diff --git a/internal/cache/db.go b/internal/cache/db.go
index f15cb1d93..73db67f0d 100644
--- a/internal/cache/db.go
+++ b/internal/cache/db.go
@@ -1,3 +1,4 @@
+// Package cache handles transaction with an underlying database to cache user and group informations.
 package cache
 
 import (
@@ -109,7 +110,7 @@ func New(cacheDir string) (cache *Cache, err error) {
 			break
 		}
 
-		if errors.Is(err, errRetryDB{}) {
+		if errors.Is(err, shouldRetryDBError{}) {
 			if i == 3 {
 				return nil, errors.Unwrap(err)
 			}
@@ -171,7 +172,7 @@ func openAndInitDB(path, dirtyFlagPath string) (*bbolt.DB, error) {
 	if err != nil {
 		if errors.Is(err, bbolt.ErrInvalid) {
 			clearDatabase(path, dirtyFlagPath)
-			return nil, errRetryDB{err: err}
+			return nil, shouldRetryDBError{err: err}
 		}
 		return nil, fmt.Errorf("can't open database file: %v", err)
 	}
@@ -197,13 +198,16 @@ func openAndInitDB(path, dirtyFlagPath string) (*bbolt.DB, error) {
 
 		// Clear up any unknown buckets
 		var bucketNamesToDelete [][]byte
-		tx.ForEach(func(name []byte, b *bbolt.Bucket) error {
+		err = tx.ForEach(func(name []byte, b *bbolt.Bucket) error {
 			if slices.Contains(allBucketsNames, string(name)) {
 				return nil
 			}
 			bucketNamesToDelete = append(bucketNamesToDelete, name)
 			return nil
 		})
+		if err != nil {
+			return err
+		}
 		for _, bucketName := range bucketNamesToDelete {
 			// We are in a RW transaction.
 			_ = tx.DeleteBucket(bucketName)
@@ -295,7 +299,7 @@ func getFromBucket[T any, K int | string](bucket bucketWithName, key K) (T, erro
 
 	data := bucket.Get(k)
 	if data == nil {
-		return r, ErrNoDataFound{key: string(k), bucketName: bucket.name}
+		return r, NoDataFoundError{key: string(k), bucketName: bucket.name}
 	}
 
 	if err := json.Unmarshal(data, &r); err != nil {
@@ -305,34 +309,34 @@ func getFromBucket[T any, K int | string](bucket bucketWithName, key K) (T, erro
 	return r, nil
 }
 
-// ErrNoDataFound is returned when we didn’t find a matching entry.
-type ErrNoDataFound struct {
+// NoDataFoundError is returned when we didn’t find a matching entry.
+type NoDataFoundError struct {
 	key        string
 	bucketName string
 }
 
 // Error implements the error interface to return key/bucket name.
-func (err ErrNoDataFound) Error() string {
+func (err NoDataFoundError) Error() string {
 	return fmt.Sprintf("no result matching %v in %v", err.key, err.bucketName)
 }
 
 // Is makes this error insensitive to the key and bucket name.
-func (ErrNoDataFound) Is(target error) bool { return target == ErrNoDataFound{} }
+func (NoDataFoundError) Is(target error) bool { return target == NoDataFoundError{} }
 
-// errRetryDB is returned when we want to retry opening the database.
-type errRetryDB struct {
+// shouldRetryDBError is returned when we want to retry opening the database.
+type shouldRetryDBError struct {
 	err error
 }
 
 // Error implements the error interface.
-func (err errRetryDB) Error() string {
+func (err shouldRetryDBError) Error() string {
 	return "ErrRetryDB"
 }
 
 // Unwrap allows to unwrap original error.
-func (err errRetryDB) Unwrap() error {
+func (err shouldRetryDBError) Unwrap() error {
 	return err.err
 }
 
 // Is makes this error insensitive to the key and bucket name.
-func (errRetryDB) Is(target error) bool { return target == errRetryDB{} }
+func (shouldRetryDBError) Is(target error) bool { return target == shouldRetryDBError{} }
diff --git a/internal/cache/db_test.go b/internal/cache/db_test.go
index 6094c7bbd..2486ca1d0 100644
--- a/internal/cache/db_test.go
+++ b/internal/cache/db_test.go
@@ -1,6 +1,7 @@
 package cache_test
 
 import (
+	"errors"
 	"io"
 	"io/fs"
 	"os"
@@ -248,9 +249,8 @@ func TestUpdateFromUserInfo(t *testing.T) {
 					requireClearedDatabase(t, c)
 				}
 				return
-			} else {
-				require.NoError(t, err)
 			}
+			require.NoError(t, err)
 
 			requireNoDirtyFileInDir(t, cacheDir)
 
@@ -259,7 +259,6 @@ func TestUpdateFromUserInfo(t *testing.T) {
 
 			want := testutils.LoadWithUpdateFromGolden(t, got)
 			require.Equal(t, want, got, "Did not get expected database content")
-
 		})
 	}
 }
@@ -274,7 +273,7 @@ func TestUserByID(t *testing.T) {
 	}{
 		"Get existing user": {dbFile: "one_user_and_group"},
 
