support accepting default values while asking for inputs

ui/color_ui.go

@@ -66,12 +66,12 @@ func (ui *ColorUI) PrintTable(table Table) {
 	ui.parent.PrintTable(table)
 }
 
-func (ui *ColorUI) AskForText(label string) (string, error) {
-	return ui.parent.AskForText(label)
+func (ui *ColorUI) AskForText(opts TextOpts) (string, error) {
+	return ui.parent.AskForText(opts)
 }
 
-func (ui *ColorUI) AskForChoice(label string, options []string) (int, error) {
-	return ui.parent.AskForChoice(label, options)
+func (ui *ColorUI) AskForChoice(opts ChoiceOpts) (int, error) {
+	return ui.parent.AskForChoice(opts)
 }
 
 func (ui *ColorUI) AskForPassword(label string) (string, error) {

ui/conf_ui.go

@@ -89,12 +89,12 @@ func (ui *ConfUI) PrintTable(table Table) {
 	ui.parent.PrintTable(table)
 }
 
-func (ui *ConfUI) AskForText(label string) (string, error) {
-	return ui.parent.AskForText(label)
+func (ui *ConfUI) AskForText(opts TextOpts) (string, error) {
+	return ui.parent.AskForText(opts)
 }
 
-func (ui *ConfUI) AskForChoice(label string, options []string) (int, error) {
-	return ui.parent.AskForChoice(label, options)
+func (ui *ConfUI) AskForChoice(opts ChoiceOpts) (int, error) {
+	return ui.parent.AskForChoice(opts)
 }
 
 func (ui *ConfUI) AskForPassword(label string) (string, error) {

ui/fakes/fake_ui.go

@@ -4,6 +4,7 @@ import (
 	"fmt"
 	"sync"
 
+	types "github.com/cppforlife/go-cli-ui/ui"
 	. "github.com/cppforlife/go-cli-ui/ui/table"
 )
 
@@ -93,24 +94,24 @@ func (ui *FakeUI) PrintTable(table Table) {
 	ui.Tables = append(ui.Tables, table)
 }
 
-func (ui *FakeUI) AskForText(label string) (string, error) {
+func (ui *FakeUI) AskForText(opts types.TextOpts) (string, error) {
 	ui.mutex.Lock()
 	defer ui.mutex.Unlock()
 
-	ui.AskedTextLabels = append(ui.AskedTextLabels, label)
+	ui.AskedTextLabels = append(ui.AskedTextLabels, opts.Label)
 	answer := ui.AskedText[0]
 	ui.AskedText = ui.AskedText[1:]
 	return answer.Text, answer.Error
 }
 
-func (ui *FakeUI) AskForChoice(label string, options []string) (int, error) {
+func (ui *FakeUI) AskForChoice(opts types.ChoiceOpts) (int, error) {
 	ui.mutex.Lock()
 	defer ui.mutex.Unlock()
 
 	ui.AskedChoiceCalled = true
 
-	ui.AskedChoiceLabel = label
-	ui.AskedChoiceOptions = options
+	ui.AskedChoiceLabel = opts.Label
+	ui.AskedChoiceOptions = opts.Choices
 
 	chosen := ui.AskedChoiceChosens[0]
 	ui.AskedChoiceChosens = ui.AskedChoiceChosens[1:]

ui/indenting_ui.go

@@ -42,12 +42,12 @@ func (ui *IndentingUI) PrintTable(table Table) {
 	ui.parent.PrintTable(table)
 }
 
-func (ui *IndentingUI) AskForText(label string) (string, error) {
-	return ui.parent.AskForText(label)
+func (ui *IndentingUI) AskForText(opts TextOpts) (string, error) {
+	return ui.parent.AskForText(opts)
 }
 
-func (ui *IndentingUI) AskForChoice(label string, options []string) (int, error) {
-	return ui.parent.AskForChoice(label, options)
+func (ui *IndentingUI) AskForChoice(opts ChoiceOpts) (int, error) {
+	return ui.parent.AskForChoice(opts)
 }
 
 func (ui *IndentingUI) AskForPassword(label string) (string, error) {

ui/interfaces.go

@@ -16,8 +16,8 @@ type UI interface {
 
 	PrintTable(Table)
 
-	AskForText(label string) (string, error)
-	AskForChoice(label string, options []string) (int, error)
+	AskForText(opts TextOpts) (string, error)
+	AskForChoice(opts ChoiceOpts) (int, error)
 	AskForPassword(label string) (string, error)
 
 	// AskForConfirmation returns error if user doesnt want to continue

ui/json_ui.go

@@ -98,11 +98,11 @@ func (ui *JSONUI) PrintTable(table Table) {
 	ui.uiResp.Tables = append(ui.uiResp.Tables, resp)
 }
 
