chore(all): use string comparisons instead of length for string variables

internal/params/json.go

@@ -136,8 +136,8 @@ func makeSettingsFromObject(common commonSettings, rawSettings json.RawMessage)
 	settingsSlice []settings.Settings, warnings []string, err error) {
 	provider := models.Provider(common.Provider)
 	if provider == constants.DuckDNS { // only hosts, no domain
-		if len(common.Domain) > 0 { // retro compatibility
-			if len(common.Host) == 0 {
+		if common.Domain != "" { // retro compatibility
+			if common.Host == "" {
 				common.Host = strings.TrimSuffix(common.Domain, ".duckdns.org")
 				warnings = append(warnings,
 					fmt.Sprintf("DuckDNS record should have %q specified as host instead of %q as domain",
@@ -151,7 +151,7 @@ func makeSettingsFromObject(common commonSettings, rawSettings json.RawMessage)
 	}
 	hosts := strings.Split(common.Host, ",")
 
-	if len(common.IPVersion) == 0 {
+	if common.IPVersion == "" {
 		common.IPVersion = ipversion.IP4or6.String()
 	}
 	ipVersion, err := ipversion.Parse(common.IPVersion)

internal/persistence/json/database.go

@@ -71,9 +71,9 @@ var (
 func (db *Database) Check() error {
 	for _, record := range db.data.Records {
 		switch {
-		case len(record.Domain) == 0:
+		case record.Domain == "":
 			return fmt.Errorf("%w: for record %s", ErrDomainEmpty, record)
-		case len(record.Host) == 0:
+		case record.Host == "":
 			return fmt.Errorf("%w: for record %s", ErrHostIsEmpty, record)
 		}
 		var t time.Time

internal/records/html.go

@@ -16,10 +16,10 @@ func (r *Record) HTML(now time.Time) models.HTMLRow {
 	if r.Status == constants.UPTODATE {
 		message = "no IP change for " + r.History.GetDurationSinceSuccess(now)
 	}
-	if len(message) > 0 {
+	if message != "" {
 		message = fmt.Sprintf("(%s)", message)
 	}
-	if len(r.Status) == 0 {
+	if r.Status == "" {
 		row.Status = NotAvailable
 	} else {
 		row.Status = models.HTML(fmt.Sprintf("%s %s, %s",

internal/records/records.go

@@ -30,7 +30,7 @@ func New(settings settings.Settings, events []models.HistoryEvent) Record {
 
 func (r *Record) String() string {
 	status := string(r.Status)
-	if len(r.Message) > 0 {
+	if r.Message != "" {
 		status += " (" + r.Message + ")"
 	}
 	return fmt.Sprintf("%s: %s %s; %s",

internal/settings/providers/cloudflare/provider.go

@@ -74,21 +74,21 @@ var (
 
 func (p *Provider) isValid() error {
 	switch {
-	case len(p.key) > 0: // email and key must be provided
+	case p.key != "": // email and key must be provided
 		switch {
 		case !keyRegex.MatchString(p.key):
 			return errors.ErrMalformedKey
 		case !verification.NewVerifier().MatchEmail(p.email):
 			return errors.ErrMalformedEmail
 		}
-	case len(p.userServiceKey) > 0: // only user service key
+	case p.userServiceKey != "": // only user service key
 		if !userServiceKeyRegex.MatchString(p.key) {
 			return errors.ErrMalformedUserServiceKey
 		}
 	default: // constants.API token only
 	}
 	switch {
-	case len(p.zoneIdentifier) == 0:
+	case p.zoneIdentifier == "":
 		return errors.ErrEmptyZoneIdentifier
 	case p.ttl == 0:
 		return errors.ErrEmptyTTL
@@ -134,11 +134,11 @@ func (p *Provider) setHeaders(request *http.Request) {
 	headers.SetContentType(request, "application/json")
 	headers.SetAccept(request, "application/json")
 	switch {
-	case len(p.token) > 0:
+	case p.token != "":
 		headers.SetAuthBearer(request, p.token)
-	case len(p.userServiceKey) > 0:
+	case p.userServiceKey != "":
 		request.Header.Set("X-Auth-User-Service-Key", p.userServiceKey)
-	case len(p.email) > 0 && len(p.key) > 0:
+	case p.email != "" && p.key != "":
 		request.Header.Set("X-Auth-Email", p.email)
 		request.Header.Set("X-Auth-Key", p.key)
 	}

