SwiftLint integration

.swiftlint.yml

@@ -0,0 +1,54 @@
+opt_in_rules:
+  - anyobject_protocol
+  - array_init
+  - attributes
+  - closure_end_indentation
+  - closure_spacing
+  - contains_over_first_not_nil
+  - convenience_type
+  - discouraged_optional_boolean
+  - discouraged_optional_collection
+  - empty_count
+  - empty_string
+  - fallthrough
+  - fatal_error_message
+  - first_where
+  - force_unwrapping
+  - implicit_return
+  - implicitly_unwrapped_optional
+  - joined_default_parameter
+  - literal_expression_end_indentation
+  - lower_acl_than_parent
+  - modifier_order
+  - multiline_arguments
+  - multiline_function_chains
+  - multiline_parameters
+  - number_separator
+  - operator_usage_whitespace
+  - overridden_super_call
+  - override_in_extension
+  - private_action
+  - private_outlet
+  - prohibited_super_call
+  - redundant_nil_coalescing
+  - sorted_first_last
+  - sorted_imports
+  - trailing_closure
+  - unavailable_function
+  - unneeded_parentheses_in_closure_argument
+  - vertical_parameter_alignment_on_call
+  - yoda_condition
+
+# Rules customization
+line_length:
+  warning: 120
+  error: 200
+
+nesting:
+  type_level:
+    warning: 2
+
+# Exclude generated files
+excluded:
+  - .build
+  - Tests/StencilTests/XCTestManifests.swift

.travis.yml

@@ -20,5 +20,8 @@ sudo: required
 dist: trusty
 install:
   - eval "$(curl -sL https://swiftenv.fuller.li/install.sh)"
+  - if [ "$TRAVIS_OS_NAME" == "osx" ]; then wget --output-document /tmp/SwiftLint.pkg https://github.com/realm/SwiftLint/releases/download/0.27.0/SwiftLint.pkg &&
+    sudo installer -pkg /tmp/SwiftLint.pkg -target /; fi
 script:
-- swift test
+  - swift test
+  - if [ "$TRAVIS_OS_NAME" == "osx" ]; then swiftlint; fi

CHANGELOG.md

@@ -28,6 +28,9 @@ _None_
 - `Token` type converted to struct to allow computing token components only once.  
   [Ilya Puchka](https://github.com/ilyapuchka)
   [#256](https://github.com/stencilproject/Stencil/pull/256)
+- Added SwiftLint to the project.  
+  [David Jennes](https://github.com/djbe)
+  [#249](https://github.com/stencilproject/Stencil/pull/249)
 
 
 ## 0.13.1

Sources/Context.swift

@@ -3,9 +3,9 @@ public class Context {
   var dictionaries: [[String: Any?]]
 
   public let environment: Environment
-  
-  init(dictionary: [String: Any]? = nil, environment: Environment? = nil) {
-    if let dictionary = dictionary {
+
+  init(dictionary: [String: Any] = [:], environment: Environment? = nil) {
+    if !dictionary.isEmpty {
       dictionaries = [dictionary]
     } else {
       dictionaries = []
@@ -28,17 +28,16 @@ public class Context {
 
     /// Set a variable in the current context, deleting the variable if it's nil
     set(value) {
-      if let dictionary = dictionaries.popLast() {
-        var mutable_dictionary = dictionary
-        mutable_dictionary[key] = value
-        dictionaries.append(mutable_dictionary)
+      if var dictionary = dictionaries.popLast() {
+        dictionary[key] = value
+        dictionaries.append(dictionary)
       }
     }
   }
 
   /// Push a new level into the Context
-  fileprivate func push(_ dictionary: [String: Any]? = nil) {
-    dictionaries.append(dictionary ?? [:])
+  fileprivate func push(_ dictionary: [String: Any] = [:]) {
+    dictionaries.append(dictionary)
   }
 
   /// Pop the last level off of the Context
@@ -47,7 +46,7 @@ public class Context {
   }
 
   /// Push a new level onto the context for the duration of the execution of the given closure
-  public func push<Result>(dictionary: [String: Any]? = nil, closure: (() throws -> Result)) rethrows -> Result {
+  public func push<Result>(dictionary: [String: Any] = [:], closure: (() throws -> Result)) rethrows -> Result {
     push(dictionary)
     defer { _ = pop() }
     return try closure()

