Make Builder's interface simple (Kuniwak#4)

Author: Kuniwak

README.md

@@ -14,10 +14,8 @@ Basic Usage
 -----------
 
 ```swift
-let result = MultipartFormData.Builder(
-        generatingBoundaryBy: RandomBoundaryGenerator()
-    )
-    .build(with: [
+let multipartFormData = try MultipartFormData.Builder.build(
+    with: [
         (
             name: "example1",
             filename: nil,
@@ -30,22 +28,17 @@ let result = MultipartFormData.Builder(
             mimeType: MIMEType.textPlain,
             data: "EXAMPLE_TXT".data(using: .utf8)!
         ),
-    ])
-
-
-switch result {
-case let .valid(multipartFormData):
-    var requrst = URLRequest(url: URL(string: "http://example.com")!)
-    request.addValue(multipartFormData.contentType, forHTTPHeaderField: "Content-Type")
-    request.httpBody = multipartFormData.body
+    ],
+    willSeparateBy: RandomBoundaryGenerator.generate()
+)
 
-    let task = URLSession.shared.dataTask(with: request)
-    task.resume()
+var request = URLRequest(url: URL(string: "http://example.com")!)
+request.httpMethod = "POST"
+request.setValue(multipartFormData.contentType, forHTTPHeaderField: "Content-Type")
+request.httpBody = multipartFormData.body
 
-case let .invalid(because: error):
-    print(error)
-    return
-}
+let task = URLSession.shared.dataTask(with: request)
+task.resume()
 ```
 
 
@@ -59,15 +52,15 @@ let multipartFormData = MultipartFormData(
     body: [
         MultipartFormData.Part(
             contentDisposition: ContentDisposition(
-                name: Name(asPercentEncoded: "field1"),
+                name: Name(asPercentEncoded: "field%201"),
                 filename: nil
             ),
             contentType: nil,
             content: "value1".data(using: .utf8)!
         ),
         MultipartFormData.Part(
             contentDisposition: ContentDisposition(
-                name: Name(asPercentEncoded: "field2"),
+                name: Name(asPercentEncoded: "field%202"),
                 filename: Filename(asPercentEncoded: "example.txt")
             ),
             contentType: ContentType(representing: .textPlain),

Sources/MultipartFormDataKit/BoundaryGenerator.swift

@@ -3,32 +3,13 @@ import Foundation
 
 
 public protocol BoundaryGenerator {
-    func generate() -> String
-}
-
-
-
-public class ConstantBoundaryGenerator: BoundaryGenerator {
-    private let boundary: String
-
-
-    public init(willReturn boundary: String) {
-        self.boundary = boundary
-    }
-
-
-    public func generate() -> String {
-        return self.boundary
-    }
+    static func generate() -> String
 }
 
 
 
 public class RandomBoundaryGenerator: BoundaryGenerator {
-    public init() {}
-
-
-    public func generate() -> String {
+    public static func generate() -> String {
         return String(format: "%08x%08x", arc4random(), arc4random())
     }
 }

Sources/MultipartFormDataKit/ContentDisposition.swift

@@ -109,7 +109,7 @@ public struct ContentDisposition {
 
 
 
-    public enum DataTransformError {
+    public enum DataTransformError: Error {
         case cannotEncodeAsUTF8(debugInfo: String)
     }
 }

Sources/MultipartFormDataKit/ContentType.swift

@@ -78,7 +78,7 @@ public struct ContentType {
 
 
 
-    public enum DataTransformError {
+    public enum DataTransformError: Error {
         case cannotEncodeAsUTF8(debugInfo: String)
     }
 }

Sources/MultipartFormDataKit/Filename.swift

@@ -37,7 +37,7 @@ public struct Filename {
     }
 
 
-    public enum FailureReason {
+    public enum FailureReason: Error {
         case cannotPercentEncode(debugInfo: String)
     }
 }

