Add resource vendoring

Fixes #13309

Author: bep

Diff for: commands/commandeer.go

@@ -365,7 +365,11 @@ func (r *rootCommand) Name() string {
 }
 
 func (r *rootCommand) Run(ctx context.Context, cd *simplecobra.Commandeer, args []string) error {
-	b := newHugoBuilder(r, nil)
+	var vendor bool
+	if vendorCmd, ok := cd.Command.(vendoredCommand); ok {
+		vendor = vendorCmd.IsVendorCommand()
+	}
+	b := newHugoBuilder(r, nil, vendor)
 
 	if !r.buildWatch {
 		defer b.postBuild("Total", time.Now())

Diff for: commands/commands.go

@@ -23,7 +23,8 @@ import (
 func newExec() (*simplecobra.Exec, error) {
 	rootCmd := &rootCommand{
 		commands: []simplecobra.Commander{
-			newHugoBuildCmd(),
+			newHugoBuildCmd(false),
+			newHugoBuildCmd(true),
 			newVersionCmd(),
 			newEnvCommand(),
 			newServerCommand(),
@@ -42,26 +43,40 @@ func newExec() (*simplecobra.Exec, error) {
 	return simplecobra.New(rootCmd)
 }
 
-func newHugoBuildCmd() simplecobra.Commander {
-	return &hugoBuildCommand{}
+func newHugoBuildCmd(vendor bool) simplecobra.Commander {
+	return &hugoBuildCommand{
+		vendor: vendor,
+	}
 }
 
 // hugoBuildCommand just delegates to the rootCommand.
 type hugoBuildCommand struct {
 	rootCmd *rootCommand
+	vendor  bool
 }
 
 func (c *hugoBuildCommand) Commands() []simplecobra.Commander {
 	return nil
 }
 
 func (c *hugoBuildCommand) Name() string {
+	if c.vendor {
+		return "vendor"
+	}
 	return "build"
 }
 
+type vendoredCommand interface {
+	IsVendorCommand() bool
+}
+
+func (c *hugoBuildCommand) IsVendorCommand() bool {
+	return c.vendor
+}
+
 func (c *hugoBuildCommand) Init(cd *simplecobra.Commandeer) error {
 	c.rootCmd = cd.Root.Command.(*rootCommand)
-	return c.rootCmd.initRootCommand("build", cd)
+	return c.rootCmd.initRootCommand(c.Name(), cd)
 }
 
 func (c *hugoBuildCommand) PreRun(cd, runner *simplecobra.Commandeer) error {

Diff for: commands/hugobuilder.go

@@ -73,6 +73,8 @@ type hugoBuilder struct {
 	showErrorInBrowser bool
 
 	errState hugoBuilderErrState
+
+	vendor bool
 }
 
 var errConfigNotSet = errors.New("config not set")
@@ -1046,11 +1048,11 @@ func (c *hugoBuilder) loadConfig(cd *simplecobra.Commandeer, running bool) error
 		}
 	}
 	cfg.Set("environment", c.r.environment)
-
 	cfg.Set("internal", maps.Params{
 		"running":        running,
 		"watch":          watch,
 		"verbose":        c.r.isVerbose(),
+		"vendor":         c.vendor,
 		"fastRenderMode": c.fastRenderMode,
 	})
 

Diff for: commands/server.go

@@ -84,14 +84,15 @@ const (
 	configChangeGoWork = "go work file"
 )
 
-func newHugoBuilder(r *rootCommand, s *serverCommand, onConfigLoaded ...func(reloaded bool) error) *hugoBuilder {
+func newHugoBuilder(r *rootCommand, s *serverCommand, vendor bool, onConfigLoaded ...func(reloaded bool) error) *hugoBuilder {
 	var visitedURLs *types.EvictingQueue[string]
 	if s != nil && !s.disableFastRender {
 		visitedURLs = types.NewEvictingQueue[string](20)
 	}
 	return &hugoBuilder{
 		r:              r,
 		s:              s,
+		vendor:         vendor,
 		visitedURLs:    visitedURLs,
 		fullRebuildSem: semaphore.NewWeighted(1),
 		debounce:       debounce.New(4 * time.Second),
@@ -563,6 +564,7 @@ func (c *serverCommand) PreRun(cd, runner *simplecobra.Commandeer) error {
 	c.hugoBuilder = newHugoBuilder(
 		c.r,
 		c,
+		false,
 		func(reloaded bool) error {
 			if !reloaded {
 				if err := c.createServerPorts(cd); err != nil {

Diff for: common/hugo/hugo.go

@@ -109,6 +109,11 @@ func (i HugoInfo) IsExtended() bool {
 	return IsExtended
 }
 
+// IsVendor returns whether we're running as `hugo vendor`.
+func (i HugoInfo) IsVendor() bool {
+	return i.conf.Vendor()
+}
+
 // WorkingDir returns the project working directory.
 func (i HugoInfo) WorkingDir() string {
 	return i.conf.WorkingDir()
@@ -166,6 +171,7 @@ type ConfigProvider interface {
 	WorkingDir() string
 	IsMultihost() bool
 	IsMultilingual() bool
+	Vendor() bool
 }
 
 // NewInfo creates a new Hugo Info object.

