Clean up the css related template funcs package structure

Deprecate and move:

* resources.ToCSS => css.SASS
* resources.PostProcess => css.PostProcess
* resources.Babel => js.Babel

Updates #12618

7 files changed, 241 insertions, 162 deletions

diff --git a/tpl/css/css.go b/tpl/css/css.go
index 51fa1d518..145cb3aad 100644
--- a/tpl/css/css.go
+++ b/tpl/css/css.go
@@ -2,17 +2,40 @@ package css
 
 import (
 	"context"
+	"errors"
+	"fmt"
+	"sync"
 
+	"github.com/gohugoio/hugo/common/maps"
+	"github.com/gohugoio/hugo/common/paths"
 	"github.com/gohugoio/hugo/common/types/css"
 	"github.com/gohugoio/hugo/deps"
+	"github.com/gohugoio/hugo/resources"
+	"github.com/gohugoio/hugo/resources/resource"
+	"github.com/gohugoio/hugo/resources/resource_transformers/babel"
+	"github.com/gohugoio/hugo/resources/resource_transformers/postcss"
+	"github.com/gohugoio/hugo/resources/resource_transformers/tocss/dartsass"
+	"github.com/gohugoio/hugo/resources/resource_transformers/tocss/scss"
 	"github.com/gohugoio/hugo/tpl/internal"
+	"github.com/gohugoio/hugo/tpl/internal/resourcehelpers"
 	"github.com/spf13/cast"
 )
 
 const name = "css"
 
 // Namespace provides template functions for the "css" namespace.
-type Namespace struct{}
+type Namespace struct {
+	d                 *deps.Deps
+	scssClientLibSass *scss.Client
+	postcssClient     *postcss.Client
+	babelClient       *babel.Client
+
+	// The Dart Client requires a os/exec process, so  only
+	// create it if we really need it.
+	// This is mostly to avoid creating one per site build test.
+	scssClientDartSassInit sync.Once
+	scssClientDartSass     *dartsass.Client
+}
 
 // Quoted returns a string that needs to be quoted in CSS.
 func (ns *Namespace) Quoted(v any) css.QuotedString {
@@ -26,17 +49,135 @@ func (ns *Namespace) Unquoted(v any) css.UnquotedString {
 	return css.UnquotedString(s)
 }
 
+// PostCSS processes the given Resource with PostCSS.
+func (ns *Namespace) PostCSS(args ...any) (resource.Resource, error) {
+	if len(args) > 2 {
+		return nil, errors.New("must not provide more arguments than resource object and options")
+	}
+
+	r, m, err := resourcehelpers.ResolveArgs(args)
+	if err != nil {
+		return nil, err
+	}
+
+	return ns.postcssClient.Process(r, m)
+}
+
+// Sass processes the given Resource with Sass.
+func (ns *Namespace) Sass(args ...any) (resource.Resource, error) {
+	if len(args) > 2 {
+		return nil, errors.New("must not provide more arguments than resource object and options")
+	}
+
+	const (
+		// Transpiler implementation can be controlled from the client by
+		// setting the 'transpiler' option.
+		// Default is currently 'libsass', but that may change.
+		transpilerDart    = "dartsass"
+		transpilerLibSass = "libsass"
+	)
+
+	var (
+		r          resources.ResourceTransformer
+		m          map[string]any
+		targetPath string
+		err        error
+		ok         bool
+		transpiler = transpilerLibSass
+	)
+
+	r, targetPath, ok = resourcehelpers.ResolveIfFirstArgIsString(args)
+
+	if !ok {
+		r, m, err = resourcehelpers.ResolveArgs(args)
+		if err != nil {
+			return nil, err
+		}
+	}
+
+	if m != nil {
+		if t, _, found := maps.LookupEqualFold(m, "transpiler"); found {
+			switch t {
+			case transpilerDart, transpilerLibSass:
+				transpiler = cast.ToString(t)
+			default:
+				return nil, fmt.Errorf("unsupported transpiler %q; valid values are %q or %q", t, transpilerLibSass, transpilerDart)
+			}
+		}
+	}
+
+	if transpiler == transpilerLibSass {
+		var options scss.Options
+		if targetPath != "" {
+			options.TargetPath = paths.ToSlashTrimLeading(targetPath)
+		} else if m != nil {
+			options, err = scss.DecodeOptions(m)
+			if err != nil {
+				return nil, err
+			}
+		}
+
+		return ns.scssClientLibSass.ToCSS(r, options)
+	}
+
+	if m == nil {
+		m = make(map[string]any)
+	}
+	if targetPath != "" {
+		m["targetPath"] = targetPath
+	}
+
+	client, err := ns.getscssClientDartSass()
+	if err != nil {
+		return nil, err
+	}
+
+	return client.ToCSS(r, m)
+}
+
 func init() {
 	f := func(d *deps.Deps) *internal.TemplateFuncsNamespace {
-		ctx := &Namespace{}
+		scssClient, err := scss.New(d.BaseFs.Assets, d.ResourceSpec)
+		if err != nil {
+			panic(err)
+		}
+		ctx := &Namespace{
+			d:                 d,
+			scssClientLibSass: scssClient,
+			postcssClient:     postcss.New(d.ResourceSpec),
+			babelClient:       babel.New(d.ResourceSpec),
+		}
 
