params: introduce --targets (#5122)

* params: add targets option

* fixup

* remove unnecessary changes

* fix isort

* params: diff: add test for --targets

* tests: roll back metric/plots unification, introduce collect test

* metrics/plots: refactoring

* missing plots test added

Author: pared

dvc/command/params.py

@@ -2,6 +2,7 @@
 import logging
 from collections import OrderedDict
 
+from dvc.command import completion
 from dvc.command.base import CmdBase, append_doc_link, fix_subparsers
 from dvc.exceptions import DvcException
 
@@ -30,11 +31,14 @@ def _show_diff(diff, markdown=False, no_path=False):
 
 
 class CmdParamsDiff(CmdBase):
+    UNINITIALIZED = True
+
     def run(self):
         try:
             diff = self.repo.params.diff(
                 a_rev=self.args.a_rev,
                 b_rev=self.args.b_rev,
+                targets=self.args.targets,
                 all=self.args.all,
             )
 
@@ -91,6 +95,12 @@ def add_parser(subparsers, parent_parser):
         nargs="?",
         help=("New Git commit to compare (defaults to the current workspace)"),
     )
+    params_diff_parser.add_argument(
+        "--targets",
+        nargs="*",
+        help="Limit command scope to these params files.",
+        metavar="<path>",
+    ).complete = completion.FILE
     params_diff_parser.add_argument(
         "--all",
         action="store_true",

dvc/exceptions.py

@@ -1,4 +1,6 @@
 """Exceptions raised by the dvc."""
+from typing import List
+
 from funcy import first
 
 from dvc.utils import error_link, format_link, relpath
@@ -170,19 +172,19 @@ def __init__(self, paths):
         )
 
 
-class NoMetricsError(DvcException):
+class MetricsError(DvcException):
     pass
 
 
-class NoMetricsParsedError(NoMetricsError):
+class NoMetricsParsedError(MetricsError):
     def __init__(self, command):
         super().__init__(
             f"Could not parse {command} files. Use `-v` option to see more "
             "details."
         )
 
 
-class NoMetricsFoundError(NoMetricsError):
+class NoMetricsFoundError(MetricsError):
     def __init__(self, command, run_options):
         super().__init__(
             f"No {command} files in this repository. "
@@ -191,6 +193,15 @@ def __init__(self, command, run_options):
         )
 
 
+class MetricDoesNotExistError(MetricsError):
+    def __init__(self, targets: List[str]):
+        if len(targets) == 1:
+            msg = "File: '{}' does not exist."
+        else:
+            msg = "Files: '{}' do not exist."
+        super().__init__(msg.format(", ".join(targets)))
+
+
 class RecursiveAddingWhileUsingFilename(DvcException):
     def __init__(self):
         super().__init__(

dvc/repo/metrics/diff.py

@@ -1,4 +1,4 @@
-from dvc.exceptions import NoMetricsError
+from dvc.exceptions import MetricsError
 from dvc.utils.diff import diff as _diff
 from dvc.utils.diff import format_dict
 
@@ -7,7 +7,7 @@ def _get_metrics(repo, *args, revs=None, **kwargs):
     try:
         metrics = repo.metrics.show(*args, **kwargs, revs=revs)
         return metrics
-    except NoMetricsError:
+    except MetricsError:
         return {}
 
 

dvc/repo/metrics/show.py

@@ -1,6 +1,10 @@
 import logging
 
-from dvc.exceptions import NoMetricsFoundError, NoMetricsParsedError
+from dvc.exceptions import (
+    MetricDoesNotExistError,
+    NoMetricsFoundError,
+    NoMetricsParsedError,
+)
 from dvc.repo import locked
 from dvc.repo.collect import collect
 from dvc.scm.base import SCMError
@@ -105,6 +109,8 @@ def show(
     if not res:
         if metrics_found:
             raise NoMetricsParsedError("metrics")
+        elif targets:
+            raise MetricDoesNotExistError(targets)
         else:
             raise NoMetricsFoundError("metrics", "-m/-M")
 

dvc/repo/params/show.py

@@ -7,6 +7,7 @@
 from dvc.path_info import PathInfo
 from dvc.repo import locked
 from dvc.repo.collect import collect
+from dvc.scm.base import SCMError
 from dvc.stage import PipelineStage
 from dvc.utils.serialize import LOADERS, ParseError
 
@@ -25,11 +26,20 @@ def _is_params(dep: "BaseOutput"):
     return isinstance(dep, ParamsDependency)
 
 
-def _collect_configs(repo: "Repo", rev) -> List[PathInfo]:
-    params, _ = collect(repo, deps=True, output_filter=_is_params, rev=rev)
-    configs = {p.path_info for p in params}
-    configs.add(PathInfo(repo.root_dir) / ParamsDependency.DEFAULT_PARAMS_FILE)
-    return list(configs)
+def _collect_configs(repo: "Repo", rev, targets=None) -> List[PathInfo]:
+    params, path_infos = collect(
+        repo,
+        targets=targets or [],
+        deps=True,
+        output_filter=_is_params,
+        rev=rev,
+    )
+    path_infos.update({p.path_info for p in params})
+    if not targets:
+        path_infos.add(
+            PathInfo(repo.root_dir) / ParamsDependency.DEFAULT_PARAMS_FILE
+        )
+    return list(path_infos)
 
 
 def _read_params(repo, configs, rev):
@@ -66,11 +76,11 @@ def _collect_vars(repo, params):
 
 
 @locked
-def show(repo, revs=None):
+def show(repo, revs=None, targets=None):
     res = {}
 
     for branch in repo.brancher(revs=revs):
-        configs = _collect_configs(repo, branch)
+        configs = _collect_configs(repo, branch, targets)
         params = _read_params(repo, configs, branch)
         vars_params = _collect_vars(repo, params)
 
@@ -87,8 +97,10 @@ def show(repo, revs=None):
     # Hide workspace params if they are the same as in the active branch
     try:
         active_branch = repo.scm.active_branch()
-    except TypeError:
-        pass  # Detached head
+    except (TypeError, SCMError):
+        # TypeError - detached head
+        # SCMError - no repo case
+        pass
     else:
         if res.get("workspace") == res.get(active_branch):
             res.pop("workspace", None)

dvc/repo/plots/__init__.py

@@ -4,6 +4,7 @@
 
 from dvc.exceptions import (
     DvcException,
+    MetricDoesNotExistError,
     NoMetricsFoundError,
     NoMetricsParsedError,
 )
@@ -96,7 +97,6 @@ def render(data, revs=None, props=None, templates=None):
         return result
 
     def show(self, targets=None, revs=None, props=None, templates=None):
-        from .data import NoMetricInHistoryError
 
         data = self.collect(targets, revs)
 
@@ -105,7 +105,7 @@ def show(self, targets=None, revs=None, props=None, templates=None):
         for target in targets:
             rpath = relpath(target, self.repo.root_dir)
             if not any("data" in d[rpath] for d in data.values()):
-                raise NoMetricInHistoryError(target)
+                raise MetricDoesNotExistError([target])
 
         # No data at all is a special error with a special message
         if not data:

dvc/repo/plots/data.py

@@ -26,11 +26,6 @@ def __init__(self):
         )
 
 
-class NoMetricInHistoryError(DvcException):
-    def __init__(self, path):
-        super().__init__(f"Could not find '{path}'.")
-
-
 class PlotParsingError(ParseError):
     def __init__(self, path, revision):
         self.path = path