Diff for: config/allconfig/allconfig.go

@@ -69,6 +69,7 @@ type InternalConfig struct {
 	Watch          bool
 	FastRenderMode bool
 	LiveReloadPort int
+	Vendor         bool
 }
 
 // All non-params config keys for language.

Diff for: config/allconfig/configlanguage.go

@@ -137,6 +137,10 @@ func (c ConfigLanguage) Watching() bool {
 	return c.m.Base.Internal.Watch
 }
 
+func (c ConfigLanguage) Vendor() bool {
+	return c.m.Base.Internal.Vendor
+}
+
 func (c ConfigLanguage) NewIdentityManager(name string, opts ...identity.ManagerOption) identity.Manager {
 	if !c.Watching() {
 		return identity.NopManager

Diff for: config/configProvider.go

@@ -58,6 +58,7 @@ type AllProvider interface {
 	BuildDrafts() bool
 	Running() bool
 	Watching() bool
+	Vendor() bool
 	NewIdentityManager(name string, opts ...identity.ManagerOption) identity.Manager
 	FastRenderMode() bool
 	PrintUnusedTemplates() bool

Diff for: hugolib/integrationtest_builder.go

@@ -665,17 +665,18 @@ func (s *IntegrationTestBuilder) initBuilder() error {
 			flags = config.New()
 		}
 
+		internal := make(maps.Params)
+
 		if s.Cfg.Running {
-			flags.Set("internal", maps.Params{
-				"running": s.Cfg.Running,
-				"watch":   s.Cfg.Running,
-			})
+			internal["running"] = true
+			internal["watch"] = true
+
 		} else if s.Cfg.Watching {
-			flags.Set("internal", maps.Params{
-				"watch": s.Cfg.Watching,
-			})
+			internal["watch"] = true
 		}
 
+		flags.Set("internal", internal)
+
 		if s.Cfg.WorkingDir != "" {
 			flags.Set("workingDir", s.Cfg.WorkingDir)
 		}

Diff for: internal/js/esbuild/build.go

@@ -34,14 +34,14 @@ import (
 // NewBuildClient creates a new BuildClient.
 func NewBuildClient(fs *filesystems.SourceFilesystem, rs *resources.Spec) *BuildClient {
 	return &BuildClient{
-		rs:  rs,
+		Rs:  rs,
 		sfs: fs,
 	}
 }
 
 // BuildClient is a client for building JavaScript resources using esbuild.
 type BuildClient struct {
-	rs  *resources.Spec
+	Rs  *resources.Spec
 	sfs *filesystems.SourceFilesystem
 }
 
@@ -52,11 +52,11 @@ func (c *BuildClient) Build(opts Options) (api.BuildResult, error) {
 		dependencyManager = identity.NopManager
 	}
 
-	opts.OutDir = c.rs.AbsPublishDir
-	opts.ResolveDir = c.rs.Cfg.BaseConfig().WorkingDir // where node_modules gets resolved
+	opts.OutDir = c.Rs.AbsPublishDir
+	opts.ResolveDir = c.Rs.Cfg.BaseConfig().WorkingDir // where node_modules gets resolved
 	opts.AbsWorkingDir = opts.ResolveDir
-	opts.TsConfig = c.rs.ResolveJSConfigFile("tsconfig.json")
-	assetsResolver := newFSResolver(c.rs.Assets.Fs)
+	opts.TsConfig = c.Rs.ResolveJSConfigFile("tsconfig.json")
+	assetsResolver := newFSResolver(c.Rs.Assets.Fs)
 
 	if err := opts.validate(); err != nil {
 		return api.BuildResult{}, err
@@ -67,7 +67,7 @@ func (c *BuildClient) Build(opts Options) (api.BuildResult, error) {
 	}
 
 	var err error
-	opts.compiled.Plugins, err = createBuildPlugins(c.rs, assetsResolver, dependencyManager, opts)
+	opts.compiled.Plugins, err = createBuildPlugins(c.Rs, assetsResolver, dependencyManager, opts)
 	if err != nil {
 		return api.BuildResult{}, err
 	}
@@ -175,7 +175,7 @@ func (c *BuildClient) Build(opts Options) (api.BuildResult, error) {
 		// Return 1, log the rest.
 		for i, err := range errors {
 			if i > 0 {
-				c.rs.Logger.Errorf("js.Build failed: %s", err)
+				c.Rs.Logger.Errorf("js.Build failed: %s", err)
 			}
 		}
 

