Fix running with no command-line arguments.

.changelog/21.bugfix

@@ -0,0 +1 @@
+Running `fil-profile` with no arguments now prints the help.

filprofiler/_script.py

@@ -100,19 +100,16 @@ def stage_1():
 parser_run = subparsers.add_parser(
     "run", help="Run a Python script or package", prefix_chars=[""], add_help=False,
 )
-# parser_run.add_argument(
-#     "-m",
-#     dest="module",
-#     action="store",
-#     help="Profile a module, equivalent to running with 'python -m <module>'",
-#     default="",
-# )
 parser_run.add_argument("rest", nargs=REMAINDER)
 del subparsers, parser_run
 
 
 def stage_2():
-    """Main CLI interface. Presumes LD_PRELOAD etc. has been set by stage_1()."""
+    """Main CLI interface.22 Presumes LD_PRELOAD etc. has been set by stage_1()."""
+    if len(sys.argv) == 1:
+        PARSER.print_help()
+        sys.exit(0)
+
     arguments = PARSER.parse_args()
     if arguments.license:
         print(LICENSE)

tests/test_endtoend.py

@@ -243,3 +243,14 @@ def test_external_behavior():
     assert url.startswith("file://")
     assert url.endswith(".html")
     assert os.path.exists(url[len("file://") :])
+
+
+def test_no_args():
+    """
+    Running fil-profile with no arguments gives same result as --help.
+    """
+    no_args = run(["fil-profile"], stdout=PIPE, stderr=PIPE)
+    with_help = run(["fil-profile", "--help"], stdout=PIPE, stderr=PIPE)
+    assert no_args.returncode == with_help.returncode
+    assert no_args.stdout == with_help.stdout
+    assert no_args.stderr == with_help.stderr