Make keyword expression matching case-insensitive

AUTHORS

@@ -59,12 +59,12 @@ Christian Fetzer
 Christian Neumüller
 Christian Theunert
 Christian Tismer
-Christopher Gilling
+Christoph Buelter
 Christopher Dignam
+Christopher Gilling
 CrazyMerlyn
 Cyrus Maden
 Damian Skrzypczak
-Dhiren Serai
 Daniel Grana
 Daniel Hahler
 Daniel Nuri
@@ -79,6 +79,7 @@ David Szotten
 David Vierra
 Daw-Ran Liou
 Denis Kirisov
+Dhiren Serai
 Diego Russo
 Dmitry Dygalo
 Dmitry Pribysh

changelog/6316.improvement.rst

@@ -0,0 +1 @@
+Matching of ``-k EXPRESSION`` to test names is now case-insensitive.

doc/en/example/markers.rst

@@ -148,6 +148,10 @@ which implements a substring match on the test names instead of the
 exact match on markers that ``-m`` provides.  This makes it easy to
 select tests based on their names:
 
+.. versionadded: 5.4
+
+The expression matching is now case-insensitive.
+
 .. code-block:: pytest
 
     $ pytest -v -k http  # running with the above defined example module

doc/en/usage.rst

@@ -94,8 +94,8 @@ Pytest supports several ways to run and select tests from the command-line.
 
     pytest -k "MyClass and not method"
 
-This will run tests which contain names that match the given *string expression*, which can
-include Python operators that use filenames, class names and function names as variables.
+This will run tests which contain names that match the given *string expression* (case-insensitive),
+which can include Python operators that use filenames, class names and function names as variables.
 The example above will run ``TestMyClass.test_something``  but not ``TestMyClass.test_method_simple``.
 
 .. _nodeids:

src/_pytest/mark/__init__.py

@@ -52,7 +52,8 @@ def pytest_addoption(parser):
         "-k 'not test_method and not test_other' will eliminate the matches. "
         "Additionally keywords are matched to classes and functions "
         "containing extra names in their 'extra_keyword_matches' set, "
-        "as well as functions which have names assigned directly to them.",
+        "as well as functions which have names assigned directly to them. "
+        "The matching is case-insensitive.",
     )
 
     group._addoption(

src/_pytest/mark/legacy.py

@@ -57,7 +57,15 @@ def from_item(cls, item):
         return cls(mapped_names)
 
     def __getitem__(self, subname):
-        for name in self._names:
+        """Return whether subname is included within stored names.
+
+        The string inclusion check is case-insensitive.
+
+        """
+        subname = subname.lower()
+        names = (name.lower() for name in self._names)
+
+        for name in names:
             if subname in name:
                 return True
         return False

testing/test_collection.py

@@ -809,6 +809,43 @@ def test___repr__():
         reprec = testdir.inline_run("-k repr")
         reprec.assertoutcome(passed=1, failed=0)
 
+    def test_keyword_matching_is_case_insensitive_by_default(self, testdir):
+        """Check that selection via -k EXPRESSION is case-insensitive.
+
+        Since markers are also added to the node keywords, they too can
+        be matched without having to think about case sensitivity.
+
+        """
+        testdir.makepyfile(
+            """
+            import pytest
+
+            def test_sPeCiFiCToPiC_1():
+                assert True
+
+            class TestSpecificTopic_2:
+                def test(self):
+                    assert True
+
+            @pytest.mark.sPeCiFiCToPic_3
+            def test():
+                assert True
+
+            @pytest.mark.sPeCiFiCToPic_4
+            class Test:
+                def test(self):
+                    assert True
+
+            def test_failing_5():
+                assert False, "This should not match"
+
+        """
+        )
+        num_matching_tests = 4
+        for expression in ("specifictopic", "SPECIFICTOPIC", "SpecificTopic"):
+            reprec = testdir.inline_run("-k " + expression)
+            reprec.assertoutcome(passed=num_matching_tests, failed=0)
+
 
 COLLECTION_ERROR_PY_FILES = dict(
     test_01_failure="""