fix: problems with latest Go1.23

.github/workflows/test.yml

@@ -0,0 +1,31 @@
+name: Go tests
+
+on:
+  push:
+    branches:
+      - main
+    paths-ignore:
+      - "**/*.md"
+      - "LICENSE"
+  pull_request:
+    paths-ignore:
+      - "**/*.md"
+      - "LICENSE"
+
+jobs:
+  test:
+    strategy:
+      matrix:
+        go-version: [1.22.x, 1.23.x]
+        os: [ubuntu-latest]
+    runs-on: ${{ matrix.os }}
+    steps:
+      - name: Checkout
+        uses: actions/checkout@v4
+      - name: Install Go
+        uses: actions/setup-go@v5
+        with:
+          go-version: ${{ matrix.go-version }}
+          cache: true
+      - name: Run tests
+        run: go test ./...

go.mod

@@ -1,5 +1,11 @@
 module github.com/jcchavezs/mergefs
 
-go 1.16
+go 1.22
 
 require github.com/stretchr/testify v1.8.2
+
+require (
+	github.com/davecgh/go-spew v1.1.1 // indirect
+	github.com/pmezard/go-difflib v1.0.0 // indirect
+	gopkg.in/yaml.v3 v3.0.1 // indirect
+)

readfile.go

@@ -20,10 +20,13 @@ func (rfs *readFileFS) ReadFile(name string) (content []byte, err error) {
 		if err == nil {
 			return content, nil
 		} else if !errors.Is(err, os.ErrNotExist) {
-			if errors.Unwrap(err).Error() != "invalid name" {
-				// invalid name is returned when the filename
-				// is an absolute path, which is only supported by
-				// the OS filesystem
+			// invalid name is returned when the filename
+			// is an absolute path, which is only supported by
+			// the OS filesystem.
+			// Starting from Go 1.23, os.ErrInvalid is used as error message.
+			// See go-review.googlesource.com/c/go/+/560137/4/src/io/fs/sub.go
+			// Both errors are checked to support both versions.
+			if errors.Unwrap(err).Error() != "invalid name" && !errors.Is(err, os.ErrInvalid) {
 				return nil, err
 			}
 		}

readfile_test.go

@@ -4,6 +4,7 @@ import (
 	"embed"
 	"io/fs"
 	"os"
+	"strings"
 	"testing"
 	"testing/fstest"
 
@@ -55,7 +56,11 @@ func TestReadfile(t *testing.T) {
 var testdataFS embed.FS
 
 func TestAbsolutePath(t *testing.T) {
-	mfs := Merge(testdataFS, io.OSFS)
+	// Emulates github.com/corazawaf/coraza-coreruleset/blob/main/coreruleset.go usage of mergefs
+	rulesFS, err := fs.Sub(testdataFS, "testdata")
+	require.NoError(t, err)
+
+	mfs := Merge(rulesFS, io.OSFS)
 
 	f, err := os.CreateTemp(t.TempDir(), "fizz.conf")
 	require.NoError(t, err)
@@ -71,4 +76,9 @@ func TestAbsolutePath(t *testing.T) {
 
 	_, err = rfmfs.ReadFile(f.Name())
 	require.NoError(t, err)
+
+	_, err = rfmfs.ReadFile("/tmp/doesnotexist.conf")
+	if !strings.Contains(err.Error(), "no such file or directory") {
+		t.Errorf("expected not found error. Got: %s", err.Error())
+	}
 }