Make setTimeout and co. globally available by default

closes #3589

js/bundle.go

@@ -283,6 +283,7 @@ func (b *Bundle) instantiate(vuImpl *moduleVUImpl, vuID uint64) (*goja.Object, e
 
 	modSys := modules.NewModuleSystem(b.ModuleResolver, vuImpl)
 	b.setInitGlobals(rt, vuImpl, modSys)
+	modules.ExportGloballyModule(rt, modSys, "k6/timers")
 	vuImpl.initEnv = initenv
 	defer func() {
 		vuImpl.initEnv = nil

js/bundle_test.go

@@ -925,3 +925,40 @@ func TestBundleMakeArchive(t *testing.T) {
 		})
 	}
 }
+
+func TestGlobalTimers(t *testing.T) {
+	t.Parallel()
+	data := `
+			import timers from "k6/timers";
+			if (setTimeout != timers.setTimeout) {
+				throw "setTimeout doesn't match";
+			}
+			if (clearTimeout != timers.clearTimeout) {
+				throw "clearTimeout doesn't match";
+			}
+			if (setInterval != timers.setInterval) {
+				throw "setInterval doesn't match";
+			}
+			if (clearInterval != timers.clearInterval) {
+				throw "clearInterval doesn't match";
+			}
+			export default function() {}
+	`
+
+	b1, err := getSimpleBundle(t, "/script.js", data)
+	require.NoError(t, err)
+	logger := testutils.NewLogger(t)
+
+	b2, err := NewBundleFromArchive(getTestPreInitState(t, logger, nil), b1.makeArchive())
+	require.NoError(t, err)
+
+	bundles := map[string]*Bundle{"Source": b1, "Archive": b2}
+	for name, b := range bundles {
+		b := b
+		t.Run(name, func(t *testing.T) {
+			t.Parallel()
+			_, err := b.Instantiate(context.Background(), 1)
+			require.NoError(t, err)
+		})
+	}
+}

js/modules/k6/timers/timers.go

@@ -62,10 +62,12 @@ func (*RootModule) NewModuleInstance(vu modules.VU) modules.Instance {
 func (e *Timers) Exports() modules.Exports {
 	return modules.Exports{
 		Named: map[string]interface{}{
-			"setTimeout":    e.setTimeout,
-			"clearTimeout":  e.clearTimeout,
-			"setInterval":   e.setInterval,
-			"clearInterval": e.clearInterval,
+			// TODO the usage of `ToValue` here is so that goja doesn't do it automatically later
+			// which will effectively create new instance each time it is accessed.
+			"setTimeout":    e.vu.Runtime().ToValue(e.setTimeout),
+			"clearTimeout":  e.vu.Runtime().ToValue(e.clearTimeout),
+			"setInterval":   e.vu.Runtime().ToValue(e.setInterval),
+			"clearInterval": e.vu.Runtime().ToValue(e.clearInterval),
 		},
 	}
 }

js/modules/resolution.go

@@ -194,3 +194,15 @@ func (ms *ModuleSystem) RunSourceData(source *loader.SourceData) (goja.Value, er
 	}
 	return ms.Require(pwd, specifier)
 }
+
+// ExportGloballyModule sets all exports of the provided module name on the globalThis.
+// effectively making them globally available
+func ExportGloballyModule(rt *goja.Runtime, modSys *ModuleSystem, moduleName string) {
+	t, _ := modSys.Require(nil, moduleName)
+
+	for _, key := range t.Keys() {
+		if err := rt.Set(key, t.Get(key)); err != nil {
+			panic(fmt.Errorf("failed to set '%s' global object: %w", key, err))
+		}
+	}
+}