added uT

Author: Akshay2191

internal/config/config.go

@@ -1597,15 +1597,24 @@ func resolveExternalDataSource() *ExternalDataSource {
 		MaxBytes:       viperInstance.GetInt64(ExternalDataSourceMaxBytesKey),
 	}
 
-	// Validate domains
-	if len(externalDataSource.AllowedDomains) > 0 {
-		for _, domain := range externalDataSource.AllowedDomains {
-			if strings.ContainsAny(domain, "/\\ ") || domain == "" {
-				slog.Error("domain is not specified in allowed_domains")
-				return nil
-			}
-		}
+	if err := validateAllowedDomains(externalDataSource.AllowedDomains); err != nil {
+		return nil
 	}
 
 	return externalDataSource
 }
+
+func validateAllowedDomains(domains []string) error {
+	if len(domains) == 0 {
+		return nil
+	}
+
+	for _, domain := range domains {
+		if strings.ContainsAny(domain, "/\\ ") || domain == "" {
+			slog.Error("domain is not specified in allowed_domains")
+			return errors.New("invalid domain found in allowed_domains")
+		}
+	}
+
+	return nil
+}

internal/config/config_test.go

@@ -1576,3 +1576,73 @@ func TestValidateLabel(t *testing.T) {
 		})
 	}
 }
+
+func TestValidateAllowedDomains(t *testing.T) {
+	tests := []struct {
+		name    string
+		domains []string
+		wantErr bool
+	}{
+		{
+			name:    "Test 1: Success: Empty slice",
+			domains: []string{},
+			wantErr: false,
+		},
+		{
+			name:    "Test 2: Success: Nil slice",
+			domains: nil,
+			wantErr: false,
+		},
+		{
+			name:    "Test 3: Success: Valid domains",
+			domains: []string{"example.com", "api.nginx.com", "sub.domain.io"},
+			wantErr: false,
+		},
+		{
+			name:    "Test 4: Failure: Domain contains space",
+			domains: []string{"valid.com", "bad domain.com"},
+			wantErr: true,
+		},
+		{
+			name:    "Test 5: Failure: Empty string domain",
+			domains: []string{"valid.com", ""},
+			wantErr: true,
+		},
+		{
+			name:    "Test 6: Failure: Domain contains forward slash /",
+			domains: []string{"domain.com/path"},
+			wantErr: true,
+		},
+		{
+			name:    "Test 7: Failure: Domain contains backward slash \\",
+			domains: []string{"domain.com\\path"},
+			wantErr: true,
+		},
+		{
+			name:    "Test 8: Failure: Mixed valid and invalid (first is invalid)",
+			domains: []string{" only.com", "good.com"},
+			wantErr: true,
+		},
+	}
+
+	for _, tt := range tests {
+		t.Run(tt.name, func(t *testing.T) {
+			var logBuffer bytes.Buffer
+			logHandler := slog.NewTextHandler(&logBuffer, &slog.HandlerOptions{Level: slog.LevelError})
+
+			originalLogger := slog.Default()
+			slog.SetDefault(slog.New(logHandler))
+			defer slog.SetDefault(originalLogger)
+
+			actualErr := validateAllowedDomains(tt.domains)
+
+			if tt.wantErr {
+				require.Error(t, actualErr, "Expected an error but got nil.")
+				assert.Contains(t, logBuffer.String(), "domain is not specified in allowed_domains",
+					"Expected the error log message to be present in the output.")
+			} else {
+				assert.NoError(t, actualErr, "Did not expect an error but got one: %v", actualErr)
+			}
+		})
+	}
+}