🥐 go: Crank up the linting settings (#25)

Crank up the linting settings so that linter runs in stricter mode and
catches more errors, before the codebase gets too big. Disable quite a few
annoying linters.

Pull-Request: #25

Author: juliaogris

.golangci.yaml

@@ -0,0 +1,40 @@
+issues:
+   exclude-use-default: false
+   exclude:
+    - "^don't use ALL_CAPS"
+    - "^ST1003: should not use ALL_CAPS"
+    - "^G304: Potential file inclusion via variable"
+
+linters:
+  enable-all: true
+  disable:
+    - cyclop
+    - exhaustive
+    - exhaustivestruct
+    - exhaustruct
+    - forbidigo
+    - forcetypeassert
+    - funlen
+    - gochecknoglobals
+    - gocyclo
+    - godox
+    - golint
+    - gomnd
+    - ifshort
+    - interfacer
+    - ireturn
+    - lll
+    - maligned
+    - nlreturn
+    - nosnakecase
+    - paralleltest
+    - revive
+    - rowserrcheck
+    - scopelint
+    - sqlclosecheck
+    - structcheck
+    - testpackage
+    - varnamelen
+    - wastedassign
+    - wrapcheck
+    - wsl

main.go

@@ -29,9 +29,11 @@ type config struct {
 type cmdRun struct {
 	Source string `arg:"" help:"Source file. Default stdin" default:"-"`
 }
+
 type cmdTokenize struct {
 	Source string `arg:"" help:"Source file. Default stdin" default:"-"`
 }
+
 type cmdParse struct {
 	Source string `arg:"" help:"Source file. Default stdin" default:"-"`
 }

pkg/assert/assert.go

@@ -1,3 +1,6 @@
+// Package assert is a testing utility package for online assertion that
+// also work with TinyGo which has only limited support for
+// reflection.
 package assert
 
 import (
@@ -7,18 +10,18 @@ import (
 )
 
 func NoError(t *testing.T, err error, msgAndArgs ...interface{}) {
+	t.Helper()
 	if err == nil {
 		return
 	}
-	t.Helper()
 	fatalf(t, "err: %v%s", err, format(msgAndArgs...))
 }
 
 func Equal(t *testing.T, want, got any, msgAndArgs ...interface{}) {
+	t.Helper()
 	if equal(want, got) {
 		return
 	}
-	t.Helper()
 	fatalf(t, "want != got\n%#v\n%#v%s", want, got, format(msgAndArgs...))
 }
 

pkg/evaluator/builtin.go

@@ -27,12 +27,12 @@ type BuiltinFunc func(args []Value) Value
 func (b BuiltinFunc) Type() ValueType { return BUILTIN }
 func (b BuiltinFunc) String() string  { return "builtin function" }
 
-func DefaultBuiltins(print func(string)) Builtins {
+func DefaultBuiltins(printFn func(string)) Builtins {
 	return Builtins{
-		"print": {Func: printFunc(print), Decl: printDecl},
+		"print": {Func: printFunc(printFn), Decl: printDecl},
 		"len":   {Func: BuiltinFunc(lenFunc), Decl: lenDecl},
-		"move":  {Func: moveFunc(print), Decl: moveDecl},
-		"line":  {Func: lineFunc(print), Decl: lineDecl},
+		"move":  {Func: moveFunc(printFn), Decl: moveDecl},
+		"line":  {Func: lineFunc(printFn), Decl: lineDecl},
 	}
 }
 
@@ -77,8 +77,8 @@ func lenFunc(args []Value) Value {
 var moveDecl = &parser.FuncDecl{
 	Name: "move",
 	Params: []*parser.Var{
-		&parser.Var{Name: "x", T: parser.NUM_TYPE},
-		&parser.Var{Name: "y", T: parser.NUM_TYPE},
+		{Name: "x", T: parser.NUM_TYPE},
+		{Name: "y", T: parser.NUM_TYPE},
 	},
 	ReturnType: parser.NUM_TYPE,
 }
@@ -93,8 +93,8 @@ func moveFunc(printFn func(string)) BuiltinFunc {
 var lineDecl = &parser.FuncDecl{
 	Name: "line",
 	Params: []*parser.Var{
-		&parser.Var{Name: "x", T: parser.NUM_TYPE},
-		&parser.Var{Name: "y", T: parser.NUM_TYPE},
+		{Name: "x", T: parser.NUM_TYPE},
+		{Name: "y", T: parser.NUM_TYPE},
 	},
 	ReturnType: parser.NUM_TYPE,
 }

pkg/evaluator/evaluator.go

@@ -1,25 +1,28 @@
+// Package evaluator evaluates a given syntax tree as created by the
+// parser packages. It also exports a Run and RunWithBuiltings function
+// which creates and calls a Parser.
 package evaluator
 
 import (
 	"foxygo.at/evy/pkg/parser"
 )
 