-		"Error on missing user":           {wantErrType: cache.ErrNoDataFound{}},
+		"Error on missing user":           {wantErrType: cache.NoDataFoundError{}},
 		"Error on invalid database entry": {dbFile: "invalid_entry_in_userByID", wantErrType: shouldError{}},
 	}
 	for name, tc := range tests {
@@ -300,7 +299,7 @@ func TestUserByName(t *testing.T) {
 	}{
 		"Get existing user": {dbFile: "one_user_and_group"},
 
-		"Error on missing user":           {wantErrType: cache.ErrNoDataFound{}},
+		"Error on missing user":           {wantErrType: cache.NoDataFoundError{}},
 		"Error on invalid database entry": {dbFile: "invalid_entry_in_userByName", wantErrType: shouldError{}},
 	}
 	for name, tc := range tests {
@@ -354,7 +353,7 @@ func TestGroupByID(t *testing.T) {
 	}{
 		"Get existing group": {dbFile: "one_user_and_group"},
 
-		"Error on missing group":          {wantErrType: cache.ErrNoDataFound{}},
+		"Error on missing group":          {wantErrType: cache.NoDataFoundError{}},
 		"Error on invalid database entry": {dbFile: "invalid_entry_in_groupByID", wantErrType: shouldError{}},
 		"Error as missing userByID":       {dbFile: "partially_valid_multiple_users_and_groups_groupByID_groupToUsers", wantErrType: shouldError{}},
 	}
@@ -381,7 +380,7 @@ func TestGroupByName(t *testing.T) {
 	}{
 		"Get existing group": {dbFile: "one_user_and_group"},
 
-		"Error on missing group":          {wantErrType: cache.ErrNoDataFound{}},
+		"Error on missing group":          {wantErrType: cache.NoDataFoundError{}},
 		"Error on invalid database entry": {dbFile: "invalid_entry_in_groupByName", wantErrType: shouldError{}},
 		"Error as missing userByID":       {dbFile: "partially_valid_multiple_users_and_groups_groupByID_groupToUsers", wantErrType: shouldError{}},
 	}
@@ -459,7 +458,7 @@ UserToGroups: {}
 
 	got, err := dumpToYaml(c)
 	require.NoError(t, err, "Created database should be valid yaml content")
-	require.Equal(t, want, string(got), "Database should only have empty buckets")
+	require.Equal(t, want, got, "Database should only have empty buckets")
 }
 
 //go:linkname dumpToYaml github.com/ubuntu/authd/internal/cache.(*Cache).dumpToYaml
@@ -498,7 +497,7 @@ func requireGetAssertions[E any](t *testing.T, got E, wantErrType, err error, c
 	t.Helper()
 
 	if wantErrType != nil {
-		if (wantErrType == cache.ErrNoDataFound{}) {
+		if (errors.Is(wantErrType, cache.NoDataFoundError{})) {
 			require.ErrorIs(t, err, wantErrType, "Should return no data found")
 			return
 		}
diff --git a/internal/cache/export_test.go b/internal/cache/export_test.go
index 6192ce9e4..45203c050 100644
--- a/internal/cache/export_test.go
+++ b/internal/cache/export_test.go
@@ -1,9 +1,9 @@
 package cache
 
 const (
-	// DbName is dbName exported for tests
+	// DbName is dbName exported for tests.
 	DbName = dbName
-	// DirtyFlagDbName is dirtyFlagDbName exported for tests
+	// DirtyFlagDbName is dirtyFlagDbName exported for tests.
 	DirtyFlagDbName = dirtyFlagDbName
 )
 
diff --git a/internal/cache/getgroups.go b/internal/cache/getgroups.go
index 6d5988b65..0a7651264 100644
--- a/internal/cache/getgroups.go
+++ b/internal/cache/getgroups.go
@@ -87,8 +87,8 @@ func getGroup[K int | string](c *Cache, bucketName string, key K) (Group, error)
 		// Get id and name of the group.
 		g, err := getFromBucket[groupDB](buckets[bucketName], key)
 		if err != nil {
-			// no entry is valid, no need to clear the database but return the error.
-			if !errors.Is(err, ErrNoDataFound{}) {
+			// no entry is valid, no need to clean the database but return the error.
+			if !errors.Is(err, NoDataFoundError{}) {
 				c.requestClearDatabase()
 			}
 			return err
diff --git a/internal/cache/getusers.go b/internal/cache/getusers.go
index a8c225baf..bed1982e0 100644
--- a/internal/cache/getusers.go
+++ b/internal/cache/getusers.go
@@ -83,7 +83,7 @@ func getUser[K int | string](c *Cache, bucketName string, key K) (u userDB, err
 
 		u, err = getFromBucket[userDB](bucket, key)
 		if err != nil {
-			if !errors.Is(err, ErrNoDataFound{}) {
+			if !errors.Is(err, NoDataFoundError{}) {
 				c.requestClearDatabase()
 			}
 			return err
diff --git a/internal/cache/serialization.go b/internal/cache/serialization.go
index 923e0504a..279af5450 100644
--- a/internal/cache/serialization.go
+++ b/internal/cache/serialization.go
@@ -11,6 +11,7 @@ import (
 	"gopkg.in/yaml.v3"
 )
 
