feat: add github action tests and linting (#418)

Leverage github actions for tests and linting.

This includes fixing a bunch of issues highlighted by golangci
including:
* Dead code.
* Ineffectual assigns.
* Goto warnings.
* Nil return err.
* Reused literal strings.
* Test parameter order.

Also:
* Setup clog.

parser/comments_test.go

@@ -2,9 +2,10 @@ package parser
 
 import (
 	"fmt"
-	"github.com/robertkrimen/otto/ast"
 	"reflect"
 	"testing"
+
+	"github.com/robertkrimen/otto/ast"
 )
 
 func checkComments(actual []*ast.Comment, expected []string, position ast.CommentPosition) error {
@@ -31,13 +32,6 @@ func checkComments(actual []*ast.Comment, expected []string, position ast.Commen
 	return nil
 }
 
-func displayStatements(statements []ast.Statement) {
-	fmt.Printf("Printing statements (%v)\n", len(statements))
-	for k, v := range statements {
-		fmt.Printf("Type of line %v: %v\n", k, reflect.TypeOf(v))
-	}
-}
-
 func displayComments(m ast.CommentMap) {
 	fmt.Printf("Displaying comments:\n")
 	for n, comments := range m {
@@ -404,7 +398,7 @@ t2 = "Nothing happens."
 		is(checkComments((parser.comments.CommentMap)[program.Body[1]], []string{"Test", "Test2"}, ast.LEADING), nil)
 
 		// Misc
-		parser, program = test(`
+		parser, _ = test(`
 var x = Object.create({y: {
 },
 // a
@@ -413,7 +407,7 @@ var x = Object.create({y: {
 		is(parser.comments.CommentMap.Size(), 1)
 
 		// Misc 2
-		parser, program = test(`
+		parser, _ = test(`
 var x = Object.create({y: {
 },
 // a
@@ -818,7 +812,7 @@ if(a) {
 		is(checkComments((parser.comments.CommentMap)[program.Body[0].(*ast.IfStatement).Alternate], []string{"comment"}, ast.TRAILING), nil)
 
 		// If then else pt 8
-		parser, program = test(`
+		parser, _ = test(`
 if
 /*comment*/
 (a) {
@@ -830,7 +824,7 @@ if
 		is(parser.comments.CommentMap.Size(), 1)
 
 		// If then else pt 9
-		parser, program = test(`
+		parser, _ = test(`
 if
 (a)
  /*comment*/{
@@ -842,7 +836,7 @@ if
 		is(parser.comments.CommentMap.Size(), 1)
 
 		// If then else pt 10
-		parser, program = test(`
+		parser, _ = test(`
 if(a){
 	b
 }
@@ -971,7 +965,7 @@ while(a) {
 		is(checkComments((parser.comments.CommentMap)[program.Body[0].(*ast.WhileStatement).Body.(*ast.BlockStatement)], []string{"comment"}, ast.FINAL), nil)
 
 		// While pt 8
-		parser, program = test(`
+		parser, _ = test(`
 while
 /*comment*/(a) {
 
@@ -980,7 +974,7 @@ while
 		is(parser.comments.CommentMap.Size(), 1)
 
 		// While pt 9
-		parser, program = test(`
+		parser, _ = test(`
 while
 (a)
  /*comment*/{
@@ -1109,7 +1103,7 @@ with(a)  {
 		is(checkComments((parser.comments.CommentMap)[program.Body[0].(*ast.WithStatement).Body], []string{"comment"}, ast.TRAILING), nil)
 
 		// With pt 7
-		parser, program = test(`
+		parser, _ = test(`
 with
 /*comment*/(a)  {
 }
@@ -1117,7 +1111,7 @@ with
 		is(parser.comments.CommentMap.Size(), 1)
 
 		// With pt 8
-		parser, program = test(`
+		parser, _ = test(`
 with
 (a)
   /*comment*/{
@@ -1176,7 +1170,7 @@ var a, b;
 		is(checkComments((parser.comments.CommentMap)[program], []string{"comment"}, ast.TRAILING), nil)
 
 		// Return
-		parser, program = test(`
+		parser, _ = test(`
 		function f() {
 /*comment*/return o
 }
@@ -1356,7 +1350,7 @@ try {
 		is(checkComments((parser.comments.CommentMap)[program.Body[0].(*ast.TryStatement).Finally], []string{"comment"}, ast.LEADING), nil)
 
 		// Switch / comment
-		parser, program = test(`
+		parser, _ = test(`
 var volvo = 1
 //comment
 switch(abra) {
@@ -1365,7 +1359,7 @@ switch(abra) {
 		is(parser.comments.CommentMap.Size(), 1)
 
