Allow core modules to be loaded both with and without the 'node:' pre…

…fix.

.github/workflows/main.yml

@@ -11,15 +11,19 @@ jobs:
     runs-on: ${{ matrix.os }}
     steps:
       - name: Install Go
-        uses: actions/setup-go@v3
+        uses: actions/setup-go@v4
         with:
           go-version: ${{ matrix.go-version }}
       - name: Checkout code
         uses: actions/checkout@v3
       - name: Check formatting
         run: diff -u <(echo -n) <(gofmt -d .)
         if: runner.os != 'Windows'
+      - name: Run go vet
+        env:
+          GOARCH: ${{ matrix.arch }}
+        run: go vet ./...
       - name: Run tests
         env:
           GOARCH: ${{ matrix.arch }}
-        run: go test ./...
+        run: go test -vet=off ./...

buffer/buffer.go

@@ -14,7 +14,7 @@ import (
 	"golang.org/x/text/encoding/unicode"
 )
 
-const ModuleName = "node:buffer"
+const ModuleName = "buffer"
 
 type Buffer struct {
 	r *goja.Runtime
@@ -442,5 +442,5 @@ func Require(runtime *goja.Runtime, module *goja.Object) {
 }
 
 func init() {
-	require.RegisterNativeModule(ModuleName, Require)
+	require.RegisterCoreModule(ModuleName, Require)
 }

console/module.go

@@ -8,7 +8,7 @@ import (
 	"github.com/dop251/goja_nodejs/util"
 )
 
-const ModuleName = "node:console"
+const ModuleName = "console"
 
 type Console struct {
 	runtime *goja.Runtime
@@ -78,5 +78,5 @@ func Enable(runtime *goja.Runtime) {
 }
 
 func init() {
-	require.RegisterNativeModule(ModuleName, Require)
+	require.RegisterCoreModule(ModuleName, Require)
 }

process/module.go

@@ -8,6 +8,8 @@ import (
 	"github.com/dop251/goja_nodejs/require"
 )
 
+const ModuleName = "process"
+
 type Process struct {
 	env map[string]string
 }
@@ -27,9 +29,9 @@ func Require(runtime *goja.Runtime, module *goja.Object) {
 }
 
 func Enable(runtime *goja.Runtime) {
-	runtime.Set("process", require.Require(runtime, "process"))
+	runtime.Set("process", require.Require(runtime, ModuleName))
 }
 
 func init() {
-	require.RegisterNativeModule("process", Require)
+	require.RegisterCoreModule(ModuleName, Require)
 }

require/module.go

@@ -24,13 +24,13 @@ type ModuleLoader func(*js.Runtime, *js.Object)
 type SourceLoader func(path string) ([]byte, error)
 
 var (
-	InvalidModuleError     = errors.New("Invalid module")
-	IllegalModuleNameError = errors.New("Illegal module name")
-
+	InvalidModuleError          = errors.New("Invalid module")
+	IllegalModuleNameError      = errors.New("Illegal module name")
+	NoSuchBuiltInModuleError    = errors.New("No such built-in module")
 	ModuleFileDoesNotExistError = errors.New("module file does not exist")
 )
 
-var native map[string]ModuleLoader
+var native, builtin map[string]ModuleLoader
 
 // Registry contains a cache of compiled modules which can be used by multiple Runtimes
 type Registry struct {
@@ -217,10 +217,30 @@ func Require(runtime *js.Runtime, name string) js.Value {
 	panic(runtime.NewTypeError("Please enable require for this runtime using new(require.Registry).Enable(runtime)"))
 }
 
+// RegisterNativeModule registers a module that isn't loaded through a SourceLoader, but rather through
+// a provided ModuleLoader. Typically, this will be a module implemented in Go (although theoretically
+// it can be anything, depending on the ModuleLoader implementation).
+// Such modules take precedence over modules loaded through a SourceLoader, i.e. if a module name resolves as
+// native, the native module is loaded, and the SourceLoader is not consulted.
+// The binding is global and affects all instances of Registry.
+// It should be called from a package init() function as it may not be used concurrently with require() calls.
+// For registry-specific bindings see Registry.RegisterNativeModule.
 func RegisterNativeModule(name string, loader ModuleLoader) {
 	if native == nil {
 		native = make(map[string]ModuleLoader)
 	}
 	name = filepathClean(name)
 	native[name] = loader
 }
+
+// RegisterCoreModule registers a nodejs core module. If the name does not start with "node:", the module
+// will also be loadable as "node:<name>". Hence, for "builtin" modules (such as buffer, console, etc.)
+// the name should not include the "node:" prefix, but for prefix-only core modules (such as "node:test")
+// it should include the prefix.
+func RegisterCoreModule(name string, loader ModuleLoader) {
+	if builtin == nil {
+		builtin = make(map[string]ModuleLoader)
+	}
+	name = filepathClean(name)
+	builtin[name] = loader
+}

