Add automatic project snapshots

tests/project-snapshot-policy.test.ts

@@ -0,0 +1,41 @@
+import assert from "node:assert/strict";
+import { describe, it } from "node:test";
+import {
+  automaticProjectSnapshotIntervalRevisions,
+  automaticProjectSnapshotRetentionCount,
+  shouldCaptureAutomaticProjectSnapshot,
+} from "../src/domain/models/project-snapshot-policy.model.js";
+
+describe("automatic project snapshot policy", () => {
+  it("captures every 25 revisions and retains twelve automatic snapshots", () => {
+    assert.equal(automaticProjectSnapshotIntervalRevisions, 25);
+    assert.equal(automaticProjectSnapshotRetentionCount, 12);
+    assert.equal(
+      shouldCaptureAutomaticProjectSnapshot(24, null),
+      false
+    );
+    assert.equal(
+      shouldCaptureAutomaticProjectSnapshot(25, null),
+      true
+    );
+    assert.equal(
+      shouldCaptureAutomaticProjectSnapshot(49, 25),
+      false
+    );
+    assert.equal(
+      shouldCaptureAutomaticProjectSnapshot(50, 25),
+      true
+    );
+  });
+
+  it("rejects invalid or inconsistent revision inputs", () => {
+    assert.throws(
+      () => shouldCaptureAutomaticProjectSnapshot(-1, null),
+      /non-negative integer/
+    );
+    assert.throws(
+      () => shouldCaptureAutomaticProjectSnapshot(25, 26),
+      /exceeds current revision/
+    );
+  });
+});