tswistak

$(go.Node, 'Auto',
	$(go.Shape, 
		'Circle', {
			width: 100,
			height: 100,
			fill: 'white'
	}),
	$(go.Shape, 
		'Rectangle', {
			portId: '',

tswistak

$(go.Node,
	'Spot',
	$(go.Shape, {
		// ...
	}),
	$(go.Shape, 
		'Rectangle', {
			portId: 'entry',
			width: 20,
			height: 20,

tswistak

diagram.model = $(go.GraphLinksModel, {
	linkFromPortIdProperty: 'fromPort',
	linkToPortIdProperty: 'toPort',
	nodeDataArray: [
		// ...
	],
	linkDataArray: [
		{from: 1, to: 2, toPort: 'entry'},
		{from: 2, to: 3, fromPort: 'exit', toPort: 'entry'},
		{from: 1, to: 3, toPort: 'entry'},

tswistak

<div id="palette-content" style="height: 800px; width: 200px; display: inline-block; border: 1px solid black"></div>
<div id="diagram-content" style="height: 800px; width: calc(100% - 220px); display: inline-block; border: 1px solid black;"></div>
<script>
	window.onload = function() {
		diagram.initDiagram();
		diagram.initPalette();
	};
</script>

tswistak

var initDiagram = function () {
    diagram = $(go.Diagram, 
        'diagram-content', {
            initialContentAlignment: go.Spot.Center,
            allowDrop: true
    });
    // ...  
}
var initPalette = function () {
    palette = $(go.Palette, 'palette-content');

tswistak

diagram.grid.visible = true;
diagram.toolManager.draggingTool.isGridSnapEnabled = true;
diagram.toolManager.draggingTool.gridSnapCellSize = new go.Size(50, 50);

tswistak

diagram = $(go.Diagram, 
    'diagram-content', {
        initialContentAlignment: go.Spot.Center,
        allowDrop: true,
        layout: $(go.LayeredDigraphLayout)
});

tswistak

type Triple = [string, number, boolean];
const a: Triple = ['a', 2, false];

tswistak

type StringAndNumbers = [string, ...number[]];
const b1: StringAndNumbers = ['a', 1, 2, 3];
const b2: StringAndNumbers = ['a'];

tswistak

type Strings = [...string];
type Empty = [];
const c1: Strings = ['a', 'b'];
const c2: Strings = [];
const c3: Empty = [];
const c4: Empty = ['a', 'b']; // invalid type