params: diff: sort table (#3617)

dvc/command/params.py

@@ -1,6 +1,8 @@
 import argparse
 import logging
 
+from collections import OrderedDict
+
 from dvc.command.base import append_doc_link
 from dvc.command.base import CmdBase
 from dvc.command.base import fix_subparsers
@@ -14,8 +16,9 @@ def _show_diff(diff):
     from dvc.utils.diff import table
 
     rows = []
-    for fname, mdiff in diff.items():
-        for param, change in mdiff.items():
+    for fname, pdiff in diff.items():
+        sorted_pdiff = OrderedDict(sorted(pdiff.items()))
+        for param, change in sorted_pdiff.items():
             rows.append([fname, param, change["old"], change["new"]])
 
     return table(["Path", "Param", "Old", "New"], rows)

tests/unit/command/test_params.py

@@ -83,3 +83,20 @@ def test_params_diff_show_json(dvc, mocker, caplog):
     with caplog.at_level(logging.INFO, logger="dvc"):
         assert cmd.run() == 0
         assert '{"params.yaml": {"a": "b"}}\n' in caplog.text
+
+
+def test_params_diff_sorted():
+    assert _show_diff(
+        {
+            "params.yaml": {
+                "x.b": {"old": 5, "new": 6},
+                "a.d.e": {"old": 3, "new": 4},
+                "a.b.c": {"old": 1, "new": 2},
+            }
+        }
+    ) == (
+        "   Path       Param   Old   New\n"
+        "params.yaml   a.b.c   1     2  \n"
+        "params.yaml   a.d.e   3     4  \n"
+        "params.yaml   x.b     5     6  "
+    )