release: WRNexusJS 0.3.0

packages/reactive/test/signal.test.ts

@@ -1,17 +1,47 @@
-import { expect, test } from "bun:test";
-import { signal } from "../src/index.ts";
+import { describe, expect, test } from "bun:test";
+import { batch, computed, effect, signal } from "../src/index.ts";
 
-test("signal skips equal writes and supports safe unsubscribe during notification", () => {
-  const count = signal(0);
-  const seen: number[] = [];
-  let off = () => {};
-  off = count.subscribe((value) => {
-    seen.push(value);
-    off();
+describe("reactive primitives", () => {
+  test("signals skip no-op updates", () => {
+    const value = signal(1);
+    const seen: number[] = [];
+    value.subscribe((next) => seen.push(next));
+    value.set(1);
+    value.set(2);
+    expect(seen).toEqual([2]);
+  });
+
+  test("batch coalesces notifications", () => {
+    const value = signal(0);
+    const seen: number[] = [];
+    value.subscribe((next) => seen.push(next));
+    batch(() => {
+      value.set(1);
+      value.set(2);
+      value.set(3);
+    });
+    expect(seen).toEqual([3]);
+  });
+
+  test("computed values and effects track dependencies", () => {
+    const count = signal(2);
+    const doubled = computed(() => count.get() * 2);
+    const seen: number[] = [];
+    const dispose = effect(() => {
+      seen.push(doubled.get());
+    });
+    count.set(3);
+    dispose();
+    count.set(4);
+    expect(seen).toEqual([4, 6]);
+  });
+
+  test("effects ignore accidental non-function return values", () => {
+    const value = signal(0);
+    const seen: number[] = [];
+    const dispose = effect(() => seen.push(value.get()) as unknown as void);
+    value.set(1);
+    dispose();
+    expect(seen).toEqual([0, 1]);
   });
-  count.set(0);
-  count.update((value) => value + 1);
-  count.set(2);
-  expect(seen).toEqual([1]);
-  expect(count.get()).toBe(2);
 });