Add a CLI option for selecting the naming strategy (#708)

### Motivation

The recently introduced naming strategy is only configurable in the
config file, but pure CLI users might also want to use it without
creating a config file.

### Modifications

Add a `--naming-strategy` option to the `swift-openapi-generator` CLI.

### Result

Users can use the new naming strategy without creating a config file, if
they didn't have one before.

### Test Plan

Tested manually on a sample project.

Author: czechboy0

Sources/_OpenAPIGeneratorCore/Config.swift

@@ -13,7 +13,7 @@
 //===----------------------------------------------------------------------===//
 
 /// A strategy for turning OpenAPI identifiers into Swift identifiers.
-public enum NamingStrategy: String, Sendable, Codable, Equatable {
+public enum NamingStrategy: String, Sendable, Codable, Equatable, CaseIterable {
 
     /// A defensive strategy that can handle any OpenAPI identifier and produce a non-conflicting Swift identifier.
     ///
@@ -54,6 +54,9 @@ public struct Config: Sendable {
     /// Defaults to `defensive`.
     public var namingStrategy: NamingStrategy
 
+    /// The default naming strategy.
+    public static let defaultNamingStrategy: NamingStrategy = .defensive
+
     /// A map of OpenAPI identifiers to desired Swift identifiers, used instead of the naming strategy.
     public var nameOverrides: [String: String]
 
@@ -76,7 +79,7 @@ public struct Config: Sendable {
         access: AccessModifier,
         additionalImports: [String] = [],
         filter: DocumentFilter? = nil,
-        namingStrategy: NamingStrategy = .defensive,
+        namingStrategy: NamingStrategy = Config.defaultNamingStrategy,
         nameOverrides: [String: String] = [:],
         featureFlags: FeatureFlags = []
     ) {

Sources/_OpenAPIGeneratorCore/Layers/StructuredSwiftRepresentation.swift

@@ -50,7 +50,7 @@ struct ImportDescription: Equatable, Codable {
 /// A description of an access modifier.
 ///
 /// For example: `public`.
-public enum AccessModifier: String, Sendable, Equatable, Codable {
+public enum AccessModifier: String, Sendable, Equatable, Codable, CaseIterable {
 
     /// A declaration accessible outside of the module.
     case `public`

Sources/swift-openapi-generator/GenerateOptions+runGenerator.swift

@@ -30,7 +30,7 @@ extension _GenerateOptions {
     func runGenerator(outputDirectory: URL, pluginSource: PluginSource?, isDryRun: Bool) async throws {
         let config = try loadedConfig()
         let sortedModes = try resolvedModes(config)
-        let resolvedAccessModifier = resolvedAccessModifier(config) ?? Config.defaultAccessModifier
+        let resolvedAccessModifier = resolvedAccessModifier(config)
         let resolvedAdditionalImports = resolvedAdditionalImports(config)
         let resolvedNamingStragy = resolvedNamingStrategy(config)
         let resolvedNameOverrides = resolvedNameOverrides(config)

Sources/swift-openapi-generator/GenerateOptions.swift

@@ -33,6 +33,11 @@ struct _GenerateOptions: ParsableArguments {
             "The access modifier to use for the API of generated code. Default: \(Config.defaultAccessModifier.rawValue)"
     ) var accessModifier: AccessModifier?
 
+    @Option(
+        help:
+            "The strategy for converting OpenAPI names into Swift names. Default: \(Config.defaultNamingStrategy.rawValue)"
+    ) var namingStrategy: NamingStrategy?
+
     @Option(help: "Additional import to add to all generated files.") var additionalImport: [String] = []
 
     @Option(help: "Pre-release feature to enable. Options: \(FeatureFlag.prettyListing).") var featureFlag:
@@ -44,6 +49,7 @@ struct _GenerateOptions: ParsableArguments {
 }
 
 extension AccessModifier: ExpressibleByArgument {}
+extension NamingStrategy: ExpressibleByArgument {}
 
 extension _GenerateOptions {
 
@@ -60,10 +66,10 @@ extension _GenerateOptions {
     /// Returns the access modifier requested by the user.
     /// - Parameter config: The configuration specified by the user.
     /// - Returns: The access modifier requested by the user, or nil if the default should be used.
-    func resolvedAccessModifier(_ config: _UserConfig?) -> AccessModifier? {
+    func resolvedAccessModifier(_ config: _UserConfig?) -> AccessModifier {
         if let accessModifier { return accessModifier }
         if let accessModifier = config?.accessModifier { return accessModifier }
-        return nil
+        return Config.defaultAccessModifier
     }
 
     /// Returns a list of additional imports requested by the user.
@@ -78,7 +84,10 @@ extension _GenerateOptions {
     /// Returns the naming strategy requested by the user.
     /// - Parameter config: The configuration specified by the user.
     /// - Returns: The naming strategy requestd by the user.
-    func resolvedNamingStrategy(_ config: _UserConfig?) -> NamingStrategy { config?.namingStrategy ?? .defensive }
+    func resolvedNamingStrategy(_ config: _UserConfig?) -> NamingStrategy {
+        if let namingStrategy { return namingStrategy }
+        return config?.namingStrategy ?? Config.defaultNamingStrategy
+    }
 
     /// Returns the name overrides requested by the user.
     /// - Parameter config: The configuration specified by the user.