Add a couple unit tests

Author: WardBrian

test/__init__.py

@@ -2,6 +2,7 @@
 
 import contextlib
 import os
+import sys
 import unittest
 from importlib import reload
 
@@ -31,6 +32,13 @@ def without_import(self, library, module):
             yield
         reload(module)
 
+    @contextlib.contextmanager
+    def replace_stdin(self, target):
+        orig = sys.stdin
+        sys.stdin = target
+        yield
+        sys.stdin = orig
+
     # recipe from https://stackoverflow.com/a/34333710
     @contextlib.contextmanager
     def modified_environ(self, *remove, **update):

test/test_utils.py

@@ -19,7 +19,7 @@
 import numpy as np
 import pandas as pd
 import pytest
-from testfixtures import LogCapture
+from testfixtures import LogCapture, StringComparison
 
 from cmdstanpy import _DOT_CMDSTAN, _TMPDIR
 from cmdstanpy.model import CmdStanModel
@@ -36,6 +36,7 @@
     do_command,
     flatten_chains,
     get_latest_cmdstan,
+    install_cmdstan,
     parse_method_vars,
     parse_rdump_value,
     parse_stan_vars,
@@ -850,6 +851,34 @@ def test_bad(self):
             flatten_chains(array_2d)
 
 
+class InstallCmdstanFunctionTest(CustomTestCase):
+    def test_bad_version(self):
+        with LogCapture() as log:
+            res = install_cmdstan(version="0.00.0")
+        log.check_present(
+            (
+                "cmdstanpy",
+                "WARNING",
+                StringComparison("CmdStan installation failed.\nVersion*"),
+            )
+        )
+        self.assertFalse(res)
+
+    def test_interactive_extra_args(self):
+        with LogCapture() as log:
+            with self.replace_stdin(io.StringIO("9.99.9\n")):
+                res = install_cmdstan(version="2.29.2", interactive=True)
+        log.check_present(
+            (
+                "cmdstanpy",
+                "WARNING",
+                "Interactive installation requested but other arguments"
+                " were used.\n\tThese values will be ignored!",
+            )
+        )
+        self.assertFalse(res)
+
+
 @pytest.mark.order(-1)
 class ShowProgressTest(unittest.TestCase):
     # this test must run after any tests that check tqdm progress bars