Upgrade packages

.github/workflows/build.yml

@@ -1,17 +1,22 @@
 name: Build/Test/Lint
-on: [push, pull_request]
+on:
+  push:
+    branches: [main]
+  pull_request:
+    branches: [main]
+
 jobs:
   build:
     name: Build
     runs-on: ubuntu-latest
     steps:
-      - name: Set up Go 1.18
-        uses: actions/setup-go@v2
+      - name: Set up Go 1.24
+        uses: actions/setup-go@v5
         with:
-          go-version: 1.18
+          go-version: 1.24
 
       - name: Check out source code
-        uses: actions/checkout@v2
+        uses: actions/checkout@v4
 
       - name: Dependencies
         run: make dep
@@ -23,6 +28,4 @@ jobs:
         run: make test
 
       - name: Lint
-        uses: golangci/golangci-lint-action@v2
-        with:
-          args: --enable-all
+        uses: golangci/golangci-lint-action@v6

.golangci.yaml

@@ -1,15 +1,17 @@
 linters:
+  enable-all: true
   disable:
     # Should eventually address, aiming for basic MVP ATM :)
     - varnamelen
-    - gomnd
-    - goerr113
-    - exhaustivestruct
-    - wsl
     - wrapcheck
     - forbidigo
-    - testpackage
     - dupl
     - lll
     - cyclop
     - funlen
+    - mnd
+    - gosec
+    - depguard
+    - err113
+    - exhaustruct
+    - testifylint

cmd/root.go

@@ -1,6 +1,7 @@
 package cmd
 
 import (
+	"errors"
 	"fmt"
 	"image"
 	"os"
@@ -9,34 +10,35 @@ import (
 	"github.com/theMagicalKarp/dithering/pkg"
 )
 
-func RunE(cmd *cobra.Command, args []string) error {
+func RunE(cmd *cobra.Command, _ []string) error {
 	inFileName, err := cmd.Flags().GetString("in")
 	if err != nil {
-		return fmt.Errorf("Failed to read 'in' flag: %w", err)
+		return fmt.Errorf("failed to read 'in' flag: %w", err)
 	}
 
 	outFileName, err := cmd.Flags().GetString("out")
 	if err != nil {
-		return fmt.Errorf("Failed to read 'out' flag: %w", err)
+		return fmt.Errorf("failed to read 'out' flag: %w", err)
 	}
 
 	if inFileName == "" || outFileName == "" {
-		return fmt.Errorf("Please specify input/output files")
+		return errors.New("please specify input/output files")
 	}
 
 	factor, err := cmd.Flags().GetInt("factor")
 	if err != nil {
-		return fmt.Errorf("Failed to read 'factor' flag: %w", err)
+		return fmt.Errorf("failed to read 'factor' flag: %w", err)
 	}
 
 	if factor < 0 || factor > 255 {
-		return fmt.Errorf("Factor must be any value between 1-255")
+		return errors.New("factor must be any value between 1-255")
 	}
 
 	validOutEncodings := pkg.GetSupportedEncodings()
+
 	outFormat, err := cmd.Flags().GetString("out-format")
 	if err != nil {
-		return fmt.Errorf("Failed to read 'out-format' flag: %w", err)
+		return fmt.Errorf("failed to read 'out-format' flag: %w", err)
 	}
 
 	encodeFunc, ok := validOutEncodings[outFormat]
@@ -46,30 +48,31 @@ func RunE(cmd *cobra.Command, args []string) error {
 
 	inFile, err := os.Open(inFileName)
 	if err != nil {
-		return fmt.Errorf("Failed to read 'in' file: %w", err)
+		return fmt.Errorf("failed to read 'in' file: %w", err)
 	}
 	defer inFile.Close()
 
 	inImg, _, err := image.Decode(inFile)
 	if err != nil {
-		return fmt.Errorf("Failed to decode 'in' file: %w", err)
+		return fmt.Errorf("failed to decode 'in' file: %w", err)
 	}
 
 	grayScale := pkg.NewGreyScale(inImg.Bounds())
 	pkg.ReadGreyScale(inImg, grayScale)
 	pkg.ApplyDither(grayScale, factor)
+
 	outImg := image.NewNRGBA(inImg.Bounds())
 	pkg.WriteGrayScale(grayScale, outImg)
 
