Merge pull request #30 from coryb/confirm

add Confirm prompt

confirm.go

@@ -0,0 +1,135 @@
+package survey
+
+import (
+	"bufio"
+	"fmt"
+	"os"
+	"regexp"
+
+	tm "github.com/buger/goterm"
+)
+
+// Confirm is a regular text input that accept yes/no answers.
+type Confirm struct {
+	Message string
+	Default bool
+	Answer  *bool
+}
+
+// data available to the templates when processing
+type ConfirmTemplateData struct {
+	Confirm
+	Answer string
+}
+
+// Templates with Color formatting. See Documentation: https://github.com/mgutz/ansi#style-format
+var ConfirmQuestionTemplate = `
+{{- color "green+hb"}}? {{color "reset"}}
+{{- color "default+hb"}}{{ .Message }} {{color "reset"}}
+{{- if .Answer}}
+  {{- color "cyan"}}{{.Answer}}{{color "reset"}}
+{{- else }}
+  {{- color "white"}}{{if .Default}}(Y/n) {{else}}(y/N) {{end}}{{color "reset"}}
+{{- end}}`
+
+func yesNo(t bool) string {
+	if t {
+		return "Yes"
+	}
+	return "No"
+}
+
+// Prompt prompts the user with a simple text field and expects a reply followed
+// by a carriage return.
+func (confirm *Confirm) Prompt() (string, error) {
+	if confirm.Answer == nil {
+		answer := false
+		confirm.Answer = &answer
+	}
+	out, err := runTemplate(
+		ConfirmQuestionTemplate,
+		ConfirmTemplateData{Confirm: *confirm},
+	)
+	if err != nil {
+		return "", err
+	}
+
+	// print the question we were given to kick off the prompt
+	fmt.Print(out)
+
+	// a scanner to look at the input from stdin
+	scanner := bufio.NewScanner(os.Stdin)
+	// wait for a response
+	yesRx := regexp.MustCompile("^(?i:y(?:es)?)$")
+	noRx := regexp.MustCompile("^(?i:n(?:o)?)$")
+	answer := confirm.Default
+	for scanner.Scan() {
+		// get the availible text in the scanner
+		res := scanner.Text()
+		// if there is no answer
+		if res == "" {
+			// use the default
+			break
+		}
+		// is answer yes?
+		if yesRx.Match([]byte(res)) {
+			answer = true
+			break
+		}
+
+		// is answer "no"
+		if noRx.Match([]byte(res)) {
+			answer = false
+			break
+		}
+
+		// we didnt get a valid answer, so print error and prompt again
+		out, err := runTemplate(ErrorTemplate, fmt.Errorf("%q is not a valid answer, try again", res))
+		if err != nil {
+			return "", err
+		}
+		// send the message to the user
+		fmt.Print(out)
+		return confirm.Prompt()
+	}
+
+	// return the value
+	*confirm.Answer = answer
+	return yesNo(answer), nil
+}
+
+// Cleanup overwrite the line with the finalized formatted version
+func (confirm *Confirm) Cleanup(val string) error {
+	// get the current cursor location
+	loc, err := CursorLocation()
+	// if something went wrong
+	if err != nil {
+		// bubble
+		return err
+	}
+
+	var initLoc int
+	// if we are printing at the end of the console
+	if loc.col == tm.Height() {
+		initLoc = loc.col - 2
+	} else {
+		initLoc = loc.col - 1
+	}
+
+	// move to the beginning of the current line
+	tm.MoveCursor(initLoc, 1)
+
+	out, err := runTemplate(
+		ConfirmQuestionTemplate,
+		ConfirmTemplateData{Confirm: *confirm, Answer: val},
+	)
+	if err != nil {
+		return err
+	}
+
+	tm.Print(out, AnsiClearLine)
+	tm.Flush()
+
+	// nothing went wrong
+	return nil
+}

confirm_test.go

@@ -0,0 +1,74 @@
+package survey
+
+import "testing"
+
+func init() {
+	// disable color output for all prompts to simplify testing
+	DisableColor = true
+}
+
+func TestConfirmFormatQuestion(t *testing.T) {
+
+	prompt := &Confirm{
+		Message: "Is pizza your favorite food?",
+		Default: true,
+	}
+
+	actual, err := runTemplate(
+		ConfirmQuestionTemplate,
+		ConfirmTemplateData{Confirm: *prompt},
+	)
+	if err != nil {
+		t.Errorf("Failed to run template to format input question: %s", err)
+	}
+
+	expected := `? Is pizza your favorite food? (Y/n) `
+
+	if actual != expected {
+		t.Errorf("Formatted input question was not formatted correctly. Found:\n%s\nExpected:\n%s", actual, expected)
+	}
+}
+
+func TestConfirmFormatQuestionDefaultFalse(t *testing.T) {
+
+	prompt := &Confirm{
+		Message: "Is pizza your favorite food?",
+		Default: false,
+	}
+
+	actual, err := runTemplate(
+		ConfirmQuestionTemplate,
+		ConfirmTemplateData{Confirm: *prompt},
+	)
+	if err != nil {
+		t.Errorf("Failed to run template to format input answer: %s", err)
+	}
+
+	expected := `? Is pizza your favorite food? (y/N) `
+
+	if actual != expected {
+		t.Errorf("Formatted input answer was not formatted correctly. Found:\n%s\nExpected:\n%s", actual, expected)
+	}
+}
+
+func TestConfirmFormatAnswer(t *testing.T) {
+
+	// default false
+	prompt := &Confirm{
+		Message: "Is pizza your favorite food?",
+	}
+
+	actual, err := runTemplate(
+		ConfirmQuestionTemplate,
+		ConfirmTemplateData{Confirm: *prompt, Answer: "Yes"},
+	)
+	if err != nil {
+		t.Errorf("Failed to run template to format input answer: %s", err)
+	}
+
+	expected := `? Is pizza your favorite food? Yes`
+
+	if actual != expected {
+		t.Errorf("Formatted input answer was not formatted correctly. Found:\n%s\nExpected:\n%s", actual, expected)
+	}
+}

examples/confirm.go

@@ -0,0 +1,26 @@
+package main
+
+import (
+	"fmt"
+
+	"github.com/alecaivazis/survey"
+)
+
+func main() {
+	var happy bool
+	prompt := &survey.Confirm{
+		Message: "Are you happy?",
+		Default: true,
+		Answer:  &happy,
+	}
+
+	answer, err := survey.AskOne(prompt)
+
+	if err != nil {
+		fmt.Println(err.Error())
+		return
+	}
+
+	fmt.Printf("response string: %s\n", answer)
+	fmt.Printf("response happy: %t\n", happy)
+}