Merge pull request #8 from brightdigit/feature/pattern-matching

Feature/pattern matching

Scripts/script.sh

@@ -27,8 +27,7 @@ if [[ $TRAVIS_OS_NAME = 'osx' ]]; then
   pod lib lint
   swift package generate-xcodeproj
   pod install --silent --project-directory=Example
-  xcodebuild -quiet -workspace Example/Example.xcworkspace -scheme "iOS Example"  ONLY_ACTIVE_ARCH=NO  CODE_SIGN_IDENTITY="" CODE_SIGNING_REQUIRED=NO  CODE_SIGNING_ALLOWED=NO &
-  xcodebuild -quiet -workspace Example/Example.xcworkspace -scheme "tvOS Example"  ONLY_ACTIVE_ARCH=NO   CODE_SIGN_IDENTITY="" CODE_SIGNING_REQUIRED=NO  CODE_SIGNING_ALLOWED=NO &
-  xcodebuild -quiet -workspace Example/Example.xcworkspace -scheme "macOS Example"  ONLY_ACTIVE_ARCH=NO CODE_SIGN_IDENTITY="" CODE_SIGNING_REQUIRED=NO  CODE_SIGNING_ALLOWED=NO &
-  wait
+  xcodebuild -quiet -workspace Example/Example.xcworkspace -scheme "iOS Example"  ONLY_ACTIVE_ARCH=NO  CODE_SIGN_IDENTITY="" CODE_SIGNING_REQUIRED=NO  CODE_SIGNING_ALLOWED=NO
+  xcodebuild -quiet -workspace Example/Example.xcworkspace -scheme "tvOS Example"  ONLY_ACTIVE_ARCH=NO   CODE_SIGN_IDENTITY="" CODE_SIGNING_REQUIRED=NO  CODE_SIGNING_ALLOWED=NO
+  xcodebuild -quiet -workspace Example/Example.xcworkspace -scheme "macOS Example"  ONLY_ACTIVE_ARCH=NO CODE_SIGN_IDENTITY="" CODE_SIGNING_REQUIRED=NO  CODE_SIGNING_ALLOWED=NO
 fi

Sources/Base32Crockford/Base32CrockfordComparer.swift

@@ -0,0 +1,5 @@
+import Foundation
+
+public protocol Base32CrockfordComparer {
+  func data(_ data: Data, hasEncodedPrefix prefix: String) -> Bool
+}

Sources/Base32Crockford/Base32CrockfordEncoding.swift

@@ -1,12 +1,61 @@
 import Foundation
 
-public struct Base32CrockfordEncoding: Base32CrockfordEncodingProtocol {
-  public static let encoding: Base32CrockfordEncodingProtocol = Base32CrockfordEncoding()
+public struct Base32CrockfordEncoding: Base32CrockfordEncodingProtocol, Base32CrockfordComparer {
+  fileprivate static let _encoding = Base32CrockfordEncoding()
 
-  static let characters = "0123456789abcdefghjkmnpqrtuvwxyz".uppercased()
-  // static let checksum = [1, 1, 2, 4]
+  public static var encoding: Base32CrockfordEncodingProtocol {
+    return _encoding
+  }
+
+  public static var comparer: Base32CrockfordComparer {
+    return _encoding
+  }
+
+  fileprivate static let characters = "0123456789abcdefghjkmnpqrtuvwxyz".uppercased()
+
+  fileprivate struct ChecksumError: Error {}
+  fileprivate func sizeOf(checksumFrom string: String) -> Int {
+    let strBitCount = string.count * 5
+    let dataBitCount = Int(floor(Double(strBitCount) / 8)) * 8
+    return strBitCount - dataBitCount
+  }
+
+  fileprivate func decodeWithoutChecksum(base32Encoded string: String) -> Data {
+    let standardized = standardize(string: string)
+    let checksumSize = sizeOf(checksumFrom: standardized)
+
+    return decode(standardizedString: standardized, withChecksumSize: checksumSize)
+  }
+
+  fileprivate func verifyChecksum(_ checksumSize: Int, _ standardized: String) throws {
+    let lastValue: UInt8?
+    if checksumSize != 0 {
+      let lastIndex = Base32CrockfordEncoding.characters.firstIndex(of: standardized.last!)!
+      lastValue = UInt8(Base32CrockfordEncoding.characters.distance(from: Base32CrockfordEncoding.characters.startIndex, to: lastIndex))
+    } else {
+      lastValue = nil
+    }
+
+    if let lastValue = lastValue {
+      let checksumValue = (lastValue << (8 - checksumSize)) >> (8 - checksumSize)
+      guard checksumValue == 0 else {
+        throw ChecksumError()
+      }
+    }
+  }
+
+  fileprivate func decode(standardizedString standardized: String, withChecksumSize checksumSize: Int) -> Data {
+    let values = standardized.map { character -> String.IndexDistance in
+      let lastIndex = Base32CrockfordEncoding.characters.firstIndex(of: character)!
+      return Base32CrockfordEncoding.characters.distance(from: Base32CrockfordEncoding.characters.startIndex, to: lastIndex)
+    }
 
