Bring up to date - switch to Go modules, add GitHub actions etc.

.github/workflows/lint.yml

@@ -0,0 +1,15 @@
+name: Lint
+on:
+  pull_request:
+jobs:
+  build:
+    name: lint
+    runs-on: ubuntu-latest
+    steps:
+      - uses: actions/checkout@v3
+      - uses: actions/setup-go@v3
+        with:
+          go-version-file: go.mod
+          cache: true
+          cache-dependency-path: go.sum
+      - run: make lint

.github/workflows/test.yml

@@ -0,0 +1,16 @@
+name: Test
+on:
+  pull_request:
+jobs:
+  build:
+    name: test
+    runs-on: ubuntu-latest
+    steps:
+      - uses: actions/checkout@v3
+      - uses: actions/setup-go@v3
+        with:
+          go-version-file: go.mod
+          cache: true
+          cache-dependency-path: go.sum
+      - run: make test
+

Makefile

@@ -1,18 +1,13 @@
-default : vet test build
+golangcilint_version := "1.53.3"
 
-.PHONY: build
-build:
-	go build
+default : lint test
 
-.PHONY: vet
-vet:
-	go vet ./...
+.PHONY: lint
+lint:
+	@echo "Linting..."
+	@(which golangci-lint &&  [[ "$$(golangci-lint --version | awk '{print $$4}')" == "$(golangcilint_version)" ]] ) || go install github.com/golangci/golangci-lint/cmd/golangci-lint@v$(golangcilint_version)
+	@golangci-lint run
 
 .PHONY: test
 test:
-	go test -v ./...
-
-.PHONY: release
-release:
-	go get github.com/goreleaser/goreleaser;
-	goreleaser;
+	go test -race ./...

go.mod

@@ -0,0 +1,16 @@
+module github.com/liamg/magic
+
+go 1.20
+
+require (
+	github.com/stretchr/testify v1.8.4
+	gotest.tools v2.2.0+incompatible
+)
+
+require (
+	github.com/davecgh/go-spew v1.1.1 // indirect
+	github.com/google/go-cmp v0.5.9 // indirect
+	github.com/pkg/errors v0.9.1 // indirect
+	github.com/pmezard/go-difflib v1.0.0 // indirect
+	gopkg.in/yaml.v3 v3.0.1 // indirect
+)

go.sum

@@ -0,0 +1,16 @@
+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/google/go-cmp v0.5.9 h1:O2Tfq5qg4qc4AmwVlvv0oLiVAGB7enBSJ2x2DqQFi38=
+github.com/google/go-cmp v0.5.9/go.mod h1:17dUlkBOakJ0+DkrSSNjCkIjxS6bF9zb3elmeNGIjoY=
+github.com/pkg/errors v0.9.1 h1:FEBLx1zS214owpjy7qsBeixbURkuhQAwrK5UwLGTwt4=
+github.com/pkg/errors v0.9.1/go.mod h1:bwawxfHBFNV+L2hUp1rHADufV3IMtnDRdf1r5NINEl0=
+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/stretchr/testify v1.8.4 h1:CcVxjf3Q8PM0mHUKJCdn+eZZtm5yQwehR5yeSVQQcUk=
+github.com/stretchr/testify v1.8.4/go.mod h1:sz/lmYIOXD/1dqDmKjjqLyZ2RngseejIcXlSw2iwfAo=
+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.v3 v3.0.1 h1:fxVm/GzAzEWqLHuvctI91KS9hhNmmWOoWu0XTYJS7CA=
+gopkg.in/yaml.v3 v3.0.1/go.mod h1:K4uyk7z7BCEPqu6E+C64Yfv1cQ7kz7rIZviUmN+EgEM=
+gotest.tools v2.2.0+incompatible h1:VsBPFP1AI068pPrMxtb/S8Zkgf9xEmTLJjfM+P5UIEo=
+gotest.tools v2.2.0+incompatible/go.mod h1:DsYFclhRJ6vuDpmuTbkuFWG+y2sxOXAzmJt81HFBacw=

magic.go

@@ -42,7 +42,7 @@ func LookupSync(bytes []byte) (*FileType, error) {
 func lookup(bytes []byte, concurrent bool, workers int) (*FileType, error) {
 	// additional worker count check: avoid deadlock when worker count is set to zero
 	if !concurrent || workers == 0 {
-		for _, t := range types {
+		for _, t := range Types {
 			ft := t.check(bytes, 0)
 			if ft != nil {
 				return ft, nil

types.go

@@ -20,7 +20,7 @@ func (ft *FileType) check(data []byte, offset int) *FileType {
 	if len(trunc) < len(ft.Magic) {
 		return nil
 	}
-	if bytes.Compare(trunc[:len(ft.Magic)], ft.Magic) == 0 {
+	if bytes.Equal(trunc[:len(ft.Magic)], ft.Magic) {
 		if ft.children == nil {
 			return ft
 		}