internal/settings/providers/dd24/provider.go

@@ -52,7 +52,7 @@ func New(data json.RawMessage, domain, host string,
 }
 
 func (p *Provider) isValid() error {
-	if len(p.password) == 0 {
+	if p.password == "" {
 		return errors.ErrEmptyPassword
 	}
 	return nil

internal/settings/providers/ddnss/provider.go

@@ -58,9 +58,9 @@ func New(data json.RawMessage, domain, host string,
 
 func (p *Provider) isValid() error {
 	switch {
-	case len(p.username) == 0:
+	case p.username == "":
 		return errors.ErrEmptyUsername
-	case len(p.password) == 0:
+	case p.password == "":
 		return errors.ErrEmptyPassword
 	case p.host == "*":
 		return errors.ErrHostWildcard

internal/settings/providers/digitalocean/provider.go

@@ -47,7 +47,7 @@ func New(data json.RawMessage, domain, host string,
 }
 
 func (p *Provider) isValid() error {
-	if len(p.token) == 0 {
+	if p.token == "" {
 		return errors.ErrEmptyToken
 	}
 	return nil

internal/settings/providers/dnsomatic/provider.go

@@ -61,7 +61,7 @@ func (p *Provider) isValid() error {
 	switch {
 	case !regexUsername.MatchString(p.username):
 		return fmt.Errorf("%w: %s", errors.ErrMalformedUsername, p.username)
-	case len(p.password) == 0:
+	case p.password == "":
 		return errors.ErrEmptyPassword
 	}
 	return nil

internal/settings/providers/dnspod/provider.go

@@ -48,7 +48,7 @@ func New(data json.RawMessage, domain, host string,
 }
 
 func (p *Provider) isValid() error {
-	if len(p.token) == 0 {
+	if p.token == "" {
 		return errors.ErrEmptyToken
 	}
 	return nil
@@ -158,7 +158,7 @@ func (p *Provider) Update(ctx context.Context, client *http.Client, ip net.IP) (
 			break
 		}
 	}
-	if len(recordID) == 0 {
+	if recordID == "" {
 		return nil, errors.ErrNotFound
 	}
 

internal/settings/providers/dondominio/provider.go

@@ -37,7 +37,7 @@ func New(data json.RawMessage, domain, host string,
 	if err != nil {
 		return nil, err
 	}
-	if len(host) == 0 {
+	if host == "" {
 		host = "@" // default
 	}
 	p = &Provider{
@@ -57,11 +57,11 @@ func New(data json.RawMessage, domain, host string,
 
 func (p *Provider) isValid() error {
 	switch {
-	case len(p.username) == 0:
+	case p.username == "":
 		return errors.ErrEmptyUsername
-	case len(p.password) == 0:
+	case p.password == "":
 		return errors.ErrEmptyPassword
-	case len(p.name) == 0:
+	case p.name == "":
 		return errors.ErrEmptyName
 	case p.host != "@":
 		return errors.ErrHostOnlyAt

internal/settings/providers/dyn/provider.go

@@ -62,7 +62,7 @@ func New(data json.RawMessage, domain, host string,
 
 func (p *Provider) isValid() error {
 	switch {
-	case len(p.username) == 0:
+	case p.username == "":
 		return errors.ErrEmptyUsername
 	case p.clientKey == "":
 		return errors.ErrEmptyPassword

internal/settings/providers/dynv6/provider.go

@@ -49,7 +49,7 @@ func New(data json.RawMessage, domain, host string,
 
 func (p *Provider) isValid() error {
 	switch {
-	case len(p.token) == 0:
+	case p.token == "":
 		return errors.ErrEmptyToken
 	case p.host == "*":
 		return errors.ErrHostWildcard

internal/settings/providers/freedns/provider.go

@@ -48,7 +48,7 @@ func New(data json.RawMessage, domain, host string,
 }
 
 func (p *Provider) isValid() error {
-	if len(p.token) == 0 {
+	if p.token == "" {
 		return errors.ErrEmptyToken
 	}
 	return nil

internal/settings/providers/gandi/provider.go

@@ -50,7 +50,7 @@ func New(data json.RawMessage, domain, host string,
 }
 
 func (p *Provider) isValid() error {
-	if len(p.key) == 0 {
+	if p.key == "" {
 		return errors.ErrEmptyKey
 	}
 	return nil

