Initial Commit

packages/foundation/flow/undo/tests/properties/command.prop.test.ts

@@ -0,0 +1,45 @@
+import { describe, it } from "@suaveplan/testing/runner";
+import * as fc from "fast-check";
+import {
+    createCommand,
+    executeCommand,
+    undoCommand,
+} from "../../src/command/command.js";
+
+interface State {
+    x: number;
+    y: number;
+    label: string;
+}
+
+describe("property: command round-trip", () => {
+    it("execute then undo restores state for arbitrary closures", {
+        timeout: 30000,
+    }, () => {
+        fc.assert(
+            fc.property(
+                fc.record({
+                    x: fc.integer(),
+                    y: fc.integer(),
+                    label: fc.string(),
+                }),
+                fc.integer({ min: 1, max: 100 }),
+                (initial, delta) => {
+                    const cmd = createCommand<State>(
+                        "Transform",
+                        (s) => ({ ...s, x: s.x + delta }),
+                        (s) => ({ ...s, x: s.x - delta })
+                    );
+                    const after = executeCommand(initial, cmd);
+                    const back = undoCommand(after, cmd);
+                    return (
+                        back.x === initial.x &&
+                        back.y === initial.y &&
+                        back.label === initial.label
+                    );
+                }
+            ),
+            { numRuns: 200 }
+        );
+    });
+});