 	outFile, err := os.Create(outFileName)
 	if err != nil {
-		return fmt.Errorf("Failed to open 'out' file: %w", err)
+		return fmt.Errorf("failed to open 'out' file: %w", err)
 	}
 	defer outFile.Close()
 
 	err = encodeFunc(outFile, outImg)
 	if err != nil {
-		return fmt.Errorf("Failed to encode 'out' file: %w", err)
+		return fmt.Errorf("failed to encode 'out' file: %w", err)
 	}
 
 	return nil

go.mod

@@ -1,13 +1,16 @@
 module github.com/theMagicalKarp/dithering
 
-go 1.18
+go 1.24
 
 require (
-	github.com/davecgh/go-spew v1.1.0 // indirect
-	github.com/inconshreveable/mousetrap v1.0.0 // indirect
+	github.com/spf13/cobra v1.9.1
+	github.com/stretchr/testify v1.10.0
+)
+
+require (
+	github.com/davecgh/go-spew v1.1.1 // indirect
+	github.com/inconshreveable/mousetrap v1.1.0 // indirect
 	github.com/pmezard/go-difflib v1.0.0 // indirect
-	github.com/spf13/cobra v1.4.0 // indirect
-	github.com/spf13/pflag v1.0.5 // indirect
-	github.com/stretchr/testify v1.7.1 // indirect
-	gopkg.in/yaml.v3 v3.0.0-20200313102051-9f266ea9e77c // indirect
+	github.com/spf13/pflag v1.0.6 // indirect
+	gopkg.in/yaml.v3 v3.0.1 // indirect
 )

