Recursive Configs

CHANGELOG.md

@@ -18,6 +18,10 @@
   [JP Simard](https://github.com/jpsim)
   [#222](https://github.com/realm/SwiftLint/issues/222)
 
+* Add nested `.swiftlint.yml` configuration support.  
+  [Scott Hoyt](https://github.com/scottrhoyt)
+  [#299](https://github.com/realm/SwiftLint/issues/299)
+
 ##### Bug Fixes
 
 * Fix multibyte handling in many rules.  

README.md

@@ -80,7 +80,7 @@ directory to see the currently implemented rules.
 ### Disable a rule in code
 
 Rules can be disabled with a comment inside a source file with the following
-format: 
+format:
 
 `// swiftlint:disable <rule>`
 
@@ -146,6 +146,20 @@ type_body_length:
 reporter: "csv" # reporter type (xcode, json, csv, checkstyle)
 ```
 
+#### Nested Configurations
+
+SwiftLint supports nesting configuration files for more granular control over
+the linting process.
+
+  * Set the `use_nested_configs: true` value in your root `.swiftlint.yml` file
+  * Include additional `.swiftlint.yml` files where necessary in your directory
+    structure.
+  * Each file will be linted using the configuration file that is in it's
+    directory or at the deepest level of it's parent directories. Otherwise the
+    root configuration will be used.
+  * `excluded`, `included`, and `use_nested_configs` are ignored for nested
+    configurations
+
 ### Auto-correct
 
 SwiftLint can automatically correct certain violations. Files on disk are

Source/SwiftLintFramework/Extensions/NSFileManager+SwiftLint.swift

@@ -15,7 +15,7 @@ extension NSFileManager {
     }
 
     public func filesToLintAtPath(path: String) -> [String] {
-        let absolutePath = (path.absolutePathRepresentation() as NSString).stringByStandardizingPath
+        let absolutePath = path.absolutePathStandardized()
         var isDirectory: ObjCBool = false
         guard fileExistsAtPath(absolutePath, isDirectory: &isDirectory) else {
             return []

Source/SwiftLintFramework/Extensions/String+SwiftLint.swift

@@ -69,4 +69,16 @@ extension String {
         }
         return nil
     }
+
+    var stringByDeletingLastPathComponent: String {
+        return (self as NSString).stringByDeletingLastPathComponent
+    }
+
+    func stringByAppendingPathComponent(pathComponent: String) -> String {
+        return (self as NSString).stringByAppendingPathComponent(pathComponent)
+    }
+
+    public func absolutePathStandardized() -> String {
+        return (self.absolutePathRepresentation() as NSString).stringByStandardizingPath
+    }
 }

Source/SwiftLintFramework/Models/Configuration.swift

@@ -21,12 +21,15 @@ extension Yaml {
     }
 }
 
-public struct Configuration {
+public struct Configuration: Equatable {
     public let disabledRules: [String] // disabled_rules
     public let included: [String]      // included
     public let excluded: [String]      // excluded
     public let reporter: String        // reporter (xcode, json, csv, checkstyle)
     public let rules: [Rule]
+    public let useNestedConfigs: Bool  // process nested configs, will default to false
+    public var rootPath: String?       // the root path of the lint to search for nested configs
+    private var configPath: String?    // if successfully load from a path
 
     public var reporterFromString: Reporter.Type {
         switch reporter {
@@ -47,10 +50,12 @@ public struct Configuration {
                  included: [String] = [],
                  excluded: [String] = [],
                  reporter: String = "xcode",
-                 rules: [Rule] = Configuration.rulesFromYAML()) {
+                 rules: [Rule] = Configuration.rulesFromYAML(),
+                 useNestedConfigs: Bool = false) {
         self.included = included
         self.excluded = excluded
         self.reporter = reporter
+        self.useNestedConfigs = useNestedConfigs
 
         // Validate that all rule identifiers map to a defined rule
 
@@ -89,23 +94,36 @@ public struct Configuration {
     }
 
     public init?(yaml: String) {
-        let yamlResult = Yaml.load(yaml)
-        guard let yamlConfig = yamlResult.value else {
-            if let error = yamlResult.error {
-                queuedPrint(error)
-            }
+        guard let yamlConfig = Configuration.loadYaml(yaml) else {
             return nil
         }
+        self.init(yamlConfig: yamlConfig)
+    }
+
+    private init?(yamlConfig: Yaml) {
         self.init(
             disabledRules: yamlConfig["disabled_rules"].arrayOfStrings ?? [],
             included: yamlConfig["included"].arrayOfStrings ?? [],
             excluded: yamlConfig["excluded"].arrayOfStrings ?? [],
             reporter: yamlConfig["reporter"].string ?? XcodeReporter.identifier,
-            rules: Configuration.rulesFromYAML(yamlConfig)
