plots/metrics: unify no metrics/plots messaging

dvc/command/plots.py

@@ -73,7 +73,7 @@ def run(self):
             )
 
         except DvcException:
-            logger.exception("")
+            logger.exception("failed to show plots")
             return 1
 
         return 0

dvc/exceptions.py

@@ -174,11 +174,20 @@ class NoMetricsError(DvcException):
     pass
 
 
-class NoPlotsError(DvcException):
-    def __init__(self):
+class NoMetricsParsedError(NoMetricsError):
+    def __init__(self, command):
+        super().__init__(
+            f"Could not parse {command} files. Use `-v` option to see more "
+            "details."
+        )
+
+
+class NoMetricsFoundError(NoMetricsError):
+    def __init__(self, command, run_options):
         super().__init__(
-            "no plots in this repository. Use `--plots/--plots-no-cache` "
-            "options for `dvc run` to mark stage outputs as plots."
+            f"No {command} files in this repository. "
+            f"Use `{run_options}` options for "
+            f"`dvc run` to mark stage outputs as {command}."
         )
 
 

dvc/repo/metrics/show.py

@@ -1,6 +1,6 @@
 import logging
 
-from dvc.exceptions import NoMetricsError
+from dvc.exceptions import NoMetricsFoundError, NoMetricsParsedError
 from dvc.repo import locked
 from dvc.repo.collect import collect
 from dvc.scm.base import SCMError
@@ -104,16 +104,9 @@ def show(
 
     if not res:
         if metrics_found:
-            msg = (
-                "Could not parse metrics files. Use `-v` option to see more "
-                "details."
-            )
+            raise NoMetricsParsedError("metrics")
         else:
-            msg = (
-                "no metrics files in this repository. Use `-m/-M` options for "
-                "`dvc run` to mark stage outputs as  metrics."
-            )
-        raise NoMetricsError(msg)
+            raise NoMetricsFoundError("metrics", "-m/-M")
 
     # Hide workspace metrics if they are the same as in the active branch
     try:

dvc/repo/plots/__init__.py

@@ -2,7 +2,11 @@
 
 from funcy import cached_property, first, project
 
-from dvc.exceptions import DvcException, NoPlotsError
+from dvc.exceptions import (
+    DvcException,
+    NoMetricsFoundError,
+    NoMetricsParsedError,
+)
 from dvc.repo.collect import collect
 from dvc.repo.plots.data import PlotParsingError
 from dvc.schema import PLOT_PROPS
@@ -65,7 +69,13 @@ def collect(self, targets=None, revs=None):
         return data
 
     @staticmethod
-    def render(plots, templates=None):
+    def render(data, revs=None, props=None, templates=None):
+        """Renders plots"""
+        props = props or {}
+
+        # Merge data by plot file and apply overriding props
+        plots = _prepare_plots(data, revs, props)
+
         result = {}
         for datafile, desc in plots.items():
             try:
@@ -81,7 +91,8 @@ def render(plots, templates=None):
                 )
 
         if not any(result.values()):
-            raise DvcException("Failed to parse any plot.")
+            raise NoMetricsParsedError("plots")
+
         return result
 
     def show(self, targets=None, revs=None, props=None, templates=None):
@@ -98,14 +109,11 @@ def show(self, targets=None, revs=None, props=None, templates=None):
 
         # No data at all is a special error with a special message
         if not data:
-            raise NoPlotsError()
+            raise NoMetricsFoundError("plots", "--plots/--plots-no-cache")
 
         if templates is None:
             templates = self.templates
-
-        plots = _prepare_plots(data, revs, props or {})
-
-        return self.render(plots, templates)
+        return self.render(data, revs, props, templates)
 
     def diff(self, *args, **kwargs):
         from .diff import diff

dvc/repo/plots/data.py

@@ -167,7 +167,8 @@ def _processors(self):
 
     def to_datapoints(self, **kwargs):
         with reraise(
-            ParseError, PlotParsingError(self.filename, self.revision)
+            [ParseError, csv.Error],
+            PlotParsingError(self.filename, self.revision),
         ):
             data = self.raw(**kwargs)
 
@@ -195,31 +196,26 @@ def __init__(self, filename, revision, content, delimiter=","):
         self.delimiter = delimiter
 
     def raw(self, header=True, **kwargs):  # pylint: disable=arguments-differ
-        with reraise(
-            csv.Error, ParseError(self.filename, f"revision: {self.revision}")
-        ):
-            first_row = first(csv.reader(io.StringIO(self.content)))
+        first_row = first(csv.reader(io.StringIO(self.content)))
 