-  struct ChecksumError: Error {}
+    let bitString = values.map { String($0, radix: 2).pad(toSize: 5) }.joined(separator: "")
+
+    let bitStringWithoutChecksum = String(bitString[bitString.startIndex ... bitString.index(bitString.endIndex, offsetBy: -checksumSize - 1)])
+    let dataBytes = bitStringWithoutChecksum.split(by: 8).compactMap { UInt8($0, radix: 2) }
+    return Data(dataBytes)
+  }
 
   public func encode(data: Data) -> String {
     let dataBitCount = data.count * 8
@@ -39,34 +88,15 @@ public struct Base32CrockfordEncoding: Base32CrockfordEncodingProtocol {
   }
 
   public func decode(base32Encoded string: String) throws -> Data {
-    let standardized = string.uppercased()
-    let strBitCount = string.count * 5
-    let dataBitCount = Int(floor(Double(strBitCount) / 8)) * 8
-    let checksumSize = strBitCount - dataBitCount
-    let lastValue: UInt8?
-    if checksumSize != 0 {
-      let lastIndex = Base32CrockfordEncoding.characters.firstIndex(of: standardized.last!)!
-      lastValue = UInt8(Base32CrockfordEncoding.characters.distance(from: Base32CrockfordEncoding.characters.startIndex, to: lastIndex))
-    } else {
-      lastValue = nil
-    }
-
-    if let lastValue = lastValue {
-      let checksumValue = (lastValue << (8 - checksumSize)) >> (8 - checksumSize)
-      guard checksumValue == 0 else {
-        throw ChecksumError()
-      }
-    }
-
-    let values = standardized.map { character -> String.IndexDistance in
-      let lastIndex = Base32CrockfordEncoding.characters.firstIndex(of: character)!
-      return Base32CrockfordEncoding.characters.distance(from: Base32CrockfordEncoding.characters.startIndex, to: lastIndex)
-    }
+    let standardized = standardize(string: string)
+    let checksumSize = sizeOf(checksumFrom: standardized)
+    try verifyChecksum(checksumSize, standardized)
 
-    let bitString = values.map { String($0, radix: 2).pad(toSize: 5) }.joined(separator: "")
+    return decode(standardizedString: standardized, withChecksumSize: checksumSize)
+  }
 
-    let bitStringWithoutChecksum = String(bitString[bitString.startIndex ... bitString.index(bitString.endIndex, offsetBy: -checksumSize - 1)])
-    let dataBytes = bitStringWithoutChecksum.split(by: 8).compactMap { UInt8($0, radix: 2) }
-    return Data(dataBytes)
+  public func data(_ data: Data, hasEncodedPrefix prefix: String) -> Bool {
+    let prefixData = decodeWithoutChecksum(base32Encoded: prefix)
+    return zip(data, prefixData).allSatisfy { $0 == $1 }
   }
 }

Sources/Base32Crockford/Base32CrockfordEncodingProtocol.swift

@@ -5,3 +5,13 @@ public protocol Base32CrockfordEncodingProtocol: Base32CrockfordGenerator {
   func decode(base32Encoded string: String) throws -> Data
   static var encoding: Base32CrockfordEncodingProtocol { get }
 }
+
+public extension Base32CrockfordEncodingProtocol {
+  func standardize(string: String) -> String {
+    return string
+      .uppercased()
+      .replacingOccurrences(of: "O", with: "0")
+      .replacingOccurrences(of: "I", with: "1")
+      .replacingOccurrences(of: "L", with: "1")
+  }
+}

Tests/Base32CrockfordTests/Base32PatternTests.swift

@@ -0,0 +1,32 @@
+@testable import Base32Crockford
+import XCTest
+
+final class Base32EqualityTests: XCTestCase {
+  func testExample() {
+    let values = ["0": "O", "1": "I", "I": "L"]
+    let encoding = Base32CrockfordEncoding()
+    var checks = 0
+    for _ in 0 ... 2000 {
+      let id = UUID()
+      let data = Data(Array(uuid: id))
+      let fullId = encoding.encode(data: data)
+      let shortId = String(fullId[fullId.startIndex ... fullId.index(fullId.startIndex, offsetBy: 4)])
+      var shortValues = values.reduce([shortId]) { (shortValues, arg1) -> [String] in
+
+        let (key, value) = arg1
+        let current = shortValues.last ?? shortId
+
+        return shortValues + [current.replacingOccurrences(of: key, with: value)]
+      }
+      shortValues.append((shortValues.last ?? shortId).lowercased())
+      shortValues = [String](Set(shortValues))
+      for aShortId in shortValues {
+        XCTAssert(Base32CrockfordEncoding.comparer.data(data, hasEncodedPrefix: aShortId))
+        checks += 1
+      }
+      if checks > 500 {
+        return
+      }
+    }
+  }
+}

