From 0d22f861cb077626a674832964ece795ac3a2d3e Mon Sep 17 00:00:00 2001
From: reuben russell <reubengrussell@gmail.com>
Date: Tue, 1 Sep 2026 13:36:18 +0000
Subject: [PATCH] STR-2927 preserve newer T3 runtime ownership

---
 apps/server/src/server.ts                  | 17 ++++---
 apps/server/src/serverRuntimeState.test.ts | 58 ++++++++++++++++++++++
 apps/server/src/serverRuntimeState.ts      | 18 +++++--
 3 files changed, 83 insertions(+), 10 deletions(-)

diff --git a/apps/server/src/server.ts b/apps/server/src/server.ts
index 32bcaaa8b96b..821f3c94e1c4 100644
--- a/apps/server/src/server.ts
+++ b/apps/server/src/server.ts
@@ -495,7 +495,7 @@ export const makeServerLayer = Layer.unwrap(
           const server = yield* HttpServer.HttpServer;
           const address = server.address;
           if (typeof address === "string" || !("port" in address)) {
-            return;
+            return null;
           }
 
           const state = yield* makePersistedServerRuntimeState({
@@ -510,13 +510,16 @@ export const makeServerLayer = Layer.unwrap(
               Effect.logWarning("Failed to persist server runtime state", { cause }),
             ),
           );
+          return state;
         }),
-        () =>
-          clearPersistedServerRuntimeState(config.serverRuntimeStatePath).pipe(
-            Effect.catchCause((cause) =>
-              Effect.logWarning("Failed to clear server runtime state", { cause }),
-            ),
-          ),
+        (state) =>
+          state === null
+            ? Effect.void
+            : clearPersistedServerRuntimeState(config.serverRuntimeStatePath, state).pipe(
+                Effect.catchCause((cause) =>
+                  Effect.logWarning("Failed to clear server runtime state", { cause }),
+                ),
+              ),
       ),
     );
     const tailscaleServeLayer = config.tailscaleServeEnabled
diff --git a/apps/server/src/serverRuntimeState.test.ts b/apps/server/src/serverRuntimeState.test.ts
index 4c2375b29a74..9858d7aa687e 100644
--- a/apps/server/src/serverRuntimeState.test.ts
+++ b/apps/server/src/serverRuntimeState.test.ts
@@ -78,6 +78,64 @@ describe("serverRuntimeState", () => {
     }).pipe(Effect.provide(NodeServices.layer)),
   );
 
+  it.effect("clears runtime state owned by the stopping server", () =>
+    Effect.gen(function* () {
+      const fileSystem = yield* FileSystem.FileSystem;
+      const path = yield* Path.Path;
+      const root = yield* fileSystem.makeTempDirectoryScoped({
+        prefix: "t3-server-runtime-state-test-",
+      });
+      const statePath = path.join(root, "server.json");
+      const state: ServerRuntimeState.PersistedServerRuntimeState = {
+        version: 1,
+        pid: 123,
+        port: 4_971,
+        origin: "http://127.0.0.1:4971",
+        startedAt: "2026-06-20T00:00:00.000Z",
+      };
+      yield* ServerRuntimeState.persistServerRuntimeState({ path: statePath, state });
+
+      yield* ServerRuntimeState.clearPersistedServerRuntimeState(statePath, state);
+
+      const restored = yield* ServerRuntimeState.readPersistedServerRuntimeState(statePath);
+      assert.isTrue(Option.isNone(restored));
+    }).pipe(Effect.provide(NodeServices.layer)),
+  );
+
+  it.effect("does not clear runtime state replaced by a newer server", () =>
+    Effect.gen(function* () {
+      const fileSystem = yield* FileSystem.FileSystem;
+      const path = yield* Path.Path;
+      const root = yield* fileSystem.makeTempDirectoryScoped({
+        prefix: "t3-server-runtime-state-test-",
+      });
+      const statePath = path.join(root, "server.json");
+      const oldState: ServerRuntimeState.PersistedServerRuntimeState = {
+        version: 1,
+        pid: 123,
+        port: 4_971,
+        origin: "http://127.0.0.1:4971",
+        startedAt: "2026-06-20T00:00:00.000Z",
+      };
+      const currentState: ServerRuntimeState.PersistedServerRuntimeState = {
+        ...oldState,
+        pid: 456,
+        port: 4_972,
+        origin: "http://127.0.0.1:4972",
+        startedAt: "2026-06-20T00:01:00.000Z",
+      };
+      yield* ServerRuntimeState.persistServerRuntimeState({
+        path: statePath,
+        state: currentState,
+      });
+
+      yield* ServerRuntimeState.clearPersistedServerRuntimeState(statePath, oldState);
+
+      const restored = yield* ServerRuntimeState.readPersistedServerRuntimeState(statePath);
+      assert.deepEqual(Option.getOrThrow(restored), currentState);
+    }).pipe(Effect.provide(NodeServices.layer)),
+  );
+
   it.effect("preserves malformed state decode failures", () => {
     const logs: CapturedLog[] = [];
     const logger = Logger.make(({ fiber, message }) => {
diff --git a/apps/server/src/serverRuntimeState.ts b/apps/server/src/serverRuntimeState.ts
index b32f3814547c..415ecca30c83 100644
--- a/apps/server/src/serverRuntimeState.ts
+++ b/apps/server/src/serverRuntimeState.ts
@@ -79,8 +79,19 @@ export const persistServerRuntimeState = (input: {
     ),
   );
 
-export const clearPersistedServerRuntimeState = (path: string) =>
-  Effect.gen(function* () {
+export const clearPersistedServerRuntimeState = Effect.fn("clearPersistedServerRuntimeState")(
+  function* (path: string, expectedOwner?: Pick<PersistedServerRuntimeState, "pid" | "startedAt">) {
+    if (expectedOwner) {
+      const current = yield* readPersistedServerRuntimeState(path);
+      if (
+        Option.isNone(current) ||
+        current.value.pid !== expectedOwner.pid ||
+        current.value.startedAt !== expectedOwner.startedAt
+      ) {
+        return;
+      }
+    }
+
     const fs = yield* FileSystem.FileSystem;
     yield* fs.remove(path, { force: true }).pipe(
       Effect.mapError(
@@ -102,7 +113,8 @@ export const clearPersistedServerRuntimeState = (path: string) =>
           ),
       }),
     );
-  });
+  },
+);
 
 export const readPersistedServerRuntimeState = (path: string) =>
   Effect.gen(function* () {