Add js.Build asset bundling

Fixes #7321

hugolib/js_test.go

@@ -0,0 +1,87 @@
+// Copyright 2020 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 hugolib
+
+import (
+	"os"
+	"path/filepath"
+	"testing"
+
+	"github.com/gohugoio/hugo/htesting"
+
+	"github.com/spf13/viper"
+
+	qt "github.com/frankban/quicktest"
+
+	"github.com/gohugoio/hugo/hugofs"
+
+	"github.com/gohugoio/hugo/common/loggers"
+)
+
+func TestJS_Build(t *testing.T) {
+	if !isCI() {
+		t.Skip("skip (relative) long running modules test when running locally")
+	}
+
+	wd, _ := os.Getwd()
+	defer func() {
+		os.Chdir(wd)
+	}()
+
+	c := qt.New(t)
+
+	mainJS := `
+	import "./included";
+	console.log("main");
+	`
+	includedJS := `
+	console.log("included");
+	`
+
+	workDir, clean, err := htesting.CreateTempDir(hugofs.Os, "hugo-test-babel")
+	c.Assert(err, qt.IsNil)
+	defer clean()
+
+	v := viper.New()
+	v.Set("workingDir", workDir)
+	v.Set("disableKinds", []string{"taxonomy", "term", "page"})
+	b := newTestSitesBuilder(t).WithLogger(loggers.NewWarningLogger())
+
+	// Need to use OS fs for this.
+	b.Fs = hugofs.NewDefault(v)
+	b.WithWorkingDir(workDir)
+	b.WithViper(v)
+	b.WithContent("p1.md", "")
+
+	b.WithTemplates("index.html", `
+	{{ $options := dict "minify" true }}
+	{{ $transpiled := resources.Get "js/main.js" | js.Build $options }}
+	Built: {{ $transpiled.Content | safeJS }}
+	`)
+
+	jsDir := filepath.Join(workDir, "assets", "js")
+	b.Assert(os.MkdirAll(jsDir, 0777), qt.IsNil)
+	b.WithSourceFile("assets/js/main.js", mainJS)
+	b.WithSourceFile("assets/js/included.js", includedJS)
+
+	_, err = captureStdout(func() error {
+		return b.BuildE(BuildCfg{})
+	})
+	b.Assert(err, qt.IsNil)
+
+	b.AssertFileContent("public/index.html", `
+  Built: (()=>{console.log("included");console.log("main");})();
+	`)
+
+}