 		ns := &internal.TemplateFuncsNamespace{
 			Name:    name,
 			Context: func(cctx context.Context, args ...any) (any, error) { return ctx, nil },
 		}
 
+		ns.AddMethodMapping(ctx.Sass,
+			[]string{"toCSS"},
+			[][2]string{},
+		)
+
+		ns.AddMethodMapping(ctx.PostCSS,
+			[]string{"postCSS"},
+			[][2]string{},
+		)
+
 		return ns
 	}
 
 	internal.AddTemplateFuncsNamespace(f)
 }
+
+func (ns *Namespace) getscssClientDartSass() (*dartsass.Client, error) {
+	var err error
+	ns.scssClientDartSassInit.Do(func() {
+		ns.scssClientDartSass, err = dartsass.New(ns.d.BaseFs.Assets, ns.d.ResourceSpec)
+		if err != nil {
+			return
+		}
+		ns.d.BuildClosers.Add(ns.scssClientDartSass)
+	})
+
+	return ns.scssClientDartSass, err
+}
diff --git a/tpl/internal/templatefuncsRegistry.go b/tpl/internal/templatefuncsRegistry.go
index fc02a6ef9..1b74bf443 100644
--- a/tpl/internal/templatefuncsRegistry.go
+++ b/tpl/internal/templatefuncsRegistry.go
@@ -51,6 +51,9 @@ type TemplateFuncsNamespace struct {
 	// This is the method receiver.
 	Context func(ctx context.Context, v ...any) (any, error)
 
+	// OnCreated is called when all the namespaces are ready.
+	OnCreated func(namespaces map[string]any)
+
 	// Additional info, aliases and examples, per method name.
 	MethodMappings map[string]TemplateFuncMethodMapping
 }
diff --git a/tpl/js/init.go b/tpl/js/init.go
index 16e6c7efa..69d7c7275 100644
--- a/tpl/js/init.go
+++ b/tpl/js/init.go
@@ -31,6 +31,11 @@ func init() {
 			Context: func(cctx context.Context, args ...any) (any, error) { return ctx, nil },
 		}
 
+		ns.AddMethodMapping(ctx.Babel,
+			[]string{"babel"},
+			[][2]string{},
+		)
+
 		return ns
 	}
 
diff --git a/tpl/js/js.go b/tpl/js/js.go
index 63a676532..c68e0af92 100644
--- a/tpl/js/js.go
+++ b/tpl/js/js.go
@@ -15,9 +15,12 @@
 package js
 
 import (
+	"errors"
+
 	"github.com/gohugoio/hugo/deps"
 	"github.com/gohugoio/hugo/resources"
 	"github.com/gohugoio/hugo/resources/resource"
+	"github.com/gohugoio/hugo/resources/resource_transformers/babel"
 	"github.com/gohugoio/hugo/resources/resource_transformers/js"
 	"github.com/gohugoio/hugo/tpl/internal/resourcehelpers"
 )
@@ -28,13 +31,15 @@ func New(deps *deps.Deps) *Namespace {
 		return &Namespace{}
 	}
 	return &Namespace{
-		client: js.New(deps.BaseFs.Assets, deps.ResourceSpec),
+		client:      js.New(deps.BaseFs.Assets, deps.ResourceSpec),
+		babelClient: babel.New(deps.ResourceSpec),
 	}
 }
 
 // Namespace provides template functions for the "js" namespace.
 type Namespace struct {
-	client *js.Client
+	client      *js.Client
+	babelClient *babel.Client
 }
 
