fix: tweak #12191 (when edge value sum is 0, edge and node disappear)

src/chart/sankey/sankeyLayout.js

@@ -400,7 +400,13 @@ function relaxRightToLeft(nodesByBreadth, alpha, orient) {
         zrUtil.each(nodes, function (node) {
             if (node.outEdges.length) {
                 var y = sum(node.outEdges, weightedTarget, orient)
-                        / sum(node.outEdges, getEdgeValue, orient);
+                    / sum(node.outEdges, getEdgeValue, orient);
+
+                if (isNaN(y)) {
+                    var len = node.outEdges.length;
+                    y = len ? sum(node.outEdges, centerTarget, orient) / len : 0;
+                }
+
                 if (orient === 'vertical') {
                     var nodeX = node.getLayout().x + (y - center(node, orient)) * alpha;
                     node.setLayout({x: nodeX}, true);
@@ -417,10 +423,16 @@ function relaxRightToLeft(nodesByBreadth, alpha, orient) {
 function weightedTarget(edge, orient) {
     return center(edge.node2, orient) * edge.getValue();
 }
+function centerTarget(edge, orient) {
+    return center(edge.node2, orient);
+}
 
 function weightedSource(edge, orient) {
     return center(edge.node1, orient) * edge.getValue();
 }
+function centerSource(edge, orient) {
+    return center(edge.node1, orient);
+}
 
 function center(node, orient) {
     return orient === 'vertical'
@@ -456,9 +468,15 @@ function relaxLeftToRight(nodesByBreadth, alpha, orient) {
     zrUtil.each(nodesByBreadth, function (nodes) {
         zrUtil.each(nodes, function (node) {
             if (node.inEdges.length) {
+
                 var y = sum(node.inEdges, weightedSource, orient)
-                        / sum(node.inEdges, getEdgeValue, orient);
-                isNaN(y) && (y = 0);
+                    / sum(node.inEdges, getEdgeValue, orient);
+
+                if (isNaN(y)) {
+                    var len = node.inEdges.length;
+                    y = len ? sum(node.inEdges, centerSource, orient) / len : 0;
+                }
+
                 if (orient === 'vertical') {
                     var nodeX = node.getLayout().x + (y - center(node, orient)) * alpha;
                     node.setLayout({x: nodeX}, true);

test/sankey-depth.html

@@ -83,7 +83,7 @@ under the License.
                         {
                             source: 'a',
                             target: 'b1',
-                            value: 3
+                            value: 0
                         },
                         {
                             source: 'b1',
@@ -93,16 +93,24 @@ under the License.
                         {
                             source: 'b1',
                             target: 'c',
-                            value: 2
+                            value: 3
                         },
                         {
                             source: 'b',
                             target: 'c',
-                            value: 1
+                            value: 3
                         }
                     ]
                 };
 
+                for (var i = 0; i < testData.nodes.length; i++) {
+                    testData.nodes[i].tooltip = {
+                        formatter: function () {
+                            return 'hello';
+                        }
+                    }
+                }
+
                 chart.setOption({
                     color: ['#67001f', '#b2182b', '#d6604d', '#f4a582', '#fddbc7', '#d1e5f0', '#92c5de', '#4393c3', '#2166ac', '#053061'],
                     tooltip: {