internal/settings/providers/godaddy/provider.go

@@ -57,7 +57,7 @@ func (p *Provider) isValid() error {
 	switch {
 	case !keyRegex.MatchString(p.key):
 		return errors.ErrMalformedKey
-	case len(p.secret) == 0:
+	case p.secret == "":
 		return errors.ErrEmptySecret
 	}
 	return nil
@@ -153,7 +153,7 @@ func (p *Provider) Update(ctx context.Context, client *http.Client, ip net.IP) (
 		Message string `json:"message"`
 	}
 	jsonErr := json.Unmarshal(b, &parsedJSON)
-	if jsonErr != nil || len(parsedJSON.Message) == 0 {
+	if jsonErr != nil || parsedJSON.Message == "" {
 		return nil, fmt.Errorf("%w: %s", err, utils.ToSingleLine(string(b)))
 	}
 	return nil, fmt.Errorf("%w: %s", err, parsedJSON.Message)

internal/settings/providers/google/provider.go

@@ -56,9 +56,9 @@ func New(data json.RawMessage, domain, host string,
 
 func (p *Provider) isValid() error {
 	switch {
-	case len(p.username) == 0:
+	case p.username == "":
 		return errors.ErrEmptyUsername
-	case len(p.password) == 0:
+	case p.password == "":
 		return errors.ErrEmptyPassword
 	}
 	return nil

internal/settings/providers/he/provider.go

@@ -52,7 +52,7 @@ func New(data json.RawMessage, domain, host string,
 }
 
 func (p *Provider) isValid() error {
-	if len(p.password) == 0 {
+	if p.password == "" {
 		return errors.ErrEmptyPassword
 	}
 	return nil

internal/settings/providers/infomaniak/provider.go

@@ -55,9 +55,9 @@ func New(data json.RawMessage, domain, host string,
 
 func (p *Provider) isValid() error {
 	switch {
-	case len(p.username) == 0:
+	case p.username == "":
 		return errors.ErrEmptyUsername
-	case len(p.password) == 0:
+	case p.password == "":
 		return errors.ErrEmptyPassword
 	case p.host == "*":
 		return errors.ErrHostWildcard

internal/settings/providers/linode/provider.go

@@ -50,7 +50,7 @@ func New(data json.RawMessage, domain, host string,
 }
 
 func (p *Provider) isValid() error {
-	if len(p.token) == 0 {
+	if p.token == "" {
 		return errors.ErrEmptyToken
 	}
 	return nil

internal/settings/providers/luadns/provider.go

@@ -55,7 +55,7 @@ func (p *Provider) isValid() error {
 	switch {
 	case !verification.NewRegex().MatchEmail(p.email):
 		return errors.ErrMalformedEmail
-	case len(p.token) == 0:
+	case p.token == "":
 		return errors.ErrEmptyToken
 	}
 	return nil

internal/settings/providers/njalla/provider.go

@@ -49,7 +49,7 @@ func New(data json.RawMessage, domain, host string,
 }
 
 func (p *Provider) isValid() error {
-	if len(p.key) == 0 {
+	if p.key == "" {
 		return errors.ErrEmptyKey
 	}
 	return nil

internal/settings/providers/noip/provider.go

@@ -57,11 +57,11 @@ func New(data json.RawMessage, domain, host string,
 func (p *Provider) isValid() error {
 	const maxUsernameLength = 50
 	switch {
-	case len(p.username) == 0:
+	case p.username == "":
 		return errors.ErrEmptyUsername
 	case len(p.username) > maxUsernameLength:
 		return fmt.Errorf("%w: longer than 50 characters", errors.ErrMalformedUsername)
-	case len(p.password) == 0:
+	case p.password == "":
 		return errors.ErrEmptyPassword
 	case p.host == "*":
 		return errors.ErrHostWildcard

internal/settings/providers/opendns/provider.go

@@ -54,9 +54,9 @@ func New(data json.RawMessage, domain, host string,
 
 func (p *Provider) isValid() error {
 	switch {
-	case len(p.username) == 0:
+	case p.username == "":
 		return errors.ErrEmptyUsername
-	case len(p.password) == 0:
+	case p.password == "":
 		return errors.ErrEmptyPassword
 	case p.host == "*":
 		return errors.ErrHostWildcard

