feat: version 2 beta

tests/adapters/store/reduce.ts

@@ -0,0 +1,103 @@
+import { assertEquals } from "@std/assert";
+import { it } from "@std/testing/bdd";
+import { nanoid } from "nanoid";
+
+import type { EventStoreFactory } from "../mocks/events.ts";
+import { userReducer } from "../mocks/user-reducer.ts";
+import { describe } from "../utilities/describe.ts";
+
+export default describe<EventStoreFactory>(".reduce", (getEventStore) => {
+  it("should return reduced state", async () => {
+    const { store } = await getEventStore();
+    const stream = nanoid();
+
+    await store.pushEvent(
+      store.event({
+        stream,
+        type: "user:created",
+        data: {
+          name: {
+            given: "John",
+            family: "Doe",
+          },
+          email: "john.doe@fixture.none",
+        },
+        meta: {
+          auditor: "super",
+        },
+      }),
+    );
+
+    await store.pushEvent(
+      store.event({
+        stream,
+        type: "user:email-set",
+        data: "jane.doe@fixture.none",
+        meta: {
+          auditor: "super",
+        },
+      }),
+    );
+
+    const state = await store.reduce({ name: "user", stream, reducer: userReducer });
+
+    assertEquals(state, {
+      name: { given: "John", family: "Doe" },
+      email: "jane.doe@fixture.none",
+      active: true,
+      posts: { list: [], count: 0 },
+    });
+  });
+
+  it("should return snapshot if it exists and no new events were found", async () => {
+    const { store } = await getEventStore();
+    const stream = nanoid();
+
+    await store.pushEvent(
+      store.event({
+        stream,
+        type: "user:created",
+        data: {
+          name: {
+            given: "John",
+            family: "Doe",
+          },
+          email: "john.doe@fixture.none",
+        },
+        meta: {
+          auditor: "super",
+        },
+      }),
+    );
+
+    await store.pushEvent(
+      store.event({
+        stream,
+        type: "user:email-set",
+        data: "jane.doe@fixture.none",
+        meta: {
+          auditor: "super",
+        },
+      }),
+    );
+
+    await store.createSnapshot({ name: "user", stream, reducer: userReducer });
+
+    const state = await store.reduce({ name: "user", stream, reducer: userReducer });
+
+    assertEquals(state, {
+      name: { given: "John", family: "Doe" },
+      email: "jane.doe@fixture.none",
+      active: true,
+      posts: { list: [], count: 0 },
+    });
+  });
+
+  it("should return undefined if stream does not have events", async () => {
+    const stream = nanoid();
+    const { store } = await getEventStore();
+    const state = await store.reduce({ name: "user", stream, reducer: userReducer });
+
+    assertEquals(state, undefined);
+  });
+});