metrics: don't show working tree if it is clean

dvc/repo/metrics/show.py

@@ -298,6 +298,15 @@ def show(
     if not res and not any(targets):
         raise NoMetricsError()
 
+    # Hide working tree metrics if they are the same as in the active branch
+    try:
+        active_branch = repo.scm.active_branch()
+    except TypeError:
+        pass  # Detached head
+    else:
+        if res.get("working tree") == res.get(active_branch):
+            res.pop("working tree", None)
+
     missing = set(targets) - found
 
     if missing:

tests/func/test_metrics.py

@@ -83,6 +83,25 @@ def setUp(self):
         self.dvc.scm.checkout("master")
 
 
+def test_show_dirty(tmp_dir, scm, dvc):
+    tmp_dir.gen("metric", "master")
+    dvc.run(metrics_no_cache=["metric"], overwrite=True)
+    tmp_dir.scm_add(["metric", "metric.dvc"], commit="add metric")
+
+    tmp_dir.gen("metric", "dirty")
+
+    assert dvc.metrics.show(["metric"]) == {"": {"metric": "dirty"}}
+
+    assert dvc.metrics.show(["metric"], all_branches=True) == {
+        "working tree": {"metric": "dirty"},
+        "master": {"metric": "master"},
+    }
+
+    assert dvc.metrics.show(["metric"], all_tags=True) == {
+        "working tree": {"metric": "dirty"}
+    }
+
+
 class TestMetrics(TestMetricsBase):
     def test_show(self):
         ret = self.dvc.metrics.show(["metric"], all_branches=True)
@@ -708,7 +727,6 @@ def _test_metrics(self, func):
                 "master": {"metrics.json": ["master"]},
                 "one": {"metrics.json": ["one"]},
                 "two": {"metrics.json": ["two"]},
-                "working tree": {"metrics.json": ["two"]},
             },
         )
 
@@ -722,7 +740,6 @@ def _test_metrics(self, func):
                 "master": {"metrics.json": ["master"]},
                 "one": {"metrics.json": ["one"]},
                 "two": {"metrics.json": ["two"]},
-                "working tree": {"metrics.json": ["two"]},
             },
         )