Add defaultConfigurationName to options

This allows users to set the defaultConfigurationName project wide. This
setting corresponds to the drop down in the project settings that says
"Use CONFIG for command line builds". This affects which configuration
Xcode looks in for some settings, even if you pass `-configuration FOO`.

Sources/ProjectSpec/ProjectSpec.swift

@@ -32,6 +32,7 @@ public struct ProjectSpec {
         public var indentWidth: UInt?
         public var xcodeVersion: String?
         public var deploymentTarget: DeploymentTarget
+        public var defaultConfigurationName: String?
 
         public enum SettingPresets: String {
             case all
@@ -66,7 +67,8 @@ public struct ProjectSpec {
             usesTabs: Bool? = nil,
             xcodeVersion: String? = nil,
             deploymentTarget: DeploymentTarget = .init(),
-            disabledValidations: [ValidationType] = []
+            disabledValidations: [ValidationType] = [],
+            defaultConfigurationName: String? = nil
         ) {
             self.carthageBuildPath = carthageBuildPath
             self.carthageExecutablePath = carthageExecutablePath
@@ -80,6 +82,7 @@ public struct ProjectSpec {
             self.xcodeVersion = xcodeVersion
             self.deploymentTarget = deploymentTarget
             self.disabledValidations = disabledValidations
+            self.defaultConfigurationName = defaultConfigurationName
         }
 
         public static func == (lhs: ProjectSpec.Options, rhs: ProjectSpec.Options) -> Bool {
@@ -217,5 +220,6 @@ extension ProjectSpec.Options: JSONObjectConvertible {
         tabWidth = (jsonDictionary.json(atKeyPath: "tabWidth") as Int?).flatMap(UInt.init)
         deploymentTarget = jsonDictionary.json(atKeyPath: "deploymentTarget") ?? DeploymentTarget()
         disabledValidations = jsonDictionary.json(atKeyPath: "disabledValidations") ?? []
+        defaultConfigurationName = jsonDictionary.json(atKeyPath: "defaultConfigurationName")
     }
 }

Sources/ProjectSpec/SpecValidation.swift

@@ -47,6 +47,12 @@ extension ProjectSpec {
             }
         }
 
+        if let configName = options.defaultConfigurationName {
+            if !configs.contains(where: { $0.name == configName }) {
+                errors.append(.missingDefaultConfigurationName(configName: configName))
+            }
+        }
+
         for settings in settingGroups.values {
             errors += validateSettings(settings)
         }

Sources/ProjectSpec/SpecValidationError.swift

@@ -19,6 +19,7 @@ public struct SpecValidationError: Error, CustomStringConvertible {
         case invalidFileGroup(String)
         case invalidConfigFileConfig(String)
         case missingConfigForTargetScheme(target: String, configType: ConfigType)
+        case missingDefaultConfigurationName(configName: String)
 
         public var description: String {
             switch self {
@@ -50,6 +51,8 @@ public struct SpecValidationError: Error, CustomStringConvertible {
                 return "Config file has invalid config \(config.quoted)"
             case let .missingConfigForTargetScheme(target, configType):
                 return "Target \(target.quoted) is missing a config of type \(configType.rawValue) to generate its scheme"
+            case let .missingDefaultConfigurationName(name):
+                return "Default configuration \(name) doesn't exist"
             }
         }
     }

Sources/XcodeGenKit/PBXProjGenerator.swift

@@ -70,11 +70,12 @@ public class PBXProjGenerator {
             )
         }
 
+        let configName = spec.options.defaultConfigurationName ?? buildConfigs.first?.object.name ?? ""
         let buildConfigList = createObject(
             id: spec.name,
             XCConfigurationList(
                 buildConfigurations: buildConfigs.map { $0.reference },
-                defaultConfigurationName: buildConfigs.first?.object.name ?? ""
+                defaultConfigurationName: configName
             )
         )
 

Tests/XcodeGenKitTests/ProjectGeneratorTests.swift

@@ -96,6 +96,20 @@ func projectGeneratorTests() {
                     try expect(XCodeVersion.parse(version)) == expected
                 }
             }
+
+            $0.it("uses the default configuration name") {
+                let options = ProjectSpec.Options(defaultConfigurationName: "Bconfig")
+                let spec = ProjectSpec(basePath: "", name: "test", configs: [Config(name: "Aconfig"), Config(name: "Bconfig")], targets: [framework], options: options)
+                let pbxProject = try getPbxProj(spec)
+
+                guard let projectConfigListReference = pbxProject.objects.projects.values.first?.buildConfigurationList,
+                    let defaultConfigurationName = pbxProject.objects.configurationLists[projectConfigListReference]?.defaultConfigurationName
+                else {
+                    throw failure("Default configuration name not found")
+                }
+
+                try expect(defaultConfigurationName) == "Bconfig"
+            }
         }
 
         $0.describe("Config") {

Tests/XcodeGenKitTests/ProjectSpecTests.swift

@@ -167,6 +167,12 @@ func projectSpecTests() {
                 )]
                 try spec.validate()
             }
+
+            $0.it("validates missing default configurations") {
+                var spec = baseSpec
+                spec.options = ProjectSpec.Options(defaultConfigurationName: "foo")
+                try expectValidationError(spec, .missingDefaultConfigurationName(configName: "foo"))
+            }
         }
     }
 }