Implement swapping edge case, restructure sources.

spec/support/ds4rolls/utils.spec.ts

@@ -0,0 +1,24 @@
+import "jasmine";
+import { isDiceSwapNecessary } from "../../../src/module/rolls/roll-utils";
+
+describe("Utility function testing if dice swap is necessery", () => {
+    it("Should not swap if all dice are crit successes.", () => {
+        expect(isDiceSwapNecessary([1, 1, 1], [], 9)).toBeFalse();
+    });
+
+    it("Should not swap if no die is crit success.", () => {
+        expect(isDiceSwapNecessary([], [2, 2, 2], 9)).toBeFalse();
+    });
+
+    it("Should not swap if all dice are already in use", () => {
+        expect(isDiceSwapNecessary([1], [9, 8], 10)).toBeFalse();
+    });
+
+    it("Should not swap if result does not get any better", () => {
+        expect(isDiceSwapNecessary([1], [8], 4)).toBeFalse();
+    });
+
+    it("Should swap if result does get better", () => {
+        expect(isDiceSwapNecessary([1], [19], 18)).toBeTrue();
+    });
+});