test(subdomain): add tests for extracting tenant from subdomain

This commit adds additional tests for the ExtractSubdomain function to ensure it correctly extracts the tenant from the subdomain. These tests enhance the reliability of our multi-tenancy handling.

middleware/middleware_test.go

@@ -55,6 +55,58 @@ func TestDefaultTenantFromSubdomain(t *testing.T) {
 			},
 			wantErr: true,
 		},
+		{
+			name: "valid:test-from-subdomain-with-port",
+			args: args{
+				r: &http.Request{
+					Method: http.MethodGet,
+					Header: map[string][]string{},
+					Host:   "tenant1.example.com:8080",
+					URL:    &url.URL{Path: "/"},
+					TLS:    &tls.ConnectionState{}, // Simulate an https request
+				},
+			},
+			want:    "tenant1",
+			wantErr: false,
+		},
+		{
+			name: "valid:test-from-subdomain-with-multiple-subdomains",
+			args: args{
+				r: &http.Request{
+					Method: http.MethodGet,
+					Header: map[string][]string{},
+					Host:   "tenant1.sub.example.com",
+					URL:    &url.URL{Path: "/"},
+					TLS:    &tls.ConnectionState{}, // Simulate an https request
+				},
+			},
+			want:    "tenant1",
+			wantErr: false,
+		},
+		{
+			name: "invalid:no-subdomain",
+			args: args{
+				r: &http.Request{
+					Method: http.MethodGet,
+					Header: map[string][]string{},
+					Host:   "example.com",
+					URL:    &url.URL{Path: "/"},
+				},
+			},
+			wantErr: true,
+		},
+		{
+			name: "invalid:host-is-ip",
+			args: args{
+				r: &http.Request{
+					Method: http.MethodGet,
+					Header: map[string][]string{},
+					Host:   "192.168.1.1",
+					URL:    &url.URL{Path: "/"},
+				},
+			},
+			wantErr: true,
+		},
 	}
 	for _, tt := range tests {
 		t.Run(tt.name, func(t *testing.T) {