Resolve misc. lint violations and formatting issues (#471)

* Ignore staticcheck violations about error message formatting

* Avoid using `strings.Title`

* Rename error type to start with "err"

* Iterate over string runes directly

* go fmt code comments

* go fmt build directives

Author: mislav

confirm.go

@@ -90,6 +90,7 @@ func (c *Confirm) getBool(showHelp bool, config *PromptConfig) (bool, error) {
 			continue
 		default:
 			// we didnt get a valid answer, so print error and prompt again
+			//lint:ignore ST1005 it should be fine for this error message to have punctuation
 			if err := c.Error(config, fmt.Errorf("%q is not a valid answer, please try again.", val)); err != nil {
 				return c.Default, err
 			}

core/template.go

@@ -23,11 +23,11 @@ var TemplateFuncsNoColor = map[string]interface{}{
 	},
 }
 
-//RunTemplate returns two formatted strings given a template and
-//the data it requires. The first string returned is generated for
-//user-facing output and may or may not contain ANSI escape codes
-//for colored output. The second string does not contain escape codes
-//and can be used by the renderer for layout purposes.
+// RunTemplate returns two formatted strings given a template and
+// the data it requires. The first string returned is generated for
+// user-facing output and may or may not contain ANSI escape codes
+// for colored output. The second string does not contain escape codes
+// and can be used by the renderer for layout purposes.
 func RunTemplate(tmpl string, data interface{}) (string, string, error) {
 	tPair, err := GetTemplatePair(tmpl)
 	if err != nil {
@@ -52,11 +52,11 @@ var (
 	memoMutex = &sync.RWMutex{}
 )
 
-//GetTemplatePair returns a pair of compiled templates where the
-//first template is generated for user-facing output and the
-//second is generated for use by the renderer. The second
-//template does not contain any color escape codes, whereas
-//the first template may or may not depending on DisableColor.
+// GetTemplatePair returns a pair of compiled templates where the
+// first template is generated for user-facing output and the
+// second is generated for use by the renderer. The second
+// template does not contain any color escape codes, whereas
+// the first template may or may not depending on DisableColor.
 func GetTemplatePair(tmpl string) ([2]*template.Template, error) {
 	memoMutex.RLock()
 	if t, ok := memoizedGetTemplate[tmpl]; ok {

core/write.go

@@ -142,12 +142,12 @@ func (err errFieldNotMatch) Is(target error) bool { // implements the dynamic er
 // It returns the Question.Name that couldn't be matched with a destination field.
 //
 // Usage:
-// err := survey.Ask(qs, &v);
-// if err != nil {
-// 	if name, ok := core.IsFieldNotMatch(err); ok {
-//		[...name is the not matched question name]
-// 	}
-// }
+//
+//	if err := survey.Ask(qs, &v); err != nil {
+//		if name, ok := core.IsFieldNotMatch(err); ok {
+//			// name is the question name that did not match a field
+//		}
+//	}
 func IsFieldNotMatch(err error) (string, bool) {
 	if err != nil {
 		if v, ok := err.(errFieldNotMatch); ok {
@@ -301,6 +301,7 @@ func copy(t reflect.Value, v reflect.Value) (err error) {
 		case reflect.Float64:
 			castVal, casterr = strconv.ParseFloat(vString, 64)
 		default:
+			//lint:ignore ST1005 allow this error message to be capitalized
 			return fmt.Errorf("Unable to convert from string to type %s", t.Kind())
 		}
 
@@ -335,6 +336,7 @@ func copy(t reflect.Value, v reflect.Value) (err error) {
 		}
 
 		// we're copying an option answer to an incorrect type
+		//lint:ignore ST1005 allow this error message to be capitalized
 		return fmt.Errorf("Unable to convert from OptionAnswer to type %s", t.Kind())
 	}
 

input.go

@@ -127,14 +127,14 @@ func (i *Input) onRune(config *PromptConfig) terminal.OnRuneFn {
 		)
 
 		if err == nil {
-			err = readLineAgain
+			err = errReadLineAgain
 		}
 
 		return []rune(i.typedAnswer), true, err
 	})
 }
 
-var readLineAgain = errors.New("read line again")
+var errReadLineAgain = errors.New("read line again")
 
 func (i *Input) Prompt(config *PromptConfig) (interface{}, error) {
 	// render the template
@@ -170,7 +170,7 @@ func (i *Input) Prompt(config *PromptConfig) (interface{}, error) {
 		}
 
 		line, err = rr.ReadLineWithDefault(0, line, i.onRune(config))
-		if err == readLineAgain {
+		if err == errReadLineAgain {
 			continue
 		}
 

survey.go

@@ -278,7 +278,6 @@ in the documentation. For example:
 	}
 
 	survey.AskOne(prompt, &name)
-
 */
 func AskOne(p Prompt, response interface{}, opts ...AskOpt) error {
 	err := Ask([]*Question{{Prompt: p}}, response, opts...)

terminal/display_posix.go

@@ -1,3 +1,4 @@
+//go:build !windows
 // +build !windows
 
 package terminal

terminal/error.go

@@ -5,5 +5,6 @@ import (
 )
 
 var (
+	//lint:ignore ST1012 keeping old name for backwards compatibility
 	InterruptErr = errors.New("interrupt")
 )

terminal/output.go

@@ -1,3 +1,4 @@
+//go:build !windows
 // +build !windows
 
 package terminal

terminal/runereader.go

@@ -405,8 +405,7 @@ func StringWidth(str string) int {
 	w := 0
 	ansi := false
 
-	rs := []rune(str)
-	for _, r := range rs {
+	for _, r := range str {
 		// increase width only when outside of ANSI escape sequences
 		if ansi || isAnsiMarker(r) {
 			ansi = !isAnsiTerminator(r)

terminal/runereader_bsd.go

@@ -3,6 +3,7 @@
 // Use of this source code is governed by a BSD-style
 // license that can be found in the LICENSE file.
 
+//go:build darwin || dragonfly || freebsd || netbsd || openbsd
 // +build darwin dragonfly freebsd netbsd openbsd
 
 package terminal