+            rules: Configuration.rulesFromYAML(yamlConfig),
+            useNestedConfigs: yamlConfig["use_nested_configs"].bool ?? false
         )
     }
 
-    public init(path: String = ".swiftlint.yml", optional: Bool = true) {
+    private static func loadYaml(yaml: String) -> Yaml? {
+        let yamlResult = Yaml.load(yaml)
+        if let yamlConfig = yamlResult.value {
+            return yamlConfig
+        } else {
+            if let error = yamlResult.error {
+                queuedPrint(error)
+            }
+            return nil
+        }
+    }
+
+    public init(path: String = ".swiftlint.yml", optional: Bool = true, silent: Bool = false) {
         let fullPath = (path as NSString).absolutePathRepresentation()
         let failIfRequired = {
             if !optional { fatalError("Could not read configuration file at path '\(fullPath)'") }
@@ -118,9 +136,12 @@ public struct Configuration {
         do {
             let yamlContents = try NSString(contentsOfFile: fullPath,
                 encoding: NSUTF8StringEncoding) as String
-            if let _ = Configuration(yaml: yamlContents) {
-                queuedPrintError("Loading configuration from '\(path)'")
-                self.init(yaml: yamlContents)!
+            if let yamlConfig = Configuration.loadYaml(yamlContents) {
+                if !silent {
+                    queuedPrintError("Loading configuration from '\(path)'")
+                }
+                self.init(yamlConfig: yamlConfig)!
+                configPath = fullPath
                 return
             } else {
                 failIfRequired()
@@ -188,4 +209,54 @@ public struct Configuration {
         let allPaths = self.lintablePathsForPath(path)
         return allPaths.flatMap { File(path: $0) }
     }
+
+    public func configForFile(file: File) -> Configuration {
+        if  useNestedConfigs,
+            let containingDir = file.path?.stringByDeletingLastPathComponent {
+            return configForPath(containingDir)
+        }
+        return self
+    }
+}
+
+// MARK: - Nested Configurations Extension
+
+public extension Configuration {
+    func configForPath(path: String) -> Configuration {
+        let configSearchPath = path.stringByAppendingPathComponent(".swiftlint.yml")
+
+        // If a config exists and it isn't us, load and merge the configs
+        if configSearchPath != configPath &&
+            NSFileManager.defaultManager().fileExistsAtPath(configSearchPath) {
+            return merge(Configuration(path: configSearchPath, optional: false, silent: true))
+        }
+
+        // If we are not at the root path, continue down the tree
+        if path != rootPath {
+            return configForPath(path.stringByDeletingLastPathComponent)
+        }
+
+        // If nothing else, return self
+        return self
+    }
+
+    // Currently merge simply overrides the current configuration with the new configuration.
+    // This requires that all config files be fully specified. In the future this will be changed
+    // to do a more intelligent merge allowing for partial nested configs.
+    func merge(config: Configuration) -> Configuration {
+        return config
+    }
+}
+
+// Mark - == Implementation
+
+public func == (lhs: Configuration, rhs: Configuration) -> Bool {
+    return (lhs.disabledRules == rhs.disabledRules) &&
+           (lhs.excluded == rhs.excluded) &&
+           (lhs.included == rhs.included) &&
+           (lhs.reporter == rhs.reporter) &&
+           (lhs.useNestedConfigs == rhs.useNestedConfigs) &&
+           (lhs.configPath == rhs.configPath) &&
+           (lhs.rootPath == lhs.rootPath) &&
+           (lhs.rules == rhs.rules)
 }

Source/SwiftLintFramework/Models/RuleParameter.swift

@@ -6,7 +6,7 @@
 //  Copyright (c) 2015 Realm. All rights reserved.
 //
 
-public struct RuleParameter<T> {
+public struct RuleParameter<T: Equatable> : Equatable {
     public let severity: ViolationSeverity
     public let value: T
 
@@ -15,3 +15,9 @@ public struct RuleParameter<T> {
         self.value = value
     }
 }
+
+// MARK: - Equatable
+
+public func ==<T: Equatable>(lhs: RuleParameter<T>, rhs: RuleParameter<T>) -> Bool {
+    return lhs.value == rhs.value && lhs.severity == rhs.severity
+}

Source/SwiftLintFramework/Protocols/Rule.swift

@@ -13,12 +13,35 @@ public protocol Rule {
     func validateFile(file: File) -> [StyleViolation]
 }
 
+extension Rule {
+    func isEqualTo(rule: Rule) -> Bool {
+        return self.dynamicType.description == rule.dynamicType.description
+    }
+}
+
 public protocol ParameterizedRule: Rule {
-    typealias ParameterType
+    typealias ParameterType: Equatable
     init(parameters: [RuleParameter<ParameterType>])
     var parameters: [RuleParameter<ParameterType>] { get }
