feat(sdk): expose active sessions

packages/core/test/session-prompt.test.ts

@@ -25,6 +25,7 @@ const wakeCalls: SessionV2.ID[] = []
 const execution = Layer.succeed(
   SessionExecution.Service,
   SessionExecution.Service.of({
+    active: Effect.succeed(new Set()),
     resume: (sessionID) =>
       Effect.sync(() => {
         executionCalls.push(sessionID)

packages/core/test/session-run-coordinator.test.ts

@@ -66,6 +66,39 @@ describe("SessionRunCoordinator", () => {
     ),
   )
 
+  it.effect("snapshots only active executions", () =>
+    Effect.scoped(
+      Effect.gen(function* () {
+        const firstStarted = yield* Deferred.make<void>()
+        const secondStarted = yield* Deferred.make<void>()
+        const firstGate = yield* Deferred.make<void>()
+        const secondGate = yield* Deferred.make<void>()
+        const coordinator = yield* SessionRunCoordinator.make({
+          drain: (key: string) =>
+            Deferred.succeed(key === "first" ? firstStarted : secondStarted, undefined).pipe(
+              Effect.andThen(Deferred.await(key === "first" ? firstGate : secondGate)),
+            ),
+        })
+
+        expect(Array.from(yield* coordinator.active)).toEqual([])
+        const first = yield* coordinator.run("first").pipe(Effect.forkChild)
+        yield* Deferred.await(firstStarted)
+        expect(Array.from(yield* coordinator.active)).toEqual(["first"])
+
+        const second = yield* coordinator.run("second").pipe(Effect.forkChild)
+        yield* Deferred.await(secondStarted)
+        expect(Array.from(yield* coordinator.active)).toEqual(["first", "second"])
+
+        yield* Deferred.succeed(firstGate, undefined)
+        yield* Fiber.join(first)
+        expect(Array.from(yield* coordinator.active)).toEqual(["second"])
+        yield* Deferred.succeed(secondGate, undefined)
+        yield* Fiber.join(second)
+        expect(Array.from(yield* coordinator.active)).toEqual([])
+      }),
+    ),
+  )
+
   it.effect("coalesces wakes received during active execution", () =>
     Effect.scoped(
       Effect.gen(function* () {

packages/core/test/session-runner-recorded.test.ts

@@ -95,6 +95,7 @@ const execution = Layer.effect(
       drain: (sessionID, force) => sessionRunner.run({ sessionID, force }),
     })
     return SessionExecution.Service.of({
+      active: coordinator.active,
       resume: coordinator.run,
       wake: coordinator.wake,
       interrupt: coordinator.interrupt,

packages/core/test/session-runner.test.ts

@@ -254,6 +254,7 @@ const execution = Layer.effect(
       drain: (sessionID, force) => sessionRunner.run({ sessionID, force }),
     })
     return SessionExecution.Service.of({
+      active: coordinator.active,
       resume: coordinator.run,
       wake: coordinator.wake,
       interrupt: coordinator.interrupt,