-            if header:
-                reader = csv.DictReader(
-                    io.StringIO(self.content), delimiter=self.delimiter,
-                )
-            else:
-                reader = csv.DictReader(
-                    io.StringIO(self.content),
-                    delimiter=self.delimiter,
-                    fieldnames=[str(i) for i in range(len(first_row))],
-                )
+        if header:
+            reader = csv.DictReader(
+                io.StringIO(self.content), delimiter=self.delimiter,
+            )
+        else:
+            reader = csv.DictReader(
+                io.StringIO(self.content),
+                delimiter=self.delimiter,
+                fieldnames=[str(i) for i in range(len(first_row))],
+            )
 
-            fieldnames = reader.fieldnames
-            data = list(reader)
+        fieldnames = reader.fieldnames
+        data = list(reader)
 
-            return [
-                OrderedDict(
-                    [(field, data_point[field]) for field in fieldnames]
-                )
-                for data_point in data
-            ]
+        return [
+            OrderedDict([(field, data_point[field]) for field in fieldnames])
+            for data_point in data
+        ]
 
 
 class YAMLPlotData(PlotData):

tests/func/metrics/plots/test_show.py

@@ -398,13 +398,6 @@ def _replace(path, src, dst):
     path.write_text(path.read_text().replace(src, dst))
 
 
-def test_no_plots(tmp_dir, dvc):
-    from dvc.exceptions import NoPlotsError
-
-    with pytest.raises(NoPlotsError):
-        dvc.plots.show()
-
-
 def test_should_raise_on_no_template(tmp_dir, dvc, run_copy_metrics):
     metric = [{"val": 2}, {"val": 3}]
     _write_json(tmp_dir, metric, "metric_t.json")

tests/func/metrics/test_common.py

@@ -2,44 +2,57 @@
 
 import pytest
 
+from dvc.main import main
 from tests.func.metrics.utils import _write_json
 
 
-def metrics_diff(dvc, filename, revision):
-    dvc.metrics.diff(targets=[filename], a_rev=revision)
-
-
-def plots_diff(dvc, filename, revision):
-    dvc.plots.diff(targets=[filename], revs=[revision])
-
-
 @pytest.mark.parametrize(
-    "diff_fun, metric_value",
-    ((metrics_diff, {"m": 1}), (plots_diff, [{"m": 1}, {"m": 2}])),
+    "command, metric_value",
+    (("metrics", {"m": 1}), ("plots", [{"m": 1}, {"m": 2}])),
 )
 def test_diff_no_file_on_target_rev(
-    tmp_dir, scm, dvc, caplog, diff_fun, metric_value
+    tmp_dir, scm, dvc, caplog, command, metric_value
 ):
     with tmp_dir.branch("new_branch", new=True):
         _write_json(tmp_dir, metric_value, "metric.json")
 
         with caplog.at_level(logging.WARNING, "dvc"):
-            diff_fun(dvc, "metric.json", "master")
+            assert (
+                main([command, "diff", "master", "--targets", "metric.json"])
+                == 0
+            )
 
     assert "'metric.json' was not found at: 'master'." in caplog.text
 
 
 @pytest.mark.parametrize(
-    "fun, malformed_metric",
-    (
-        (lambda repo: repo.metrics, '{"m": 1'),
-        (lambda repo: repo.plots, '[{"m": 1}, {"m": 2}'),
-    ),
+    "command, malformed_metric",
+    (("metrics", '{"m": 1'), ("plots", '[{"m": 1}, {"m": 2}'),),
 )
-def test_show_malformed_metric(tmp_dir, scm, dvc, fun, malformed_metric):
+def test_show_malformed_metric(
+    tmp_dir, scm, dvc, caplog, command, malformed_metric
+):
     tmp_dir.gen("metric.json", malformed_metric)
-    _write_json(
-        tmp_dir, {"val": 1, "val2": [{"p": 1}, {"p": 2}]}, "metric_proper.json"
-    )
 
-    fun(dvc).show(targets=["metric.json", "metric_proper.json"])
+    with caplog.at_level(logging.ERROR, "dvc"):
+        assert main([command, "show", "metric.json"]) == 1
+
+    assert (
+        f"Could not parse {command} files. "
+        "Use `-v` option to see more details."
+    ) in caplog.text
+
+
+@pytest.mark.parametrize(
+    "command, run_options",
+    (("metrics", "-m/-M"), ("plots", "--plots/--plots-no-cache"),),
+)
+def test_show_no_metrics_files(tmp_dir, dvc, caplog, command, run_options):
+    with caplog.at_level(logging.ERROR, "dvc"):
+        assert main([command, "show"]) == 1
+
+    assert (
+        f"No {command} files in this repository. "
+        f"Use `{run_options}` options for "
+        f"`dvc run` to mark stage outputs as {command}."
+    ) in caplog.text