go.sum

@@ -1,19 +1,18 @@
-github.com/cpuguy83/go-md2man/v2 v2.0.1/go.mod h1:tgQtvFlXSQOSOSIRvRPT7W67SCa46tRHOmNcaadrF8o=
-github.com/davecgh/go-spew v1.1.0 h1:ZDRjVQ15GmhC3fiQ8ni8+OwkZQO4DARzQgrnXU1Liz8=
-github.com/davecgh/go-spew v1.1.0/go.mod h1:J7Y8YcW2NihsgmVo/mv3lAwl/skON4iLHjSsI+c5H38=
-github.com/inconshreveable/mousetrap v1.0.0 h1:Z8tu5sraLXCXIcARxBp/8cbvlwVa7Z1NHg9XEKhtSvM=
-github.com/inconshreveable/mousetrap v1.0.0/go.mod h1:PxqpIevigyE2G7u3NXJIT2ANytuPF1OarO4DADm73n8=
+github.com/cpuguy83/go-md2man/v2 v2.0.6/go.mod h1:oOW0eioCTA6cOiMLiUPZOpcVxMig6NIQQ7OS05n1F4g=
+github.com/davecgh/go-spew v1.1.1 h1:vj9j/u1bqnvCEfJOwUhtlOARqs3+rkHYY13jYWTU97c=
+github.com/davecgh/go-spew v1.1.1/go.mod h1:J7Y8YcW2NihsgmVo/mv3lAwl/skON4iLHjSsI+c5H38=
+github.com/inconshreveable/mousetrap v1.1.0 h1:wN+x4NVGpMsO7ErUn/mUI3vEoE6Jt13X2s0bqwp9tc8=
+github.com/inconshreveable/mousetrap v1.1.0/go.mod h1:vpF70FUmC8bwa3OWnCshd2FqLfsEA9PFc4w1p2J65bw=
 github.com/pmezard/go-difflib v1.0.0 h1:4DBwDE0NGyQoBHbLQYPwSUPoCMWR5BEzIk/f1lZbAQM=
 github.com/pmezard/go-difflib v1.0.0/go.mod h1:iKH77koFhYxTK1pcRnkKkqfTogsbg7gZNVY4sRDYZ/4=
 github.com/russross/blackfriday/v2 v2.1.0/go.mod h1:+Rmxgy9KzJVeS9/2gXHxylqXiyQDYRxCVz55jmeOWTM=
-github.com/spf13/cobra v1.4.0 h1:y+wJpx64xcgO1V+RcnwW0LEHxTKRi2ZDPSBjWnrg88Q=
-github.com/spf13/cobra v1.4.0/go.mod h1:Wo4iy3BUC+X2Fybo0PDqwJIv3dNRiZLHQymsfxlB84g=
-github.com/spf13/pflag v1.0.5 h1:iy+VFUOCP1a+8yFto/drg2CJ5u0yRoB7fZw3DKv/JXA=
-github.com/spf13/pflag v1.0.5/go.mod h1:McXfInJRrz4CZXVZOBLb0bTZqETkiAhM9Iw0y3An2Bg=
-github.com/stretchr/objx v0.1.0/go.mod h1:HFkY916IF+rwdDfMAkV7OtwuqBVzrE8GR6GFx+wExME=
-github.com/stretchr/testify v1.7.1 h1:5TQK59W5E3v0r2duFAb7P95B6hEeOyEnHRa8MjYSMTY=
-github.com/stretchr/testify v1.7.1/go.mod h1:6Fq8oRcR53rry900zMqJjRRixrwX3KX962/h/Wwjteg=
+github.com/spf13/cobra v1.9.1 h1:CXSaggrXdbHK9CF+8ywj8Amf7PBRmPCOJugH954Nnlo=
+github.com/spf13/cobra v1.9.1/go.mod h1:nDyEzZ8ogv936Cinf6g1RU9MRY64Ir93oCnqb9wxYW0=
+github.com/spf13/pflag v1.0.6 h1:jFzHGLGAlb3ruxLB8MhbI6A8+AQX/2eW4qeyNZXNp2o=
+github.com/spf13/pflag v1.0.6/go.mod h1:McXfInJRrz4CZXVZOBLb0bTZqETkiAhM9Iw0y3An2Bg=
+github.com/stretchr/testify v1.10.0 h1:Xv5erBjTwe/5IxqUQTdXv5kgmIvbHo3QQyRwhJsOfJA=
+github.com/stretchr/testify v1.10.0/go.mod h1:r2ic/lqez/lEtzL7wO/rwa5dbSLXVDPFyf8C91i36aY=
+gopkg.in/check.v1 v0.0.0-20161208181325-20d25e280405 h1:yhCVgyC4o1eVCa2tZl7eS0r+SDo693bJlVdllGtEeKM=
 gopkg.in/check.v1 v0.0.0-20161208181325-20d25e280405/go.mod h1:Co6ibVJAznAaIkqp8huTwlJQCZ016jof/cbN4VW5Yz0=
-gopkg.in/yaml.v2 v2.4.0/go.mod h1:RDklbk79AGWmwhnvt/jBztapEOGDOx6ZbXqjP6csGnQ=
-gopkg.in/yaml.v3 v3.0.0-20200313102051-9f266ea9e77c h1:dUUwHk2QECo/6vqA44rthZ8ie2QXMNeKRTHCNY2nXvo=
-gopkg.in/yaml.v3 v3.0.0-20200313102051-9f266ea9e77c/go.mod h1:K4uyk7z7BCEPqu6E+C64Yfv1cQ7kz7rIZviUmN+EgEM=
+gopkg.in/yaml.v3 v3.0.1 h1:fxVm/GzAzEWqLHuvctI91KS9hhNmmWOoWu0XTYJS7CA=
+gopkg.in/yaml.v3 v3.0.1/go.mod h1:K4uyk7z7BCEPqu6E+C64Yfv1cQ7kz7rIZviUmN+EgEM=

pkg/dithering.go

@@ -12,11 +12,12 @@ func quantize(value, factor int) (int, int) {
 
 func ApplyDither(grayScale [][]int, factor int) {
 	var quantErr int
+
 	width := len(grayScale)
 	height := len(grayScale[0])
 
-	for y := 0; y < height; y++ {
-		for x := 0; x < width; x++ {
+	for y := range height {
+		for x := range width {
 			grayScale[x][y], quantErr = quantize(grayScale[x][y], factor)
 
 			if x+1 >= width || y+1 >= height || x == 0 {

pkg/dithering_test.go

@@ -1,9 +1,10 @@
-package pkg
+package pkg_test
 
 import (
 	"testing"
 
 	"github.com/stretchr/testify/assert"
+	"github.com/theMagicalKarp/dithering/pkg"
 )
 
 func TestApplyBasicDither(t *testing.T) {
@@ -27,7 +28,7 @@ func TestApplyBasicDither(t *testing.T) {
 		},
 	}
 
-	ApplyDither(img, 1)
+	pkg.ApplyDither(img, 1)
 
 	expected := [][]int{
 		{
@@ -71,7 +72,7 @@ func TestApplyBasicDitherWithFactor(t *testing.T) {
 		},
 	}
 