+//nolint:unused // This is used for tests, with methods that are using go linking. Not part of exported API.
 var redactedTimes = map[string]string{
 	"AAAAATIME": "2004-10-20T11:06:23Z",
 	"BBBBBTIME": "2006-06-01T10:08:04Z",
@@ -21,6 +22,8 @@ var redactedTimes = map[string]string{
 }
 
 // redactTime replace current time by a redacted version.
+//
+//nolint:unused // This is used for tests, with methods that are using go linking. Not part of exported API.
 func redactTime(line string) string {
 	re := regexp.MustCompile(`"LastLogin":"(.*?)"`)
 	match := re.FindSubmatch([]byte(line))
@@ -51,6 +54,8 @@ func redactTime(line string) string {
 }
 
 // dumpToYaml deserializes the cache database to a writer in a yaml format.
+//
+//nolint:unused // This is used for tests, with go linking. Not part of exported API.
 func (c *Cache) dumpToYaml() (string, error) {
 	d := make(map[string]map[string]string)
 
@@ -75,6 +80,8 @@ func (c *Cache) dumpToYaml() (string, error) {
 }
 
 // dbfromYAML loads a yaml formatted of the buckets and dump it into destDir, with its dbname.
+//
+//nolint:unused // This is used for tests, with go linking. Not part of exported API.
 func dbfromYAML(r io.Reader, destDir string) error {
 	dbPath := filepath.Join(destDir, dbName)
 	db, err := bbolt.Open(dbPath, 0600, nil)
diff --git a/internal/cache/update.go b/internal/cache/update.go
index ddf5b2d01..64db28bf9 100644
--- a/internal/cache/update.go
+++ b/internal/cache/update.go
@@ -53,7 +53,7 @@ func (c *Cache) UpdateFromUserInfo(u UserInfo) error {
 
 		previousGroupsForCurrentUser, err := getFromBucket[userToGroupsDB](buckets[userToGroupsBucketName], userDB.UID)
 		// No data is valid and means this is the first insertion.
-		if err != nil && !errors.Is(err, ErrNoDataFound{}) {
+		if err != nil && !errors.Is(err, NoDataFoundError{}) {
 			c.requestClearDatabase()
 			return err
 		}
@@ -99,7 +99,7 @@ func (c *Cache) UpdateFromUserInfo(u UserInfo) error {
 // updateUser updates both user buckets with userContent. It handles any potential login rename.
 func updateUser(buckets map[string]bucketWithName, userContent userDB) {
 	existingUser, err := getFromBucket[userDB](buckets[userByIDBucketName], userContent.UID)
-	if err != nil && !errors.Is(err, ErrNoDataFound{}) {
+	if err != nil && !errors.Is(err, NoDataFoundError{}) {
 		slog.Warn(fmt.Sprintf("Could not fetch previous record for user %v: %v", userContent.UID, err))
 	}
 
@@ -117,7 +117,7 @@ func updateUser(buckets map[string]bucketWithName, userContent userDB) {
 func updateGroups(buckets map[string]bucketWithName, groupContents []groupDB) {
 	for _, groupContent := range groupContents {
 		existingGroup, err := getFromBucket[groupDB](buckets[groupByIDBucketName], groupContent.GID)
-		if err != nil && !errors.Is(err, ErrNoDataFound{}) {
+		if err != nil && !errors.Is(err, NoDataFoundError{}) {
 			slog.Warn(fmt.Sprintf("Could not fetch previous record for group %v: %v", groupContent.GID, err))
 		}
 
@@ -140,7 +140,7 @@ func updateUsersAndGroups(buckets map[string]bucketWithName, uid int, groupConte
 		currentGIDs = append(currentGIDs, groupContent.GID)
 		grpToUsers, err := getFromBucket[groupToUsersDB](buckets[groupToUsersBucketName], groupContent.GID)
 		// No data is valid and means that this is the first time we record it.
-		if err != nil && !errors.Is(err, ErrNoDataFound{}) {
+		if err != nil && !errors.Is(err, NoDataFoundError{}) {
 			return err
 		}
 
@@ -159,7 +159,7 @@ func updateUsersAndGroups(buckets map[string]bucketWithName, uid int, groupConte
 		}
 		grpToUsers, err := getFromBucket[groupToUsersDB](buckets[groupToUsersBucketName], previousGID)
 		// No data means the database was corrupted but we can forgive this (exist in previous user gid but not on system).
-		if err != nil && !errors.Is(err, ErrNoDataFound{}) {
+		if err != nil && !errors.Is(err, NoDataFoundError{}) {
 			return err
 		}
 
@@ -182,7 +182,6 @@ func updateUsersAndGroups(buckets map[string]bucketWithName, uid int, groupConte
 		_ = buckets[groupByIDBucketName].Delete([]byte(strconv.Itoa(previousGID)))
 		_ = buckets[groupByNameBucketName].Delete([]byte(group.Name))
 		_ = buckets[groupToUsersBucketName].Delete([]byte(strconv.Itoa(previousGID)))
-
 	}
 
 	return nil