-func Run(input string, print func(string)) {
-	RunWithBuiltins(input, print, DefaultBuiltins(print))
+func Run(input string, printFn func(string)) {
+	RunWithBuiltins(input, printFn, DefaultBuiltins(printFn))
 }
 
-func RunWithBuiltins(input string, print func(string), builtins Builtins) {
+func RunWithBuiltins(input string, printFn func(string), builtins Builtins) {
 	p := parser.New(input, builtins.Decls())
 	prog := p.Parse()
 	if p.HasErrors() {
-		print(p.MaxErrorsString(8))
+		printFn(p.MaxErrorsString(8))
 		return
 	}
-	e := &Evaluator{print: print}
+	e := &Evaluator{print: printFn}
 	e.builtins = builtins
 	val := e.Eval(newScope(), prog)
 	if isError(val) {
-		print(val.String())
+		printFn(val.String())
 	}
 }
 

pkg/evaluator/scope.go

@@ -33,7 +33,6 @@ func (s *scope) getScope(name string) (*scope, bool) {
 	return s.outer.getScope(name)
 }
 
-func (s *scope) set(name string, val Value) Value {
+func (s *scope) set(name string, val Value) {
 	s.values[name] = val
-	return val
 }

pkg/evaluator/value.go

@@ -99,9 +99,11 @@ func (e *Error) String() string  { return "ERROR: " + e.Message }
 func isError(val Value) bool { // TODO: replace with panic flow
 	return val != nil && val.Type() == ERROR
 }
+
 func isReturn(val Value) bool {
 	return val != nil && val.Type() == RETURN_VALUE
 }
+
 func newError(msg string) *Error {
 	return &Error{Message: msg}
 }

pkg/lexer/lexer.go

@@ -1,3 +1,7 @@
+// Package lexer tokenizes input and lets follow up phases in compiler,
+// such as parser, iterate over tokens via Lexer.Next() function. The
+// lexer package also exposes a Run method for debugging the lexing
+// phase only.
 package lexer
 
 import (

pkg/lexer/lexer_test.go

@@ -11,13 +11,45 @@ func TestSingleToken(t *testing.T) {
 		in   string
 		want TokenType
 	}{
-		{in: ":=", want: DECLARE}, {in: "=", want: ASSIGN}, {in: "+", want: PLUS}, {in: "-", want: MINUS}, {in: "!", want: BANG}, {in: "*", want: ASTERISK}, {in: "/", want: SLASH},
-		{in: "==", want: EQ}, {in: "!=", want: NOT_EQ}, {in: "<", want: LT}, {in: ">", want: GT}, {in: "<=", want: LTEQ}, {in: ">=", want: GTEQ},
-		{in: "(", want: LPAREN}, {in: ")", want: RPAREN}, {in: "[", want: LBRACKET}, {in: "]", want: RBRACKET}, {in: "{", want: LCURLY}, {in: "}", want: RCURLY},
-		{in: ":", want: COLON}, {in: ".", want: DOT}, {in: "...", want: DOT3},
-		{in: "num", want: NUM}, {in: "string", want: STRING}, {in: "bool", want: BOOL}, {in: "any", want: ANY},
-		{in: "true", want: TRUE}, {in: "false", want: FALSE}, {in: "and", want: AND}, {in: "or", want: OR},
-		{in: "if", want: IF}, {in: "else", want: ELSE}, {in: "func", want: FUNC}, {in: "return", want: RETURN}, {in: "for", want: FOR}, {in: "range", want: RANGE}, {in: "while", want: WHILE}, {in: "break", want: BREAK}, {in: "end", want: END},
+		{in: ":=", want: DECLARE},
+		{in: "=", want: ASSIGN},
+		{in: "+", want: PLUS},
+		{in: "-", want: MINUS},
+		{in: "!", want: BANG},
+		{in: "*", want: ASTERISK},
+		{in: "/", want: SLASH},
+		{in: "==", want: EQ},
+		{in: "!=", want: NOT_EQ},
+		{in: "<", want: LT},
+		{in: ">", want: GT},
+		{in: "<=", want: LTEQ},
+		{in: ">=", want: GTEQ},
+		{in: "(", want: LPAREN},
+		{in: ")", want: RPAREN},
+		{in: "[", want: LBRACKET},
+		{in: "]", want: RBRACKET},
+		{in: "{", want: LCURLY},
+		{in: "}", want: RCURLY},
+		{in: ":", want: COLON},
+		{in: ".", want: DOT},
+		{in: "...", want: DOT3},
+		{in: "num", want: NUM},
+		{in: "string", want: STRING},
+		{in: "bool", want: BOOL},
+		{in: "any", want: ANY},
+		{in: "true", want: TRUE},
+		{in: "false", want: FALSE},
+		{in: "and", want: AND},
+		{in: "or", want: OR},
+		{in: "if", want: IF},
+		{in: "else", want: ELSE},
+		{in: "func", want: FUNC},
+		{in: "return", want: RETURN},
+		{in: "for", want: FOR},
+		{in: "range", want: RANGE},
+		{in: "while", want: WHILE},
+		{in: "break", want: BREAK},
+		{in: "end", want: END},
 	}
 
