Merge pull request #6817 from blueyed/argparsing-_split_lines-upstream

changelog/6817.improvement.rst

@@ -0,0 +1,2 @@
+Explicit new-lines in help texts of command-line options are preserved, allowing plugins better control
+of the help displayed to users.

src/_pytest/assertion/__init__.py

@@ -27,11 +27,12 @@ def pytest_addoption(parser):
         choices=("rewrite", "plain"),
         default="rewrite",
         metavar="MODE",
-        help="""Control assertion debugging tools.  'plain'
-                            performs no assertion debugging.  'rewrite'
-                            (the default) rewrites assert statements in
-                            test modules on import to provide assert
-                            expression information.""",
+        help=(
+            "Control assertion debugging tools.\n"
+            "'plain' performs no assertion debugging.\n"
+            "'rewrite' (the default) rewrites assert statements in test modules"
+            " on import to provide assert expression information."
+        ),
     )
     parser.addini(
         "enable_assertion_pass_hook",

src/_pytest/cacheprovider.py

@@ -397,9 +397,9 @@ def pytest_addoption(parser):
         "--failed-first",
         action="store_true",
         dest="failedfirst",
-        help="run all tests but run the last failures first.  "
+        help="run all tests, but run the last failures first.\n"
         "This may re-order tests and thus lead to "
-        "repeated fixture setup/teardown",
+        "repeated fixture setup/teardown.",
     )
     group.addoption(
         "--nf",

src/_pytest/config/argparsing.py

@@ -509,3 +509,15 @@ class DropShorterLongHelpFormatter(argparse.HelpFormatter):
         formatted_action_invocation = ", ".join(return_list)
         action._formatted_action_invocation = formatted_action_invocation  # type: ignore
         return formatted_action_invocation
+
+    def _split_lines(self, text, width):
+        """Wrap lines after splitting on original newlines.
+
+        This allows to have explicit line breaks in the help text.
+        """
+        import textwrap
+
+        lines = []
+        for line in text.splitlines():
+            lines.extend(textwrap.wrap(line.strip(), width))
+        return lines

src/_pytest/helpconfig.py

@@ -57,7 +57,7 @@ def pytest_addoption(parser):
         dest="plugins",
         default=[],
         metavar="name",
-        help="early-load given plugin module name or entry point (multi-allowed). "
+        help="early-load given plugin module name or entry point (multi-allowed).\n"
         "To avoid loading of plugins, use the `no:` prefix, e.g. "
         "`no:doctest`.",
     )

src/_pytest/mark/__init__.py

@@ -79,8 +79,8 @@ def pytest_addoption(parser):
         dest="markexpr",
         default="",
         metavar="MARKEXPR",
-        help="only run tests matching given mark expression.  "
-        "example: -m 'mark1 and not mark2'.",
+        help="only run tests matching given mark expression.\n"
+        "For example: -m 'mark1 and not mark2'.",
     )
 
     group.addoption(

testing/test_helpconfig.py

@@ -19,7 +19,10 @@ def test_help(testdir):
     assert result.ret == 0
     result.stdout.fnmatch_lines(
         """
-        *-v*verbose*
+          -m MARKEXPR           only run tests matching given mark expression.
+                                For example: -m 'mark1 and not mark2'.
+        reporting:
+          --durations=N *
         *setup.cfg*
         *minversion*
         *to see*markers*pytest --markers*