From b393c305017da958d01d91ed73fe506cbb006e2b Mon Sep 17 00:00:00 2001
From: Sylvain <sylvain.joyeux@tidewise.io>
Date: Tue, 8 Oct 2024 10:53:29 -0300
Subject: [PATCH] feat: define polars_to_vega

Little work to do, but we do need to remove NaNs as vega does not
support them.
---
 lib/syskit/log/dsl.rb |  5 +++++
 test/dsl_test.rb      | 14 ++++++++++++++
 2 files changed, 19 insertions(+)

diff --git a/lib/syskit/log/dsl.rb b/lib/syskit/log/dsl.rb
index 615de12..8ac6bfa 100644
--- a/lib/syskit/log/dsl.rb
+++ b/lib/syskit/log/dsl.rb
@@ -648,6 +648,11 @@ def roby_vega_task_timeline_data(*tasks)
                 end
             end
 
+            # Convert a Daru frame into a vega data array
+            def polars_to_vega(frame)
+                frame.fill_nan(nil).to_a
+            end
+
             # Convert a Daru frame into a vega data array
             def daru_to_vega(frame, every: 1)
                 data = []
diff --git a/test/dsl_test.rb b/test/dsl_test.rb
index 82ac109..caa1756 100644
--- a/test/dsl_test.rb
+++ b/test/dsl_test.rb
@@ -502,6 +502,20 @@ def assert_polars_frame_near(expected, actual)
                 end
             end
 
+            describe "polars_to_vega" do
+                before do
+                    @context = make_context
+                end
+
+                it "converts NaN into nil" do
+                    frame = ::Polars::DataFrame.new(
+                        { "a" => [Float::NAN, 0.1] }, schema: nil
+                    )
+                    vega = @context.polars_to_vega(frame)
+                    assert_equal [{ "a" => nil }, { "a" => 0.1 }], vega
+                end
+            end
+
             describe "daru_to_vega" do
                 before do
                     @context = make_context