 		// Switch / comment
-		parser, program = test(`
+		parser, _ = test(`
 f("string",{
    key: "val"
    //comment

parser/dbg.go

@@ -1,9 +0,0 @@
-// This file was AUTOMATICALLY GENERATED by dbg-import (smuggol) for github.com/robertkrimen/dbg
-
-package parser
-
-import (
-	Dbg "github.com/robertkrimen/otto/dbg"
-)
-
-var dbg, dbgf = Dbg.New()

parser/error.go

@@ -11,7 +11,6 @@ import (
 const (
 	err_UnexpectedToken      = "Unexpected token %v"
 	err_UnexpectedEndOfInput = "Unexpected end of input"
-	err_UnexpectedEscape     = "Unexpected escape"
 )
 
 //    UnexpectedNumber:  'Unexpected number',
@@ -70,7 +69,7 @@ func (self Error) Error() string {
 }
 
 func (self *_parser) error(place interface{}, msg string, msgValues ...interface{}) *Error {
-	idx := file.Idx(0)
+	var idx file.Idx
 	switch place := place.(type) {
 	case int:
 		idx = self.idxOf(place)
@@ -120,8 +119,7 @@ func (self *_parser) errorUnexpectedToken(tkn token.Token) error {
 }
 
 // ErrorList is a list of *Errors.
-//
-type ErrorList []*Error
+type ErrorList []*Error // nolint: errname
 
 // Add adds an Error with given position and message to an ErrorList.
 func (self *ErrorList) Add(position file.Position, msg string) {

parser/expression.go

@@ -352,7 +352,7 @@ func (self *_parser) parseArrayLiteral() ast.Expression {
 	for self.token != token.RIGHT_BRACKET && self.token != token.EOF {
 		if self.token == token.COMMA {
 			// This kind of comment requires a special empty expression node.
-			empty := &ast.EmptyExpression{self.idx, self.idx}
+			empty := &ast.EmptyExpression{Begin: self.idx, End: self.idx}
 
 			if self.mode&StoreComments != 0 {
 				self.comments.SetExpression(empty)

parser/lexer.go

@@ -628,14 +628,14 @@ func parseNumberLiteral(literal string) (value interface{}, err error) {
 	// TODO Is Uint okay? What about -MAX_UINT
 	value, err = strconv.ParseInt(literal, 0, 64)
 	if err == nil {
-		return
+		return value, nil
 	}
 
 	parseIntErr := err // Save this first error, just in case
 
 	value, err = strconv.ParseFloat(literal, 64)
 	if err == nil {
-		return
+		return value, nil
 	} else if err.(*strconv.NumError).Err == strconv.ErrRange {
 		// Infinity, etc.
 		return value, nil
@@ -651,7 +651,7 @@ func parseNumberLiteral(literal string) (value interface{}, err error) {
 			for _, chr := range literal {
 				digit := digitValue(chr)
 				if digit >= 16 {
-					goto error
+					return nil, errors.New("Illegal numeric literal")
 				}
 				value = value*16 + float64(digit)
 			}
@@ -659,7 +659,6 @@ func parseNumberLiteral(literal string) (value interface{}, err error) {
 		}
 	}
 
-error:
 	return nil, errors.New("Illegal numeric literal")
 }
 

parser/marshal_test.go

@@ -854,8 +854,6 @@ func TestParserAST(t *testing.T) {
 ]
             `)
 
-		return
-
 		test(`
         if (!abc && abc.jkl(def) && abc[0] === +abc[0] && abc.length < ghi) {
         }

parser/parser_test.go

@@ -98,9 +98,9 @@ func TestParserErr(t *testing.T) {
 			return program, parser
 		}
 
-		program, parser := test("", nil)
+		test("", nil)
 
-		program, parser = test(`
+		program, parser := test(`
         var abc;
         break; do {
         } while(true);
@@ -523,7 +523,7 @@ func TestParser(t *testing.T) {
             abc()
         `, nil)
 
-		program := test("", nil)
+		test("", nil)
 
 		test("//", nil)
 
@@ -541,7 +541,7 @@ func TestParser(t *testing.T) {
 
 		test("new +", "(anonymous): Line 1:5 Unexpected token +")
 
-		program = test(";", nil)
+		program := test(";", nil)
 		is(len(program.Body), 1)
 		is(program.Body[0].(*ast.EmptyStatement).Semicolon, file.Idx(1))
 
@@ -1012,6 +1012,7 @@ func TestPosition(t *testing.T) {
 
 		parser = _newParser("", "this.style", 1, nil)
 		program, err = parser.parse()
+		is(err, nil)
 		node = program.Body[0].(*ast.ExpressionStatement).Expression.(*ast.DotExpression).Left.(*ast.ThisExpression)
 		is(node.Idx0(), file.Idx(1))
 		is(node.Idx1(), file.Idx(5))