test: add immutability.

Author: sciborrudnicki

src/test/immutability.spec.ts

@@ -0,0 +1,45 @@
+import { BooleanState } from "../lib";
+
+export class ActiveState extends BooleanState {
+  public override get state() {
+    return super.state;
+  }
+
+  public override false() {
+    super.false();
+    return this;
+  }
+
+
+  public activate() {
+    super.true();
+    return this;
+  }
+
+  public deactivate() {
+    super.false();
+    return this;
+  }
+}
+
+const activeState = new ActiveState();
+
+activeState.seal();
+
+console.log(`--Sealed`);
+console.log(activeState);
+console.log(activeState.false());
+console.log(activeState.activate());
+
+activeState.freeze();
+
+console.log(`--Frozen`);
+console.log(activeState.activate());
+console.log(activeState.false());
+
+activeState.lock();
+
+console.log(`--Locked`);
+console.log(activeState.activate());
+console.log(activeState.false());
+