Sankey Diagram Edge's tooltip's content doesn't show as formatter define.

[Dabaitu2]

Version

Steps to reproduce

• go https://www.echartsjs.com/examples/zh/editor.html?c=sankey-energy
• use Option below

myChart.showLoading();
const defaultFormatter = params => {
  return 'hello'
};
$.get('https://www.echartsjs.com/data/asset/data/energy.json', function (data) {
    myChart.hideLoading();

    myChart.setOption(option = {
        title: {
            text: 'Sankey Diagram'
        },
        tooltip: {
            trigger: 'item',
            triggerOn: 'mousemove'
        },
        series: [
            {
                type: 'sankey',
                data: data.nodes.map(n => ({
                    ...n,
                    tooltip: {
                        trigger: 'item',
                        formatter: defaultFormatter
                    }
                })),
                links: data.links,
                focusNodeAdjacency: 'allEdges',
                itemStyle: {
                    borderWidth: 1,
                    borderColor: '#aaa'
                },
                lineStyle: {
                    color: 'source',
                    curveness: 0.5
                }
            }
        ]
    });
});

What is expected?

When I hover all edges, the tooltip should show "hello".

What is actually happening?

some of the edges will show tooltips like 'A -- B' rather than 'hello'

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[susiwen8]

Yes, it is a bug

[susiwen8]

Actually, This might be a new feature, because right now edges'(links) tooltip are nodes'(datas) tooltip, It would be better to separate those two. That means add tooltip option for edges(links)
Just add a missing parameter at
https://github.com/apache/incubator-echarts/blob/master/src/component/tooltip/TooltipView.js#L486