Improve deprecation and disabling mechanisms

Sources/Arguments.swift

@@ -509,12 +509,12 @@ func warningsForArguments(_ args: [String: String]) -> [String] {
     var warnings = [String]()
     for option in FormatOptions.Descriptor.all {
         if args[option.argumentName] != nil, let message = option.deprecationMessage {
-            warnings.append(message)
+            warnings.append("--\(option.argumentName) option is deprecated. \(message)")
         }
     }
     for name in Set(rulesArguments.flatMap { (try? args[$0].map(parseRules) ?? []) ?? [] }) {
         if let message = FormatRules.byName[name]?.deprecationMessage {
-            warnings.append(message)
+            warnings.append("\(name) rule is deprecated. \(message)")
         }
     }
     return warnings

Sources/CommandLine.swift

@@ -136,6 +136,12 @@ func printRuleInfo(for name: String, as type: CLI.OutputType) throws {
     print(name, as: type)
     print("", as: type)
     print(stripMarkdown(rule.help), as: type)
+    if let message = rule.deprecationMessage {
+        print("", as: type)
+        print("Note: \(rule.name) rule is deprecated. \(message)")
+        print("")
+        return
+    }
     if !rule.options.isEmpty {
         print("\nOptions:\n", as: type)
         print(rule.options.compactMap {

Sources/OptionsDescriptor.swift

@@ -47,20 +47,17 @@ extension FormatOptions {
         let propertyName: String // internal property; ok to change this
         let displayName: String
         let help: String
+        let deprecationMessage: String?
         let toOptions: (String, inout FormatOptions) throws -> Void
         let fromOptions: (FormatOptions) -> String
         private(set) var type: ArgumentType
 
-        var deprecationMessage: String? {
-            return FormatOptions.Descriptor.deprecatedMessage[argumentName]
-        }
-
         var isDeprecated: Bool {
             return deprecationMessage != nil
         }
 