require/module_test.go

@@ -50,6 +50,84 @@ func TestRequireNativeModule(t *testing.T) {
 	}
 }
 
+func TestRegisterCoreModule(t *testing.T) {
+	vm := js.New()
+
+	registry := new(Registry)
+	registry.Enable(vm)
+
+	RegisterCoreModule("coremod", func(runtime *js.Runtime, module *js.Object) {
+		o := module.Get("exports").(*js.Object)
+		o.Set("test", func(call js.FunctionCall) js.Value {
+			return runtime.ToValue("passed")
+		})
+	})
+
+	RegisterCoreModule("coremod1", func(runtime *js.Runtime, module *js.Object) {
+		o := module.Get("exports").(*js.Object)
+		o.Set("test", func(call js.FunctionCall) js.Value {
+			return runtime.ToValue("passed1")
+		})
+	})
+
+	RegisterCoreModule("node:test1", func(runtime *js.Runtime, module *js.Object) {
+		o := module.Get("exports").(*js.Object)
+		o.Set("test", func(call js.FunctionCall) js.Value {
+			return runtime.ToValue("test1 passed")
+		})
+	})
+
+	registry.RegisterNativeModule("bob", func(runtime *js.Runtime, module *js.Object) {
+
+	})
+
+	_, err := vm.RunString(`
+	const m1 = require("coremod");
+	const m2 = require("node:coremod");
+	if (m1 !== m2) {
+		throw new Error("Modules are not equal");
+	}
+	if (m1.test() !== "passed") {
+		throw new Error("m1.test() has failed");
+	}
+
+	const m3 = require("node:coremod1");
+	const m4 = require("coremod1");
+	if (m3 !== m4) {
+		throw new Error("Modules are not equal (1)");
+	}
+	if (m3.test() !== "passed1") {
+		throw new Error("m3.test() has failed");
+	}
+
+	try {
+		require("node:bob");
+	} catch (e) {
+		if (!e.message.includes("No such built-in module")) {
+			throw e;
+		}
+	}
+	require("bob");
+
+	try {
+		require("test1");
+		throw new Error("Expected exception");
+	} catch (e) {
+		if (!e.message.includes("Invalid module")) {
+			throw e;
+		}
+	}
+
+	if (require("node:test1").test() !== "test1 passed") {
+		throw new Error("test1.test() has failed");
+	}
+	`)
+
+	if err != nil {
+		t.Fatal(err)
+	}
+}
+
 func TestRequireRegistryNativeModule(t *testing.T) {
 	const SCRIPT = `
 	var log = require("test/log");

require/resolve.go

@@ -9,6 +9,8 @@ import (
 	js "github.com/dop251/goja"
 )
 
+const NodePrefix = "node:"
+
 // NodeJS module search algorithm described by
 // https://nodejs.org/api/modules.html#modules_all_together
 func (r *RequireModule) resolve(modpath string) (module *js.Object, err error) {
@@ -41,7 +43,11 @@ func (r *RequireModule) resolve(modpath string) (module *js.Object, err error) {
 		if err == nil {
 			return
 		} else {
-			err = nil
+			if err == InvalidModuleError {
+				err = nil
+			} else {
+				return
+			}
 		}
 		if module = r.nodeModules[p]; module != nil {
 			return
@@ -69,9 +75,31 @@ func (r *RequireModule) loadNative(path string) (*js.Object, error) {
 		ldr = native[path]
 	}
 
+	var isBuiltIn, withPrefix bool
+	if ldr == nil {
+		ldr = builtin[path]
+		if ldr == nil && strings.HasPrefix(path, NodePrefix) {
+			ldr = builtin[path[len(NodePrefix):]]
+			if ldr == nil {
+				return nil, NoSuchBuiltInModuleError
+			}
+			withPrefix = true
+		}
+		isBuiltIn = true
+	}
+
 	if ldr != nil {
 		module = r.createModuleObject()
 		r.modules[path] = module
+		if isBuiltIn {
+			if withPrefix {
+				r.modules[path[len(NodePrefix):]] = module
+			} else {
+				if !strings.HasPrefix(path, NodePrefix) {
+					r.modules[NodePrefix+path] = module
+				}
+			}
+		}
 		ldr(r.runtime, module)
 		return module, nil
 	}

url/module.go

@@ -13,7 +13,7 @@ import (
 	"github.com/dop251/goja_nodejs/require"
 )
 
-const ModuleName = "node:url"
+const ModuleName = "url"
 
 var (
 	reflectTypeURL = reflect.TypeOf((*url.URL)(nil))
@@ -360,5 +360,5 @@ func Enable(runtime *goja.Runtime) {
 }
 
 func init() {
-	require.RegisterNativeModule(ModuleName, Require)
+	require.RegisterCoreModule(ModuleName, Require)
 }

util/module.go

@@ -6,7 +6,7 @@ import (
 	"github.com/dop251/goja_nodejs/require"
 )
 
-const ModuleName = "node:util"
+const ModuleName = "util"
 
 type Util struct {
 	runtime *goja.Runtime
@@ -100,5 +100,5 @@ func New(runtime *goja.Runtime) *Util {
 }
 
 func init() {
-	require.RegisterNativeModule(ModuleName, Require)
+	require.RegisterCoreModule(ModuleName, Require)
 }