feat(sdk): expose live event stream (#34098)

packages/client/test/effect.test.ts

@@ -15,6 +15,50 @@ test("sessions.get returns the decoded Effect projection", async () => {
   expect(DateTime.toEpochMillis(result.time.created)).toBe(1_717_171_717_000)
 })
 
+test("events.subscribe exposes and decodes the native Effect event stream", async () => {
+  const httpClient = HttpClient.make((request) =>
+    Effect.succeed(
+      HttpClientResponse.fromWeb(
+        request,
+        new Response(
+          `data: ${JSON.stringify({ id: "evt_connected", type: "server.connected", data: {} })}\n\n` +
+            `data: ${JSON.stringify(modelSwitchedEvent)}\n\n`,
+          { headers: { "content-type": "text/event-stream" } },
+        ),
+      ),
+    ),
+  )
+  const events = await Effect.gen(function* () {
+    const client = yield* OpenCode.make({ baseUrl: "http://localhost:3000" })
+    return yield* client.events.subscribe().pipe(Stream.runCollect)
+  }).pipe(Effect.provideService(HttpClient.HttpClient, httpClient), Effect.runPromise)
+
+  expect(Array.from(events).map((event) => event.type)).toEqual(["server.connected", "session.next.model.switched"])
+  const durable = events[1]
+  if (durable?.type !== "session.next.model.switched") throw new Error("Expected model event")
+  expect(DateTime.toEpochMillis(durable.data.timestamp)).toBe(1_717_171_717_000)
+  expect(durable.durable).toEqual({ aggregateID: "ses_test", seq: 1, version: 1 })
+})
+
+test("events.subscribe terminates on Effect protocol decode failures", async () => {
+  const httpClient = HttpClient.make((request) =>
+    Effect.succeed(
+      HttpClientResponse.fromWeb(
+        request,
+        new Response(`data: {"type":"server.connected"}\n\n`, {
+          headers: { "content-type": "text/event-stream" },
+        }),
+      ),
+    ),
+  )
+  const error = await Effect.gen(function* () {
+    const client = yield* OpenCode.make({ baseUrl: "http://localhost:3000" })
+    return yield* client.events.subscribe().pipe(Stream.runCollect, Effect.flip)
+  }).pipe(Effect.provideService(HttpClient.HttpClient, httpClient), Effect.runPromise)
+
+  expect(error._tag).toBe("ClientError")
+})
+
 test("session methods retain decoded Effect inputs and outputs", async () => {
   const historyQueries: Array<Record<string, string>> = []
   let historyPage = 0