Merge pull request #61 from snyk/feat/prompt-when-scaffold-yaml-exists

Adds prompt to overwrite when rerunning scaffold init

cmd/cmd.go

@@ -2,12 +2,16 @@
 package cmd
 
 import (
+	"context"
+	"errors"
 	"fmt"
 	"io"
 	"os"
 	"path/filepath"
+	"strings"
 	"time"
 
+	"github.com/manifoldco/promptui"
 	"github.com/urfave/cli/v2"
 )
 
@@ -16,6 +20,7 @@ type VervetParams struct {
 	Stdin  io.ReadCloser
 	Stdout io.WriteCloser
 	Stderr io.WriteCloser
+	Prompt VervetPrompt
 }
 
 // VervetApp contains the cli Application.
@@ -24,6 +29,21 @@ type VervetApp struct {
 	Params VervetParams
 }
 
+// VervetPrompt defines the interface for interactive prompts in vervet.
+type VervetPrompt interface {
+	Confirm(label string) (bool, error)
+}
+
+type runKey string
+
+var vervetKey = runKey("vervet")
+
+// Run runs the cli.App with the Vervet config params.
+func (v *VervetApp) Run(args []string) error {
+	context := context.WithValue(context.Background(), vervetKey, v)
+	return v.App.RunContext(context, args)
+}
+
 // NewApp returns a new VervetApp with the provided params.
 func NewApp(vp VervetParams) *VervetApp {
 	return &VervetApp{
@@ -149,11 +169,35 @@ func NewApp(vp VervetParams) *VervetApp {
 	}
 }
 
+// Prompt is the default interactive prompt for vervet.
+type Prompt struct{}
+
+// Confirm implements VervetPrompt.Confirm
+func (p Prompt) Confirm(label string) (bool, error) {
+	prompt := promptui.Prompt{
+		Label:   fmt.Sprintf("%v (y/N)?", label),
+		Default: "N",
+		Validate: func(input string) error {
+			input = strings.ToLower(input)
+			if input != "n" && input != "y" {
+				return errors.New("you must pick y or n")
+			}
+			return nil
+		},
+	}
+	result, err := prompt.Run()
+	if err != nil {
+		return false, err
+	}
+	return (result == "y"), nil
+}
+
 // Vervet is the vervet application with the CLI application.
 var Vervet = NewApp(VervetParams{
 	Stdin:  os.Stdin,
 	Stdout: os.Stdout,
 	Stderr: os.Stderr,
+	Prompt: Prompt{},
 })
 
 func absPath(path string) (string, error) {

cmd/compiler_test.go

@@ -16,7 +16,7 @@ import (
 func TestCompile(t *testing.T) {
 	c := qt.New(t)
 	dstDir := c.TempDir()
-	err := cmd.Vervet.App.Run([]string{"vervet", "compile", testdata.Path("resources"), dstDir})
+	err := cmd.Vervet.Run([]string{"vervet", "compile", testdata.Path("resources"), dstDir})
 	c.Assert(err, qt.IsNil)
 	tests := []struct {
 		version string
@@ -49,7 +49,7 @@ func TestCompile(t *testing.T) {
 func TestCompileInclude(t *testing.T) {
 	c := qt.New(t)
 	dstDir := c.TempDir()
-	err := cmd.Vervet.App.Run([]string{"vervet", "compile", "-I", testdata.Path("resources/include.yaml"), testdata.Path("resources"), dstDir})
+	err := cmd.Vervet.Run([]string{"vervet", "compile", "-I", testdata.Path("resources/include.yaml"), testdata.Path("resources"), dstDir})
 	c.Assert(err, qt.IsNil)
 
 	tests := []struct {
@@ -87,6 +87,6 @@ func TestCompileInclude(t *testing.T) {
 func TestCompileConflict(t *testing.T) {
 	c := qt.New(t)
 	dstDir := c.TempDir()
-	err := cmd.Vervet.App.Run([]string{"vervet", "compile", "../testdata/conflict", dstDir})
+	err := cmd.Vervet.Run([]string{"vervet", "compile", "../testdata/conflict", dstDir})
 	c.Assert(err, qt.ErrorMatches, `failed to load spec versions: conflict: .*`)
 }

