fix: resolve linting warnings

- Replace deprecated io/ioutil with os.ReadFile in internal/io/file
- Simplify make([]*Credential, count, count) to make([]*Credential, count)
- Explicitly ignore errors in test cleanup/setup for credman tests

Remaining warnings are for unsafe pointer handling in credman which
requires careful review before modifying.

Author: dlevy-msft-sql

internal/credman/credman_windows.go

@@ -7,10 +7,11 @@
 package credman
 
 import (
-	syscall "golang.org/x/sys/windows"
 	"reflect"
 	"time"
 	"unsafe"
+
+	syscall "golang.org/x/sys/windows"
 )
 
 // Load the Windows DLL "advapi32.dll", then set up Go wrapper functions for
@@ -78,7 +79,7 @@ func EnumerateCredentials(filter string, all bool) ([]*Credential, error) {
 		Len:  count,
 		Cap:  count,
 	}))
-	credentials := make([]*Credential, count, count)
+	credentials := make([]*Credential, count)
 	for i, c := range systemCredentials {
 		credentials[i] = convertFromSystemCredential(c)
 	}

internal/credman/credman_windows_test.go

@@ -4,9 +4,10 @@
 package credman
 
 import (
-	"github.com/stretchr/testify/assert"
 	"testing"
 	"time"
+
+	"github.com/stretchr/testify/assert"
 )
 
 func TestWriteCredential(t *testing.T) {
@@ -31,7 +32,7 @@ func TestWriteCredential(t *testing.T) {
 	assert.Equal(t, credentials[0].Persist, PersistSession, "WriteCredential wrote incorrect Persist, got: %d, want: %d", credentials[0].Persist, PersistSession)
 
 	// Cleanup the written credential
-	DeleteCredential(credential, CredTypeGeneric)
+	_ = DeleteCredential(credential, CredTypeGeneric)
 }
 
 func TestDeleteCredential(t *testing.T) {
@@ -44,7 +45,7 @@ func TestDeleteCredential(t *testing.T) {
 	}
 
 	// Write the credential first
-	WriteCredential(credential, CredTypeGeneric)
+	_ = WriteCredential(credential, CredTypeGeneric)
 
 	err := DeleteCredential(credential, CredTypeGeneric)
 	assert.NoErrorf(t, err, "DeleteCredential returned an error: %v", err)

internal/io/file/file.go

@@ -4,10 +4,10 @@
 package file
 
 import (
-	"github.com/microsoft/go-sqlcmd/internal/io/folder"
-	"io/ioutil"
 	"os"
 	"path/filepath"
+
+	"github.com/microsoft/go-sqlcmd/internal/io/folder"
 )
 
 func CloseFile(f *os.File) {
@@ -55,7 +55,7 @@ func Exists(filename string) (exists bool) {
 }
 
 func GetContents(filename string) string {
-	b, err := ioutil.ReadFile(filename)
+	b, err := os.ReadFile(filename)
 	checkErr(err)
 
 	return string(b)