         var isRenamed: Bool {
-            return deprecationMessage != nil && FormatOptions.Descriptor.all.contains(where: {
+            return isDeprecated && FormatOptions.Descriptor.all.contains(where: {
                 $0.propertyName == propertyName && $0.argumentName != argumentName
             })
         }
@@ -85,6 +82,7 @@ extension FormatOptions {
              propertyName: String,
              displayName: String,
              help: String,
+             deprecationMessage: String? = nil,
              keyPath: WritableKeyPath<FormatOptions, Bool>,
              trueValues: [String],
              falseValues: [String])
@@ -94,6 +92,7 @@ extension FormatOptions {
             self.propertyName = propertyName
             self.displayName = displayName
             self.help = help
+            self.deprecationMessage = deprecationMessage
             type = .binary(true: trueValues, false: falseValues)
             toOptions = { value, options in
                 switch value.lowercased() {
@@ -114,6 +113,7 @@ extension FormatOptions {
                 propertyName: String,
                 displayName: String,
                 help: String,
+                deprecationMessage: String? = nil,
                 keyPath: WritableKeyPath<FormatOptions, T>,
                 fromArgument: @escaping (String) -> T?,
                 toArgument: @escaping (T) -> String)
@@ -122,6 +122,7 @@ extension FormatOptions {
             self.propertyName = propertyName
             self.displayName = displayName
             self.help = help
+            self.deprecationMessage = deprecationMessage
             type = .text
             toOptions = { key, options in
                 guard let value = fromArgument(key) else {
@@ -138,6 +139,7 @@ extension FormatOptions {
              propertyName: String,
              displayName: String,
              help: String,
+             deprecationMessage: String? = nil,
              keyPath: WritableKeyPath<FormatOptions, String>,
              options: DictionaryLiteral<String, String>)
         {
@@ -147,6 +149,7 @@ extension FormatOptions {
                       propertyName: propertyName,
                       displayName: displayName,
                       help: help,
+                      deprecationMessage: deprecationMessage,
                       keyPath: keyPath,
                       fromArgument: { map[$0.lowercased()] },
                       toArgument: { value in
@@ -166,13 +169,15 @@ extension FormatOptions {
              propertyName: String,
              displayName: String,
              help: String,
+             deprecationMessage: String? = nil,
              keyPath: WritableKeyPath<FormatOptions, Int>)
         {
             self.init(
                 argumentName: argumentName,
                 propertyName: propertyName,
                 displayName: displayName,
                 help: help,
+                deprecationMessage: deprecationMessage,
                 keyPath: keyPath,
                 fromArgument: { Int($0).map { max(0, $0) } },
                 toArgument: { String($0) }
@@ -183,13 +188,15 @@ extension FormatOptions {
         init<T: RawRepresentable>(argumentName: String,
                                   propertyName: String,
                                   displayName: String,
-                                  help: String = "",
+                                  help: String,
+                                  deprecationMessage: String? = nil,
                                   keyPath: WritableKeyPath<FormatOptions, T>) where T.RawValue == String
         {
             self.argumentName = argumentName
             self.propertyName = propertyName
             self.displayName = displayName
             self.help = help
+            self.deprecationMessage = deprecationMessage
             type = .text
             toOptions = { value, options in
                 guard let value = T(rawValue: value) ?? T(rawValue: value.lowercased()) else {
@@ -205,7 +212,8 @@ extension FormatOptions {
         init<T: RawRepresentable>(argumentName: String,
                                   propertyName: String,
                                   displayName: String,
-                                  help: String = "",
+                                  help: String,
+                                  deprecationMessage: String? = nil,
                                   keyPath: WritableKeyPath<FormatOptions, T>,
                                   options: [String]) where T.RawValue == String
         {
@@ -214,6 +222,7 @@ extension FormatOptions {
                 propertyName: propertyName,
                 displayName: displayName,
                 help: help,
+                deprecationMessage: deprecationMessage,
                 keyPath: keyPath
             )
             type = .enum(options)
@@ -223,13 +232,15 @@ extension FormatOptions {
              propertyName: String,
              displayName: String,
              help: String,
+             deprecationMessage: String? = nil,
              keyPath: WritableKeyPath<FormatOptions, [String]>,
              validate: @escaping (String) throws -> Void = { _ in })
         {
             self.argumentName = argumentName
             self.propertyName = propertyName
             self.displayName = displayName
             self.help = help
+            self.deprecationMessage = deprecationMessage
             type = .array
             toOptions = { value, options in
                 let values = parseCommaDelimitedList(value)
@@ -250,13 +261,15 @@ extension FormatOptions {
              propertyName: String,
              displayName: String,
              help: String,
+             deprecationMessage: String? = nil,
              keyPath: WritableKeyPath<FormatOptions, Set<String>>,
              validate: @escaping (String) throws -> Void = { _ in })
         {
             self.argumentName = argumentName
             self.propertyName = propertyName
             self.displayName = displayName
             self.help = help
+            self.deprecationMessage = deprecationMessage
             type = .set
             toOptions = { value, options in
                 let values = parseCommaDelimitedList(value)
@@ -821,22 +834,12 @@ extension FormatOptions.Descriptor {
 