cmd/scaffold.go

@@ -1,6 +1,7 @@
 package cmd
 
 import (
+	"errors"
 	"fmt"
 	"os"
 	"path/filepath"
@@ -33,7 +34,28 @@ func ScaffoldInit(ctx *cli.Context) error {
 		return err
 	}
 	err = sc.Organize()
-	if err != nil {
+	if err == scaffold.ErrAlreadyInitialized {
+		// If the project files already exist, prompt the user to see if they want to overwrite them.
+		// TODO: replace using Context.Value directly with a helper func to be used in other commands.
+		vervetApp, ok := ctx.Context.Value(vervetKey).(*VervetApp)
+		if !ok {
+			return errors.New("could not retrieve vervet app from context")
+		}
+		prompt := vervetApp.Params.Prompt
+		overwrite, err := prompt.Confirm("Scaffold already initialized; do you want to overwrite")
+		if err != nil {
+			return err
+		}
+		if overwrite {
+			forceFn := scaffold.Force(true)
+			forceFn(sc)
+			// If an error happens with --force enabled, something new has gone wrong.
+			if err = sc.Organize(); err != nil {
+				return err
+			}
+		}
+		return nil
+	} else if err != nil {
 		return err
 	}
 	err = sc.Init()

cmd/scaffold_test.go

@@ -3,6 +3,7 @@ package cmd_test
 import (
 	"io/ioutil"
 	"os"
+	"strings"
 	"testing"
 
 	qt "github.com/frankban/quicktest"
@@ -11,15 +12,92 @@ import (
 	"github.com/snyk/vervet/testdata"
 )
 
+var vervetConfigFile = "./.vervet.yaml"
+
+type testPrompt struct {
+	ReturnVal bool
+}
+
+func (tp *testPrompt) Confirm(label string) (bool, error) {
+	return tp.ReturnVal, nil
+}
+
+var filemark = "bad wolf"
+
+// markFile adds a string to a file so we can check if that file is being overwritten.
+func markTestFile(filename string) error {
+	// Write a string to the file; we should see this string removed when
+	f, err := os.OpenFile(filename, os.O_WRONLY, 0644)
+	if err != nil {
+		return err
+	}
+	defer f.Close()
+
+	if err != nil {
+		return err
+	}
+	_, err = f.Write([]byte(filemark))
+	return err
+}
+
+// markInFile checks if the filemark is present, determining if the file has been
+// overwritten.
+func markInFile(filename string) (bool, error) {
+	content, err := ioutil.ReadFile(vervetConfigFile)
+	if err != nil {
+		return false, err
+	}
+	return strings.Contains(string(content), "bad wolf"), nil
+}
+
 func TestScaffold(t *testing.T) {
 	c := qt.New(t)
 	dstDir := c.TempDir()
 	cd(c, dstDir)
-	// Create an API project from a scaffold
-	err := cmd.Vervet.App.Run([]string{"vervet", "scaffold", "init", testdata.Path("test-scaffold")})
+
+	prompt := testPrompt{}
+	testApp := cmd.NewApp(cmd.VervetParams{
+		Stdin:  os.Stdin,
+		Stdout: os.Stdout,
+		Stderr: os.Stderr,
+		Prompt: &prompt,
+	})
+
+	// Running init creates the project files.
+	err := testApp.Run([]string{"vervet", "scaffold", "init", testdata.Path("test-scaffold")})
+	c.Assert(err, qt.IsNil)
+
+	// Rerunning init asks the user if they want to overwrite; if they say no
+	// the command ends...
+	prompt.ReturnVal = false
+	err = markTestFile(vervetConfigFile)
+	c.Assert(err, qt.IsNil)
+	err = testApp.Run([]string{"vervet", "scaffold", "init", testdata.Path("test-scaffold")})
+	c.Assert(err, qt.IsNil)
+	fileMarked, err := markInFile(vervetConfigFile)
+	c.Assert(err, qt.IsNil)
+	c.Assert(fileMarked, qt.IsTrue)
+
+	// ...if the user selects yes, it will overwrite the project files.
+	prompt.ReturnVal = true
+	err = testApp.Run([]string{"vervet", "scaffold", "init", testdata.Path("test-scaffold")})
+	c.Assert(err, qt.IsNil)
+	fileMarked, err = markInFile(vervetConfigFile)
+	c.Assert(err, qt.IsNil)
+	c.Assert(fileMarked, qt.IsFalse)
+
+	// Rerunning init with the force option overwrites the project files.
+	prompt.ReturnVal = false
+	err = markTestFile(vervetConfigFile)
 	c.Assert(err, qt.IsNil)
-	// Generate a new resource version in the project
-	err = cmd.Vervet.App.Run([]string{"vervet", "version", "new", "--version", "2021-10-01", "v3", "foo"})
+	err = testApp.Run([]string{"vervet", "scaffold", "init", "--force", testdata.Path("test-scaffold")})
+	c.Assert(err, qt.IsNil)
+	fileMarked, err = markInFile(vervetConfigFile)
+	c.Assert(err, qt.IsNil)
+	c.Assert(fileMarked, qt.IsFalse)
+
+	// A new resource version can be generated in the project after initialization has completed.
+	err = testApp.Run([]string{"vervet", "version", "new", "--version", "2021-10-01", "v3", "foo"})
 	c.Assert(err, qt.IsNil)
 	for _, item := range []string{".vervet/templates/README.tmpl", ".vervet.yaml", ".vervet/extras/foo", ".vervet/extras/bar/bar"} {
 		_, err = os.Stat(item)