Sources/Environment.swift

@@ -5,12 +5,12 @@ public struct Environment {
   public var loader: Loader?
 
   public init(loader: Loader? = nil,
-              extensions: [Extension]? = nil,
+              extensions: [Extension] = [],
               templateClass: Template.Type = Template.self) {
 
     self.templateClass = templateClass
     self.loader = loader
-    self.extensions = (extensions ?? []) + [DefaultExtension()]
+    self.extensions = extensions + [DefaultExtension()]
   }
 
   public func loadTemplate(name: String) throws -> Template {
@@ -29,17 +29,17 @@ public struct Environment {
     }
   }
 
-  public func renderTemplate(name: String, context: [String: Any]? = nil) throws -> String {
+  public func renderTemplate(name: String, context: [String: Any] = [:]) throws -> String {
     let template = try loadTemplate(name: name)
     return try render(template: template, context: context)
   }
 
-  public func renderTemplate(string: String, context: [String: Any]? = nil) throws -> String {
+  public func renderTemplate(string: String, context: [String: Any] = [:]) throws -> String {
     let template = templateClass.init(templateString: string, environment: self)
     return try render(template: template, context: context)
   }
 
-  func render(template: Template, context: [String: Any]?) throws -> String {
+  func render(template: Template, context: [String: Any]) throws -> String {
     // update template environment as it can be created from string literal with default environment
     template.environment = self
     return try template.render(context)

Sources/Errors.swift

@@ -18,14 +18,14 @@ public class TemplateDoesNotExist: Error, CustomStringConvertible {
   }
 }
 
-public struct TemplateSyntaxError : Error, Equatable, CustomStringConvertible {
+public struct TemplateSyntaxError: Error, Equatable, CustomStringConvertible {
   public let reason: String
   public var description: String { return reason }
   public internal(set) var token: Token?
   public internal(set) var stackTrace: [Token]
   public var templateName: String? { return token?.sourceMap.filename }
   var allTokens: [Token] {
-    return stackTrace + (token.map({ [$0] }) ?? [])
+    return stackTrace + (token.map { [$0] } ?? [])
   }
 
   public init(reason: String, token: Token? = nil, stackTrace: [Token] = []) {
@@ -50,7 +50,7 @@ extension Error {
   }
 }
 
-public protocol ErrorReporter: class {
+public protocol ErrorReporter: AnyObject {
   func renderError(_ error: Error) -> String
 }
 

Sources/Expression.swift

@@ -2,17 +2,14 @@ public protocol Expression: CustomStringConvertible {
   func evaluate(context: Context) throws -> Bool
 }
 
-
 protocol InfixOperator: Expression {
   init(lhs: Expression, rhs: Expression)
 }
 
-
 protocol PrefixOperator: Expression {
   init(expression: Expression)
 }
 
-
 final class StaticExpression: Expression, CustomStringConvertible {
   let value: Bool
 
@@ -29,7 +26,6 @@ final class StaticExpression: Expression, CustomStringConvertible {
   }
 }
 
-
 final class VariableExpression: Expression, CustomStringConvertible {
   let variable: Resolvable
 
@@ -48,7 +44,7 @@ final class VariableExpression: Expression, CustomStringConvertible {
 
     if let result = result as? [Any] {
       truthy = !result.isEmpty
-    } else if let result = result as? [String:Any] {
+    } else if let result = result as? [String: Any] {
       truthy = !result.isEmpty
     } else if let result = result as? Bool {
       truthy = result
@@ -68,7 +64,6 @@ final class VariableExpression: Expression, CustomStringConvertible {
   }
 }
 
-
 final class NotExpression: Expression, PrefixOperator, CustomStringConvertible {
   let expression: Expression
 
@@ -144,7 +139,6 @@ final class OrExpression: Expression, InfixOperator, CustomStringConvertible {
   }
 }
 
-
 final class AndExpression: Expression, InfixOperator, CustomStringConvertible {
   let lhs: Expression
   let rhs: Expression
@@ -168,7 +162,6 @@ final class AndExpression: Expression, InfixOperator, CustomStringConvertible {
   }
 }
 
