mark: deprecate a couple undocumented -k syntaxes

The `-k '-expr'` syntax is an old alias to `-k 'not expr'`. It's also
not a very convenient to have syntax that start with `-` on the CLI.
Deprecate it and suggest replacing with `not`.

---

The `-k 'expr:'` syntax discards all items until the first match and
keeps all subsequent, e.g. `-k foo` with

    test_bar
    test_foo
    test_baz

results in `test_foo`, `test_baz`. That's a bit weird, so deprecate it
without a replacement. If someone complains we can reconsider or devise
a better alternative.

1 files changed, 24 insertions, 0 deletions

diff --git a/testing/deprecated_test.py b/testing/deprecated_test.py
index 5ad055bd2..edd5505c0 100644
--- a/testing/deprecated_test.py
+++ b/testing/deprecated_test.py
@@ -164,3 +164,27 @@ def test__fillfuncargs_is_deprecated() -> None:
         match="The `_fillfuncargs` function is deprecated",
     ):
         pytest._fillfuncargs(mock.Mock())
+
+
+def test_minus_k_dash_is_deprecated(testdir) -> None:
+    threepass = testdir.makepyfile(
+        test_threepass="""
+        def test_one(): assert 1
+        def test_two(): assert 1
+        def test_three(): assert 1
+    """
+    )
+    result = testdir.runpytest("-k=-test_two", threepass)
+    result.stdout.fnmatch_lines(["*The `-k '-expr'` syntax*deprecated*"])
+
+
+def test_minus_k_colon_is_deprecated(testdir) -> None:
+    threepass = testdir.makepyfile(
+        test_threepass="""
+        def test_one(): assert 1
+        def test_two(): assert 1
+        def test_three(): assert 1
+    """
+    )
+    result = testdir.runpytest("-k", "test_two:", threepass)
+    result.stdout.fnmatch_lines(["*The `-k 'expr:'` syntax*deprecated*"])