-	ApplyDither(img, 3)
+	pkg.ApplyDither(img, 3)
 
 	expected := [][]int{
 		{

pkg/gray.go

@@ -23,7 +23,7 @@ type WritableImage interface {
 
 func NewGreyScale(bounds image.Rectangle) [][]int {
 	grayscale := make([][]int, bounds.Max.X)
-	for i := 0; i < bounds.Max.X; i++ {
+	for i := range bounds.Max.X {
 		grayscale[i] = make([]int, bounds.Max.Y)
 	}
 
@@ -32,18 +32,18 @@ func NewGreyScale(bounds image.Rectangle) [][]int {
 
 func ReadGreyScale(src ReadableImage, dst [][]int) {
 	bounds := src.Bounds()
-	for x := 0; x < bounds.Max.X; x++ {
-		for y := 0; y < bounds.Max.Y; y++ {
+	for x := range bounds.Max.X {
+		for y := range bounds.Max.Y {
 			dst[x][y] = toGray(src.At(x, y))
 		}
 	}
 }
 
 func WriteGrayScale(src [][]int, dst WritableImage) {
 	bounds := dst.Bounds()
-	for x := 0; x < bounds.Max.X; x++ {
-		for y := 0; y < bounds.Max.Y; y++ {
-			dst.Set(x, y, color.Gray{intToUInt8(src[x][y])})
+	for x := range bounds.Max.X {
+		for y := range bounds.Max.Y {
+			dst.Set(x, y, color.Gray{IntToUInt8(src[x][y])})
 		}
 	}
 }

pkg/gray_test.go

@@ -1,4 +1,4 @@
-package pkg
+package pkg_test
 
 import (
 	"encoding/base64"
@@ -8,6 +8,7 @@ import (
 	"testing"
 
 	"github.com/stretchr/testify/assert"
+	"github.com/theMagicalKarp/dithering/pkg"
 )
 
 func TestNewGreyScale(t *testing.T) {
@@ -23,7 +24,7 @@ func TestNewGreyScale(t *testing.T) {
 		{0, 0, 0, 0, 0},
 	}
 
-	assert.Equal(t, expected, NewGreyScale(bounds))
+	assert.Equal(t, expected, pkg.NewGreyScale(bounds))
 }
 
 func TestReadGreyScale(t *testing.T) {
@@ -32,7 +33,7 @@ func TestReadGreyScale(t *testing.T) {
 	const rawGopher = `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`
 
 	src, err := png.Decode(base64.NewDecoder(base64.StdEncoding, strings.NewReader(rawGopher)))
-	assert.Nil(t, err)
+	assert.NoError(t, err)
 
 	expected := [][]int{
 		{0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0},
@@ -112,14 +113,15 @@ func TestReadGreyScale(t *testing.T) {
 		{0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0},
 	}
 
-	dst := NewGreyScale(image.Rect(0, 0, 75, 60))
-	ReadGreyScale(src, dst)
+	dst := pkg.NewGreyScale(image.Rect(0, 0, 75, 60))
+	pkg.ReadGreyScale(src, dst)
 
 	assert.Equal(t, expected, dst)
 }
 
 func TestWriteGrayScale(t *testing.T) {
 	t.Parallel()
+
 	src := [][]int{
 		{0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0},
 		{0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0},
@@ -199,10 +201,10 @@ func TestWriteGrayScale(t *testing.T) {
 	}
 	bounds := image.Rect(0, 0, 75, 60)
 	dst := image.NewNRGBA(bounds)
-	WriteGrayScale(src, dst)
+	pkg.WriteGrayScale(src, dst)
 
-	for x := 0; x < bounds.Max.X; x++ {
-		for y := 0; y < bounds.Max.Y; y++ {
+	for x := range bounds.Max.X {
+		for y := range bounds.Max.Y {
 			r, g, b, a := dst.At(x, y).RGBA()
 			assert.Equal(t, uint32(src[x][y])*257, r)
 			assert.Equal(t, uint32(src[x][y])*257, g)

pkg/utils.go

@@ -1,9 +1,10 @@
 package pkg
 
-func intToUInt8(value int) uint8 {
+func IntToUInt8(value int) uint8 {
 	if value < 0 {
 		return 0
 	}
+
 	if value > 255 {
 		return 255
 	}