 // Build processes the given Resource with ESBuild.
@@ -62,3 +67,24 @@ func (ns *Namespace) Build(args ...any) (resource.Resource, error) {
 
 	return ns.client.Process(r, m)
 }
+
+// Babel processes the given Resource with Babel.
+func (ns *Namespace) Babel(args ...any) (resource.Resource, error) {
+	if len(args) > 2 {
+		return nil, errors.New("must not provide more arguments than resource object and options")
+	}
+
+	r, m, err := resourcehelpers.ResolveArgs(args)
+	if err != nil {
+		return nil, err
+	}
+	var options babel.Options
+	if m != nil {
+		options, err = babel.DecodeOptions(m)
+		if err != nil {
+			return nil, err
+		}
+	}
+
+	return ns.babelClient.Process(r, options)
+}
diff --git a/tpl/resources/init.go b/tpl/resources/init.go
index db51b0287..5cea482ac 100644
--- a/tpl/resources/init.go
+++ b/tpl/resources/init.go
@@ -17,7 +17,9 @@ import (
 	"context"
 
 	"github.com/gohugoio/hugo/deps"
+	"github.com/gohugoio/hugo/tpl/css"
 	"github.com/gohugoio/hugo/tpl/internal"
+	"github.com/gohugoio/hugo/tpl/js"
 )
 
 const name = "resources"
@@ -33,6 +35,22 @@ func init() {
 		ns := &internal.TemplateFuncsNamespace{
 			Name:    name,
 			Context: func(cctx context.Context, args ...any) (any, error) { return ctx, nil },
+			OnCreated: func(m map[string]any) {
+				for _, v := range m {
+					switch v := v.(type) {
+					case *css.Namespace:
+						ctx.cssNs = v
+					case *js.Namespace:
+						ctx.jsNs = v
+					}
+				}
+				if ctx.cssNs == nil {
+					panic("css namespace not found")
+				}
+				if ctx.jsNs == nil {
+					panic("js namespace not found")
+				}
+			},
 		}
 
 		ns.AddMethodMapping(ctx.Get,
@@ -57,21 +75,6 @@ func init() {
 			[][2]string{},
 		)
 
-		ns.AddMethodMapping(ctx.ToCSS,
-			[]string{"toCSS"},
-			[][2]string{},
-		)
-
-		ns.AddMethodMapping(ctx.PostCSS,
-			[]string{"postCSS"},
-			[][2]string{},
-		)
-
-		ns.AddMethodMapping(ctx.Babel,
-			[]string{"babel"},
-			[][2]string{},
-		)
-
 		return ns
 	}
 
diff --git a/tpl/resources/resources.go b/tpl/resources/resources.go
index 34b4464be..78340b1ff 100644
--- a/tpl/resources/resources.go
+++ b/tpl/resources/resources.go
@@ -18,12 +18,12 @@ import (
 	"context"
 	"errors"
 	"fmt"
-	"sync"
 
+	"github.com/gohugoio/hugo/common/hugo"
 	"github.com/gohugoio/hugo/common/maps"
-	"github.com/gohugoio/hugo/common/paths"
 
-	"github.com/gohugoio/hugo/tpl/internal/resourcehelpers"
+	"github.com/gohugoio/hugo/tpl/css"
+	"github.com/gohugoio/hugo/tpl/js"
 
 	"github.com/gohugoio/hugo/resources/postpub"
 
@@ -33,13 +33,9 @@ import (
 
 	"github.com/gohugoio/hugo/resources/resource_factories/bundler"
 	"github.com/gohugoio/hugo/resources/resource_factories/create"
-	"github.com/gohugoio/hugo/resources/resource_transformers/babel"
 	"github.com/gohugoio/hugo/resources/resource_transformers/integrity"
 	"github.com/gohugoio/hugo/resources/resource_transformers/minifier"
-	"github.com/gohugoio/hugo/resources/resource_transformers/postcss"
 	"github.com/gohugoio/hugo/resources/resource_transformers/templates"
-	"github.com/gohugoio/hugo/resources/resource_transformers/tocss/dartsass"
-	"github.com/gohugoio/hugo/resources/resource_transformers/tocss/scss"
 
 	"github.com/spf13/cast"
 )
@@ -50,26 +46,18 @@ func New(deps *deps.Deps) (*Namespace, error) {
 		return &Namespace{}, nil
 	}
 
