From a34792ce1600449af3ee50be6cc63445da1ddad7 Mon Sep 17 00:00:00 2001
From: Jarred Sumner <jarred@jarredsumner.com>
Date: Wed, 22 Dec 2021 21:39:05 -0800
Subject: [PATCH] [Bun.js] Fix SSR when using `fetch`

---
 src/javascript/jsc/javascript.zig       | 15 +++++++++++----
 src/javascript/jsc/webcore/response.zig |  1 -
 2 files changed, 11 insertions(+), 5 deletions(-)

diff --git a/src/javascript/jsc/javascript.zig b/src/javascript/jsc/javascript.zig
index f185a720cd..9807c84363 100644
--- a/src/javascript/jsc/javascript.zig
+++ b/src/javascript/jsc/javascript.zig
@@ -779,8 +779,13 @@ pub const VirtualMachine = struct {
     }
 
     pub fn tick(this: *VirtualMachine) void {
-        this.global.vm().drainMicrotasks();
-        _ = this.eventLoopTick();
+        while (this.eventLoopTick() > 0) {}
+    }
+
+    pub fn waitForTasks(this: *VirtualMachine) void {
+        while (this.pending_tasks_count.load(.Monotonic) > 0 or this.ready_tasks_count.load(.Monotonic) > 0) {
+            while (this.eventLoopTick() > 0) {}
+        }
     }
 
     // 👶👶👶 event loop 👶👶👶
@@ -793,6 +798,7 @@ pub const VirtualMachine = struct {
                 .Microtask => {
                     var micro: *Microtask = task.get(Microtask).?;
                     _ = this.microtasks_queue.swapRemove(i);
+                    _ = this.pending_tasks_count.fetchSub(1, .Monotonic);
                     micro.run(this.global);
 
                     finished += 1;
@@ -802,6 +808,7 @@ pub const VirtualMachine = struct {
                     var fetch_task: *Fetch.FetchTasklet = task.get(Fetch.FetchTasklet).?;
                     if (fetch_task.status == .done) {
                         _ = this.ready_tasks_count.fetchSub(1, .Monotonic);
+                        _ = this.pending_tasks_count.fetchSub(1, .Monotonic);
                         _ = this.microtasks_queue.swapRemove(i);
                         fetch_task.onDone();
                         finished += 1;
@@ -1951,7 +1958,7 @@ pub const EventListenerMixin = struct {
 
             var result = js.JSObjectCallAsFunctionReturnValue(vm.global.ref(), listener_ref, null, 1, &fetch_args);
             var promise = JSPromise.resolvedPromise(vm.global, result);
-            vm.tick();
+            vm.waitForTasks();
 
             if (fetch_event.rejected) return;
 
@@ -1962,7 +1969,7 @@ pub const EventListenerMixin = struct {
                 _ = promise.result(vm.global.vm());
             }
 
-            vm.tick();
+            vm.waitForTasks();
 
             if (fetch_event.request_context.has_called_done) {
                 break;
diff --git a/src/javascript/jsc/webcore/response.zig b/src/javascript/jsc/webcore/response.zig
index dfb9944926..065ab98843 100644
--- a/src/javascript/jsc/webcore/response.zig
+++ b/src/javascript/jsc/webcore/response.zig
@@ -611,7 +611,6 @@ pub const Fetch = struct {
             var task: *FetchTasklet = @fieldParentPtr(FetchTasklet, "http", http_);
             @atomicStore(Status, &task.status, Status.done, .Monotonic);
             _ = task.javascript_vm.ready_tasks_count.fetchAdd(1, .Monotonic);
-            _ = task.javascript_vm.pending_tasks_count.fetchSub(1, .Monotonic);
             sender.release();
         }
     };