Cleanup __main__.py - remove stray print statements (#1078)

* Cleanup __main__.py - remove stray print statements
use rich's print traceback instead

fix double printing of version when --version
is called

Add some tests for the subcommands

Signed-off-by: Naveen M K <[email protected]>

* Run black

* tests: remove importlib_metadata usage

Author: naveen521kk

manim/__main__.py

@@ -81,23 +81,19 @@ def main():
                 server.start()
                 server.wait_for_termination()
             except ModuleNotFoundError as e:
-                print("\n\n")
-                print(
+                console.print(
                     "Dependencies for the WebGL render are missing. Run "
                     "pip install manim[webgl_renderer] to install them."
                 )
-                print(e)
-                print("\n\n")
+                console.print_exception()
         else:
             for SceneClass in scene_classes_from_file(input_file):
                 try:
                     scene = SceneClass()
                     scene.render()
                     open_file_if_needed(scene.renderer.file_writer)
                 except Exception:
-                    print("\n\n")
-                    traceback.print_exc()
-                    print("\n\n")
+                    console.print_exception()
 
 
 if __name__ == "__main__":

manim/_config/main_utils.py

@@ -111,7 +111,6 @@ def parse_args(args: list) -> argparse.Namespace:
     elif subcmd == "plugins":
         return _parse_args_plugins(args)
     elif args[1] == "--version":
-        print(f"Manim Community v{ __version__ }")
         sys.exit()
     # elif subcmd == some_other_future_subcmd:
     #     return _parse_args_some_other_subcmd(args)

tests/test_commands.py

@@ -0,0 +1,63 @@
+import subprocess
+import sys
+
+from .test_plugins.test_plugins import function_like_plugin
+
+import manim
+
+
+def call_command(command, cwd=None, env=None):
+    a = subprocess.run(
+        command,
+        stdout=subprocess.PIPE,
+        stderr=subprocess.PIPE,
+        check=True,
+        text=True,
+        cwd=cwd,
+        env=env,
+    )
+    return a
+
+
+def test_manim_version_from_command_line():
+    a = call_command(
+        [
+            sys.executable,
+            "-m",
+            "manim",
+            "--version",
+        ]
+    )
+    version = manim.__version__
+    assert version in a.stdout
+    assert a.stdout.strip() == f"Manim Community v{version}"
+
+
+def test_manim_cfg_subcommand_no_subcommand():
+    a = call_command(
+        [
+            sys.executable,
+            "-m",
+            "manim",
+            "cfg",
+        ]
+    )
+    assert "No subcommand provided; Exiting..." in a.stdout
+
+
+def test_manim_plugis_subcommand_no_subcommand():
+    a = call_command(
+        [
+            sys.executable,
+            "-m",
+            "manim",
+            "plugins",
+        ]
+    )
+    assert "No flag provided; Exiting..." in a.stdout
+
+
+def test_manim_plugis_subcommand_listing(function_like_plugin):
+    # Check whether `test_plugin` is in plugins list
+    a = call_command([sys.executable, "-m", "manim", "plugins", "--list"])
+    assert "test_plugin" in a.stdout