From 6fc0a6ff98aa41e4a0fcc2120413132ab2ba76a1 Mon Sep 17 00:00:00 2001
From: dberenbaum <dave@iterative.ai>
Date: Thu, 15 Dec 2022 20:19:14 -0500
Subject: [PATCH] plots: accept any number of y data sources

---
 dvc/render/converter/vega.py             |  8 +++-
 tests/unit/render/test_vega_converter.py | 48 ++++++++++++++++++++++++
 2 files changed, 54 insertions(+), 2 deletions(-)

diff --git a/dvc/render/converter/vega.py b/dvc/render/converter/vega.py
index c635495d6..8996d113e 100644
--- a/dvc/render/converter/vega.py
+++ b/dvc/render/converter/vega.py
@@ -134,8 +134,12 @@ class VegaConverter(Converter):
             self.inferred_properties["x"] = {}
             # If multiple y files, duplicate x for each file.
             if isinstance(y, dict):
-                for file in y.keys():
-                    self.inferred_properties["x"][file] = x
+                for file, fields in y.items():
+                    # Duplicate x for each y.
+                    if isinstance(fields, list):
+                        self.inferred_properties["x"][file] = [x] * len(fields)
+                    else:
+                        self.inferred_properties["x"][file] = x
             # Otherwise use plot ID as file.
             else:
                 self.inferred_properties["x"][self.plot_id] = x
diff --git a/tests/unit/render/test_vega_converter.py b/tests/unit/render/test_vega_converter.py
index 52ea7f8c3..3bd01d9a5 100644
--- a/tests/unit/render/test_vega_converter.py
+++ b/tests/unit/render/test_vega_converter.py
@@ -331,6 +331,54 @@ def test_finding_lists(dictionary, expected_result):
             },
             id="y_list",
         ),
+        pytest.param(
+            {
+                "f": {"metric": [{"v": 1, "v2": 0.1, "v3": 0.01}]},
+                "f2": {"metric": [{"v": 1, "v2": 0.1}]},
+            },
+            {"y": {"f": ["v2", "v3"], "f2": ["v2"]}, "x": "v"},
+            [
+                {
+                    "dvc_inferred_y_value": 0.1,
+                    "v": 1,
+                    "v2": 0.1,
+                    "v3": 0.01,
+                    VERSION_FIELD: {
+                        "revision": "r",
+                        "filename": "f",
+                        "field": "v2",
+                    },
+                },
+                {
+                    "dvc_inferred_y_value": 0.01,
+                    "v": 1,
+                    "v2": 0.1,
+                    "v3": 0.01,
+                    VERSION_FIELD: {
+                        "revision": "r",
+                        "filename": "f",
+                        "field": "v3",
+                    },
+                },
+                {
+                    "dvc_inferred_y_value": 0.1,
+                    "v": 1,
+                    "v2": 0.1,
+                    VERSION_FIELD: {
+                        "revision": "r",
+                        "filename": "f2",
+                        "field": "v2",
+                    },
+                },
+            ],
+            {
+                "x": "v",
+                "y": "dvc_inferred_y_value",
+                "x_label": "v",
+                "y_label": "y",
+            },
+            id="multi_source_y_single_x",
+        ),
     ],
 )
 def test_convert(