internal/settings/providers/ovh/provider.go

@@ -82,18 +82,18 @@ func New(data json.RawMessage, domain, host string,
 func (p *Provider) isValid() error {
 	if p.mode == "api" {
 		switch {
-		case len(p.appKey) == 0:
+		case p.appKey == "":
 			return errors.ErrEmptyAppKey
-		case len(p.consumerKey) == 0:
+		case p.consumerKey == "":
 			return errors.ErrEmptyConsumerKey
-		case len(p.appSecret) == 0:
+		case p.appSecret == "":
 			return errors.ErrEmptySecret
 		}
 	} else {
 		switch {
-		case len(p.username) == 0:
+		case p.username == "":
 			return errors.ErrEmptyUsername
-		case len(p.password) == 0:
+		case p.password == "":
 			return errors.ErrEmptyPassword
 		case p.host == "*":
 			return errors.ErrHostWildcard

internal/settings/providers/selfhostde/provider.go

@@ -55,9 +55,9 @@ func New(data json.RawMessage, domain, host string,
 
 func (p *Provider) isValid() error {
 	switch {
-	case len(p.username) == 0:
+	case p.username == "":
 		return errors.ErrEmptyUsername
-	case len(p.password) == 0:
+	case p.password == "":
 		return errors.ErrEmptyPassword
 	case p.host == "*":
 		return errors.ErrHostWildcard

internal/settings/providers/spdyn/provider.go

@@ -57,13 +57,13 @@ func New(data json.RawMessage, domain, host string,
 }
 
 func (p *Provider) isValid() error {
-	if len(p.token) > 0 {
+	if p.token != "" {
 		return nil
 	}
 	switch {
-	case len(p.user) == 0:
+	case p.user == "":
 		return errors.ErrEmptyUsername
-	case len(p.password) == 0:
+	case p.password == "":
 		return errors.ErrEmptyPassword
 	case p.host == "*":
 		return errors.ErrHostWildcard
@@ -119,7 +119,7 @@ func (p *Provider) Update(ctx context.Context, client *http.Client, ip net.IP) (
 	} else {
 		values.Set("myip", ip.String())
 	}
-	if len(p.token) > 0 {
+	if p.token != "" {
 		values.Set("user", hostname)
 		values.Set("pass", p.token)
 	} else {

internal/settings/providers/strato/provider.go

@@ -52,7 +52,7 @@ func New(data json.RawMessage, domain, host string,
 
 func (p *Provider) isValid() error {
 	switch {
-	case len(p.password) == 0:
+	case p.password == "":
 		return errors.ErrEmptyPassword
 	case p.host == "*":
 		return errors.ErrHostWildcard

internal/settings/providers/variomedia/provider.go

@@ -55,9 +55,9 @@ func New(data json.RawMessage, domain, host string,
 
 func (p *Provider) isValid() error {
 	switch {
-	case len(p.email) == 0:
+	case p.email == "":
 		return errors.ErrEmptyEmail
-	case len(p.password) == 0:
+	case p.password == "":
 		return errors.ErrEmptyPassword
 	case p.host == "*":
 		return errors.ErrHostWildcard

pkg/publicip/dns/providers_test.go

@@ -76,7 +76,7 @@ func Test_data(t *testing.T) {
 		t.Run(name, func(t *testing.T) {
 			t.Parallel()
 
-			if len(testCase.panicMessage) > 0 {
+			if testCase.panicMessage != "" {
 				assert.PanicsWithValue(t, testCase.panicMessage, func() {
 					testCase.provider.data()
 				})

pkg/publicip/http/providers.go

@@ -100,7 +100,7 @@ func (provider Provider) url(version ipversion.IPVersion) (url string, ok bool)
 		url = strings.TrimPrefix(s, "url:")
 	}
 
-	if len(url) == 0 {
+	if url == "" {
 		return "", false
 	}
 

pkg/publicip/info/countries.go

@@ -256,7 +256,7 @@ func countryCodeToName(countryCode string) (name string) {
 		"zw": "Zimbabwe",
 	}
 	name = mapping[countryCode]
-	if len(name) == 0 {
+	if name == "" {
 		name = countryCode
 	}
 	return name