-func (ui *JSONUI) AskForText(_ string) (string, error) {
+func (ui *JSONUI) AskForText(_ TextOpts) (string, error) {
 	panic("Cannot ask for input in JSON UI")
 }
 
-func (ui *JSONUI) AskForChoice(_ string, _ []string) (int, error) {
+func (ui *JSONUI) AskForChoice(_ ChoiceOpts) (int, error) {
 	panic("Cannot ask for a choice in JSON UI")
 }
 

ui/json_ui_test.go

@@ -310,7 +310,7 @@ func TestJSONUI(t *testing.T) {
 			parentUI := &fakeui.FakeUI{}
 			ui := NewJSONUI(parentUI, NewRecordingLogger())
 
-			assert.Panics(t, func() { ui.AskForText("") })
+			assert.Panics(t, func() { ui.AskForText(TextOpts{}) })
 		})
 	})
 
@@ -328,7 +328,7 @@ func TestJSONUI(t *testing.T) {
 			parentUI := &fakeui.FakeUI{}
 			ui := NewJSONUI(parentUI, NewRecordingLogger())
 
-			assert.Panics(t, func() { ui.AskForChoice("", nil) })
+			assert.Panics(t, func() { ui.AskForChoice(ChoiceOpts{}) })
 		})
 	})
 

ui/non_interactive.go

@@ -1,6 +1,8 @@
 package ui
 
 import (
+	"fmt"
+
 	. "github.com/cppforlife/go-cli-ui/ui/table"
 )
 
@@ -40,12 +42,21 @@ func (ui *NonInteractiveUI) PrintTable(table Table) {
 	ui.parent.PrintTable(table)
 }
 
-func (ui *NonInteractiveUI) AskForText(label string) (string, error) {
-	panic("Cannot ask for input in non-interactive UI")
+func (ui *NonInteractiveUI) AskForText(opts TextOpts) (string, error) {
+	if opts.ValidateFunc != nil {
+		isValid, message, err := opts.ValidateFunc(opts.Default)
+		if err != nil || !isValid {
+			return "", fmt.Errorf("Validation error: %s", message)
+		}
+	}
+	return opts.Default, nil
 }
 
-func (ui *NonInteractiveUI) AskForChoice(label string, options []string) (int, error) {
-	panic("Cannot ask for a choice in non-interactive UI")
+func (ui *NonInteractiveUI) AskForChoice(opts ChoiceOpts) (int, error) {
+	if opts.Default >= len(opts.Choices) || opts.Default < 0 {
+		return 0, fmt.Errorf("Default value should be index and must be in (0-%d)", len(opts.Choices)-1)
+	}
+	return opts.Default, nil
 }
 
 func (ui *NonInteractiveUI) AskForPassword(label string) (string, error) {

ui/non_interactive_test.go

@@ -1,6 +1,7 @@
 package ui_test
 
 import (
+	"fmt"
 	"testing"
 
 	. "github.com/cppforlife/go-cli-ui/ui"
@@ -87,11 +88,41 @@ func TestNonInteractiveUI(t *testing.T) {
 	})
 
 	t.Run("AskForText", func(t *testing.T) {
-		t.Run("panics", func(t *testing.T) {
+		t.Run("default non empty", func(t *testing.T) {
 			parentUI := &fakeui.FakeUI{}
 			ui := NewNonInteractiveUI(parentUI)
 
-			assert.Panics(t, func() { ui.AskForText("") })
+			text, err := ui.AskForText(TextOpts{
+				Label:   "",
+				Default: "foo",
+				ValidateFunc: func(s string) (bool, string, error) {
+					if s == "" {
+						return false, "", fmt.Errorf("should not be empty")
+					}
+					return true, "", nil
+				},
+			})
+
+			assert.Equal(t, text, "foo")
+			assert.Nil(t, err)
+		})
+		t.Run("default empty", func(t *testing.T) {
+			parentUI := &fakeui.FakeUI{}
+			ui := NewNonInteractiveUI(parentUI)
+
+			text, err := ui.AskForText(TextOpts{
+				Label:   "",
+				Default: "",
+				ValidateFunc: func(s string) (bool, string, error) {
+					if s == "" {
+						return false, "", fmt.Errorf("should not be empty")
+					}
+					return true, "", nil
+				},
+			})
+
+			assert.Equal(t, text, "")
+			assert.NotNil(t, err)
 		})
 	})
 
@@ -105,11 +136,18 @@ func TestNonInteractiveUI(t *testing.T) {
 	})
 
 	t.Run("AskForChoice", func(t *testing.T) {
-		t.Run("panics", func(t *testing.T) {
+		t.Run("non negative default value", func(t *testing.T) {
 			parentUI := &fakeui.FakeUI{}
 			ui := NewNonInteractiveUI(parentUI)
 