Sources/MultipartFormDataKit/MultipartFormData+Builder.swift

@@ -3,38 +3,47 @@ import Foundation
 
 
 extension MultipartFormData {
-    public class Builder {
-        public typealias Part = (
-            name: String,
-            filename: String?,
-            mimeType: MIMEType?,
-            data: Data
-        )
-
-        private let boundaryGenerator: BoundaryGenerator
-
-
-        public init(generatingBoundaryBy boundaryGenerator: BoundaryGenerator) {
-            self.boundaryGenerator = boundaryGenerator
+    public typealias PartParam = (
+        name: String,
+        filename: String?,
+        mimeType: MIMEType?,
+        data: Data
+    )
+
+
+
+    public enum Builder {
+        public static func build(
+            with partParams: [PartParam],
+            willSeparateBy uniqueBoundary: String
+        ) throws -> BuildResult {
+            switch TypedBuilder.build(with: partParams, willSeparateBy: uniqueBoundary) {
+            case let .invalid(because: error):
+                throw error
+
+            case let .valid(result):
+                return result
+            }
         }
+    }
 
 
 
-        public func build(
-            with parts: [Part]
+    public enum TypedBuilder {
+        public static func build(
+            with partParams: [PartParam],
+            willSeparateBy uniqueBoundary: String
         ) -> ValidationResult<BuildResult, BuildError> {
-            let uniqueBoundary = self.boundaryGenerator.generate()
-
             var validParts = [MultipartFormData.Part]()
-            for part in parts {
+            for partParam in partParams {
                 switch MultipartFormData.Part.create(
-                    name: part.name,
-                    filename: part.filename,
-                    mimeType: part.mimeType,
-                    data: part.data
+                    name: partParam.name,
+                    filename: partParam.filename,
+                    mimeType: partParam.mimeType,
+                    data: partParam.data
                 ) {
-                case let .valid(validPart):
-                    validParts.append(validPart)
+                case let .valid(part):
+                    validParts.append(part)
 
                 case let .invalid(because: reason):
                     return .invalid(because: .partCreationError(reason))
@@ -57,33 +66,36 @@ extension MultipartFormData {
                 return .invalid(because: .dataTransformError(reason))
             }
         }
+    }
 
 
 
-        public enum BuildError {
-            case partCreationError(MultipartFormData.Part.CreationError)
-            case dataTransformError(MultipartFormData.DataTransformError)
-        }
+    public enum BuildError: Error {
+        case partCreationError(MultipartFormData.Part.CreationError)
+        case dataTransformError(MultipartFormData.DataTransformError)
+    }
 
 
 
-        public struct BuildResult {
-            public let contentType: String
-            public let body: Data
+    public struct BuildResult {
+        public let contentType: String
+        public let body: Data
 
 
-            public init(contentType: String, body: Data) {
-                self.contentType = contentType
-                self.body = body
-            }
+        public init(contentType: String, body: Data) {
+            self.contentType = contentType
+            self.body = body
         }
     }
 }
 
 
 
-extension MultipartFormData.Builder.BuildResult: Equatable {
-    public static func ==(lhs: MultipartFormData.Builder.BuildResult, rhs: MultipartFormData.Builder.BuildResult) -> Bool {
+extension MultipartFormData.BuildResult: Equatable {
+    public static func ==(
+        lhs: MultipartFormData.BuildResult,
+        rhs: MultipartFormData.BuildResult
+    ) -> Bool {
         return lhs.contentType == rhs.contentType
             && lhs.body == rhs.body
     }

Sources/MultipartFormDataKit/MultipartFormData+Part.swift

@@ -134,7 +134,7 @@ extension MultipartFormData {
 
 
 
-        public enum CreationError {
+        public enum CreationError: Error {
             case invalidName(Name.FailureReason)
             case invalidFilename(Filename.FailureReason)
         }

Sources/MultipartFormDataKit/MultipartFormData.swift

@@ -79,7 +79,7 @@ public struct MultipartFormData {
 
 
 
-    public enum DataTransformError {
+    public enum DataTransformError: Error {
         case contentDispositionError(ContentDisposition.DataTransformError)
         case contentTypeError(ContentType.DataTransformError)
         case boundaryError(debugInfo: String)

Sources/MultipartFormDataKit/Name.swift

@@ -20,7 +20,7 @@ public struct Name {
     }
 
 
-    public enum FailureReason {
+    public enum FailureReason: Error {
         case cannotPercentEncode(debugInfo: String)
     }
 }