Change minLength prompt password check from validator to option (#166)

Author: dopey

ui/options.go

@@ -14,6 +14,7 @@ type options struct {
 	value           string
 	allowEdit       bool
 	printTemplate   string
+	minLength       int
 	promptTemplates *promptui.PromptTemplates
 	selectTemplates *promptui.SelectTemplates
 	validateFunc    promptui.ValidateFunc
@@ -109,6 +110,15 @@ func WithAllowEdit(b bool) Option {
 	}
 }
 
+// WithMinLength sets a minimum length requirement that will be verified
+// at the time when the prompt is run.
+// checks the input string meets the minimum length requirement.
+func WithMinLength(minLength int) Option {
+	return func(o *options) {
+		o.minLength = minLength
+	}
+}
+
 // WithPrintTemplate sets the template to use on the print methods.
 func WithPrintTemplate(template string) Option {
 	return func(o *options) {
@@ -143,12 +153,6 @@ func WithValidateNotEmpty() Option {
 	return WithValidateFunc(NotEmpty())
 }
 
-// WithValidateMinLength adds a custom validation function to a prompt that
-// checks the input string meets the minimum length requirement.
-func WithValidateMinLength(minLength int) Option {
-	return WithValidateFunc(MinLength(minLength))
-}
-
 // WithValidateYesNo adds a custom validation function to a prompt for a Yes/No
 // prompt.
 func WithValidateYesNo() Option {

ui/options_test.go

@@ -0,0 +1,32 @@
+package ui
+
+import "testing"
+
+func TestWithMinLength(t *testing.T) {
+	tests := []struct {
+		name   string
+		length int
+	}{
+		{
+			name:   "negative",
+			length: -5,
+		},
+		{
+			name:   "zero",
+			length: 0,
+		},
+		{
+			name:   "positive",
+			length: 11,
+		},
+	}
+	for _, tt := range tests {
+		t.Run(tt.name, func(t *testing.T) {
+			o := &options{}
+			WithMinLength(tt.length)(o)
+			if o.minLength != tt.length {
+				t.Errorf("want %v, but got %v", tt.length, o.minLength)
+			}
+		})
+	}
+}

ui/ui.go

@@ -5,6 +5,7 @@ import (
 	"os"
 	"strings"
 	"text/template"
+	"unicode"
 
 	"github.com/chzyer/readline"
 	"github.com/manifoldco/promptui"
@@ -203,13 +204,33 @@ func PromptPassword(label string, opts ...Option) ([]byte, error) {
 		Validate:  o.validateFunc,
 		Templates: o.promptTemplates,
 	}
-	pass, err := prompt.Run()
+
+	pass, err := runPrompt(prompt.Run, o)
 	if err != nil {
-		return nil, errors.Wrap(err, "error reading password")
+		return nil, err
 	}
 	return []byte(pass), nil
 }
 
+// runPrompt is a helper for the method prompt.Run. This helper will loop the
+// prompt indefinitely while the input does not meet a minimum length requirement.
+func runPrompt(run func() (string, error), opts *options) (string, error) {
+	for {
+		pass, err := run()
+		if err != nil {
+			return "", errors.Wrap(err, "error reading password")
+		}
+
+		pass = strings.TrimRightFunc(pass, unicode.IsSpace)
+
+		if opts.minLength <= 0 || len(pass) >= opts.minLength {
+			return pass, nil
+		}
+
+		fmt.Printf(">>> input does not meet minimum length requirement; must be at least %v characters\n", opts.minLength)
+	}
+}
+
 // PromptPasswordGenerate creates and runs a promptui.Prompt with the given label.
 // This prompt will mask the key entries with \r. If the result password length
 // is 0, it will generate a new prompt with a generated password that can be

