release - fix(bounded area chart): update bounded area chart so bound…

…s don't sh… (carbon-design-system#985)

* fix(bounded area chart): update bounded area chart so bounds don't show for null values

Behaviour of bounded area chart now match that of the line chart where null values are shown as a
break in the chart

fix carbon-design-system#980

* fix(area chart): update so area chart also does not display when a point is defined as null

Matches behaviour of line chart where line is not displayed for null values

Co-authored-by: Shazia Kayani <shazia.kayani@ibm.com>

packages/core/src/components/graphs/area.ts

@@ -41,7 +41,16 @@ export class Area extends Component {
 		const { cartesianScales } = this.services;
 
 		const orientation = cartesianScales.getOrientation();
-		const areaGenerator = area().curve(this.services.curves.getD3Curve());
+		const areaGenerator = area()
+			.curve(this.services.curves.getD3Curve())
+			.defined((datum: any, i) => {
+				const rangeIdentifier = cartesianScales.getRangeIdentifier();
+				const value = datum[rangeIdentifier];
+				if (value === null || value === undefined) {
+					return false;
+				}
+				return true;
+			});
 
 		// Update the bound data on area groups
 		const groupedData = this.model.getGroupedData(this.configs.groups);
@@ -126,7 +135,7 @@ export class Area extends Component {
 				.select(
 					`path.${this.model.getColorClassName({
 						classNameTypes: [ColorClassNameTypes.STROKE],
-						dataGroupName: groupedData[0].name
+						dataGroupName: groupedData[0].name,
 					})}`
 				)
 				.node();