Fix coverage settings and cover semfree

pyproject.toml

@@ -105,7 +105,8 @@ exclude = '''
 [tool.coverage.run]
 branch = true
 parallel = true
-concurrency = ["multiprocessing"]
+concurrency = ["multiprocessing", "thread"]
+sigterm = true
 
 [tool.coverage.paths]
 source = ["src/ocrmypdf"]

src/ocrmypdf/pdfinfo/info.py

@@ -1159,7 +1159,7 @@ class PdfInfo:
         return f"<PdfInfo('...'), page count={len(self)}>"
 
 
-def main():
+def main():  # pragma: no cover
     """Run as a script."""
     import argparse  # pylint: disable=import-outside-toplevel
     from pprint import pprint  # pylint: disable=import-outside-toplevel

tests/test_semfree.py

@@ -0,0 +1,23 @@
+# SPDX-FileCopyrightText: 2023 James R. Barlow
+# SPDX-License-Identifier: MPL-2.0
+
+from __future__ import annotations
+
+from ocrmypdf.exceptions import ExitCode
+
+from .conftest import run_ocrmypdf_api
+
+
+def test_semfree(resources, outpdf):
+    exitcode = run_ocrmypdf_api(
+        resources / 'multipage.pdf',
+        outpdf,
+        '--skip-text',
+        '--skip-big',
+        '2',
+        '--plugin',
+        'ocrmypdf.extra_plugins.semfree',
+        '--plugin',
+        'tests/plugins/tesseract_noop.py',
+    )
+    assert exitcode == ExitCode.ok