diff --git a/dvc/api.py b/dvc/api.py
index bf976dcf01..8da4cf6ba6 100644
--- a/dvc/api.py
+++ b/dvc/api.py
@@ -15,7 +15,7 @@ def get_url(path, repo=None, rev=None, remote=None):
     """Returns an url of a resource specified by path in repo"""
     with _make_repo(repo, rev=rev) as _repo:
         abspath = os.path.join(_repo.root_dir, path)
-        out, = _repo.find_outs_by_path(abspath)
+        (out,) = _repo.find_outs_by_path(abspath)
         remote_obj = _repo.cloud.get_remote(remote)
         return str(remote_obj.checksum_to_path_info(out.checksum))
 
diff --git a/dvc/repo/__init__.py b/dvc/repo/__init__.py
index 8a0afc2d3c..94f792880a 100644
--- a/dvc/repo/__init__.py
+++ b/dvc/repo/__init__.py
@@ -263,7 +263,7 @@ def used_cache(
 
             for stage in stages:
                 if stage.is_repo_import:
-                    dep, = stage.deps
+                    (dep,) = stage.deps
                     cache.external[dep.repo_pair].add(dep.def_path)
                     continue
 
@@ -445,7 +445,7 @@ def func(out):
 
     def find_out_by_relpath(self, relpath):
         path = os.path.join(self.root_dir, relpath)
-        out, = self.find_outs_by_path(path)
+        (out,) = self.find_outs_by_path(path)
         return out
 
     def is_dvc_internal(self, path):
@@ -457,7 +457,7 @@ def open(self, path, remote=None, mode="r", encoding=None):
         """Opens a specified resource as a file descriptor"""
         cause = None
         try:
-            out, = self.find_outs_by_path(path)
+            (out,) = self.find_outs_by_path(path)
         except OutputNotFoundError as e:
             out = None
             cause = e
diff --git a/dvc/repo/get_url.py b/dvc/repo/get_url.py
index fbc173b640..5718b20ecd 100644
--- a/dvc/repo/get_url.py
+++ b/dvc/repo/get_url.py
@@ -14,6 +14,6 @@ def get_url(url, out=None):
 
     out = os.path.abspath(out)
 
-    dep, = dependency.loads_from(None, [url])
-    out, = output.loads_from(None, [out], use_cache=False)
+    (dep,) = dependency.loads_from(None, [url])
+    (out,) = output.loads_from(None, [out], use_cache=False)
     dep.download(out)
diff --git a/setup.py b/setup.py
index 29a4a09363..81dadf1cba 100644
--- a/setup.py
+++ b/setup.py
@@ -141,7 +141,7 @@ def run(self):
 ]
 
 if (sys.version_info) >= (3, 6):
-    tests_requirements.append("black==19.3b0")
+    tests_requirements.append("black==19.10b0")
 
 setup(
     name="dvc",
diff --git a/tests/func/test_add.py b/tests/func/test_add.py
index 8a76263da2..bbb4fc4bf0 100644
--- a/tests/func/test_add.py
+++ b/tests/func/test_add.py
@@ -32,7 +32,7 @@
 
 
 def test_add(tmp_dir, dvc):
-    stage, = tmp_dir.dvc_gen({"foo": "foo"})
+    (stage,) = tmp_dir.dvc_gen({"foo": "foo"})
     md5, _ = file_md5("foo")
 
     assert stage is not None
@@ -50,7 +50,7 @@ def test_add_unicode(tmp_dir, dvc):
     with open("\xe1", "wb") as fd:
         fd.write("something".encode("utf-8"))
 
-    stage, = dvc.add("\xe1")
+    (stage,) = dvc.add("\xe1")
 
     assert os.path.isfile(stage.path)
 
