Add css.TailwindCSS

Closes gohugoio#12618

resources/resource_transformers/postcss/postcss.go

@@ -400,6 +400,11 @@ func (imp *importResolver) shouldImport(s string) bool {
 		return false
 	}
 
+	// TODO1
+	if strings.Contains(s, "tailwindcss") {
+		return false
+	}
+
 	return shouldImportRe.MatchString(s)
 }
 

resources/resource_transformers/postcss/tailwindcss.go

@@ -0,0 +1,141 @@
+// Copyright 2024 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 postcss
+
+import (
+	"bytes"
+	"fmt"
+	"io"
+
+	"github.com/gohugoio/hugo/common/herrors"
+	"github.com/gohugoio/hugo/common/hexec"
+	"github.com/gohugoio/hugo/common/hugo"
+	"github.com/gohugoio/hugo/common/loggers"
+	"github.com/gohugoio/hugo/resources"
+	"github.com/gohugoio/hugo/resources/internal"
+	"github.com/gohugoio/hugo/resources/resource"
+)
+
+// NewTailwindCSSClient creates a new TailwindCSSClient with the given specification.
+func NewTailwindCSSClient(rs *resources.Spec) *TailwindCSSClient {
+	return &TailwindCSSClient{rs: rs}
+}
+
+// Client is the client used to do TailwindCSS transformations.
+type TailwindCSSClient struct {
+	rs *resources.Spec
+}
+
+// Process transforms the given Resource with the PostCSS processor.
+func (c *TailwindCSSClient) Process(res resources.ResourceTransformer, options map[string]any) (resource.Resource, error) {
+	return res.Transform(&tailwindcssTransformation{rs: c.rs, optionsm: options})
+}
+
+type tailwindcssTransformation struct {
+	optionsm map[string]any
+	rs       *resources.Spec
+}
+
+func (t *tailwindcssTransformation) Key() internal.ResourceTransformationKey {
+	return internal.NewResourceTransformationKey("tailwindcss", t.optionsm)
+}
+
+type TailwindCSSOptions struct{}
+
+func debug(what ...any) {
+	fmt.Println(what...) // TODO1
+}
+
+func (t *tailwindcssTransformation) Transform(ctx *resources.ResourceTransformationCtx) error {
+	const binaryName = "tailwindcss"
+
+	debug(binaryName)
+
+	infol := t.rs.Logger.InfoCommand(binaryName)
+	infow := loggers.LevelLoggerToWriter(infol)
+
+	ex := t.rs.ExecHelper
+
+	// The tailwindcss CLI does not support streaming, so we need to write to temporary files.
+	// tempDir := os.TempDir()
+	// defer os.RemoveAll(tempDir)
+
+	// outFilename := filepath.Join(tempDir, "hugo-tailwind-out.css")
+	workingDir := t.rs.Cfg.BaseConfig().WorkingDir
+
+	var cmdArgs []any = []any{
+		"--input=-", // Read from stdin.
+		//"--output", outFilename,
+		//"--cwd", workingDir,
+		"--optimize", // TDOO1 opts also: minimize?
+	}
+
+	// TODO1
+	//   npm i tailwindcss @tailwindcss/cli
+	// npm i tailwindcss@next @tailwindcss/cli@next
+	// npx tailwindcss -h
+
+	var errBuf bytes.Buffer
+
+	stderr := io.MultiWriter(infow, &errBuf)
+	cmdArgs = append(cmdArgs, hexec.WithStderr(stderr))
+	cmdArgs = append(cmdArgs, hexec.WithStdout(ctx.To))
+	cmdArgs = append(cmdArgs, hexec.WithEnviron(hugo.GetExecEnviron(workingDir, t.rs.Cfg, t.rs.BaseFs.Assets.Fs)))
+
+	cmd, err := ex.Npx(binaryName, cmdArgs...)
+	if err != nil {
+		if hexec.IsNotFound(err) {
+			// This may be on a CI server etc. Will fall back to pre-built assets.
+			return &herrors.FeatureNotAvailableError{Cause: err}
+		}
+		return err
+	}
+
+	stdin, err := cmd.StdinPipe()
+	if err != nil {
+		return err
+	}
+
+	src := ctx.From
+
+	imp := newImportResolver(
+		ctx.From,
+		ctx.InPath,
+		Options{}, // TODO1
+		t.rs.Assets.Fs, t.rs.Logger, ctx.DependencyManager,
+	)
+
+	// TODO1 option {
+	src, err = imp.resolve()
+	if err != nil {
+		return err
+	}
+
+	go func() {
+		defer stdin.Close()
+		io.Copy(stdin, src)
+	}()
+
+	err = cmd.Run()
+	if err != nil {
+		if hexec.IsNotFound(err) {
+			return &herrors.FeatureNotAvailableError{
+				Cause: err,
+			}
+		}
+		return imp.toFileError(errBuf.String())
+	}
+
+	return nil
+}

tpl/css/css.go

@@ -28,6 +28,7 @@ type Namespace struct {
 	d                 *deps.Deps
 	scssClientLibSass *scss.Client
 	postcssClient     *postcss.Client
+	tailwindcssClient *postcss.TailwindCSSClient
 	babelClient       *babel.Client
 
 	// The Dart Client requires a os/exec process, so  only
@@ -63,7 +64,21 @@ func (ns *Namespace) PostCSS(args ...any) (resource.Resource, error) {
 	return ns.postcssClient.Process(r, m)
 }
 
-// Sass processes the given Resource with Sass.
+// TailwindCSS processes the given Resource with tailwindcss.
+func (ns *Namespace) TailwindCSS(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.tailwindcssClient.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")
@@ -145,6 +160,7 @@ func init() {
 			d:                 d,
 			scssClientLibSass: scssClient,
 			postcssClient:     postcss.New(d.ResourceSpec),
+			tailwindcssClient: postcss.NewTailwindCSSClient(d.ResourceSpec),
 			babelClient:       babel.New(d.ResourceSpec),
 		}