Added multiline input (#157)

* Added multiline input

* Test for multiline input

* Use of existing API to clear lines instead of escape sequence

* Multiline input example added to README

* multiline-input: change message to finish

* multiline-input: show the response in a new line

* MultilineInput renamed to Multiline

* README updated

README.md

@@ -61,6 +61,7 @@ func main() {
 1. [Examples](#examples)
 1. [Prompts](#prompts)
    1. [Input](#input)
+   1. [Multiline](#multiline)
    1. [Password](#password)
    1. [Confirm](#confirm)
    1. [Select](#select)
@@ -103,6 +104,18 @@ prompt := &survey.Input{
 survey.AskOne(prompt, &name, nil)
 ```
 
+### Multiline
+
+<img src="https://thumbs.gfycat.com/ImperfectShimmeringBeagle-size_restricted.gif" width="400px"/>
+
+```golang
+text := ""
+prompt := &survey.Multiline{
+    Message: "ping",
+}
+survey.AskOne(prompt, &text, nil)
+```
+
 ### Password
 
 <img src="https://thumbs.gfycat.com/CompassionateSevereHypacrosaurus-size_restricted.gif" width="400px" />

multiline.go

@@ -0,0 +1,103 @@
+package survey
+
+import (
+	"fmt"
+	"strings"
+
+	"gopkg.in/AlecAivazis/survey.v1/core"
+	"gopkg.in/AlecAivazis/survey.v1/terminal"
+)
+
+type Multiline struct {
+	core.Renderer
+	Message string
+	Default string
+	Help    string
+}
+
+// data available to the templates when processing
+type MultilineTemplateData struct {
+	Multiline
+	Answer     string
+	ShowAnswer bool
+	ShowHelp   bool
+}
+
+// Templates with Color formatting. See Documentation: https://github.com/mgutz/ansi#style-format
+var MultilineQuestionTemplate = `
+{{- if .ShowHelp }}{{- color "cyan"}}{{ HelpIcon }} {{ .Help }}{{color "reset"}}{{"\n"}}{{end}}
+{{- color "green+hb"}}{{ QuestionIcon }} {{color "reset"}}
+{{- color "default+hb"}}{{ .Message }} {{color "reset"}}
+{{- if .ShowAnswer}}
+  {{- "\n"}}{{color "cyan"}}{{.Answer}}{{color "reset"}}{{"\n"}}
+{{- else }}
+  {{- if .Default}}{{color "white"}}({{.Default}}) {{color "reset"}}{{end}}
+  {{- color "cyan"}}[Enter 2 empty lines to finish]{{color "reset"}}
+{{- end}}`
+
+func (i *Multiline) Prompt() (interface{}, error) {
+	// render the template
+	err := i.Render(
+		MultilineQuestionTemplate,
+		MultilineTemplateData{Multiline: *i},
+	)
+	if err != nil {
+		return "", err
+	}
+	fmt.Println()
+
+	// start reading runes from the standard in
+	rr := i.NewRuneReader()
+	rr.SetTermMode()
+	defer rr.RestoreTermMode()
+
+	cursor := i.NewCursor()
+
+	multiline := make([]string, 0)
+
+	emptyOnce := false
+	// get the next line
+	for {
+		line := []rune{}
+		line, err = rr.ReadLine(0)
+		if err != nil {
+			return string(line), err
+		}
+
+		if string(line) == "" {
+			if emptyOnce {
+				numLines := len(multiline) + 2
+				cursor.PreviousLine(numLines)
+				for j := 0; j < numLines; j++ {
+					terminal.EraseLine(i.Stdio().Out, terminal.ERASE_LINE_ALL)
+					cursor.NextLine(1)
+				}
+				cursor.PreviousLine(numLines)
+				break
+			}
+			emptyOnce = true
+		} else {
+			emptyOnce = false
+		}
+		multiline = append(multiline, string(line))
+	}
+
+	val := strings.Join(multiline, "\n")
+	val = strings.TrimSpace(val)
+
+	// if the line is empty
+	if len(val) == 0 {
+		// use the default value
+		return i.Default, err
+	}
+
+	// we're done
+	return val, err
+}
+
+func (i *Multiline) Cleanup(val interface{}) error {
+	return i.Render(
+		MultilineQuestionTemplate,
+		MultilineTemplateData{Multiline: *i, Answer: val.(string), ShowAnswer: true},
+	)
+}

multiline_test.go

@@ -0,0 +1,154 @@
+package survey
+
+import (
+	"bytes"
+	"fmt"
+	"io"
+	"os"
+	"testing"
+
+	expect "github.com/Netflix/go-expect"
+	"github.com/stretchr/testify/assert"
+	"gopkg.in/AlecAivazis/survey.v1/core"
+	"gopkg.in/AlecAivazis/survey.v1/terminal"
+)
+
+func init() {
+	// disable color output for all prompts to simplify testing
+	core.DisableColor = true
+}
+
+func TestMultilineRender(t *testing.T) {
+
+	tests := []struct {
+		title    string
+		prompt   Multiline
+		data     MultilineTemplateData
+		expected string
+	}{
+		{