-	scssClient, err := scss.New(deps.BaseFs.Assets, deps.ResourceSpec)
-	if err != nil {
-		return nil, err
-	}
-
 	minifyClient, err := minifier.New(deps.ResourceSpec)
 	if err != nil {
 		return nil, err
 	}
 
 	return &Namespace{
-		deps:              deps,
-		scssClientLibSass: scssClient,
-		createClient:      create.New(deps.ResourceSpec),
-		bundlerClient:     bundler.New(deps.ResourceSpec),
-		integrityClient:   integrity.New(deps.ResourceSpec),
-		minifyClient:      minifyClient,
-		postcssClient:     postcss.New(deps.ResourceSpec),
-		templatesClient:   templates.New(deps.ResourceSpec, deps),
-		babelClient:       babel.New(deps.ResourceSpec),
+		deps:            deps,
+		createClient:    create.New(deps.ResourceSpec),
+		bundlerClient:   bundler.New(deps.ResourceSpec),
+		integrityClient: integrity.New(deps.ResourceSpec),
+		minifyClient:    minifyClient,
+		templatesClient: templates.New(deps.ResourceSpec, deps),
 	}, nil
 }
 
@@ -79,33 +67,16 @@ var _ resource.ResourceFinder = (*Namespace)(nil)
 type Namespace struct {
 	deps *deps.Deps
 
-	createClient      *create.Client
-	bundlerClient     *bundler.Client
-	scssClientLibSass *scss.Client
-	integrityClient   *integrity.Client
-	minifyClient      *minifier.Client
-	postcssClient     *postcss.Client
-	babelClient       *babel.Client
-	templatesClient   *templates.Client
-
-	// The Dart Client requires a os/exec process, so  only
-	// create it if we really need it.
-	// This is mostly to avoid creating one per site build test.
-	scssClientDartSassInit sync.Once
-	scssClientDartSass     *dartsass.Client
-}
-
-func (ns *Namespace) getscssClientDartSass() (*dartsass.Client, error) {
-	var err error
-	ns.scssClientDartSassInit.Do(func() {
-		ns.scssClientDartSass, err = dartsass.New(ns.deps.BaseFs.Assets, ns.deps.ResourceSpec)
-		if err != nil {
-			return
-		}
-		ns.deps.BuildClosers.Add(ns.scssClientDartSass)
-	})
+	createClient    *create.Client
+	bundlerClient   *bundler.Client
+	integrityClient *integrity.Client
+	minifyClient    *minifier.Client
+	templatesClient *templates.Client
 
-	return ns.scssClientDartSass, err
+	// We moved some CSS and JS related functions to the css and js package in Hugo 0.128.0.
+	// Keep this here until the deprecation period is over.
+	cssNs *css.Namespace
+	jsNs  *js.Namespace
 }
 
 // Copy copies r to the new targetPath in s.
@@ -337,89 +308,17 @@ func (ns *Namespace) Minify(r resources.ResourceTransformer) (resource.Resource,
 // ToCSS converts the given Resource to CSS. You can optional provide an Options object
 // as second argument. As an option, you can e.g. specify e.g. the target path (string)
 // for the converted CSS resource.
+// Deprecated: Moved to the css namespace in Hugo 0.128.0.
 func (ns *Namespace) ToCSS(args ...any) (resource.Resource, error) {
-	if len(args) > 2 {
-		return nil, errors.New("must not provide more arguments than resource object and options")
-	}
-
-	const (
-		// Transpiler implementation can be controlled from the client by
-		// setting the 'transpiler' option.
-		// Default is currently 'libsass', but that may change.
-		transpilerDart    = "dartsass"
-		transpilerLibSass = "libsass"
-	)
-
-	var (
-		r          resources.ResourceTransformer
-		m          map[string]any
-		targetPath string
-		err        error
-		ok         bool
-		transpiler = transpilerLibSass
-	)
-
-	r, targetPath, ok = resourcehelpers.ResolveIfFirstArgIsString(args)
-
-	if !ok {
-		r, m, err = resourcehelpers.ResolveArgs(args)
-		if err != nil {
-			return nil, err
-		}
-	}
-
-	if m != nil {
-		if t, _, found := maps.LookupEqualFold(m, "transpiler"); found {
-			switch t {
-			case transpilerDart, transpilerLibSass:
-				transpiler = cast.ToString(t)
-			default:
-				return nil, fmt.Errorf("unsupported transpiler %q; valid values are %q or %q", t, transpilerLibSass, transpilerDart)
-			}
-		}
-	}
-
-	if transpiler == transpilerLibSass {
-		var options scss.Options
-		if targetPath != "" {
-			options.TargetPath = paths.ToSlashTrimLeading(targetPath)
-		} else if m != nil {
-			options, err = scss.DecodeOptions(m)
-			if err != nil {
-				return nil, err
-			}
-		}
-
-		return ns.scssClientLibSass.ToCSS(r, options)
-	}
-
-	if m == nil {
-		m = make(map[string]any)
-	}
-	if targetPath != "" {
-		m["targetPath"] = targetPath
-	}
-
-	client, err := ns.getscssClientDartSass()
-	if err != nil {
-		return nil, err
-	}
-
-	return client.ToCSS(r, m)
+	hugo.Deprecate("resources.ToCSS", "Use css.SASS.", "v0.128.0")
+	return ns.cssNs.Sass(args...)
 }
 
