Add test to Biz/Repl.py

It's just a simple test, but it effectively tests that the `CustomRepl` can be
instantiated for the ns and path. I also copied the unittest recipes I came up
with in the other place I used Python tests so far: Biz/Llamacpp.py.

Also, I'm beginning to see how a Biz/Cli.py module might work. Probably just a
simple abstract base class with move, test, help, and tidy methods, pretty
similar to the Haskell version.

2 files changed, 78 insertions, 28 deletions

diff --git a/Biz/Llamacpp.py b/Biz/Llamacpp.py
index 9a2ff86..66b57d8 100644
--- a/Biz/Llamacpp.py
+++ b/Biz/Llamacpp.py
@@ -19,14 +19,22 @@ class TestLlamaCpp(unittest.TestCase):
 
     def test_in_path(self) -> None:
         """Test that llama.cpp is in $PATH."""
-        self.assertTrue("llama-cpp" in os.environ.get("PATH", ""))
+        self.assertIn("llama-cpp", os.environ.get("PATH", ""))
+
+
+def test() -> None:
+    """Run this module's test suite."""
+    suite = unittest.TestSuite()
+    suite.addTests(
+        unittest.defaultTestLoader.loadTestsFromTestCase(TestLlamaCpp),
+    )
+    unittest.TextTestRunner().run(suite)
 
 
 def main() -> None:
     """Entrypoint."""
     if sys.argv[1] == "test":
-        sys.argv.pop()
-        unittest.main()
+        test()
     else:
         sys.exit(0)
 
diff --git a/Biz/Repl.py b/Biz/Repl.py
index 595b555..cd7bad6 100644
--- a/Biz/Repl.py
+++ b/Biz/Repl.py
@@ -23,6 +23,7 @@ import inspect
 import logging
 import mypy.api
 import os
+import pathlib
 import pydoc
 import string
 import subprocess
@@ -30,6 +31,11 @@ import sys
 import textwrap
 import types
 import typing
+import unittest
+
+
+class ReplError(Exception):
+    """Type for errors at the repl."""
 
 
 def use(ns: str, path: str) -> None:
@@ -41,8 +47,8 @@ def use(ns: str, path: str) -> None:
     logging.info("loading %s from %s", ns, path)
     spec = importlib.util.spec_from_file_location(ns, path)
     if spec is None or spec.loader is None:
-        msg = "spec could not be loaded for %s at %s"
-        raise ValueError(msg, ns, path)
+        msg = f"spec could not be loaded for {ns} at {path}"
+        raise ReplError(msg)
     module = importlib.util.module_from_spec(spec)
     # delete module and its imported names if its already loaded
     if ns in sys.modules:
@@ -115,18 +121,20 @@ class CustomRepl:
         sys.ps1 = f"{self.ns}> "
         sys.ps2 = f"{self.ns}| "
 
-    def show_help(self) -> None:
-        """Print info about how to use this repl."""
-        sys.stdout.write(
-            textwrap.dedent(f"""
+    def help(self) -> str:
+        """Return help text."""
+        return textwrap.dedent(f"""
             repl commands:
               :e        open {self.ns} in {self.editor}
               :r        reload {self.ns}
               :t obj    show the type of obj
               obj?      expands to 'help(obj)'
               :?        show this help
-        """),
-        )
+        """)
+
+    def show_help(self) -> None:
+        """Print info about how to use this repl."""
+        sys.stdout.write(self.help())
         sys.stdout.flush()
 
     def excepthook(
@@ -146,22 +154,21 @@ class CustomRepl:
         if not isinstance(value, SyntaxError):
             return self.default(type_, value, traceback)
         if value.text is None:
-            msg = "value.text is None: %s"
-            raise ValueError(msg, value)
+            msg = f"value.text is None: {value}"
+            raise ReplError(msg)
         stmt = value.text.rstrip()
         if stmt == ":?":
-            self.repl_help()
+            self.show_help()
             return None
         if stmt.endswith("?"):
             name = stmt.rstrip("?(" + self.whitespace)
-            self.wut(name)
+            self.get_help(name)
             return None
         if stmt == ":e":
-            edit_file(self.ns, self.path, self.editor)
+            self.edit()
             return None
         if stmt == ":r":
-            use(self.ns, self.path)
-            typecheck(self.path)
+            self.reload()
             return None
         if stmt.startswith(":t"):
             var = stmt.split()[1]
@@ -179,7 +186,7 @@ class CustomRepl:
             return eval(cmd, frame.f_globals, frame.f_locals)  # noqa: S307
         return None
 
-    def wut(self, name: str) -> typing.Any | None:
+    def get_help(self, name: str) -> typing.Any | None:
         """Return the documentation for `name` to the caller."""
         for record in self.stack():
             frame = record[0]
@@ -199,18 +206,53 @@ class CustomRepl:
         edit_file(self.ns, self.path, self.editor)
 
 
+class TestCustomRepl(unittest.TestCase):
+    """Test the CustomRepl functionality."""
+
+    def setUp(self) -> None:
+        """Create a CustomRepl for testing."""
+        ns = __name__
+        path = pathlib.Path(__name__.replace(".", "/"))
+        path = path.with_suffix(".py")
+        self.repl = CustomRepl(ns, str(path), "true")
+        self.repl.setup()
+
+    def tearDown(self) -> None:
+        """Undo `self.setUp`."""
+        sys.excepthook = self.repl.default
+        del self.repl
+
+    def test_help(self) -> None:
+        """Help message should include the ns and path."""
+        self.assertIn(self.repl.ns, self.repl.help())
+
+
+def test() -> None:
+    """Run this module's test suite."""
+    suite = unittest.TestSuite()
+    suite.addTests(
+        unittest.defaultTestLoader.loadTestsFromTestCase(TestCustomRepl),
+    )
+    unittest.TextTestRunner().run(suite)
+
+
+def move() -> None:
+    """Actual entrypoint."""
+    Log.setup()
+    ns = sys.argv[1]
+    path = sys.argv[2]
+    editor = os.environ.get("EDITOR", "$EDITOR")
+    repl = CustomRepl(ns, path, editor)
+    repl.setup()
+    repl.show_help()
+
+
 def main() -> None:
-    """Entrypoint."""
+    """Entrypoint, should be replaced by a `Biz.Cli.main`."""
     if sys.argv[1] == "test":
-        pass
+        test()
     else:
-        Log.setup()
-        ns = sys.argv[1]
-        path = sys.argv[2]
-        editor = os.environ.get("EDITOR", "$EDITOR")
-        repl = CustomRepl(ns, path, editor)
-        repl.setup()
-        repl.show_help()
+        move()
 
 
 if __name__ == "__main__":