ui/ui_test.go

@@ -0,0 +1,91 @@
+package ui
+
+import (
+	"errors"
+	"testing"
+)
+
+func Test_promptRun(t *testing.T) {
+	promptRunner := func(input []string, err error) func() (string, error) {
+		i := 0
+		return func() (string, error) {
+			ret := input[i]
+			i++
+			return ret, err
+		}
+	}
+
+	tests := []struct {
+		name      string
+		minLength int
+		promptRun func() (string, error)
+		want      string
+		wantErr   bool
+	}{
+		{
+			name:      "prompt-error",
+			minLength: -5,
+			promptRun: promptRunner([]string{"foobar"}, errors.New("prompt-error")),
+			want:      "foobar",
+			wantErr:   true,
+		},
+		{
+			name:      "negative",
+			minLength: -5,
+			promptRun: promptRunner([]string{"foobar"}, nil),
+			want:      "foobar",
+			wantErr:   false,
+		},
+		{
+			name:      "zero",
+			minLength: 0,
+			promptRun: promptRunner([]string{"foobar"}, nil),
+			want:      "foobar",
+			wantErr:   false,
+		},
+		{
+			name:      "greater-than-min-length",
+			minLength: 5,
+			promptRun: promptRunner([]string{"foobar"}, nil),
+			want:      "foobar",
+			wantErr:   false,
+		},
+		{
+			name:      "equal-min-length",
+			minLength: 6,
+			promptRun: promptRunner([]string{"foobar"}, nil),
+			want:      "foobar",
+			wantErr:   false,
+		},
+		{
+			name:      "less-than-min-length",
+			minLength: 8,
+			promptRun: promptRunner([]string{"pass", "foobar", "password"}, nil),
+			want:      "password",
+			wantErr:   false,
+		},
+		{
+			name:      "ignore-post-whitespace-characters",
+			minLength: 7,
+			promptRun: promptRunner([]string{"pass   ", "foobar ", "password  "}, nil),
+			want:      "password",
+			wantErr:   false,
+		},
+	}
+	for _, tt := range tests {
+		t.Run(tt.name, func(t *testing.T) {
+			val, err := runPrompt(tt.promptRun, &options{minLength: tt.minLength})
+			gotErr := err != nil
+			if gotErr != tt.wantErr {
+				t.Errorf("expected error=%v, but got error=%v", tt.wantErr, err)
+				return
+			}
+			if gotErr {
+				return
+			}
+			if val != tt.want {
+				t.Errorf("expected %v, but got %v", tt.want, val)
+			}
+		})
+	}
+}

ui/validators.go

@@ -5,7 +5,6 @@ import (
 	"fmt"
 	"net"
 	"strings"
-	"unicode"
 
 	"github.com/manifoldco/promptui"
 )
@@ -74,17 +73,3 @@ func YesNo() promptui.ValidateFunc {
 		}
 	}
 }
-
-// MinLength is a validation function that checks for a minimum length.
-// An input length <= 0 indicates that the check should not be performed.
-func MinLength(minLength int) promptui.ValidateFunc {
-	return func(s string) error {
-		if minLength <= 0 {
-			return nil
-		}
-		if len(strings.TrimRightFunc(s, unicode.IsSpace)) < minLength {
-			return fmt.Errorf("input does not meet minimum length requirement; must be at least %v characters", minLength)
-		}
-		return nil
-	}
-}

ui/validators_test.go

@@ -90,63 +90,3 @@ func TestDNS(t *testing.T) {
 		})
 	}
 }
-
-func TestMinLength(t *testing.T) {
-	tests := []struct {
-		name    string
-		length  int
-		input   string
-		wantErr bool
-	}{
-		{
-			name:    "negative",
-			length:  -5,
-			input:   "foobar",
-			wantErr: false,
-		},
-		{
-			name:    "zero",
-			length:  0,
-			input:   "localhost",
-			wantErr: false,
-		},
-		{
-			name:    "greater-than-min-length",
-			length:  5,
-			input:   "foobar",
-			wantErr: false,
-		},
-		{
-			name:    "equal-min-length",
-			length:  6,
-			input:   "foobar",
-			wantErr: false,
-		},
-		{
-			name:    "less-than-min-length",
-			length:  8,
-			input:   "foobar",
-			wantErr: true,
-		},
-		{
-			name:    "ignore-post-whitespace-characters",
-			length:  7,
-			input:   "  pass  ",
-			wantErr: true,
-		},
-		{
-			name:    "ignore-post-whitespace-characters-ok",
-			length:  6,
-			input:   "  pass  ",
-			wantErr: false,
-		},
-	}
-	for _, tt := range tests {
-		t.Run(tt.name, func(t *testing.T) {
-			gotErr := MinLength(tt.length)(tt.input) != nil
-			if gotErr != tt.wantErr {
-				t.Errorf("MinLength(%v)(%s) = %v, want %v", tt.length, tt.input, gotErr, tt.wantErr)
-			}
-		})
-	}
-}