fix(point): fix usePoint defs id value

Incorrect id value was set for custom data point.
Side-effect caused by 6ff9aec

Fix #1887

src/ChartInternal/shape/point.ts

@@ -447,7 +447,6 @@ export default {
 		return function(method, context, ...args) {
 			return function(d) {
 				const id: string = $$.getTargetSelectorSuffix(d.id || (d.data && d.data.id) || d);
-
 				const element = d3Select(this);
 
 				ids.indexOf(id) < 0 && ids.push(id);
@@ -457,7 +456,7 @@ export default {
 				if ($$.hasValidPointType(point)) {
 					point = $$[point];
 				} else if (!$$.hasValidPointDrawMethods(point)) {
-					const pointId = `${datetimeId}-point-${id}`;
+					const pointId = `${datetimeId}-point${id}`;
 					const pointFromDefs = $$.pointFromDefs(pointId);
 
 					if (pointFromDefs.size() < 1) {

test/internals/legend-spec.ts

@@ -461,15 +461,20 @@ describe("LEGEND", () => {
 		});
 
 		it("should render custom points in legend", () => {
-			const nodes = chart.internal.$el.svg.selectAll(`.${CLASS.legendItem} .${CLASS.legendItemPoint}`);
+			const {$el} = chart.internal;
+			const nodes = $el.svg.selectAll(`.${CLASS.legendItem} .${CLASS.legendItemPoint}`);
+			const pointTagName = ["circle", "rect", "use", "circle"];
 
-			nodes.each((data, idx, selection) => {
+			nodes.each(function(data, idx, selection) {
 				const node = selection[idx];
 				const nodeName = node.nodeName.toLowerCase();
-				const expected = (idx === 0 || idx === 3) ?
-				  "circle" : (idx === 1) ? "rect" : (idx === 2) ? "use" : "";
 
-				expect(nodeName).to.be.equal(expected);
+				// check if referenced defs node exists
+				if (pointTagName[idx] === "use") {					
+					expect($el.defs.select(this.getAttribute("href")).size()).to.be.equal(1);
+				}
+
+				expect(nodeName).to.be.equal(pointTagName[idx]);
 			});
 
 			expect(nodes.size()).to.be.equal(chart.data().length);