[FEATURE] Introduces homebrew task (#67)

* Respond to code review and migrate to the new task api

* Fix naming

* Files to formulas

* Simplify constructor for homebrew

* Split the work for homebrew between cask and cellar

* Fixes comments

* Adds more tests for caskroom

* Privatize getPathParts/setPathParts

* Adds some explanation about formula construction

* Privatize isInstalled of cellar and caskroom

* Removes uncessary outputfilter

* Moves codes that test installation in needed

dev.yml

@@ -1,6 +1,8 @@
 up:
   - go: 1.10.1
   - golang_dep
+  - homebrew:
+    - curl
   - custom:
       name: Install shellcheck
       met?: test -e /usr/local/Cellar/shellcheck

pkg/env/env.go

@@ -62,30 +62,22 @@ func (e *Env) Environ() (vars []string) {
 	return vars
 }
 
-func (e *Env) getAndSplitPath() []string {
-	return strings.Split(e.env["PATH"], ":")
-}
-
-func (e *Env) joinAndSetPath(elems ...string) {
-	e.env["PATH"] = strings.Join(elems, ":")
-}
-
 // PrependToPath inserts a new path at the beginning of the PATH variable
 func (e *Env) PrependToPath(path string) {
-	elems := e.getAndSplitPath()
+	elems := e.getPathParts()
 	elems = append([]string{path}, elems...)
-	e.joinAndSetPath(elems...)
+	e.setPathParts(elems...)
 }
 
 // RemoveFromPath removes all path entries matching a substring
 func (e *Env) RemoveFromPath(substring string) {
 	newElems := []string{}
-	for _, elem := range e.getAndSplitPath() {
+	for _, elem := range e.getPathParts() {
 		if !strings.Contains(elem, substring) {
 			newElems = append(newElems, elem)
 		}
 	}
-	e.joinAndSetPath(newElems...)
+	e.setPathParts(newElems...)
 }
 
 // Changed returns all changes made on the variables
@@ -104,3 +96,11 @@ func (e *Env) Changed() []VariableChange {
 	}
 	return c
 }
+
+func (e *Env) getPathParts() []string {
+	return strings.Split(e.env["PATH"], ":")
+}
+
+func (e *Env) setPathParts(elems ...string) {
+	e.env["PATH"] = strings.Join(elems, ":")
+}

pkg/helpers/homebrew.go

@@ -0,0 +1,77 @@
+package helpers
+
+import (
+	"path/filepath"
+	"strings"
+
+	"github.com/devbuddy/devbuddy/pkg/utils"
+)
+
+type caskroom struct {
+	prefix string
+}
+
+type cellar struct {
+	prefix string
+}
+
+// Homebrew represent an homebrew installation
+type Homebrew struct {
+	caskroom *caskroom
+	cellar   *cellar
+}
+
+// NewHomebrew is returning a new Cellar
+func NewHomebrew() *Homebrew {
+	prefix := "/usr/local"
+
+	return &Homebrew{
+		cellar:   &cellar{prefix: prefix},
+		caskroom: &caskroom{prefix: prefix},
+	}
+}
+
+// NewHomebrewWithPrefix is returning a new Cellar at prefix
+func NewHomebrewWithPrefix(prefix string) *Homebrew {
+	return &Homebrew{
+		cellar:   &cellar{prefix: prefix},
+		caskroom: &caskroom{prefix: prefix},
+	}
+}
+
+// IsInstalled returns true if `pkg` is installed in cellar or in caskroom
+func (h *Homebrew) IsInstalled(formula string) (installed bool) {
+	path := buildFormulaPath(formula)
+
+	return h.cellar.isInstalled(path) || h.caskroom.isInstalled(path)
+}
+
+// buildFormulaPath building a formula name from a full path by doing the following operations:
+// 1. split the path by `/`
+// 2. returns the filename
+// 3. removes the file extension
+// 4. returns the resulting formula name
+func buildFormulaPath(path string) string {
+	results := strings.Split(path, "/")
+	formula := results[len(results)-1]
+	return strings.TrimSuffix(formula, filepath.Ext(formula))
+}
+
+// isInstalled returns true if formulua was installed in Caskrook
+func (c *caskroom) isInstalled(formula string) bool {
+	path := "/opt/homebrew-cask/Caskroom"
+
+	if !utils.PathExists(path) {
+		path = filepath.Join(c.prefix, "Caskroom")
+	}
+
+	return utils.PathExists(filepath.Join(path, formula))
+}
+
+// isInstalled returns true if formulua was installed in cellar
+func (c *cellar) isInstalled(formula string) bool {
+	path := filepath.Join(c.prefix, "Cellar")
+
+	path = filepath.Join(path, formula)
+	return utils.PathExists(path)
+}