     // MARK: - DEPRECATED
 
-    static let deprecatedMessage = [
-        empty.argumentName: "--empty option is deprecated. Use --voidtype instead.",
-        indentComments.argumentName: "--comments option is deprecated. Relative indent within multiline comments is now preserved by default.",
-        insertBlankLines.argumentName: "--insertlines option is deprecated. Use '--enable blankLinesBetweenScopes' or '--enable blankLinesAroundMark' or '--disable blankLinesBetweenScopes' or '--disable blankLinesAroundMark' instead.",
-        removeBlankLines.argumentName: "--removelines option is deprecated. Use '--enable blankLinesAtStartOfScope' or '--enable blankLinesAtEndOfScope' or '--disable blankLinesAtStartOfScope' or '--disable blankLinesAtEndOfScope' instead.",
-        hexLiterals.argumentName: "--hexliterals option is deprecated. Use --hexliteralcase instead.",
-        wrapElements.argumentName: "--wrapelements option is deprecated. Use --wrapcollections instead.",
-        experimentalRules.argumentName: "--experimentalRules option is deprecated. Use --enable to opt-in to rules individually.",
-        specifierOrder.argumentName: "--specifierorder option is deprecated. Use --modifierorder instead.",
-    ]
-
     static let empty = FormatOptions.Descriptor(
         argumentName: "empty",
         propertyName: "empty",
         displayName: "Empty",
         help: "deprecated",
+        deprecationMessage: "Use --voidtype instead.",
         keyPath: \.useVoid,
         trueValues: ["void"],
         falseValues: ["tuple", "tuples"]
@@ -846,6 +849,7 @@ extension FormatOptions.Descriptor {
         propertyName: "indentComments",
         displayName: "Comments",
         help: "Indenting of comment bodies: \"indent\" (default) or \"ignore\"",
+        deprecationMessage: "Relative indent within multiline comments is now preserved by default.",
         keyPath: \.indentComments,
         trueValues: ["indent", "indented"],
         falseValues: ["ignore"]
@@ -855,6 +859,7 @@ extension FormatOptions.Descriptor {
         propertyName: "insertBlankLines",
         displayName: "Insert Lines",
         help: "deprecated",
+        deprecationMessage: "Use '--enable blankLinesBetweenScopes' or '--enable blankLinesAroundMark' or '--disable blankLinesBetweenScopes' or '--disable blankLinesAroundMark' instead.",
         keyPath: \.insertBlankLines,
         trueValues: ["enabled", "true"],
         falseValues: ["disabled", "false"]
@@ -864,6 +869,7 @@ extension FormatOptions.Descriptor {
         propertyName: "removeBlankLines",
         displayName: "Remove Lines",
         help: "deprecated",
+        deprecationMessage: "Use '--enable blankLinesAtStartOfScope' or '--enable blankLinesAtEndOfScope' or '--disable blankLinesAtStartOfScope' or '--disable blankLinesAtEndOfScope' instead.",
         keyPath: \.removeBlankLines,
         trueValues: ["enabled", "true"],
         falseValues: ["disabled", "false"]
@@ -873,6 +879,7 @@ extension FormatOptions.Descriptor {
         propertyName: "uppercaseHex",
         displayName: "hexliterals",
         help: "deprecated",
+        deprecationMessage: "Use --hexliteralcase instead.",
         keyPath: \.uppercaseHex,
         trueValues: ["uppercase", "upper"],
         falseValues: ["lowercase", "lower"]
@@ -882,6 +889,7 @@ extension FormatOptions.Descriptor {
         propertyName: "wrapCollections",
         displayName: "Wrap Elements",
         help: "deprecated",
+        deprecationMessage: "Use --wrapcollections instead.",
         keyPath: \.wrapCollections,
         options: ["before-first", "after-first", "preserve", "disabled"]
     )
@@ -890,6 +898,7 @@ extension FormatOptions.Descriptor {
         propertyName: "experimentalRules",
         displayName: "Experimental Rules",
         help: "Experimental rules: \"enabled\" or \"disabled\" (default)",
+        deprecationMessage: "Use --enable to opt-in to rules individually.",
         keyPath: \.experimentalRules,
         trueValues: ["enabled", "true"],
         falseValues: ["disabled", "false"]
@@ -899,6 +908,7 @@ extension FormatOptions.Descriptor {
         propertyName: "modifierOrder",
         displayName: "Specifier Order",
         help: "deprecated",
+        deprecationMessage: "Use --modifierorder instead.",
         keyPath: \FormatOptions.modifierOrder,
         validate: {
             guard _FormatRules.allModifiers.contains($0) else {

Sources/Rules.swift

@@ -37,20 +37,20 @@ public final class FormatRule: Equatable, Comparable {
     fileprivate(set) var index = 0
     let help: String
     let runOnceOnly: Bool
+    let disabledByDefault: Bool
     let orderAfter: [String]
     let options: [String]
     let sharedOptions: [String]
-
-    var deprecationMessage: String? {
-        return FormatRule.deprecatedMessage[name]
-    }
+    let deprecationMessage: String?
 
