Install yarn with node

Fixes #40

bin/ec/main_test.go

@@ -212,7 +212,7 @@ var _ = Describe("main", func() {
 
 			fmt.Println("Removing node@6.4.0")
 
-			fmt.Println("Install tmp version")
+			fmt.Println("Install 5.1.0 version")
 			Execute("go", "run", path, "node@5.1.0")
 
 			Execute("go", "run", path, "rm", "node@6.4.0")
@@ -288,6 +288,14 @@ var _ = Describe("main", func() {
 
 			Expect(result).To(Equal(true))
 		})
+
+		It("should install yarn", func() {
+			yarnBin := filepath.Join(variables.Path("node", "5.1.0"), "bin/yarn")
+
+			bytes, _ := Command(yarnBin, "--help").CombinedOutput()
+
+			Expect(string(bytes)).To(ContainSubstring("Usage: yarn [command] [flags]"))
+		})
 	})
 
 	Describe("elm", func() {

plugins/nodejs/nodejs.go

@@ -45,14 +45,16 @@ func (node Node) Install() error {
 	return nil
 }
 
-func (node Node) PostInstall() error {
-	path := variables.Path("node", node.Version)
-	etc := filepath.Join(path, "etc")
-	npmrc := filepath.Join(etc, "npmrc")
+func (node Node) PostInstall() (err error) {
+	err = node.setNpm()
+	if err != nil {
+		return err
+	}
 
-	// Remove needless warnings from npm output
-	io.CreateDir(etc)
-	io.WriteFile(npmrc, "scripts-prepend-node-path=false")
+	ok, err := node.Yarn()
+	if err != nil && ok == false {
+		return err
+	}
 
 	return nil
 }
@@ -125,3 +127,22 @@ func (node Node) ListRemote() ([]string, error) {
 
 	return result, nil
 }
+
+// Removes needless warnings from npm output
+func (node Node) setNpm() (err error) {
+	path := variables.Path("node", node.Version)
+	etc := filepath.Join(path, "etc")
+	npmrc := filepath.Join(etc, "npmrc")
+
+	_, err = io.CreateDir(etc)
+	if err != nil {
+		return
+	}
+
+	err = io.WriteFile(npmrc, "scripts-prepend-node-path=false")
+	if err != nil {
+		return
+	}
+
+	return nil
+}

plugins/nodejs/yarn.go

@@ -0,0 +1,73 @@
+package nodejs
+
+import (
+	"errors"
+	"os"
+	"path/filepath"
+
+	"github.com/blang/semver"
+	"github.com/cavaliercoder/grab"
+	"github.com/markelog/archive"
+	"github.com/markelog/cprf"
+
+	"github.com/markelog/eclectica/io"
+	"github.com/markelog/eclectica/variables"
+)
+
+var (
+	minimalForYarn, _ = semver.Make("4.0.0")
+	yarnUrl           = "https://yarnpkg.com/latest.tar.gz"
+)
+
+func (node Node) download(path string) (err error) {
+	_, err = grab.Get(path, yarnUrl)
+	if err != nil {
+		return
+	}
+
+	return
+}
+
+func (node Node) Yarn() (ok bool, err error) {
+	version, _ := semver.Make(node.Version)
+	ok = false
+
+	path := variables.Path("node", node.Version)
+	modules := filepath.Join(path, "lib/node_modules")
+	dist := filepath.Join(modules, "yarn-archive")
+	temp := filepath.Join(modules, "yarn-temp")
+	from := filepath.Join(temp, "dist/")
+	dest := filepath.Join(modules, "yarn")
+
+	if version.LT(minimalForYarn) {
+		return true, errors.New("\"" + node.Version + "\" version is not supported by yarn")
+	}
+
+	err = node.download(dist)
+	if err != nil {
+		return
+	}
+
+	err = archive.Extract(dist, temp)
+	if err != nil {
+		return
+	}
+
+	err = cprf.Copy(from+"/", dest)
+	if err != nil {
+		return
+	}
+
+	os.RemoveAll(dist)
+	os.RemoveAll(temp)
+
+	current := filepath.Join(modules, "yarn/bin/yarn.js")
+	base := filepath.Join(path, "bin/yarn")
+
+	err = io.Symlink(base, current)
+	if err != nil {
+		return
+	}
+
+	return true, nil
+}

plugins/nodejs/yarn_test.go

@@ -0,0 +1,93 @@
+package nodejs_test
+
+import (
+	"os"
+
+	. "github.com/onsi/ginkgo"
+	. "github.com/onsi/gomega"
+
+	"github.com/bouk/monkey"
+	"github.com/cavaliercoder/grab"
+	"github.com/markelog/archive"
+	"github.com/markelog/cprf"
+
+	"github.com/markelog/eclectica/io"
+	. "github.com/markelog/eclectica/plugins/nodejs"
+)
+
+var _ = Describe("yarn", func() {
+	var (
+		grabGet        bool
+		archiveExtract bool
+		cprfCopy       bool
+		osRemovaAll    bool
+		ioSymlink      bool
+	)
+
+	BeforeEach(func() {
+		grabGet = false
+		archiveExtract = false
+		cprfCopy = false
+		osRemovaAll = false
+		ioSymlink = false
+
+		monkey.Patch(grab.Get, func(path, url string) (*grab.Response, error) {
+			grabGet = true
+			return nil, nil
+		})
+
+		monkey.Patch(archive.Extract, func(from, to string) error {
+			archiveExtract = true
+			return nil
+		})
+
+		monkey.Patch(cprf.Copy, func(from, to string) error {
+			cprfCopy = true
+			return nil
+		})
+
+		monkey.Patch(os.RemoveAll, func(path string) error {
+			osRemovaAll = true
+			return nil
+		})
+
+		monkey.Patch(io.Symlink, func(from, to string) error {
+			ioSymlink = true
+			return nil
+		})
+	})
+
+	AfterEach(func() {
+		monkey.Unpatch(grab.Get)
+		monkey.Unpatch(archive.Extract)
+		monkey.Unpatch(cprf.Copy)
+		monkey.Unpatch(os.RemoveAll)
+		monkey.Unpatch(io.Symlink)
+	})
+
+	It("should not try to install yarn for unsupported node version", func() {
+		working, err := (&Node{Version: "0.10.0"}).Yarn()
+
+		Expect(grabGet).To(Equal(false))
+		Expect(archiveExtract).To(Equal(false))
+		Expect(cprfCopy).To(Equal(false))
+		Expect(osRemovaAll).To(Equal(false))
+		Expect(ioSymlink).To(Equal(false))
+
+		Expect(working).To(Equal(true))
+		Expect(err.Error()).To(Equal("\"0.10.0\" version is not supported by yarn"))
+	})
+
+	It("installs yarn", func() {
+		working, err := (&Node{Version: "6.10.0"}).Yarn()
+
+		Expect(grabGet).To(Equal(true))
+		Expect(archiveExtract).To(Equal(true))
+		Expect(cprfCopy).To(Equal(true))
+		Expect(osRemovaAll).To(Equal(true))
+		Expect(ioSymlink).To(Equal(true))
+
+		Expect(working).To(Equal(true))
+		Expect(err).To(BeNil())
+	})
+})