Diff for: resources/internal/vendor/vendor.go

@@ -0,0 +1,109 @@
+// Copyright 2025 The Hugo Authors. All rights reserved.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+// http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package vendor
+
+import (
+	"io"
+	"path/filepath"
+
+	"github.com/cespare/xxhash/v2"
+	"github.com/gohugoio/hugo/common/herrors"
+	"github.com/gohugoio/hugo/common/hugio"
+	"github.com/gohugoio/hugo/helpers"
+	"github.com/spf13/afero"
+)
+
+var _ io.Closer = (*ResourceVendor)(nil)
+
+type ResourceVendor struct {
+	// For the from hash.
+	Digest *xxhash.Digest
+
+	closeFunc func() error
+
+	VendoredFile hugio.ReadSeekCloser
+
+	// TODO1 names.
+	FinalFrom io.Reader
+	FinalTo   io.Writer
+}
+
+func (v *ResourceVendor) Close() error {
+	if v.closeFunc != nil {
+		return v.closeFunc()
+	}
+	return nil
+}
+
+func NewVendorer(fs afero.Fs, workingDir string) *Vendorer {
+	return &Vendorer{
+		fs:         fs,
+		workingDir: workingDir,
+	}
+}
+
+type Vendorer struct {
+	fs         afero.Fs
+	workingDir string
+}
+
+type ResourceVendorOptions struct {
+	Name   string
+	InPath string
+	From   io.Reader
+	To     io.Writer
+}
+
+const (
+	vendorRoot      = "_vendor"
+	vendorModules   = "mod"
+	vendorResources = "res"
+	vendorScopeAll  = "_all"
+)
+
+// TODO1 add --vendorScope=* or {development,production} e.g. Encode it into the root folder. Or: At least create a "all" root folder for future use.
+// add resources.txt to root with file/hash listing + version.
+func (v *Vendorer) NewResourceVendor(opts ResourceVendorOptions) (*ResourceVendor, error) {
+	digest := xxhash.New()
+	finalFrom := io.TeeReader(opts.From, digest)
+	vendorFileName := filepath.Join(v.workingDir, vendorRoot, vendorResources, vendorScopeAll, opts.Name, opts.InPath)
+	vendoredFile, err := helpers.OpenFileForWriting(v.fs, vendorFileName)
+	if err != nil {
+		return nil, err
+	}
+	finalTo := io.MultiWriter(opts.To, vendoredFile)
+	return &ResourceVendor{
+		Digest:    digest,
+		FinalFrom: finalFrom,
+		FinalTo:   finalTo,
+		closeFunc: vendoredFile.Close,
+	}, nil
+}
+
+// OpenVendoredFile opens a vendored file for reading or nil if not found.
+func (v *Vendorer) OpenVendoredFile(opts ResourceVendorOptions) (hugio.ReadSeekCloser, error) {
+	vendorFileName := v.vendorFilename(opts)
+	f, err := v.fs.Open(vendorFileName)
+	if err != nil {
+		if herrors.IsNotExist(err) {
+			return nil, nil
+		}
+		return nil, err
+	}
+	return f, nil
+}
+
+func (v *Vendorer) vendorFilename(opts ResourceVendorOptions) string {
+	return filepath.Join(v.workingDir, vendorRoot, vendorResources, vendorScopeAll, opts.Name, opts.InPath)
+}

Diff for: resources/internal/vendor/vendor_test.go

@@ -0,0 +1,19 @@
+// Copyright 2025 The Hugo Authors. All rights reserved.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+// http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package vendor
+
+import "testing"
+
+func TestResourceVendor(t *testing.T) {
+}

Diff for: resources/resource_spec.go

@@ -22,6 +22,7 @@ import (
 	"github.com/gohugoio/hugo/config/allconfig"
 	"github.com/gohugoio/hugo/output"
 	"github.com/gohugoio/hugo/resources/internal"
+	"github.com/gohugoio/hugo/resources/internal/vendor"
 	"github.com/gohugoio/hugo/resources/jsconfig"
 	"github.com/gohugoio/hugo/resources/page/pagemeta"
 
@@ -103,6 +104,7 @@ func NewSpec(
 			memCache,
 			s,
 		),
+		Vendorer:   vendor.NewVendorer(s.SourceFs, s.Cfg.WorkingDir()),
 		ExecHelper: execHelper,
 
 		Permalinks: permalinks,
@@ -122,6 +124,7 @@ type Spec struct {
 	ErrorSender  herrors.ErrorSender
 	BuildClosers types.CloseAdder
 	Rebuilder    identity.SignalRebuilder
+	Vendorer     *vendor.Vendorer
 
 	TextTemplates tpl.TemplateParseFinder