Enable staticcheck, fix issues (#542)

cmd/litestream/main.go

@@ -5,7 +5,6 @@ import (
 	"errors"
 	"flag"
 	"fmt"
-	"io/ioutil"
 	"log/slog"
 	"net/url"
 	"os"
@@ -223,7 +222,7 @@ func ReadConfigFile(filename string, expandEnv bool) (_ Config, err error) {
 	}
 
 	// Read configuration.
-	buf, err := ioutil.ReadFile(filename)
+	buf, err := os.ReadFile(filename)
 	if os.IsNotExist(err) {
 		return config, fmt.Errorf("config file not found: %s", filename)
 	} else if err != nil {

cmd/litestream/main_test.go

@@ -1,7 +1,6 @@
 package main_test
 
 import (
-	"io/ioutil"
 	"os"
 	"path/filepath"
 	"testing"
@@ -16,7 +15,7 @@ func TestReadConfigFile(t *testing.T) {
 	// Ensure global AWS settings are propagated down to replica configurations.
 	t.Run("PropagateGlobalSettings", func(t *testing.T) {
 		filename := filepath.Join(t.TempDir(), "litestream.yml")
-		if err := ioutil.WriteFile(filename, []byte(`
+		if err := os.WriteFile(filename, []byte(`
 access-key-id: XXX
 secret-access-key: YYY
 
@@ -48,7 +47,7 @@ dbs:
 		os.Setenv("LITESTREAM_TEST_1872363", "s3://foo/bar")
 
 		filename := filepath.Join(t.TempDir(), "litestream.yml")
-		if err := ioutil.WriteFile(filename, []byte(`
+		if err := os.WriteFile(filename, []byte(`
 dbs:
   - path: $LITESTREAM_TEST_0129380
     replicas:
@@ -75,7 +74,7 @@ dbs:
 		os.Setenv("LITESTREAM_TEST_9847533", "s3://foo/bar")
 
 		filename := filepath.Join(t.TempDir(), "litestream.yml")
-		if err := ioutil.WriteFile(filename, []byte(`
+		if err := os.WriteFile(filename, []byte(`
 dbs:
   - path: /path/to/db
     replicas: