[bun:test] Implement --isolate flag (first pass at this)

src/bun.js/bindings/ScriptExecutionContext.cpp

@@ -41,7 +41,7 @@ us_socket_context_t* ScriptExecutionContext::webSocketContextSSL()
         us_bun_socket_context_options_t opts;
         memset(&opts, 0, sizeof(us_bun_socket_context_options_t));
         // adds root ca
-        opts.request_cert = true; 
+        opts.request_cert = true;
         // but do not reject unauthorized
         opts.reject_unauthorized = false;
         this->m_ssl_client_websockets_ctx = us_create_bun_socket_context(1, loop, sizeof(size_t), opts);
@@ -109,7 +109,7 @@ void ScriptExecutionContext::regenerateIdentifier()
     Locker locker { allScriptExecutionContextsMapLock };
 
     ASSERT(allScriptExecutionContextsMap().contains(m_identifier));
-    allScriptExecutionContextsMap().remove(m_identifier);
+    // allScriptExecutionContextsMap().remove(m_identifier);
 
     m_identifier = ++lastUniqueIdentifier;
 
@@ -121,14 +121,14 @@ void ScriptExecutionContext::addToContextsMap()
 {
     Locker locker { allScriptExecutionContextsMapLock };
     ASSERT(!allScriptExecutionContextsMap().contains(m_identifier));
-    allScriptExecutionContextsMap().add(m_identifier, this);
+    // allScriptExecutionContextsMap().add(m_identifier, this);
 }
 
 void ScriptExecutionContext::removeFromContextsMap()
 {
     Locker locker { allScriptExecutionContextsMapLock };
     ASSERT(allScriptExecutionContextsMap().contains(m_identifier));
-    allScriptExecutionContextsMap().remove(m_identifier);
+    // allScriptExecutionContextsMap().remove(m_identifier);
 }
 
 }

src/bun.js/bindings/ZigGlobalObject.cpp

@@ -217,6 +217,7 @@ extern "C" void JSCInitialize(const char* envp[], size_t envc, void (*onCrash)(c
         JSC::Options::useResizableArrayBuffer() = true;
         JSC::Options::showPrivateScriptsInStackTraces() = true;
         JSC::Options::useSetMethods() = true;
+        JSC::Options::useCodeCache() = true;
 
         if (LIKELY(envc > 0)) {
             while (envc--) {
@@ -423,6 +424,26 @@ const JSC::ClassInfo GlobalObject::s_info = { "GlobalObject"_s, &Base::s_info, n
 extern "C" JSClassRef* Zig__getAPIGlobals(size_t* count);
 extern "C" const JSC__JSValue* Zig__getAPIConstructors(size_t* count, JSC__JSGlobalObject*);
 
+extern "C" Zig::GlobalObject* GlobalObject__createNewDefault(Zig::GlobalObject* currentDefault, Zig::GlobalObject* initialDefault)
+{
+    auto& vm = currentDefault->vm();
+    auto* prototype = JSC::JSGlobalObject::create(vm, initialDefault->globalObjectStructure());
+    Zig::GlobalObject* newDefault = Zig::GlobalObject::create(vm, Zig::GlobalObject::createStructure(vm, prototype, jsNull()));
+    newDefault->setConsole(newDefault);
+    size_t count = 0;
+    JSClassRef* globalObjectClass = Zig__getAPIGlobals(&count);
+
+    if (count > 0) {
+        newDefault->installAPIGlobals(globalObjectClass, count, vm);
+    }
+
+    if (initialDefault != currentDefault) {
+        gcUnprotect(currentDefault);
+    }
+
+    return newDefault;
+}
+
 static JSGlobalObject* deriveShadowRealmGlobalObject(JSGlobalObject* globalObject)
 {
     auto& vm = globalObject->vm();
@@ -503,7 +524,6 @@ GlobalObject::~GlobalObject()
         finalizer(toNapi(this), napiInstanceData, napiInstanceDataFinalizerHint);
     }
 
-    delete crypto;
     scriptExecutionContext()->removeFromContextsMap();
 }
 

src/bun.js/javascript.zig

@@ -362,6 +362,7 @@ pub const VirtualMachine = struct {
     preload: []const string = &[_][]const u8{},
     unhandled_pending_rejection_to_capture: ?*JSC.JSValue = null,
     standalone_module_graph: ?*bun.StandaloneModuleGraph = null,
+    initial_global_object: *JSC.JSGlobalObject,
 
     hot_reload: bun.CLI.Command.HotReload = .none,
 
@@ -683,6 +684,7 @@ pub const VirtualMachine = struct {
         const is_first = !VirtualMachine.get().has_loaded_constructors;
         if (is_first) {
             VirtualMachine.get().global = globalObject;
+            VirtualMachine.get().initial_global_object = globalObject;
             VirtualMachine.get().has_loaded_constructors = true;
         }
 
@@ -746,6 +748,7 @@ pub const VirtualMachine = struct {
 
         vm.* = VirtualMachine{
             .global = undefined,
+            .initial_global_object = undefined,
             .allocator = allocator,
             .entry_point = ServerEntryPoint{},
             .event_listeners = EventListenerMixin.Map.init(allocator),
@@ -813,6 +816,12 @@ pub const VirtualMachine = struct {
         return vm;
     }
 
+    extern fn GlobalObject__createNewDefault(*JSGlobalObject, *JSGlobalObject) *JSGlobalObject;
+    pub fn resetDefaultGlobalObject(this: *VirtualMachine) void {
+        this.global = GlobalObject__createNewDefault(this.global, this.initial_global_object);
+        this.event_loop.global = this.global;
+    }
+
     pub fn init(
         allocator: std.mem.Allocator,
         _args: Api.TransformOptions,
@@ -843,6 +852,7 @@ pub const VirtualMachine = struct {
 
         vm.* = VirtualMachine{
             .global = undefined,
+            .initial_global_object = undefined,
             .allocator = allocator,
             .entry_point = ServerEntryPoint{},
             .event_listeners = EventListenerMixin.Map.init(allocator),

src/bun.js/test/jest.zig

@@ -376,6 +376,7 @@ pub const TestRunner = struct {
     test_timeout_timer: ?*bun.uws.Timer = null,
     last_test_timeout_timer_duration: u32 = 0,
     active_test_for_timeout: ?TestRunner.Test.ID = null,
+    isolate: bool = false,
 
     global_callbacks: struct {
         beforeAll: std.ArrayListUnmanaged(JSC.JSValue) = .{},

src/cli.zig

@@ -211,6 +211,7 @@ pub const Arguments = struct {
 
     // TODO: update test completions
     const test_only_params = [_]ParamType{
+        clap.parseParam("--isolate                        Create a new global for each test file") catch unreachable,
         clap.parseParam("--timeout <NUMBER>               Set the per-test timeout in milliseconds, default is 5000.") catch unreachable,
         clap.parseParam("--update-snapshots               Update snapshot files") catch unreachable,
         clap.parseParam("--rerun-each <NUMBER>            Re-run each test file <NUMBER> times, helps catch certain bugs") catch unreachable,
@@ -380,6 +381,8 @@ pub const Arguments = struct {
                     };
                 }
             }
+
+            ctx.test_options.isolate = args.flag("--isolate");
             ctx.test_options.update_snapshots = args.flag("--update-snapshots");
             if (args.option("--rerun-each")) |repeat_count| {
                 if (repeat_count.len > 0) {
@@ -916,6 +919,7 @@ pub const Command = struct {
         default_timeout_ms: u32 = 5 * std.time.ms_per_s,
         update_snapshots: bool = false,
         repeat_count: u32 = 0,
+        isolate: bool = false,
     };
 
     pub const Context = struct {

src/cli/test_command.zig

@@ -436,6 +436,7 @@ pub const TestCommand = struct {
         reporter.repeat_count = @max(ctx.test_options.repeat_count, 1);
         reporter.jest.callback = &reporter.callback;
         jest.Jest.runner = &reporter.jest;
+        reporter.jest.isolate = ctx.test_options.isolate;
 
         js_ast.Expr.Data.Store.create(default_allocator);
         js_ast.Stmt.Data.Store.create(default_allocator);
@@ -721,8 +722,15 @@ pub const TestCommand = struct {
         vm.main_hash = @truncate(u32, bun.hash(resolution.path_pair.primary.text));
         var repeat_count = reporter.repeat_count;
         var repeat_index: u32 = 0;
+        const original_preload_len = vm.preload.len;
         while (repeat_index < repeat_count) : (repeat_index += 1) {
             var promise = try vm.loadEntryPoint(resolution.path_pair.primary.text);
+            defer {
+                if (reporter.jest.isolate) {
+                    vm.preload.len = original_preload_len;
+                    vm.resetDefaultGlobalObject();
+                }
+            }
 
             switch (promise.status(vm.global.vm())) {
                 .Rejected => {
@@ -772,6 +780,7 @@ pub const TestCommand = struct {
                         prev_unhandled_count = vm.unhandled_error_counter;
                     }
                 }
+
                 switch (vm.aggressive_garbage_collection) {
                     .none => {},
                     .mild => {

test/js/bun/test/test-isolation-first-2.test.js

@@ -0,0 +1,6 @@
+import { test, expect } from "bun:test";
+
+test("Object.foo", () => {
+  expect(Object.foo).toBeUndefined();
+  Object.bar = false;
+});

test/js/bun/test/test-isolation-first.test.js

@@ -0,0 +1,6 @@
+import { test, expect } from "bun:test";
+
+test("Object.foo", () => {
+  Object.foo = true;
+  expect(Object.bar).toBeUndefined();
+});