Drop legacy require support

js/bundle.go

@@ -280,10 +280,10 @@ func (b *Bundle) instantiate(vuImpl *moduleVUImpl, vuID uint64) (*goja.Object, e
 		FileSystems:      b.filesystems,
 		CWD:              b.pwd,
 	}
+	vuImpl.initEnv = initenv
 
 	modSys := modules.NewModuleSystem(b.ModuleResolver, vuImpl)
 	b.setInitGlobals(rt, vuImpl, modSys)
-	vuImpl.initEnv = initenv
 	defer func() {
 		vuImpl.initEnv = nil
 	}()
@@ -303,7 +303,6 @@ func (b *Bundle) instantiate(vuImpl *moduleVUImpl, vuID uint64) (*goja.Object, e
 	var exportsV goja.Value
 	err = common.RunWithPanicCatching(b.preInitState.Logger, rt, func() error {
 		return vuImpl.eventLoop.Start(func() error {
-			//nolint:govet // here we shadow err on purpose
 			var err error
 			exportsV, err = modSys.RunSourceData(b.sourceData)
 			return err
@@ -369,17 +368,40 @@ func (b *Bundle) setupJSRuntime(rt *goja.Runtime, vuID int64, logger logrus.Fiel
 	return nil
 }
 
-// this exists only to make the check in the init context.
+// this exists to support `open` current behaviour and to check init context conformity
 type requireImpl struct {
-	inInitContext func() bool
-	internal      *modules.LegacyRequireImpl
+	vu     *moduleVUImpl
+	modSys *modules.ModuleSystem
 }
 
 func (r *requireImpl) require(specifier string) (*goja.Object, error) {
-	if !r.inInitContext() {
+	if r.vu.state != nil {
 		return nil, fmt.Errorf(cantBeUsedOutsideInitContextMsg, "require")
 	}
-	return r.internal.Require(specifier)
+	return r.modSys.Require(specifier)
+}
+
+// getPreviousRequiringFile is a helper that is currently need for the implemnetation of `open`.
+// it depends on the `require` method above
+func (r *requireImpl) getPreviousRequiringFile() (*url.URL, error) {
+	var buf [1000]goja.StackFrame
+
+	frames := r.vu.Runtime().CaptureCallStack(1000, buf[:0])
+
+	for i, frame := range frames[1:] { // first one should be the current require
+		// TODO have this precalculated automatically
+		if frame.FuncName() == "go.k6.io/k6/js.(*requireImpl).require-fm" {
+			// we need to get the one *before* but as we skip the first one the index matches ;)
+			return url.Parse(frames[i].SrcName())
+		}
+	}
+	// hopefully nobody is calling `require` with 1000 big stack :crossedfingers:
+	if len(frames) == 1000 {
+		return nil, errors.New("stack too big")
+	}
+
+	// fallback
+	return url.Parse(frames[len(frames)-1].SrcName())
 }
 
 func (b *Bundle) setInitGlobals(rt *goja.Runtime, vu *moduleVUImpl, modSys *modules.ModuleSystem) {
@@ -390,8 +412,8 @@ func (b *Bundle) setInitGlobals(rt *goja.Runtime, vu *moduleVUImpl, modSys *modu
 	}
 
 	impl := requireImpl{
-		inInitContext: func() bool { return vu.state == nil },
-		internal:      modules.NewLegacyRequireImpl(vu, modSys, *b.pwd),
+		vu:     vu,
+		modSys: modSys,
 	}
 
 	mustSet("require", impl.require)
@@ -406,8 +428,12 @@ func (b *Bundle) setInitGlobals(rt *goja.Runtime, vu *moduleVUImpl, modSys *modu
 			return nil, errors.New("open() can't be used with an empty filename")
 		}
 		// This uses the pwd from the requireImpl
-		pwd := impl.internal.CurrentlyRequiredModule()
-		return openImpl(rt, b.filesystems["file"], &pwd, filename, args...)
+		requiringFile, err := impl.getPreviousRequiringFile()
+		if err != nil {
+			return nil, err // TODO:wrap
+		}
+		pwd := loader.Dir(requiringFile)
+		return openImpl(rt, b.filesystems["file"], pwd, filename, args...)
 	})
 }
 

js/modules/resolution.go

@@ -1,6 +1,7 @@
 package modules
 
 import (
+	"errors"
 	"fmt"
 	"net/url"
 	"strings"
@@ -148,6 +149,7 @@ type ModuleSystem struct {
 	vu            VU
 	instanceCache map[module]moduleInstance
 	resolver      *ModuleResolver
+	backupCWD     *url.URL
 }
 
