feat: use slices.Contains instead of for loops (#2111)

Use `slices.Contains` instead of manual loops. Some of these were
suggested by the gopls language server, and I did a quick search of the
codebase for similar patterns which could use the same.

Co-authored-by: Cemal Kılıç <[email protected]>

Author: bnjmnt4n

internal/api/auth.go

@@ -4,6 +4,7 @@ import (
 	"context"
 	"fmt"
 	"net/http"
+	"slices"
 	"strings"
 
 	"github.com/gofrs/uuid"
@@ -51,7 +52,7 @@ func (a *API) requireAdmin(ctx context.Context) (context.Context, error) {
 
 	adminRoles := a.config.JWT.AdminRoles
 
-	if isStringInSlice(claims.Role, adminRoles) {
+	if slices.Contains(adminRoles, claims.Role) {
 		// successful authentication
 		return withAdminUser(ctx, &models.User{Role: claims.Role, Email: storage.NullString(claims.Role)}), nil
 	}

internal/api/helpers.go

@@ -4,6 +4,7 @@ import (
 	"context"
 	"encoding/json"
 	"net/http"
+	"slices"
 
 	"github.com/supabase/auth/internal/api/apierrors"
 	"github.com/supabase/auth/internal/api/shared"
@@ -34,7 +35,7 @@ func (a *API) requestAud(ctx context.Context, r *http.Request) string {
 
 	// ignore the JWT's aud claim if the role is admin
 	// this is because anon, service_role never had an aud claim to begin with
-	if claims != nil && !isStringInSlice(claims.Role, config.JWT.AdminRoles) {
+	if claims != nil && !slices.Contains(config.JWT.AdminRoles, claims.Role) {
 		aud, _ := claims.GetAudience()
 		if len(aud) != 0 && aud[0] != "" {
 			return aud[0]
@@ -45,15 +46,6 @@ func (a *API) requestAud(ctx context.Context, r *http.Request) string {
 	return config.JWT.Aud
 }
 
-func isStringInSlice(checkValue string, list []string) bool {
-	for _, val := range list {
-		if val == checkValue {
-			return true
-		}
-	}
-	return false
-}
-
 type RequestParams interface {
 	AdminUserParams |
 		CreateSSOProviderParams |

internal/api/middleware.go

@@ -7,6 +7,7 @@ import (
 	"fmt"
 	"net/http"
 	"net/url"
+	"slices"
 	"strings"
 	"sync"
 	"time"
@@ -214,18 +215,12 @@ func (a *API) isValidExternalHost(w http.ResponseWriter, req *http.Request) (con
 		protocol := "https"
 
 		if xForwardedHost != "" {
-			for _, host := range config.Mailer.ExternalHosts {
-				if host == xForwardedHost {
-					hostname = host
-					break
-				}
+			if slices.Contains(config.Mailer.ExternalHosts, xForwardedHost) {
+				hostname = xForwardedHost
 			}
 		} else if reqHost != "" {
-			for _, host := range config.Mailer.ExternalHosts {
-				if host == reqHost {
-					hostname = host
-					break
-				}
+			if slices.Contains(config.Mailer.ExternalHosts, reqHost) {
+				hostname = reqHost
 			}
 		}
 

internal/api/token_oidc.go

@@ -5,6 +5,7 @@ import (
 	"crypto/sha256"
 	"fmt"
 	"net/http"
+	"slices"
 
 	"github.com/coreos/go-oidc/v3/oidc"
 	"github.com/supabase/auth/internal/api/apierrors"
@@ -112,14 +113,11 @@ func (p *IdTokenGrantParams) getProvider(ctx context.Context, config *conf.Globa
 		log.WithField("issuer", p.Issuer).WithField("client_id", p.ClientID).Warn("Use of POST /token with arbitrary issuer and client_id is deprecated for security reasons. Please switch to using the API with provider only!")
 
 		allowed := false
-		for _, allowedIssuer := range config.External.AllowedIdTokenIssuers {
-			if p.Issuer == allowedIssuer {
-				allowed = true
-				providerType = allowedIssuer
-				acceptableClientIDs = []string{p.ClientID}
-				issuer = allowedIssuer
-				break
-			}
+		if slices.Contains(config.External.AllowedIdTokenIssuers, p.Issuer) {
+			allowed = true
+			providerType = p.Issuer
+			acceptableClientIDs = []string{p.ClientID}
+			issuer = p.Issuer
 		}
 
 		if !allowed {
@@ -213,14 +211,8 @@ func (a *API) IdTokenGrant(ctx context.Context, w http.ResponseWriter, r *http.R
 			continue
 		}
 
-		for _, aud := range idToken.Audience {
-			if aud == clientID {
-				correctAudience = true
-				break
-			}
-		}
-
-		if correctAudience {
+		if slices.Contains(idToken.Audience, clientID) {
+			correctAudience = true
 			break
 		}
 	}

internal/conf/jwk.go

@@ -3,6 +3,7 @@ package conf
 import (
 	"encoding/json"
 	"fmt"
+	"slices"
 
 	"github.com/golang-jwt/jwt/v5"
 	"github.com/lestrrat-go/jwx/v2/jwk"
@@ -97,11 +98,8 @@ func (j *JwtKeysDecoder) Validate() error {
 			}
 		}
 
-		for _, op := range key.PrivateKey.KeyOps() {
-			if op == jwk.KeyOpSign {
-				signingKeys = append(signingKeys, key.PrivateKey)
-				break
-			}
+		if slices.Contains(key.PrivateKey.KeyOps(), jwk.KeyOpSign) {
+			signingKeys = append(signingKeys, key.PrivateKey)
 		}
 	}
 
@@ -117,11 +115,9 @@ func (j *JwtKeysDecoder) Validate() error {
 
 func GetSigningJwk(config *JWTConfiguration) (jwk.Key, error) {
 	for _, key := range config.Keys {
-		for _, op := range key.PrivateKey.KeyOps() {
-			// the private JWK with key_ops "sign" should be used as the signing key
-			if op == jwk.KeyOpSign {
-				return key.PrivateKey, nil
-			}
+		// the private JWK with key_ops "sign" should be used as the signing key
+		if slices.Contains(key.PrivateKey.KeyOps(), jwk.KeyOpSign) {
+			return key.PrivateKey, nil
 		}
 	}
 	return nil, fmt.Errorf("no signing key found")

internal/models/sessions.go

@@ -3,6 +3,7 @@ package models
 import (
 	"database/sql"
 	"fmt"
+	"slices"
 	"sort"
 	"strings"
 	"time"
@@ -174,10 +175,8 @@ func (s *Session) DetermineTag(tags []string) string {
 		return tags[0]
 	}
 
-	for _, t := range tags {
-		if t == tag {
-			return tag
-		}
+	if slices.Contains(tags, tag) {
+		return tag
 	}
 
 	return tags[0]