+			"Test Multiline question output without default",
+			Multiline{Message: "What is your favorite month:"},
+			MultilineTemplateData{},
+			fmt.Sprintf("%s What is your favorite month: [Enter 2 empty lines to finish]", core.QuestionIcon),
+		},
+		{
+			"Test Multiline question output with default",
+			Multiline{Message: "What is your favorite month:", Default: "April"},
+			MultilineTemplateData{},
+			fmt.Sprintf("%s What is your favorite month: (April) [Enter 2 empty lines to finish]", core.QuestionIcon),
+		},
+		{
+			"Test Multiline answer output",
+			Multiline{Message: "What is your favorite month:"},
+			MultilineTemplateData{Answer: "October", ShowAnswer: true},
+			fmt.Sprintf("%s What is your favorite month: \nOctober\n", core.QuestionIcon),
+		},
+		{
+			"Test Multiline question output without default but with help hidden",
+			Multiline{Message: "What is your favorite month:", Help: "This is helpful"},
+			MultilineTemplateData{},
+			fmt.Sprintf("%s What is your favorite month: [Enter 2 empty lines to finish]", string(core.HelpInputRune)),
+		},
+		{
+			"Test Multiline question output with default and with help hidden",
+			Multiline{Message: "What is your favorite month:", Default: "April", Help: "This is helpful"},
+			MultilineTemplateData{},
+			fmt.Sprintf("%s What is your favorite month: (April) [Enter 2 empty lines to finish]", string(core.HelpInputRune)),
+		},
+		{
+			"Test Multiline question output without default but with help shown",
+			Multiline{Message: "What is your favorite month:", Help: "This is helpful"},
+			MultilineTemplateData{ShowHelp: true},
+			fmt.Sprintf("%s This is helpful\n%s What is your favorite month: [Enter 2 empty lines to finish]", core.HelpIcon, core.QuestionIcon),
+		},
+		{
+			"Test Multiline question output with default and with help shown",
+			Multiline{Message: "What is your favorite month:", Default: "April", Help: "This is helpful"},
+			MultilineTemplateData{ShowHelp: true},
+			fmt.Sprintf("%s This is helpful\n%s What is your favorite month: (April) [Enter 2 empty lines to finish]", core.HelpIcon, core.QuestionIcon),
+		},
+	}
+
+	for _, test := range tests {
+		r, w, err := os.Pipe()
+		assert.Nil(t, err, test.title)
+
+		test.prompt.WithStdio(terminal.Stdio{Out: w})
+		test.data.Multiline = test.prompt
+		err = test.prompt.Render(
+			MultilineQuestionTemplate,
+			test.data,
+		)
+		assert.Nil(t, err, test.title)
+
+		w.Close()
+		var buf bytes.Buffer
+		io.Copy(&buf, r)
+
+		assert.Contains(t, buf.String(), test.expected, test.title)
+	}
+}
+
+func TestMultilinePrompt(t *testing.T) {
+	tests := []PromptTest{
+		{
+			"Test Multiline prompt interaction",
+			&Multiline{
+				Message: "What is your name?",
+			},
+			func(c *expect.Console) {
+				c.ExpectString("What is your name?")
+				c.SendLine("Larry Bird\nI guess...\nnot sure\n\n")
+				c.ExpectEOF()
+			},
+			"Larry Bird\nI guess...\nnot sure",
+		},
+		{
+			"Test Multiline prompt interaction with default",
+			&Multiline{
+				Message: "What is your name?",
+				Default: "Johnny Appleseed",
+			},
+			func(c *expect.Console) {
+				c.ExpectString("What is your name?")
+				c.SendLine("\n\n")
+				c.ExpectEOF()
+			},
+			"Johnny Appleseed",
+		},
+		{
+			"Test Multiline prompt interaction overriding default",
+			&Multiline{
+				Message: "What is your name?",
+				Default: "Johnny Appleseed",
+			},
+			func(c *expect.Console) {
+				c.ExpectString("What is your name?")
+				c.SendLine("Larry Bird\n\n")
+				c.ExpectEOF()
+			},
+			"Larry Bird",
+		},
+		{
+			"Test Multiline does not implement help interaction",
+			&Multiline{
+				Message: "What is your name?",
+				Help:    "It might be Satoshi Nakamoto",
+			},
+			func(c *expect.Console) {
+				c.ExpectString("What is your name?")
+				c.SendLine("?")
+				c.SendLine("Satoshi Nakamoto\n\n")
+				c.ExpectEOF()
+			},
+			"?\nSatoshi Nakamoto",
+		},
+	}
+
+	for _, test := range tests {
+		t.Run(test.name, func(t *testing.T) {
+			RunPromptTest(t, test)
+		})
+	}
+}