Initial Commit

packages/foundation/random/pseudo-random/src/algorithms/xoshiro256.extra.test.ts

@@ -0,0 +1,26 @@
+import { describe, expect, it } from "@suaveplan/testing/runner";
+import { Xoshiro256PlusPlusRng } from "./xoshiro256.js";
+
+class ZeroXoshiro extends Xoshiro256PlusPlusRng {
+    public constructor() {
+        super(1);
+        this.s0 = 0n;
+        this.s1 = 0n;
+        this.s2 = 0n;
+        this.s3 = 0n;
+    }
+    public callEnsureNonZero(): void {
+        this.ensureNonZeroState();
+    }
+    public readState(): [bigint, bigint, bigint, bigint] {
+        return [this.s0, this.s1, this.s2, this.s3];
+    }
+}
+
+describe("Xoshiro256 ensureNonZeroState guard", () => {
+    it("repairs an all-zero state by setting s0=1", { timeout: 5000 }, () => {
+        const rng = new ZeroXoshiro();
+        rng.callEnsureNonZero();
+        expect(rng.readState()).toEqual([1n, 0n, 0n, 0n]);
+    });
+});