-// PostCSS processes the given Resource with PostCSS
+// PostCSS processes the given Resource with PostCSS.
+// Deprecated: Moved to the css namespace in Hugo 0.128.0.
 func (ns *Namespace) PostCSS(args ...any) (resource.Resource, error) {
-	if len(args) > 2 {
-		return nil, errors.New("must not provide more arguments than resource object and options")
-	}
-
-	r, m, err := resourcehelpers.ResolveArgs(args)
-	if err != nil {
-		return nil, err
-	}
-
-	return ns.postcssClient.Process(r, m)
+	hugo.Deprecate("resources.PostCSS", "Use css.PostCSS.", "v0.128.0")
+	return ns.cssNs.PostCSS(args...)
 }
 
 // PostProcess processes r after the build.
@@ -428,22 +327,8 @@ func (ns *Namespace) PostProcess(r resource.Resource) (postpub.PostPublishedReso
 }
 
 // Babel processes the given Resource with Babel.
+// Deprecated: Moved to the js namespace in Hugo 0.128.0.
 func (ns *Namespace) Babel(args ...any) (resource.Resource, error) {
-	if len(args) > 2 {
-		return nil, errors.New("must not provide more arguments than resource object and options")
-	}
-
-	r, m, err := resourcehelpers.ResolveArgs(args)
-	if err != nil {
-		return nil, err
-	}
-	var options babel.Options
-	if m != nil {
-		options, err = babel.DecodeOptions(m)
-		if err != nil {
-			return nil, err
-		}
-	}
-
-	return ns.babelClient.Process(r, options)
+	hugo.Deprecate("resources.Babel", "Use js.Babel.", "v0.128.0")
+	return ns.jsNs.Babel(args...)
 }
diff --git a/tpl/tplimpl/template_funcs.go b/tpl/tplimpl/template_funcs.go
index e5ee4d54f..815270631 100644
--- a/tpl/tplimpl/template_funcs.go
+++ b/tpl/tplimpl/template_funcs.go
@@ -252,6 +252,9 @@ func newTemplateExecuter(d *deps.Deps) (texttemplate.Executer, map[string]reflec
 func createFuncMap(d *deps.Deps) map[string]any {
 	funcMap := template.FuncMap{}
 
+	nsMap := make(map[string]any)
+	var onCreated []func(namespaces map[string]any)
+
 	// Merge the namespace funcs
 	for _, nsf := range internal.TemplateFuncsNamespaceRegistry {
 		ns := nsf(d)
@@ -259,6 +262,11 @@ func createFuncMap(d *deps.Deps) map[string]any {
 			panic(ns.Name + " is a duplicate template func")
 		}
 		funcMap[ns.Name] = ns.Context
+		contextV, err := ns.Context(context.Background())
+		if err != nil {
+			panic(err)
+		}
+		nsMap[ns.Name] = contextV
 		for _, mm := range ns.MethodMappings {
 			for _, alias := range mm.Aliases {
 				if _, exists := funcMap[alias]; exists {
@@ -267,6 +275,14 @@ func createFuncMap(d *deps.Deps) map[string]any {
 				funcMap[alias] = mm.Method
 			}
 		}
+
+		if ns.OnCreated != nil {
+			onCreated = append(onCreated, ns.OnCreated)
+		}
+	}
+
+	for _, f := range onCreated {
+		f(nsMap)
 	}
 
 	if d.OverloadedTemplateFuncs != nil {