Tests/Base32CrockfordTests/EncodeDecodeTests.swift

@@ -31,20 +31,33 @@ final class EncodeDecodeTests: XCTestCase {
     }
   }
 
+  func decode(value: String, withExpected expected: Data) {
+    let actual: Data
+    do {
+      actual = try Base32CrockfordEncoding.encoding.decode(base32Encoded: value)
+    } catch {
+      XCTFail(error.localizedDescription)
+      return
+    }
+    XCTAssertEqual(actual, expected)
+  }
+
   func testDecoding() {
     for (expectedString, value) in data {
-      let actual: Data
       guard let expected = expectedString.data(using: .utf8) else {
         XCTFail("Unable to create data from string")
         continue
       }
-      do {
-        actual = try Base32CrockfordEncoding.encoding.decode(base32Encoded: value)
-      } catch {
-        XCTFail(error.localizedDescription)
-        continue
-      }
-      XCTAssertEqual(actual, expected)
+      var newValue = value
+      decode(value: value, withExpected: expected)
+      newValue = newValue.replacingOccurrences(of: "0", with: "O")
+      decode(value: newValue, withExpected: expected)
+      newValue = newValue.replacingOccurrences(of: "1", with: "L")
+      decode(value: newValue, withExpected: expected)
+      newValue = newValue.replacingOccurrences(of: "L", with: "I")
+      decode(value: newValue, withExpected: expected)
+      newValue = newValue.lowercased()
+      decode(value: newValue, withExpected: expected)
     }
   }
 }

Tests/Base32CrockfordTests/XCTestManifests.swift

@@ -25,6 +25,15 @@
     ]
   }
 
+  extension Base32EqualityTests {
+    // DO NOT MODIFY: This is autogenerated, use:
+    //   `swift test --generate-linuxmain`
+    // to regenerate.
+    static let __allTests__Base32EqualityTests = [
+      ("testExample", testExample)
+    ]
+  }
+
   extension EncodeDecodeTests {
     // DO NOT MODIFY: This is autogenerated, use:
     //   `swift test --generate-linuxmain`
@@ -39,6 +48,7 @@
     return [
       testCase(ArrayTests.__allTests__ArrayTests),
       testCase(Base32CrockfordTests.__allTests__Base32CrockfordTests),
+      testCase(Base32EqualityTests.__allTests__Base32EqualityTests),
       testCase(EncodeDecodeTests.__allTests__EncodeDecodeTests)
     ]
   }

docs/README.md

@@ -1,5 +1,6 @@
 ## Protocols
 
+-   [Base32CrockfordComparer](protocols/Base32CrockfordComparer.md)
 -   [Base32CrockfordEncodingProtocol](protocols/Base32CrockfordEncodingProtocol.md)
 -   [Base32CrockfordGenerator](protocols/Base32CrockfordGenerator.md)
 

docs/extensions/Base32CrockfordEncodingProtocol.md

@@ -3,6 +3,12 @@
 # `Base32CrockfordEncodingProtocol`
 
 ## Methods
+### `standardize(string:)`
+
+```swift
+func standardize(string: String) -> String
+```
+
 ### `generateIdentifier(from:)`
 
 ```swift

docs/protocols/Base32CrockfordComparer.md

@@ -0,0 +1,14 @@
+**PROTOCOL**
+
+# `Base32CrockfordComparer`
+
+```swift
+public protocol Base32CrockfordComparer
+```
+
+## Methods
+### `data(_:hasEncodedPrefix:)`
+
+```swift
+func data(_ data: Data, hasEncodedPrefix prefix: String) -> Bool
+```

docs/structs/Base32CrockfordEncoding.md

@@ -3,7 +3,7 @@
 # `Base32CrockfordEncoding`
 
 ```swift
-public struct Base32CrockfordEncoding: Base32CrockfordEncodingProtocol
+public struct Base32CrockfordEncoding: Base32CrockfordEncodingProtocol, Base32CrockfordComparer
 ```
 
 ## Methods
@@ -18,3 +18,9 @@ public func encode(data: Data) -> String
 ```swift
 public func decode(base32Encoded string: String) throws -> Data
 ```
+
+### `data(_:hasEncodedPrefix:)`
+
+```swift
+public func data(_ data: Data, hasEncodedPrefix prefix: String) -> Bool
+```