flow like the river

VISUALIZACION/node_modules/ngraph.forcelayout/test/dragForce.js

@@ -0,0 +1,21 @@
+var test = require('tap').test;
+var dimensions = 2;
+var createDragForce = require('../lib/codeGenerators/generateCreateDragForce')(dimensions);
+var Body = require('../lib/codeGenerators/generateCreateBody')(dimensions);
+
+test('reduces force value', function (t) {
+  var body = new Body();
+  body.force.x = 1; body.force.y = 1;
+  body.velocity.x = 1; body.velocity.y = 1;
+
+  var dragForce = createDragForce({ dragCoefficient: 0.1 });
+  dragForce.update(body);
+
+  t.ok(body.force.x < 1 && body.force.y < 1, 'Force value is reduced');
+  t.end();
+});
+
+test('Initialized with default value', function (t) {
+  t.throws(() => createDragForce());
+  t.end();
+});