Description

string.IsNullOrWhiteSpace() and string.IsNullOrEmpty() are used interchangeably throughout the codebase for the same semantic purpose (checking if a value is set):

IsNullOrWhiteSpace (~50+ instances):

• Servy.CLI/Validators/ServiceInstallValidator.cs — 30+ validation checks
• Servy.Core/Native/NativeMethods.cs:389,415 — username validation
• Servy.CLI/Commands/ExportServiceCommand.cs:38,42,45

IsNullOrEmpty (~45 instances):

• Servy.CLI/Commands/BaseCommand.cs:30,41,69,80 — suggestion checks
• Servy.Manager/Services/ServiceCommands.cs:147,149,204,206
• Servy.Service/Service.cs:662,694,733
• Servy.Core/Logging/Logger.cs:72,281

Sometimes both appear in the same file: ServiceDependenciesValidator.cs uses IsNullOrWhiteSpace on line 22 and IsNullOrEmpty on line 36.

These have different semantics: IsNullOrWhiteSpace also rejects " " (whitespace-only). Using them interchangeably means some paths accept whitespace-only strings while equivalent paths don't.

Severity

Info — inconsistent validation strictness across equivalent checks.

Suggested fix

Standardize on IsNullOrWhiteSpace for user-facing validation (the stricter check), and IsNullOrEmpty only where whitespace-only strings are intentionally valid.