Keep original line endings when reading expectation files

ChangeLog.rst

@@ -44,6 +44,7 @@ Fixed
   ``<test-module-name>`` component despite the ``README.rst`` claimed.
   Existed projects could set ``pm-pattern-file-fmt`` to
   ``{class}/{fn}{callspec}`` to preserve backward compatibility.
+- Keep original line endings when reading expectation files.
 
 Removed
 -------

src/matcher/plugin.py

@@ -111,7 +111,8 @@ def _read_expected_file_content(self) -> None:
             pytest.skip(f'Pattern file not found `{self._pattern_filename}`')
 
         if self._expected_file_content is None:
-            self._expected_file_content = self._pattern_filename.read_text()
+            with self._pattern_filename.open(newline='') as f:
+                self._expected_file_content = f.read()
 
     def __eq__(self, text: object) -> bool:
         if not isinstance(text, str):

test/test_matcher.py

@@ -433,3 +433,21 @@ def test_sfx(capfd, expected_out):
     # Run all tests with pytest
     result = pytester.runpytest()
     result.assert_outcomes(passed=1)
+
+
+def crlf_test(ourtestdir, expectdir) -> None:
+    # Write a sample expectations file
+    expectdir.makepatternfile('.out', test_sample_out='Hello Africa!\r\n')
+    # Write a sample test
+    ourtestdir.makepyfile(r"""
+        def test_sample_out(capfd, expected_out):
+            print('Hello Africa!\r\n', end='')
+            stdout, stderr = capfd.readouterr()
+            assert expected_out == stdout
+            assert stderr == ''
+        """
+      )
+
+    # Run all tests with pytest
+    result = ourtestdir.runpytest()
+    result.assert_outcomes(passed=1)