From 4946cc82825c277754979cf6ea995482e5b1e2d5 Mon Sep 17 00:00:00 2001
From: NNRepos <45516943+NNRepos@users.noreply.github.com>
Date: Fri, 1 Nov 2019 22:01:37 +0200
Subject: [PATCH] Add --co option to collect-only

Fix #5845
---
 changelog/6116.improvement.rst | 1 +
 src/_pytest/main.py            | 1 +
 testing/test_collection.py     | 4 ++--
 3 files changed, 4 insertions(+), 2 deletions(-)
 create mode 100644 changelog/6116.improvement.rst

diff --git a/changelog/6116.improvement.rst b/changelog/6116.improvement.rst
new file mode 100644
index 000000000..4fc96ec77
--- /dev/null
+++ b/changelog/6116.improvement.rst
@@ -0,0 +1 @@
+Add ``--co`` as a synonym to ``--collect-only``.
diff --git a/src/_pytest/main.py b/src/_pytest/main.py
index 843c5b5f7..b4261c188 100644
--- a/src/_pytest/main.py
+++ b/src/_pytest/main.py
@@ -109,6 +109,7 @@ def pytest_addoption(parser):
     group.addoption(
         "--collectonly",
         "--collect-only",
+        "--co",
         action="store_true",
         help="only collect tests, don't execute them.",
     ),
diff --git a/testing/test_collection.py b/testing/test_collection.py
index 259868357..83345d2c6 100644
--- a/testing/test_collection.py
+++ b/testing/test_collection.py
@@ -402,7 +402,7 @@ class TestCustomConftests:
         )
         testdir.mkdir("sub")
         testdir.makepyfile("def test_x(): pass")
-        result = testdir.runpytest("--collect-only")
+        result = testdir.runpytest("--co")
         result.stdout.fnmatch_lines(["*MyModule*", "*test_x*"])
 
     def test_pytest_collect_file_from_sister_dir(self, testdir):
@@ -433,7 +433,7 @@ class TestCustomConftests:
         p = testdir.makepyfile("def test_x(): pass")
         p.copy(sub1.join(p.basename))
         p.copy(sub2.join(p.basename))
-        result = testdir.runpytest("--collect-only")
+        result = testdir.runpytest("--co")
         result.stdout.fnmatch_lines(["*MyModule1*", "*MyModule2*", "*test_x*"])