 // NewModuleSystem returns a new ModuleSystem for the provide VU using the provided resoluter
@@ -156,28 +158,56 @@ func NewModuleSystem(resolver *ModuleResolver, vu VU) *ModuleSystem {
 		resolver:      resolver,
 		instanceCache: make(map[module]moduleInstance),
 		vu:            vu,
+		backupCWD:     vu.InitEnv().CWD,
 	}
 }
 
 // Require is called when a module/file needs to be loaded by a script
-func (ms *ModuleSystem) Require(pwd *url.URL, arg string) (*goja.Object, error) {
-	mod, err := ms.resolver.resolve(pwd, arg)
+func (ms *ModuleSystem) Require(specifier string) (*goja.Object, error) {
+	if specifier == "" {
+		return nil, errors.New("require() can't be used with an empty specifier")
+	}
+
+	currentModuleURL, err := ms.getCurrentModuleScript()
+	if err != nil {
+		return nil, err
+	}
+
+	dir := loader.Dir(currentModuleURL)
+	if currentModuleURL.String() == "file://-" {
+		dir = ms.backupCWD
+	}
+
+	mod, err := ms.resolver.resolve(dir, specifier)
 	if err != nil {
 		return nil, err
 	}
+	return ms.instantiate(mod)
+}
+
+// Require is called when a module/file needs to be loaded by a script
+func (ms *ModuleSystem) instantiate(mod module) (*goja.Object, error) {
 	if instance, ok := ms.instanceCache[mod]; ok {
 		return instance.exports(), nil
 	}
 
 	instance := mod.instantiate(ms.vu)
 	ms.instanceCache[mod] = instance
-	if err = instance.execute(); err != nil {
+	if err := instance.execute(); err != nil {
 		return nil, err
 	}
 
 	return instance.exports(), nil
 }
 
+func (ms *ModuleSystem) getCurrentModuleScript() (*url.URL, error) {
+	var parent string
+	var buf [2]goja.StackFrame
+	frames := ms.vu.Runtime().CaptureCallStack(2, buf[:0])
+	parent = frames[1].SrcName()
+	return url.Parse(parent)
+}
+
 // RunSourceData runs the provided sourceData and adds it to the cache.
 // If a module with the same specifier as the source is already cached
 // it will be used instead of reevaluating the source from the provided SourceData.
@@ -187,8 +217,9 @@ func (ms *ModuleSystem) Require(pwd *url.URL, arg string) (*goja.Object, error)
 func (ms *ModuleSystem) RunSourceData(source *loader.SourceData) (goja.Value, error) {
 	specifier := source.URL.String()
 	pwd := source.URL.JoinPath("../")
-	if _, err := ms.resolver.resolveLoaded(pwd, specifier, source.Data); err != nil {
+	mod, err := ms.resolver.resolveLoaded(pwd, specifier, source.Data)
+	if err != nil {
 		return nil, err // TODO wrap as this should never happen
 	}
-	return ms.Require(pwd, specifier)
+	return ms.instantiate(mod)
 }

js/modulestest/runtime.go

@@ -3,7 +3,6 @@ package modulestest
 
 import (
 	"context"
-	"net/url"
 	"testing"
 
 	"github.com/dop251/goja"
@@ -104,6 +103,5 @@ func (r *Runtime) RunOnEventLoop(code string) (value goja.Value, err error) {
 
 func (r *Runtime) innerSetupModuleSystem() error {
 	ms := modules.NewModuleSystem(r.mr, r.VU)
-	impl := modules.NewLegacyRequireImpl(r.VU, ms, url.URL{})
-	return r.VU.RuntimeField.Set("require", impl.Require)
+	return r.VU.RuntimeField.Set("require", ms.Require)
 }