     var isDeprecated: Bool {
         return deprecationMessage != nil
     }
 
     fileprivate init(help: String,
+                     deprecationMessage: String? = nil,
                      runOnceOnly: Bool = false,
+                     disabledByDefault: Bool = false,
                      orderAfter: [String] = [],
                      options: [String] = [],
                      sharedOptions: [String] = [],
@@ -59,9 +59,11 @@ public final class FormatRule: Equatable, Comparable {
         self.fn = fn
         self.help = help
         self.runOnceOnly = runOnceOnly
+        self.disabledByDefault = disabledByDefault || deprecationMessage != nil
         self.orderAfter = orderAfter
         self.options = options
         self.sharedOptions = sharedOptions
+        self.deprecationMessage = deprecationMessage
     }
 
     public func apply(with formatter: Formatter) {
@@ -77,10 +79,6 @@ public final class FormatRule: Equatable, Comparable {
     public static func < (lhs: FormatRule, rhs: FormatRule) -> Bool {
         return lhs.index < rhs.index
     }
-
-    static let deprecatedMessage = [
-        "specifiers": "specifiers rule is deprecated. Use modifierOrder instead.",
-    ]
 }
 
 public let FormatRules = _FormatRules()
@@ -124,14 +122,8 @@ private func allRules(except rules: [String]) -> [FormatRule] {
 }
 
 private let _allRules = allRules(except: [])
+private let _disabledByDefault = _allRules.filter { $0.disabledByDefault }.map { $0.name }
 private let _defaultRules = allRules(except: _disabledByDefault)
-private let _deprecatedRules = FormatRule.deprecatedMessage.keys
-private let _disabledByDefault = _deprecatedRules + [
-    "isEmpty",
-    "multilineEnumCases",
-    "multilineSwitchCases",
-    "organizeDeclarations",
-]
 
 public extension _FormatRules {
     /// A Dictionary of rules by name
@@ -1888,6 +1880,7 @@ public struct _FormatRules {
     /// Deprecated
     public let specifiers = FormatRule(
         help: "Use consistent ordering for member modifiers.",
+        deprecationMessage: "Use modifierOrder instead.",
         options: ["modifierorder"]
     ) { formatter in
         _ = formatter.options.modifierOrder
@@ -3503,7 +3496,7 @@ public struct _FormatRules {
     /// Formats enum cases declaration into one case per line
     public let multilineEnumCases = FormatRule(
         help: "Writes one enum case per line.",
-        options: [],
+        disabledByDefault: true,
         sharedOptions: ["linebreaks"]
     ) { formatter in
         formatter.forEach(.keyword("case")) { i, _ in
@@ -3531,7 +3524,7 @@ public struct _FormatRules {
     /// Writes one switch case per line
     public let multilineSwitchCases = FormatRule(
         help: "Writes one switch case per line.",
-        options: [],
+        disabledByDefault: true,
         sharedOptions: ["linebreaks", "tabwidth", "indent", "smarttabs"]
     ) { formatter in
         formatter.forEach(.endOfScope("case")) { i, _ in
@@ -4066,7 +4059,8 @@ public struct _FormatRules {
 
     /// Replace count == 0 with isEmpty
     public let isEmpty = FormatRule(
-        help: "Prefer `isEmpty` over comparing `count` against zero."
+        help: "Prefer `isEmpty` over comparing `count` against zero.",
+        disabledByDefault: true
     ) { formatter in
         formatter.forEach(.identifier("count")) { i, _ in
             guard let dotIndex = formatter.index(of: .nonSpaceOrLinebreak, before: i, if: {
@@ -4900,7 +4894,9 @@ public struct _FormatRules {
     public let organizeDeclarations = FormatRule(
         help: "Organizes declarations within class, struct, and enum bodies.",
         runOnceOnly: true,
-        options: ["categorymark", "beforemarks", "lifecycle", "structthreshold", "classthreshold", "enumthreshold"]
+        disabledByDefault: true,
+        options: ["categorymark", "beforemarks", "lifecycle", "structthreshold",
+                  "classthreshold", "enumthreshold"]
     ) { formatter in
         /// Categories of declarations within an individual type
         enum Category: String, CaseIterable {

Tests/MetadataTests.swift

@@ -34,7 +34,7 @@ class MetadataTests: XCTestCase {
         for rule in FormatRules.all {
             result += "\n\n## \(rule.name)\n\n\(rule.help)"
             if let message = rule.deprecationMessage {
-                result += "\n\n*Note: \(message)*"
+                result += "\n\n*Note: \(rule.name) rule is deprecated. \(message)*"
                 continue
             }
             if !rule.options.isEmpty {