Add unit tests for dysh shell

src/dysh/shell.py

@@ -28,6 +28,9 @@
 --------------------------------------------------------------------------
 """
 
+DEFAULT_PROFILE = "dysh"
+DEFAULT_COLORS = "LightBG"
+
 
 def parse_args():
     parser = argparse.ArgumentParser(
@@ -37,15 +40,18 @@ def parse_args():
         )
     )
     parser.add_argument("paths", help="FITS file paths to load initially", nargs="*", type=Path)
-    parser.add_argument("-p", "--profile", help="The IPython profile to use", default="dysh")
+    parser.add_argument("-p", "--profile", help="The IPython profile to use", default=DEFAULT_PROFILE)
     parser.add_argument("-L", "--fits-loader", help="The SDFITS loader class name to use", default="GBTFITSLoad")
     parser.add_argument(
-        "--colors", help="Set the color scheme", choices=["NoColor", "Neutral", "Linux", "LightBG"], default="LightBG"
+        "--colors",
+        help="Set the color scheme",
+        choices=["NoColor", "Neutral", "Linux", "LightBG"],
+        default=DEFAULT_COLORS,
     )
     return parser.parse_known_args()
 
 
-def init_shell(colors: str, profile: str | Path, *ipython_args, sdfits_files=None):
+def init_shell(*ipython_args, colors=DEFAULT_COLORS, profile: str | Path = "DEFAULT_PROFILE", sdfits_files=None):
     c = Config()
     import numpy as np
     import pandas as pd
@@ -81,7 +87,7 @@ def open_sdfits_files(paths: List[Path], loader_class_name="GBTFITSLoad") -> Lis
 def main():
     args, remaining_args = parse_args()
     sdfits_files = open_sdfits_files(args.paths, args.fits_loader)
-    init_shell(colors=args.colors, profile=args.profile, *remaining_args, sdfits_files=sdfits_files)
+    init_shell(*remaining_args, colors=args.colors, profile=args.profile, sdfits_files=sdfits_files)
 
 
 if __name__ == "__main__":

src/dysh/test_shell.py

@@ -0,0 +1,27 @@
+import subprocess
+import sys
+import uuid
+from io import StringIO
+
+from dysh.shell import init_shell
+
+
+def test_shell_cli():
+    """Simply prove that we can launch $ dysh from CLI"""
+    subprocess.check_call(["dysh"])
+
+
+def test_init_shell(monkeypatch):
+    """Prove that we can open the shell, print something, and exit without error"""
+
+    # Generate a unique string that we will look for in stdout later
+    test_str = uuid.uuid4().hex.upper()
+    mock_input = StringIO(f"print('{test_str}')\n")
+    monkeypatch.setattr(sys, "stdin", mock_input)
+
+    mock_stdout = StringIO()
+    monkeypatch.setattr(sys, "stdout", mock_stdout)
+    init_shell("--no-banner", colors="NoColor", profile="dysh")
+
+    mock_stdout.seek(0)
+    assert test_str in mock_stdout.read()