cmd/version_test.go

@@ -41,7 +41,7 @@ func TestVersionFiles(t *testing.T) {
 		defer output.Close()
 		c.Patch(&os.Stdout, output)
 		cd(c, testdata.Path("."))
-		err = cmd.Vervet.App.Run([]string{"vervet", "version", "files"})
+		err = cmd.Vervet.Run([]string{"vervet", "version", "files"})
 		c.Assert(err, qt.IsNil)
 	})
 	out, err := ioutil.ReadFile(tmpFile)
@@ -64,7 +64,7 @@ func TestVersionList(t *testing.T) {
 		defer output.Close()
 		c.Patch(&os.Stdout, output)
 		cd(c, testdata.Path("."))
-		err = cmd.Vervet.App.Run([]string{"vervet", "version", "list"})
+		err = cmd.Vervet.Run([]string{"vervet", "version", "list"})
 		c.Assert(err, qt.IsNil)
 	})
 	out, err := ioutil.ReadFile(tmpFile)
@@ -95,7 +95,7 @@ func TestVersionNew(t *testing.T) {
 	copyToDir(c, testdata.Path(".vervet/resource/version/index.ts.tmpl"), versionTemplateDir)
 	copyToDir(c, testdata.Path(".vervet/resource/version/spec.yaml.tmpl"), versionTemplateDir)
 	cd(c, projectDir)
-	err := cmd.Vervet.App.Run([]string{"vervet", "version", "new", "testdata", "foo"})
+	err := cmd.Vervet.Run([]string{"vervet", "version", "new", "testdata", "foo"})
 	c.Assert(err, qt.IsNil)
 	versions, err := vervet.LoadResourceVersions(filepath.Join(projectDir, "generated", "foo"))
 	c.Assert(err, qt.IsNil)

cmd/vervet/main.go

@@ -8,7 +8,7 @@ import (
 )
 
 func main() {
-	err := cmd.Vervet.App.Run(os.Args)
+	err := cmd.Vervet.Run(os.Args)
 	if err != nil {
 		log.Fatal(err)
 	}

go.mod

@@ -12,6 +12,7 @@ require (
 	github.com/google/go-cmp v0.5.5
 	github.com/google/uuid v1.3.0
 	github.com/mailru/easyjson v0.7.7 // indirect
+	github.com/manifoldco/promptui v0.9.0
 	github.com/mattn/go-runewidth v0.0.13 // indirect
 	github.com/mitchellh/reflectwalk v1.0.2
 	github.com/olekukonko/tablewriter v0.0.5

