tweak principal-axes spec

src/mol-math/linear-algebra/_spec/principal-axes.spec.ts

@@ -2,9 +2,11 @@
  * Copyright (c) 2023 mol* contributors, licensed under MIT, See LICENSE file for more info.
  *
  * @author Gianluca Tomasello <giagitom@gmail.com>
+ * @author Alexander Rose <alexander.rose@weirdbyte.de>
  */
 
 import { NumberArray } from '../../../mol-util/type-helpers';
+import { Vec3 } from '../3d/vec3';
 import { PrincipalAxes } from '../matrix/principal-axes';
 
 describe('PrincipalAxes', () => {
@@ -13,7 +15,18 @@ describe('PrincipalAxes', () => {
             0.1945, -0.0219, -0.0416,
             -0.0219, -0.0219, -0.0119,
         ];
-        const { origin } = PrincipalAxes.ofPositions(positions).boxAxes;
-        expect(origin[0] !== Infinity && origin[1] !== Infinity && origin[2] !== Infinity).toBe(true);
+        const pa = PrincipalAxes.ofPositions(positions);
+        expect(Vec3.isFinite(pa.boxAxes.origin)).toBe(true);
+        expect(Vec3.equals(pa.boxAxes.origin, pa.momentsAxes.origin)).toBe(true);
+    });
+
+    it('same-point', () => {
+        const positions: NumberArray = [ // same coordinates
+            0.1945, -0.0219, -0.0416,
+            0.1945, -0.0219, -0.0416,
+        ];
+        const pa = PrincipalAxes.ofPositions(positions);
+        expect(Vec3.isFinite(pa.boxAxes.origin)).toBe(true);
+        expect(Vec3.equals(pa.boxAxes.origin, pa.momentsAxes.origin)).toBe(true);
     });
 });