refactor(schema): extract public event definitions (#33579)

packages/schema/test/event.test.ts

@@ -0,0 +1,37 @@
+import { describe, expect, test } from "bun:test"
+import { Schema } from "effect"
+import { Event } from "../src/event"
+
+describe("public event schemas", () => {
+  test("definition is pure", () => {
+    const definitions = Event.inventory()
+    Event.define({ type: "test.pure", schema: { value: Schema.String } })
+    expect(definitions).toEqual([])
+  })
+
+  test("latest selection is independent of declaration order", () => {
+    const historical = Event.define({
+      type: "test.versioned",
+      durable: { aggregate: "id", version: 1 },
+      schema: { id: Schema.String },
+    })
+    const current = Event.define({
+      type: "test.versioned",
+      durable: { aggregate: "id", version: 2 },
+      schema: { id: Schema.String, value: Schema.String },
+    })
+
+    expect(Event.latest([historical, current]).get(current.type)).toBe(current)
+    expect(Event.latest([current, historical]).get(current.type)).toBe(current)
+  })
+
+  test("durable definitions are indexed by type and version", () => {
+    const definition = Event.define({
+      type: "test.durable",
+      durable: { aggregate: "id", version: 1 },
+      schema: { id: Schema.String },
+    })
+
+    expect(Event.durable([definition]).get("test.durable.1")).toBe(definition)
+  })
+})