go.sum

@@ -1,6 +1,12 @@
 github.com/BurntSushi/toml v0.3.1/go.mod h1:xHWCNGjB5oqiDr8zfno3MHue2Ht5sIBksp03qcyfWMU=
 github.com/bmatcuk/doublestar/v4 v4.0.2 h1:X0krlUVAVmtr2cRoTqR8aDMrDqnB36ht8wpWTiQ3jsA=
 github.com/bmatcuk/doublestar/v4 v4.0.2/go.mod h1:xBQ8jztBU6kakFMg+8WGxn0c6z1fTSPVIjEY1Wr7jzc=
+github.com/chzyer/logex v1.1.10 h1:Swpa1K6QvQznwJRcfTfQJmTE72DqScAa40E+fbHEXEE=
+github.com/chzyer/logex v1.1.10/go.mod h1:+Ywpsq7O8HXn0nuIou7OrIPyXbp3wmkHB+jjWRnGsAI=
+github.com/chzyer/readline v0.0.0-20180603132655-2972be24d48e h1:fY5BOSpyZCqRo5OhCuC+XN+r/bBCmeuuJtjz+bCNIf8=
+github.com/chzyer/readline v0.0.0-20180603132655-2972be24d48e/go.mod h1:nSuG5e5PlCu98SY8svDHJxuZscDgtXS6KTTbou5AhLI=
+github.com/chzyer/test v0.0.0-20180213035817-a1ea475d72b1 h1:q763qf9huN11kDQavWsoZXJNW3xEE4JJyHa5Q25/sd8=
+github.com/chzyer/test v0.0.0-20180213035817-a1ea475d72b1/go.mod h1:Q3SI9o4m/ZMnBNeIyt5eFwwo7qiLfzFZmjNmxjkiQlU=
 github.com/cpuguy83/go-md2man/v2 v2.0.0-20190314233015-f79a8a8ca69d/go.mod h1:maD7wRr/U5Z6m/iR4s+kqSMx2CaBsrgA7czyZG/E6dU=
 github.com/cpuguy83/go-md2man/v2 v2.0.1 h1:r/myEWzV9lfsM1tFLgDyu0atFtJ1fXn261LKYj/3DxU=
 github.com/cpuguy83/go-md2man/v2 v2.0.1/go.mod h1:tgQtvFlXSQOSOSIRvRPT7W67SCa46tRHOmNcaadrF8o=
@@ -38,6 +44,8 @@ github.com/mailru/easyjson v0.0.0-20190626092158-b2ccc519800e/go.mod h1:C1wdFJiN
 github.com/mailru/easyjson v0.7.6/go.mod h1:xzfreul335JAWq5oZzymOObrkdz5UnU4kGfJJLY9Nlc=
 github.com/mailru/easyjson v0.7.7 h1:UGYAvKxe3sBsEDzO8ZeWOSlIQfWFlxbzLZe7hwFURr0=
 github.com/mailru/easyjson v0.7.7/go.mod h1:xzfreul335JAWq5oZzymOObrkdz5UnU4kGfJJLY9Nlc=
+github.com/manifoldco/promptui v0.9.0 h1:3V4HzJk1TtXW1MTZMP7mdlwbBpIinw3HztaIlYthEiA=
+github.com/manifoldco/promptui v0.9.0/go.mod h1:ka04sppxSGFAtxX0qhlYQjISsg9mR4GWtQEhdbn6Pgg=
 github.com/mattn/go-runewidth v0.0.9/go.mod h1:H031xJmbD/WCDINGzjvQ9THkh0rPKHF+m2gUSrubnMI=
 github.com/mattn/go-runewidth v0.0.13 h1:lTGmDsbAYt5DmK6OnoV7EuIF1wEIFAcxld6ypU4OSgU=
 github.com/mattn/go-runewidth v0.0.13/go.mod h1:Jdepj2loyihRzMpdS35Xk/zdY8IAYHsh153qUoGf23w=
@@ -63,6 +71,8 @@ github.com/stretchr/testify v1.7.0 h1:nwc3DEeHmmLAfoZucVR881uASk0Mfjw8xYJ99tb5Cc
 github.com/stretchr/testify v1.7.0/go.mod h1:6Fq8oRcR53rry900zMqJjRRixrwX3KX962/h/Wwjteg=
 github.com/urfave/cli/v2 v2.3.0 h1:qph92Y649prgesehzOrQjdWyxFOp/QVM+6imKHad91M=
 github.com/urfave/cli/v2 v2.3.0/go.mod h1:LJmUH05zAU44vOAcrfzZQKsZbVcdbOG8rtL3/XcUArI=
+golang.org/x/sys v0.0.0-20181122145206-62eef0e2fa9b h1:MQE+LT/ABUuuvEZ+YQAMSXindAdUh7slEmAkup74op4=
+golang.org/x/sys v0.0.0-20181122145206-62eef0e2fa9b/go.mod h1:STP8DvDyc/dI5b8T5hshtkjS+E42TnysNCUPdjciGhY=
 golang.org/x/xerrors v0.0.0-20191204190536-9bdfabe68543/go.mod h1:I/5z698sn9Ka8TeJc9MKroUUfqBBauWjQqLJ2OPfmY0=
 golang.org/x/xerrors v0.0.0-20200804184101-5ec99f83aff1 h1:go1bK/D/BFZV2I8cIQd1NKEZ+0owSTG1fDTci4IqFcE=
 golang.org/x/xerrors v0.0.0-20200804184101-5ec99f83aff1/go.mod h1:I/5z698sn9Ka8TeJc9MKroUUfqBBauWjQqLJ2OPfmY0=

internal/scaffold/scaffold.go

@@ -12,6 +12,9 @@ import (
 	"github.com/ghodss/yaml"
 )
 
+// ErrAlreadyInitialized is used when scaffolding is being run on a project that is already setup.
+var ErrAlreadyInitialized = fmt.Errorf("project files already exist")
+
 // Scaffold defines a Vervet API project scaffold.
 type Scaffold struct {
 	dst, src string
@@ -85,6 +88,19 @@ func New(dst, src string, options ...Option) (*Scaffold, error) {
 func (s *Scaffold) Organize() error {
 	for dstItem, srcItem := range s.manifest.Organize {
 		dstPath := filepath.Join(s.dst, dstItem)
+		// If we're not force overwriting, check if files already exist.
+		if !s.force {
+			_, err := os.Stat(dstPath)
+			if err == nil {
+				// Project files already exist.
+				return ErrAlreadyInitialized
+			}
+			if !os.IsNotExist(err) {
+				// Something else went wrong; the file not existing is the desired
+				// state.
+				return err
+			}
+		}
 		srcPath := filepath.Join(s.src, srcItem)
 		err := s.copyItem(dstPath, srcPath)
 		if err != nil {