add tests

dvc/repo/metrics/show.py

@@ -34,7 +34,9 @@ def _collect_top_level_metrics(repo):
         wdir = repo.dvcfs.path.relpath(
             repo.dvcfs.path.parent(dvcfile), repo.root_dir
         )
-        yield from (repo.dvcfs.path.join(wdir, file) for file in metrics)
+        for file in metrics:
+            path = repo.dvcfs.path.join(wdir, file)
+            yield repo.dvcfs.path.normpath(path)
 
 
 def _collect_metrics(repo, targets, revision, recursive):

dvc/repo/params/show.py

@@ -41,7 +41,9 @@ def _collect_top_level_params(repo):
         wdir = repo.dvcfs.path.relpath(
             repo.dvcfs.path.parent(dvcfile), repo.root_dir
         )
-        yield from (repo.dvcfs.path.join(wdir, file) for file in params)
+        for file in params:
+            path = repo.dvcfs.path.join(wdir, file)
+            yield repo.dvcfs.path.normpath(path)
 
 
 def _collect_configs(

tests/func/metrics/test_diff.py

@@ -1,6 +1,10 @@
 import json
+from os.path import join
+
+import pytest
 
 from dvc.cli import main
+from dvc.utils import relpath
 
 
 def test_metrics_diff_simple(tmp_dir, scm, dvc, run_copy_metrics):
@@ -206,3 +210,28 @@ def test_metrics_diff_non_metrics(tmp_dir, scm, dvc):
     assert result == {
         "some_file.yaml": {"foo": {"old": 1, "new": 3, "diff": 2}}
     }
+
+
+@pytest.mark.parametrize(
+    "dvcfile, metrics_file",
+    [
+        ("dvc.yaml", "my_metrics.yaml"),
+        ("dir/dvc.yaml", "my_metrics.yaml"),
+        ("dir/dvc.yaml", join("..", "my_metrics.yaml")),
+    ],
+)
+def test_diff_top_level_metrics(tmp_dir, dvc, scm, dvcfile, metrics_file):
+    directory = (tmp_dir / dvcfile).parent
+    directory.mkdir(exist_ok=True)
+    (tmp_dir / dvcfile).dump({"metrics": [metrics_file]})
+
+    metrics_file = directory / metrics_file
+    metrics_file.dump({"foo": 3})
+    scm.add_commit([metrics_file, tmp_dir / dvcfile], message="add metrics")
+
+    metrics_file.dump({"foo": 5})
+    assert dvc.metrics.diff() == {
+        relpath(directory / metrics_file): {
+            "foo": {"diff": 2, "new": 5, "old": 3}
+        }
+    }

tests/func/params/test_diff.py

@@ -1,3 +1,5 @@
+from os.path import join
+
 import pytest
 
 from dvc.utils import relpath
@@ -241,3 +243,28 @@ def test_diff_without_targets_specified(tmp_dir, dvc, scm, file):
             "y": {"new": "100", "old": None},
         }
     }
+
+
+@pytest.mark.parametrize(
+    "dvcfile, params_file",
+    [
+        ("dvc.yaml", "my_params.yaml"),
+        ("dir/dvc.yaml", "my_params.yaml"),
+        ("dir/dvc.yaml", join("..", "my_params.yaml")),
+    ],
+)
+def test_diff_top_level_params(tmp_dir, dvc, scm, dvcfile, params_file):
+    directory = (tmp_dir / dvcfile).parent
+    directory.mkdir(exist_ok=True)
+    (tmp_dir / dvcfile).dump({"params": [params_file]})
+
+    params_file = directory / params_file
+    params_file.dump({"foo": 3})
+    scm.add_commit([params_file, tmp_dir / dvcfile], message="add params")
+
+    params_file.dump({"foo": 5})
+    assert dvc.params.diff() == {
+        relpath(directory / params_file): {
+            "foo": {"diff": 2, "new": 5, "old": 3}
+        }
+    }