https://github.com/shopkeep/pytest-black/issues/66

--- pytest-black-0.3.12/tests/test_black.py.orig
+++ pytest-black-0.3.12/tests/test_black.py
@@ -20,7 +20,7 @@
             print('Hello, world')
     """
     )
-    result = testdir.runpytest("--black")
+    result = testdir.runpytest("--black", "-p", "no:cov", "-p", "no:mypy")
     result.assert_outcomes(failed=1)
 
 
@@ -36,7 +36,7 @@
     # replace trailing newline (stripped by testdir.makepyfile)
     p = p.write(p.read() + "\n")
 
-    result = testdir.runpytest("--black")
+    result = testdir.runpytest("--black", "-p", "no:cov", "-p", "no:mypy")
     result.assert_outcomes(passed=1)
 
 
@@ -54,17 +54,17 @@
     p.write(contents)
 
     # Test once to populate the cache
-    result = testdir.runpytest("--black")
+    result = testdir.runpytest("--black", "-p", "no:cov", "-p", "no:mypy")
     result.assert_outcomes(passed=1)
 
     # Run it again, it should be skipped
-    result = testdir.runpytest("--black", "-rs")
+    result = testdir.runpytest("--black", "-rs", "-p", "no:cov", "-p", "no:mypy")
     result.assert_outcomes(skipped=1)
     result.stdout.fnmatch_lines(["SKIP*previously passed black format checks"])
 
     # Update the file and test again.
     p.write(contents)
-    result = testdir.runpytest("--black")
+    result = testdir.runpytest("--black", "-p", "no:cov", "-p", "no:mypy")
     result.assert_outcomes(passed=1)
 
 
@@ -92,7 +92,7 @@
     # Rename pyproject.toml ¯\_(ツ)_/¯
     testdir.run("mv", "test_exclude.pyproject.toml", "pyproject.toml")
 
-    result = testdir.runpytest("--black")
+    result = testdir.runpytest("--black", "-p", "no:checkdocs", "-p", "no:cov", "-p", "no:mypy")
     result.assert_outcomes(skipped=1, passed=0)
 
 
@@ -129,7 +129,7 @@
     # Rename pyproject.toml ¯\_(ツ)_/¯
     testdir.run("mv", "test_exclude_folder.pyproject.toml", "pyproject.toml")
 
-    result = testdir.runpytest("--black")
+    result = testdir.runpytest("--black", "-p", "no:checkdocs", "-p", "no:cov", "-p", "no:mypy")
     result.assert_outcomes(skipped=1, passed=0)
 
 
@@ -156,7 +156,7 @@
     # Rename pyproject.toml ¯\_(ツ)_/¯
     testdir.run("mv", "test_include.pyproject.toml", "pyproject.toml")
 
-    result = testdir.runpytest("--black")
+    result = testdir.runpytest("--black", "-p", "no:checkdocs", "-p", "no:cov", "-p", "no:mypy")
     result.assert_outcomes(skipped=0, passed=1)
 
 
@@ -171,7 +171,7 @@
     # replace trailing newline (stripped by testdir.makepyfile)
     p = p.write(p.read() + "\n")
 
-    result = testdir.runpytest("--black")
+    result = testdir.runpytest("--black", "-p", "no:cov", "-p", "no:mypy")
     result.assert_outcomes(passed=1)
 
     out = "\n".join(result.stdout.lines)