@@ -61,7 +61,7 @@ def test_add_unsupported_file(dvc):
 
 
 def test_add_directory(tmp_dir, dvc):
-    stage, = tmp_dir.dvc_gen({"dir": {"file": "file"}})
+    (stage,) = tmp_dir.dvc_gen({"dir": {"file": "file"}})
 
     assert stage is not None
     assert len(stage.deps) == 0
@@ -162,7 +162,7 @@ def test_add_file_in_dir(tmp_dir, dvc):
     tmp_dir.gen({"dir": {"subdir": {"subdata": "subdata content"}}})
     subdir_path = os.path.join("dir", "subdir", "subdata")
 
-    stage, = dvc.add(subdir_path)
+    (stage,) = dvc.add(subdir_path)
 
     assert stage is not None
     assert len(stage.deps) == 0
diff --git a/tests/func/test_api.py b/tests/func/test_api.py
index 54623c080d..b6ddc9dd5a 100644
--- a/tests/func/test_api.py
+++ b/tests/func/test_api.py
@@ -101,7 +101,7 @@ def _set_remote_url_and_commit(repo, remote_url):
 
 # FIXME: this test doesn't use scm ;D
 def test_open_scm_controlled(dvc_repo, repo_dir):
-    stage, = dvc_repo.add(repo_dir.FOO)
+    (stage,) = dvc_repo.add(repo_dir.FOO)
 
     stage_content = open(stage.path, "r").read()
     with api.open(stage.path) as fd:
diff --git a/tests/func/test_commit.py b/tests/func/test_commit.py
index 8d6a8e57d6..85c3623b59 100644
--- a/tests/func/test_commit.py
+++ b/tests/func/test_commit.py
@@ -20,7 +20,7 @@ def test_commit_recursive(tmp_dir, dvc):
 
 def test_commit_force(tmp_dir, dvc):
     tmp_dir.gen({"dir": {"file": "text1", "file2": "text2"}})
-    stage, = dvc.add("dir", no_commit=True)
+    (stage,) = dvc.add("dir", no_commit=True)
 
     with dvc.state:
         assert stage.outs[0].changed_cache()
@@ -42,7 +42,7 @@ def test_commit_force(tmp_dir, dvc):
 
 def test_commit_with_deps(tmp_dir, dvc, run_copy):
     tmp_dir.gen("foo", "foo")
-    foo_stage, = dvc.add("foo", no_commit=True)
+    (foo_stage,) = dvc.add("foo", no_commit=True)
     assert foo_stage is not None
     assert len(foo_stage.outs) == 1
 
@@ -62,7 +62,7 @@ def test_commit_with_deps(tmp_dir, dvc, run_copy):
 
 def test_commit_changed_md5(tmp_dir, dvc):
     tmp_dir.gen({"file": "file content"})
-    stage, = dvc.add("file", no_commit=True)
+    (stage,) = dvc.add("file", no_commit=True)
 
     stage_file_content = load_stage_file(stage.path)
     stage_file_content["md5"] = "1111111111"
diff --git a/tests/func/test_destroy.py b/tests/func/test_destroy.py
deleted file mode 100644
index 3535c9d7ac..0000000000
--- a/tests/func/test_destroy.py
+++ /dev/null
@@ -1,28 +0,0 @@
-import os
-
-from dvc.system import System
-
-
-def test_destroy(repo_dir, dvc_repo):
-    # NOTE: using symlink to ensure that data was unprotected after `destroy`
-    dvc_repo.config.set("cache", "type", "symlink")
-
-    foo_stage, = dvc_repo.add(repo_dir.FOO)
-    data_dir_stage, = dvc_repo.add(repo_dir.DATA_DIR)
-
-    dvc_repo.destroy()
-
-    assert not os.path.exists(dvc_repo.dvc_dir)
-    assert not os.path.exists(foo_stage.path)
-    assert not os.path.exists(data_dir_stage.path)
-
-    assert os.path.isfile(repo_dir.FOO)
-    assert os.path.isdir(repo_dir.DATA_DIR)
-    assert os.path.isfile(repo_dir.DATA)
-    assert os.path.isdir(repo_dir.DATA_SUB_DIR)
-    assert os.path.isfile(repo_dir.DATA_SUB)
-
-    assert not System.is_symlink(repo_dir.FOO)
-    assert not System.is_symlink(repo_dir.DATA_DIR)
-    assert not System.is_symlink(repo_dir.DATA)
-    assert not System.is_symlink(repo_dir.DATA_SUB)
diff --git a/tests/func/test_gc.py b/tests/func/test_gc.py
index 7d06cb9a38..2fb46eb0ca 100644
--- a/tests/func/test_gc.py
+++ b/tests/func/test_gc.py
@@ -192,7 +192,7 @@ def test_all_commits(tmp_dir, scm, dvc):
 
