         self.assertEqual(
@@ -134,18 +119,18 @@ class testCommand(unittest.TestCase):
     def test_run(self):
         cmd = MyCommand()
         cmd_help = cmd.parser.format_help()
-        stream = self._run_with_argv(cmd, ["mycommand"])
+        stream = self.run_with_argv(cmd, ["mycommand"])
         self.assertEqual(stream["stdout"].getvalue(), cmd_help)
 
     def test_run_with_option(self):
         cmd = MyCommand()
         cmd_help = cmd.parser.format_help()
-        stream = self._run_with_argv(cmd, [
+        stream = self.run_with_argv(cmd, [
             "mycommand",
             "--verbose",
         ])
         self.assertEqual(stream["stdout"].getvalue(), cmd_help)
-        stream = self._run_with_argv(cmd, [
+        stream = self.run_with_argv(cmd, [
             "mycommand",
             "--debug",
         ])
@@ -153,12 +138,12 @@ class testCommand(unittest.TestCase):
 
     def test_run_subcommand(self):
         cmd = MyCommand()
-        stream = self._run_with_argv(cmd, ["mycommand", "mysubcommand"])
+        stream = self.run_with_argv(cmd, ["mycommand", "mysubcommand"])
         self.assertEqual(stream["stdout"].getvalue(), "Hello World\n")
 
     def test_run_subcommand_with_option(self):
         cmd = MyCommand()
-        stream = self._run_with_argv(cmd, [
+        stream = self.run_with_argv(cmd, [
             "mycommand",
             "mysubcommand",
             "--bar",
@@ -168,13 +153,13 @@ class testCommand(unittest.TestCase):
     def test_run_no_verbose(self):
         cmd = MyCommandWithNoVerbose()
         cmd_help = cmd.parser.format_help()
-        stream = self._run_with_argv(cmd, ["mycommand"])
+        stream = self.run_with_argv(cmd, ["mycommand"])
         self.assertEqual(stream["stdout"].getvalue(), cmd_help)
 
     def test_logging_regular(self):
         cmd = MyCommand()
         with self.assertLogs():
-            stream = self._run_with_argv(cmd, [
+            stream = self.run_with_argv(cmd, [
                 "mycommand",
                 "loggingsubcommand",
             ])
@@ -184,7 +169,7 @@ class testCommand(unittest.TestCase):
     def test_logging_verbose(self):
         cmd = MyCommand()
         with self.assertLogs():
-            stream = self._run_with_argv(cmd, [
+            stream = self.run_with_argv(cmd, [
                 "mycommand",
                 "--verbose",
                 "loggingsubcommand",
@@ -195,7 +180,7 @@ class testCommand(unittest.TestCase):
     def test_logging_debug(self):
         cmd = MyCommand()
         with self.assertLogs():
-            stream = self._run_with_argv(cmd, [
+            stream = self.run_with_argv(cmd, [
                 "mycommand",
                 "--debug",
                 "loggingsubcommand",