 	for _, tt := range tests {
@@ -101,7 +133,7 @@ func TestNums(t *testing.T) {
 y := 1
 y = y * ( 3 + 7)
 `
-	wantTokens := []Token{
+	wantTokens := []*Token{
 		{Type: NL, Literal: "", Offset: 0, Line: 1, Col: 1},
 		{Type: IDENT, Literal: "y", Offset: 1, Line: 2, Col: 1},
 		{Type: DECLARE, Literal: "", Offset: 3, Line: 2, Col: 3},
@@ -122,7 +154,7 @@ y = y * ( 3 + 7)
 	l := New(in)
 	for _, want := range wantTokens {
 		got := l.Next()
-		assert.Equal(t, &want, got)
+		assert.Equal(t, want, got)
 	}
 }
 
@@ -131,7 +163,7 @@ func TestStrings(t *testing.T) {
 s:string
 s = "abc"
 s = s[:1] // "bc"`
-	wantTokens := []Token{
+	wantTokens := []*Token{
 		{Type: NL, Literal: "", Offset: 0, Line: 1, Col: 1},
 		{Type: IDENT, Literal: "s", Offset: 1, Line: 2, Col: 1},
 		{Type: COLON, Literal: "", Offset: 2, Line: 2, Col: 2},
@@ -156,7 +188,7 @@ s = s[:1] // "bc"`
 	l := New(in)
 	for _, want := range wantTokens {
 		got := l.Next()
-		assert.Equal(t, &want, got)
+		assert.Equal(t, want, got)
 	}
 }
 
@@ -167,7 +199,7 @@ for key := range m
     print key m[key] // Mali climbing
 end
 `
-	wantTokens := []Token{
+	wantTokens := []*Token{
 		{Type: NL, Literal: "", Offset: 0, Line: 1, Col: 1},
 		{Type: IDENT, Literal: "m", Offset: 1, Line: 2, Col: 1},
 		{Type: DECLARE, Literal: "", Offset: 3, Line: 2, Col: 3},
@@ -206,7 +238,7 @@ end
 	l := New(in)
 	for _, want := range wantTokens {
 		got := l.Next()
-		assert.Equal(t, &want, got)
+		assert.Equal(t, want, got)
 	}
 }
 

pkg/lexer/token.go

@@ -20,12 +20,12 @@ const (
 	EOF
 	COMMENT // `// a comment`
 
-	// Identifiers and Literals
+	// Identifiers and Literals.
 	IDENT      // some_identifier
 	NUM_LIT    // 123 456.78
 	STRING_LIT // "a string 🧵"
 
-	// Operators
+	// Operators.
 	DECLARE  // :=
 	ASSIGN   // =
 	PLUS     // +
@@ -41,7 +41,7 @@ const (
 	LTEQ   // <=
 	GTEQ   // >=
 
-	// Delimiters
+	// Delimiters.
 	LPAREN   // (
 	RPAREN   // )
 	LBRACKET // [
@@ -54,7 +54,7 @@ const (
 	DOT   // .
 	DOT3  // ...
 
-	// Keywords
+	// Keywords.
 	NUM    // num
 	STRING // string
 	BOOL   // bool