-
 class EqualityExpression: Expression, InfixOperator, CustomStringConvertible {
   let lhs: Expression
   let rhs: Expression
@@ -204,7 +197,6 @@ class EqualityExpression: Expression, InfixOperator, CustomStringConvertible {
   }
 }
 
-
 class NumericExpression: Expression, InfixOperator, CustomStringConvertible {
   let lhs: Expression
   let rhs: Expression
@@ -215,7 +207,7 @@ class NumericExpression: Expression, InfixOperator, CustomStringConvertible {
   }
 
   var description: String {
-    return "(\(lhs) \(op) \(rhs))"
+    return "(\(lhs) \(symbol) \(rhs))"
   }
 
   func evaluate(context: Context) throws -> Bool {
@@ -233,7 +225,7 @@ class NumericExpression: Expression, InfixOperator, CustomStringConvertible {
     return false
   }
 
-  var op: String {
+  var symbol: String {
     return ""
   }
 
@@ -242,9 +234,8 @@ class NumericExpression: Expression, InfixOperator, CustomStringConvertible {
   }
 }
 
-
 class MoreThanExpression: NumericExpression {
-  override var op: String {
+  override var symbol: String {
     return ">"
   }
 
@@ -253,9 +244,8 @@ class MoreThanExpression: NumericExpression {
   }
 }
 
-
 class MoreThanEqualExpression: NumericExpression {
-  override var op: String {
+  override var symbol: String {
     return ">="
   }
 
@@ -264,9 +254,8 @@ class MoreThanEqualExpression: NumericExpression {
   }
 }
 
-
 class LessThanExpression: NumericExpression {
-  override var op: String {
+  override var symbol: String {
     return "<"
   }
 
@@ -275,9 +264,8 @@ class LessThanExpression: NumericExpression {
   }
 }
 
-
 class LessThanEqualExpression: NumericExpression {
-  override var op: String {
+  override var symbol: String {
     return "<="
   }
 
@@ -286,7 +274,6 @@ class LessThanEqualExpression: NumericExpression {
   }
 }
 
-
 class InequalityExpression: EqualityExpression {
   override var description: String {
     return "(\(lhs) != \(rhs))"
@@ -297,7 +284,7 @@ class InequalityExpression: EqualityExpression {
   }
 }
 
-
+// swiftlint:disable:next cyclomatic_complexity
 func toNumber(value: Any) -> Number? {
     if let value = value as? Float {
         return Number(value)

Sources/Extension.swift

@@ -14,12 +14,13 @@ open class Extension {
 
   /// Registers a simple template tag with a name and a handler
   public func registerSimpleTag(_ name: String, handler: @escaping (Context) throws -> String) {
-    registerTag(name, parser: { parser, token in
-      return SimpleNode(token: token, handler: handler)
-    })
+    registerTag(name) { _, token in
+      SimpleNode(token: token, handler: handler)
+    }
   }
-  
+
   /// Registers boolean filter with it's negative counterpart
+  // swiftlint:disable:next discouraged_optional_boolean
   public func registerFilter(name: String, negativeFilterName: String, filter: @escaping (Any?) throws -> Bool?) {
     filters[name] = .simple(filter)
     filters[negativeFilterName] = .simple {
@@ -44,7 +45,6 @@ open class Extension {
   }
 }
 
-
 class DefaultExtension: Extension {
   override init() {
     super.init()
@@ -77,7 +77,6 @@ class DefaultExtension: Extension {
   }
 }
 
-
 protocol FilterType {
   func invoke(value: Any?, arguments: [Any?], context: Context) throws -> Any?
 }

Sources/FilterTag.swift

@@ -1,4 +1,4 @@
-class FilterNode : NodeType {
+class FilterNode: NodeType {
   let resolvable: Resolvable
   let nodes: [NodeType]
   let token: Token?
@@ -30,8 +30,7 @@ class FilterNode : NodeType {
     let value = try renderNodes(nodes, context)
 
     return try context.push(dictionary: ["filter_value": value]) {
-      return try VariableNode(variable: resolvable, token: token).render(context)
+      try VariableNode(variable: resolvable, token: token).render(context)
     }
   }
 }
-