 }
 
+extension ParameterizedRule {
+    func isEqualTo(rule: Self) -> Bool {
+        return (self.dynamicType.description == rule.dynamicType.description) &&
+               (self.parameters == rule.parameters)
+    }
+}
+
 public protocol CorrectableRule: Rule {
     func correctFile(file: File) -> [Correction]
 }
+
+// MARK: - == Implementations
+
+func == (lhs: [Rule], rhs: [Rule]) -> Bool {
+    if lhs.count == rhs.count {
+        return zip(lhs, rhs).map { $0.isEqualTo($1) }.reduce(true) { $0 && $1 }
+    }
+
+    return false
+}

Source/SwiftLintFrameworkTests/ConfigurationTests.swift

@@ -6,7 +6,8 @@
 //  Copyright © 2015 Realm. All rights reserved.
 //
 
-import SwiftLintFramework
+@testable import SwiftLintFramework
+import SourceKittenFramework
 import XCTest
 
 class ConfigurationTests: XCTestCase {
@@ -89,4 +90,105 @@ class ConfigurationTests: XCTestCase {
         let paths = configuration.lintablePathsForPath("", fileManager: TestFileManager())
         XCTAssertEqual(["directory/File1.swift", "directory/File2.swift"], paths)
     }
+
+    // MARK: - Testing Configuration Equality
+
+    private var projectMockConfig0: Configuration {
+        var config = Configuration(path: projectMockYAML0, optional: false, silent: true)
+        config.rootPath = projectMockPathLevel0
+        return config
+    }
+
+    private var projectMockConfig2: Configuration {
+        return Configuration(path: projectMockYAML2, optional: false, silent: true)
+    }
+
+    func testIsEqualTo() {
+        XCTAssertEqual(projectMockConfig0, projectMockConfig0)
+    }
+
+    func testIsNotEqualTo() {
+        XCTAssertNotEqual(projectMockConfig0, projectMockConfig2)
+    }
+
+    // MARK: - Testing Nested Configurations
+
+    func testMerge() {
+        XCTAssertEqual(projectMockConfig0.merge(projectMockConfig2), projectMockConfig2)
+    }
+
+    func testLevel0() {
+        XCTAssertEqual(projectMockConfig0.configForFile(File(path: projectMockSwift0)!),
+                       projectMockConfig0)
+    }
+
+    func testLevel1() {
+        XCTAssertEqual(projectMockConfig0.configForFile(File(path: projectMockSwift1)!),
+                       projectMockConfig0)
+    }
+
+    func testLevel2() {
+        XCTAssertEqual(projectMockConfig0.configForFile(File(path: projectMockSwift2)!),
+                       projectMockConfig0.merge(projectMockConfig2))
+    }
+
+    func testLevel3() {
+        XCTAssertEqual(projectMockConfig0.configForFile(File(path: projectMockSwift3)!),
+                       projectMockConfig0.merge(projectMockConfig2))
+    }
+
+    func testDoNotUseNestedConfigs() {
+        var config = Configuration(yaml: "use_nested_configs: false\n")!
+        config.rootPath = projectMockPathLevel0
+        XCTAssertEqual(config.configForFile(File(path: projectMockSwift3)!),
+                       config)
+    }
+}
+
+// MARK: - ProjectMock Paths
+
+extension XCTestCase {
+    var bundlePath: String {
+        return NSBundle(forClass: self.dynamicType).resourcePath!
+    }
+
+    var projectMockPathLevel0: String {
+        return bundlePath.stringByAppendingPathComponent("ProjectMock")
+    }
+
+    var projectMockPathLevel1: String {
+        return projectMockPathLevel0.stringByAppendingPathComponent("Level1")
+    }
+
+    var projectMockPathLevel2: String {
+        return projectMockPathLevel1.stringByAppendingPathComponent("Level2")
+    }
+
+    var projectMockPathLevel3: String {
+        return projectMockPathLevel2.stringByAppendingPathComponent("Level3")
+    }
+
+    var projectMockYAML0: String {
+        return projectMockPathLevel0.stringByAppendingPathComponent(".swiftlint.yml")
+    }
+
+    var projectMockYAML2: String {
+        return projectMockPathLevel2.stringByAppendingPathComponent(".swiftlint.yml")
+    }
+
+    var projectMockSwift0: String {
+        return projectMockPathLevel0.stringByAppendingPathComponent("Level0.swift")
+    }
+
+    var projectMockSwift1: String {
+        return projectMockPathLevel1.stringByAppendingPathComponent("Level1.swift")
+    }
+
+    var projectMockSwift2: String {
+        return projectMockPathLevel2.stringByAppendingPathComponent("Level2.swift")
+    }
+
+    var projectMockSwift3: String {
+        return projectMockPathLevel3.stringByAppendingPathComponent("Level3.swift")
+    }
 }

Source/SwiftLintFrameworkTests/Resources/ProjectMock/.swiftlint.yml

@@ -0,0 +1,9 @@
+disabled_rules:
+  - force_cast
+included:
+  - "everything"
+exluded:
+  - "the place where i committed many coding sins"
+line_length: 10000000000
+reporter: "json"
+use_nested_configs: true

Source/SwiftLintFrameworkTests/Resources/ProjectMock/Level0.swift

@@ -0,0 +1 @@
+// This is just a mock Swift file