 def test_gc_no_dir_cache(tmp_dir, dvc, repo_template):
     dvc.add(["foo", "bar"])
-    dir_stage, = dvc.add("dir")
+    (dir_stage,) = dvc.add("dir")
 
     os.unlink(dir_stage.outs[0].cache_path)
 
diff --git a/tests/func/test_repo.py b/tests/func/test_repo.py
index 2bf2340b0c..2bd799668f 100644
--- a/tests/func/test_repo.py
+++ b/tests/func/test_repo.py
@@ -1,71 +1,53 @@
-from dvc.ignore import DvcIgnore
-from dvc.main import main
 from dvc.repo import Repo
 from dvc.scm.git import GitTree
-from dvc.scm.tree import WorkingTree
-from dvc.stage import Stage
-from tests.basic_env import TestDvcGit
+from dvc.system import System
+from dvc.utils.compat import fspath
 
 
-class TestCollect(TestDvcGit):
-    def setUp(self):
-        super(TestCollect, self).setUp()
-        self.dvc.add(self.FOO)
-        self.dvc.run(
-            deps=[self.FOO],
-            outs=[self.BAR],
-            cmd="python code.py {} {}".format(self.FOO, self.BAR),
-        )
-        self.dvc.scm.add([".gitignore", self.FOO + ".dvc", self.BAR + ".dvc"])
-        self.dvc.scm.commit("foo.dvc and bar.dvc")
-        self.dvc.scm.checkout("new_branch", True)
-        self.dvc.run(
-            deps=[self.BAR],
-            outs=["buzz"],
-            cmd="python code.py {} {}".format(self.BAR, "buzz"),
-        )
-        self.dvc.scm.add([".gitignore", "buzz.dvc"])
-        self.dvc.scm.commit("add buzz")
-        self.dvc.scm.checkout("master")
+def test_destroy(tmp_dir, dvc):
+    dvc.config.set("cache", "type", "symlink")
 
-    def _check(self, branch, target, with_deps, expected):
-        if branch:
-            self.dvc.tree = GitTree(self.dvc.scm.repo, branch)
-        else:
-            self.dvc.tree = WorkingTree()
-        result = self.dvc.collect(target + ".dvc", with_deps=with_deps)
-        self.assertEqual([[str(j) for j in i.outs] for i in result], expected)
-        return result
+    tmp_dir.dvc_gen("file", "text")
+    tmp_dir.dvc_gen({"dir": {"file": "lorem", "subdir/file": "ipsum"}})
 
-    def test(self):
-        self._check("", self.BAR, True, [[self.FOO], [self.BAR]])
-        self._check("master", self.BAR, True, [[self.FOO], [self.BAR]])
-        self._check(
-            "new_branch", "buzz", True, [[self.FOO], [self.BAR], ["buzz"]]
-        )
-        result = self._check("new_branch", "buzz", False, [["buzz"]])
-        self.assertEqual([str(i) for i in result[0].deps], ["bar"])
+    dvc.destroy()
+
+    # Remove all the files related to DVC
+    for path in [".dvc", "file.dvc", "dir.dvc"]:
+        assert not (tmp_dir / path).exists()
 
+    # Leave the rest of the files
+    for path in ["file", "dir/file", "dir/subdir/file"]:
+        assert (tmp_dir / path).is_file()
+
+    # Make sure that data was unprotected after `destroy`
+    for path in ["file", "dir", "dir/file", "dir/subdir", "dir/subdir/file"]:
+        assert not System.is_symlink(fspath(tmp_dir / path))
+
+
+def test_collect(tmp_dir, scm, dvc, run_copy):
+    def collect_outs(*args, **kwargs):
+        return set(
+            str(out.path_info)
+            for stage in dvc.collect(*args, **kwargs)
+            for out in stage.outs
+        )
 
