Allow array for line opts in dataset (#10179)

* fix line as array ts error

* added test

* implement only for the border,background color and radius

types/index.esm.d.ts

@@ -177,8 +177,10 @@ export interface LineControllerDatasetOptions
   extends ControllerDatasetOptions,
   ScriptableAndArrayOptions<PointPrefixedOptions, ScriptableContext<'line'>>,
   ScriptableAndArrayOptions<PointPrefixedHoverOptions, ScriptableContext<'line'>>,
-  ScriptableOptions<LineOptions, ScriptableContext<'line'>>,
-  ScriptableOptions<LineHoverOptions, ScriptableContext<'line'>>,
+  ScriptableOptions<Omit<LineOptions, keyof CommonElementOptions>, ScriptableContext<'line'>>,
+  ScriptableAndArrayOptions<CommonElementOptions, ScriptableContext<'line'>>,
+  ScriptableOptions<Omit<LineHoverOptions, keyof CommonHoverOptions>, ScriptableContext<'line'>>,
+  ScriptableAndArrayOptions<CommonHoverOptions, ScriptableContext<'line'>>,
   AnimationOptions<'line'> {
   /**
    * The ID of the x axis to plot this dataset on.

types/tests/controllers/line_styling_array.ts

@@ -0,0 +1,13 @@
+import { Chart } from '../../index.esm';
+
+const chart = new Chart('id', {
+  type: 'line',
+  data: {
+    labels: [],
+    datasets: [{
+      data: [],
+      backgroundColor: ['red', 'blue'],
+      hoverBackgroundColor: ['red', 'blue'],
+    }]
+  },
+});