From 0e2522cedc8ca1765bd243d8cca9c2df6daba04b Mon Sep 17 00:00:00 2001
From: Jordan Speicher <jordan@jspeicher.com>
Date: Fri, 9 Feb 2018 17:44:03 -0600
Subject: [PATCH] Add --deselect command line option

Fixes #3198
---
 AUTHORS                             |  1 +
 _pytest/main.py                     | 20 ++++++++++++++++++++
 changelog/3198.feature.rst          |  1 +
 doc/en/example/pythoncollection.rst |  8 ++++++++
 testing/test_session.py             | 14 ++++++++++++++
 5 files changed, 44 insertions(+)
 create mode 100644 changelog/3198.feature.rst

diff --git a/AUTHORS b/AUTHORS
index 3f43c7479d7..a4ce2e8e6d3 100644
--- a/AUTHORS
+++ b/AUTHORS
@@ -97,6 +97,7 @@ Jon Sonesen
 Jonas Obrist
 Jordan Guymon
 Jordan Moldow
+Jordan Speicher
 Joshua Bronson
 Jurko Gospodnetić
 Justyna Janczyszyn
diff --git a/_pytest/main.py b/_pytest/main.py
index f3dbd43448e..97c6e276ca6 100644
--- a/_pytest/main.py
+++ b/_pytest/main.py
@@ -66,6 +66,8 @@ def pytest_addoption(parser):
                     help="try to interpret all arguments as python packages.")
     group.addoption("--ignore", action="append", metavar="path",
                     help="ignore path during collection (multi-allowed).")
+    group.addoption("--deselect", action="append", metavar="nodeid_prefix",
+                    help="deselect item during collection (multi-allowed).")
     # when changing this to --conf-cut-dir, config.py Conftest.setinitial
     # needs upgrading as well
     group.addoption('--confcutdir', dest="confcutdir", default=None,
@@ -208,6 +210,24 @@ def pytest_ignore_collect(path, config):
     return False
 
 
+def pytest_collection_modifyitems(items, config):
+    deselect_prefixes = tuple(config.getoption("deselect") or [])
+    if not deselect_prefixes:
+        return
+
+    remaining = []
+    deselected = []
+    for colitem in items:
+        if colitem.nodeid.startswith(deselect_prefixes):
+            deselected.append(colitem)
+        else:
+            remaining.append(colitem)
+
+    if deselected:
+        config.hook.pytest_deselected(items=deselected)
+        items[:] = remaining
+
+
 @contextlib.contextmanager
 def _patched_find_module():
     """Patch bug in pkgutil.ImpImporter.find_module
diff --git a/changelog/3198.feature.rst b/changelog/3198.feature.rst
new file mode 100644
index 00000000000..3c7838302c6
--- /dev/null
+++ b/changelog/3198.feature.rst
@@ -0,0 +1 @@
+Add command line option ``--deselect`` to allow deselection of individual tests at collection time.
diff --git a/doc/en/example/pythoncollection.rst b/doc/en/example/pythoncollection.rst
index c9d31d7c420..fc8dbf1b515 100644
--- a/doc/en/example/pythoncollection.rst
+++ b/doc/en/example/pythoncollection.rst
@@ -39,6 +39,14 @@ you will see that ``pytest`` only collects test-modules, which do not match the
 
     ======= 5 passed in 0.02 seconds =======
 
+Deselect tests during test collection
+-------------------------------------
+
+Tests can individually be deselected during collection by passing the ``--deselect=item`` option.
+For example, say ``tests/foobar/test_foobar_01.py`` contains ``test_a`` and ``test_b``.
+You can run all of the tests within ``tests/`` *except* for ``tests/foobar/test_foobar_01.py::test_a``
+by invoking ``pytest`` with ``--deselect tests/foobar/test_foobar_01.py::test_a``.
+``pytest`` allows multiple ``--deselect`` options.
 
 Keeping duplicate paths specified from command line
 ----------------------------------------------------
diff --git a/testing/test_session.py b/testing/test_session.py
index 68534b102d9..32d8ce689b9 100644
--- a/testing/test_session.py
+++ b/testing/test_session.py
@@ -240,6 +240,20 @@ def test_exclude(testdir):
     result.stdout.fnmatch_lines(["*1 passed*"])
 
 
+def test_deselect(testdir):
+    testdir.makepyfile(test_a="""
+        import pytest
+        def test_a1(): pass
+        @pytest.mark.parametrize('b', range(3))
+        def test_a2(b): pass
+    """)
+    result = testdir.runpytest("-v", "--deselect=test_a.py::test_a2[1]", "--deselect=test_a.py::test_a2[2]")
+    assert result.ret == 0
+    result.stdout.fnmatch_lines(["*2 passed, 2 deselected*"])
+    for line in result.stdout.lines:
+        assert not line.startswith(('test_a.py::test_a2[1]', 'test_a.py::test_a2[2]'))
+
+
 def test_sessionfinish_with_start(testdir):
     testdir.makeconftest("""
         import os