pkg/helpers/homebrew_test.go

@@ -0,0 +1,28 @@
+package helpers
+
+import (
+	"io/ioutil"
+	"os"
+	"path/filepath"
+	"testing"
+
+	"github.com/stretchr/testify/require"
+)
+
+func TestIsInCellar(t *testing.T) {
+	prefix, err := ioutil.TempDir("/tmp", "dad-brew")
+	require.NoError(t, err, "ioutil.TempDir() failed")
+
+	cellarPath := filepath.Join(prefix, "Cellar")
+
+	caskroomPath := filepath.Join(prefix, "Caskroom")
+
+	os.MkdirAll(filepath.Join(cellarPath, "curl", "1.2.3"), os.ModePerm)
+	os.MkdirAll(filepath.Join(caskroomPath, "emacs", "26.1"), os.ModePerm)
+
+	h := NewHomebrewWithPrefix(prefix)
+
+	require.Truef(t, h.IsInstalled("curl"), "Curl is properly installed in Cellar %s", cellarPath)
+	require.Falsef(t, h.IsInstalled("vim"), "vim is missing from Homebrew %s", prefix)
+	require.True(t, h.IsInstalled("emacs"), "Emacs is properly installed in caskroom %s", caskroomPath)
+}

pkg/tasks/homebrew.go

@@ -0,0 +1,77 @@
+package tasks
+
+import (
+	"fmt"
+	"strings"
+
+	"github.com/devbuddy/devbuddy/pkg/helpers"
+)
+
+func init() {
+	allTasks["homebrew"] = newHomebrew
+}
+
+type Homebrew struct {
+	formulas []string
+}
+
+func newHomebrew(config *taskConfig) (Task, error) {
+	task := &Homebrew{}
+
+	for _, value := range config.payload.([]interface{}) {
+		if v, ok := value.(string); ok {
+			task.formulas = append(task.formulas, v)
+		} else {
+			return nil, fmt.Errorf("invalid homebrew formulas")
+		}
+	}
+
+	if len(task.formulas) == 0 {
+		return nil, fmt.Errorf("no homebrew formulas specified")
+	}
+
+	return task, nil
+}
+
+func (h *Homebrew) name() string {
+	return "Homebrew"
+}
+
+func (h *Homebrew) header() string {
+	return strings.Join(h.formulas, ", ")
+}
+
+func (h *Homebrew) actions(ctx *context) (actions []taskAction) {
+	for _, f := range h.formulas {
+		actions = append(actions, &brewInstall{formula: f})
+	}
+	return
+}
+
+type brewInstall struct {
+	formula string
+	success bool
+}
+
+func (b *brewInstall) description() string {
+	return fmt.Sprintf("installing %s", b.formula)
+}
+
+func (b *brewInstall) needed(ctx *context) (bool, error) {
+	brew := helpers.NewHomebrew()
+
+	installed := brew.IsInstalled(b.formula)
+
+	return !installed, nil
+}
+
+func (b *brewInstall) run(ctx *context) error {
+	err := command(ctx, "brew", "install", b.formula).Run()
+
+	if err != nil {
+		return fmt.Errorf("Homebrew failed: %s", err)
+	}
+
+	b.success = true
+	return nil
+}

pkg/tasks/homebrew_test.go

@@ -0,0 +1,16 @@
+package tasks
+
+import (
+	"testing"
+
+	"github.com/stretchr/testify/require"
+)
+
+func TestHomebrew(t *testing.T) {
+	task := ensureLoadTestTask(t, `
+homebrew:
+  - file1
+  - file2
+`)
+	require.Equal(t, task.(*Homebrew).formulas, []string{"file1", "file2"})
+}