-			assert.Panics(t, func() { ui.AskForChoice("", nil) })
+			choice, err := ui.AskForChoice(ChoiceOpts{
+				Label:   "",
+				Default: 1,
+				Choices: []string{"a", "b", "c"},
+			})
+
+			assert.Equal(t, choice, 1)
+			assert.Nil(t, err)
 		})
 	})
 

ui/non_tty_ui.go

@@ -39,12 +39,12 @@ func (ui *NonTTYUI) PrintTable(table Table) {
 	ui.parent.PrintTable(table)
 }
 
-func (ui *NonTTYUI) AskForText(label string) (string, error) {
-	return ui.parent.AskForText(label)
+func (ui *NonTTYUI) AskForText(opts TextOpts) (string, error) {
+	return ui.parent.AskForText(opts)
 }
 
-func (ui *NonTTYUI) AskForChoice(label string, options []string) (int, error) {
-	return ui.parent.AskForChoice(label, options)
+func (ui *NonTTYUI) AskForChoice(opts ChoiceOpts) (int, error) {
+	return ui.parent.AskForChoice(opts)
 }
 
 func (ui *NonTTYUI) AskForPassword(label string) (string, error) {

ui/padding_ui.go

@@ -57,14 +57,14 @@ func (ui *PaddingUI) PrintTable(table Table) {
 	ui.parent.PrintTable(table)
 }
 
-func (ui *PaddingUI) AskForText(label string) (string, error) {
+func (ui *PaddingUI) AskForText(opts TextOpts) (string, error) {
 	ui.padBefore(paddingUIModeAskText)
-	return ui.parent.AskForText(label)
+	return ui.parent.AskForText(opts)
 }
 
-func (ui *PaddingUI) AskForChoice(label string, options []string) (int, error) {
+func (ui *PaddingUI) AskForChoice(opts ChoiceOpts) (int, error) {
 	ui.padBefore(paddingUIModeAuto)
-	return ui.parent.AskForChoice(label, options)
+	return ui.parent.AskForChoice(opts)
 }
 
 func (ui *PaddingUI) AskForPassword(label string) (string, error) {

ui/types.go

@@ -0,0 +1,16 @@
+package ui
+
+// TextOpts Asking for text options
+type TextOpts struct {
+	Label   string
+	Default string
+	// ValidateFunc: method to validate input/default value
+	ValidateFunc func(string) (bool, string, error)
+}
+
+// ChoiceOpts asking for choice options
+type ChoiceOpts struct {
+	Label   string
+	Default int
+	Choices []string
+}

ui/ui.go

@@ -96,27 +96,44 @@ func (ui *WriterUI) PrintTable(table Table) {
 	}
 }
 
-func (ui *WriterUI) AskForText(label string) (string, error) {
-	var text string
-
-	err := interact.NewInteraction(label).Resolve(&text)
-	if err != nil {
-		return "", fmt.Errorf("Asking for text: %s", err)
+func (ui *WriterUI) AskForText(opts TextOpts) (string, error) {
+	if opts.ValidateFunc == nil {
+		opts.ValidateFunc = func(s string) (bool, string, error) {
+			return true, "", nil
+		}
 	}
 
-	return text, nil
+	for {
+		text := opts.Default
+		err := interact.NewInteraction(opts.Label).Resolve(&text)
+		if err != nil {
+			return "", fmt.Errorf("Asking for text: %s", err)
+		}
+
+		isValid, message, err := opts.ValidateFunc(text)
+		if err != nil {
+			return "", fmt.Errorf("Validation input: %s", err)
+		}
+		if isValid {
+			return text, nil
+		} else {
+			if len(message) == 0 {
+				message = "(reason for failure not specified)"
+			}
+			ui.ErrorLinef("Failed validation: %s", message)
+		}
+	}
 }
 
-func (ui *WriterUI) AskForChoice(label string, options []string) (int, error) {
+func (ui *WriterUI) AskForChoice(opts ChoiceOpts) (int, error) {
 	var choices []interact.Choice
 
-	for i, opt := range options {
+	for i, opt := range opts.Choices {
 		choices = append(choices, interact.Choice{Display: opt, Value: i})
 	}
 
-	var chosen int
-
-	err := interact.NewInteraction(label, choices...).Resolve(&chosen)
+	chosen := opts.Default
+	err := interact.NewInteraction(opts.Label, choices...).Resolve(&chosen)
 	if err != nil {
 		return 0, fmt.Errorf("Asking for choice: %s", err)
 	}