-class TestIgnore(TestDvcGit):
-    def _stage_name(self, file):
-        return file + Stage.STAGE_FILE_SUFFIX
+    tmp_dir.dvc_gen("foo", "foo")
+    run_copy("foo", "bar")
+    assert collect_outs("bar.dvc", with_deps=True) == {"foo", "bar"}
 
-    def test_should_not_gather_stage_files_from_ignored_dir(self):
-        ret = main(["add", self.FOO, self.BAR, self.DATA, self.DATA_SUB])
-        self.assertEqual(0, ret)
+    run_copy("bar", "buzz")
+    assert collect_outs("buzz.dvc", with_deps=True) == {"foo", "bar", "buzz"}
+    assert collect_outs("buzz.dvc", with_deps=False) == {"buzz"}
 
-        stages = self.dvc.stages
-        self.assertEqual(4, len(stages))
 
-        self.create(DvcIgnore.DVCIGNORE_FILE, self.DATA_DIR)
+def test_stages(tmp_dir, dvc):
+    def stages():
+        return set(stage.relpath for stage in Repo(str(tmp_dir)).stages)
 
-        self.dvc = Repo(self.dvc.root_dir)
-        stages = self.dvc.stages
-        self.assertEqual(2, len(stages))
+    tmp_dir.dvc_gen({"file": "a", "dir/file": "b", "dir/subdir/file": "c"})
+    assert stages() == {"file.dvc", "dir/file.dvc", "dir/subdir/file.dvc"}
 
-        stagenames = [s.relpath for s in stages]
-        self.assertIn(self._stage_name(self.FOO), stagenames)
-        self.assertIn(self._stage_name(self.BAR), stagenames)
-        self.assertNotIn(self._stage_name(self.DATA), stagenames)
-        self.assertNotIn(self._stage_name(self.DATA_SUB), stagenames)
+    tmp_dir.gen(".dvcignore", "dir")
+    assert stages() == {"file.dvc"}
diff --git a/tests/func/test_stage.py b/tests/func/test_stage.py
index b87a32d76f..d4e9e8b979 100644
--- a/tests/func/test_stage.py
+++ b/tests/func/test_stage.py
@@ -155,7 +155,7 @@ def test_remote_dependency(self):
 
 
 def test_md5_ignores_comments(repo_dir, dvc_repo):
-    stage, = dvc_repo.add("foo")
+    (stage,) = dvc_repo.add("foo")
 
     with open(stage.path, "a") as f:
         f.write("# End comment\n")
@@ -165,7 +165,7 @@ def test_md5_ignores_comments(repo_dir, dvc_repo):
 
 
 def test_meta_is_preserved(dvc_repo):
-    stage, = dvc_repo.add("foo")
+    (stage,) = dvc_repo.add("foo")
 
     # Add meta to DVC-file
     data = load_stage_file(stage.path)
diff --git a/tests/unit/test_repo.py b/tests/unit/test_repo.py
index ad7426154a..f21c5a0f0d 100644
--- a/tests/unit/test_repo.py
+++ b/tests/unit/test_repo.py
@@ -1,13 +1,6 @@
-import os
+from dvc.utils.compat import fspath
 
-from tests.basic_env import TestDvc
 
-
-class TestIsDvcInternal(TestDvc):
-    def test_return_false_on_non_dvc_file(self):
-        path = os.path.join("path", "to-non-.dvc", "file")
-        self.assertFalse(self.dvc.is_dvc_internal(path))
-
-    def test_return_true_on_dvc_internal_file(self):
-        path = os.path.join("path", "to", ".dvc", "file")
-        self.assertTrue(path)
+def test_is_dvc_internal(tmp_dir, dvc):
+    assert dvc.is_dvc_internal(fspath(tmp_dir / ".dvc" / "file"))
+    assert not dvc.is_dvc_internal("file")