Add kebab case

README.md

@@ -1,6 +1,6 @@
 # StringCase
 
-Converts `String` to `lowerCamelCase`, `UpperCamelCase` and `snake_case`.
+Converts `String` to `lowerCamelCase`, `UpperCamelCase`, `snake_case` and `kebab-case`.
 
 ## Usage
 
@@ -12,6 +12,7 @@ let input = "Keynote Event"
 input.lowerCamelCased() // "keynoteEvent"
 input.upperCamelCased() // "KeynoteEvent"
 input.snakeCased() // "keynote_event"
+input.kebabCased() // "keynote-event"
 ```
 
 ```swift
@@ -20,6 +21,7 @@ let input = "_this is* not-Very%difficult"
 input.lowerCamelCased() // "thisIsNotVeryDifficult"
 input.upperCamelCased() // "ThisIsNotVeryDifficult"
 input.snakeCased() // "this_is_not_very_difficult"
+input.kebabCased() // "this-is-not-very-difficult"
 ```
 
 ### Boolean checks
@@ -42,6 +44,12 @@ input.snakeCased() // "this_is_not_very_difficult"
 "keynote_event".isSnakeCase // true
 ```
 
+```swift
+"KeynoteEvent".isKebabCase // false
+"keynoteEvent".isKebabCase // false
+"keynote-event".isKebabCase // true
+```
+
 ## Contact
 
 * Devran "Cosmo" Uenal

Sources/StringCase/StringCase.swift

@@ -13,7 +13,26 @@ public extension String {
  /// In snake case, words are separated by underscores.
  var isSnakeCase: Bool {
  // Strip all underscores and check if the rest is lowercase
- return self.filter{ $0 != "_" }.allSatisfy { $0.isLowercase }
+ return self
+ .filter { $0 != "_" }
+ .allSatisfy(\.isLowercase)
+ }
+
+ /// A Boolean value indicating whether this string is considered kebab case.
+ ///
+ /// For example, the following strings are all kebab case:
+ ///
+ /// - "kebab-case"
+ /// - "example"
+ /// - "date-formatter"
+ ///
+ /// String can contain lowercase letters and dashes only.
+ /// In kebab case, words are separated by dashes.
+ var isKebabCase: Bool {
+ // Strip all dashes and check if the rest is lowercase
+ return self
+ .filter { $0 != "-" }
+ .allSatisfy(\.isLowercase)
  }
 
  /// A Boolean value indicating whether this string is considered lower camel case.
@@ -28,10 +47,11 @@ public extension String {
  /// In lower camel case, words are separated by uppercase letters.
  var isLowerCamelCase: Bool {
  // Check if the first character is lowercase and the rest contains letters
- if let firstCharacter = self.first, firstCharacter.isLowercase && self.allSatisfy { $0.isLetter } {
- return true
+ if let firstCharacter = self.first {
+ return firstCharacter.isLowercase && self.allSatisfy(\.isLetter)
+ } else {
+ return false
  }
- return false
  }
 
  /// A Boolean value indicating whether this string is considered upper camel case.
@@ -46,10 +66,11 @@ public extension String {
  /// In upper camel case, words are separated by uppercase letters.
  var isUpperCamelCase: Bool {
  // Check if the first character is uppercase and the rest contains letters
- if let firstCharacter = self.first, firstCharacter.isUppercase && self.allSatisfy { $0.isLetter } {
- return true
+ if let firstCharacter = self.first {
+ return firstCharacter.isUppercase && self.allSatisfy(\.isLetter)
+ } else {
+ return false
  }
- return false
  }
 }
 
@@ -74,7 +95,7 @@ public extension String {
  lastCharacter = character
  }
 
- return results.map { $0.capitalized }
+ return results.map(\.capitalized)
  }
 
  /// Returns a lower camel case version of the string.
@@ -120,6 +141,24 @@ public extension String {
  /// - Returns: A snake case copy of the string.
  func snakeCased() -> String {
  if self.isSnakeCase { return self }
- return lowercasedStrings().map{ $0.lowercased() }.joined(separator: "_")
+ return lowercasedStrings()
+ .map { $0.lowercased() }
+ .joined(separator: "_")
+ }
+
+ /// Returns kebab case version of the string.
+ ///
+ /// Here's an example of transforming a string to kebab case.
+ ///
+ /// let event = "Keynote Event"
+ /// print(event.kebabCased())
+ /// // Prints "keynote-event"
+ ///
+ /// - Returns: A kebab case copy of the string.
+ func kebabCased() -> String {
+ if self.isKebabCase { return self }
+ return lowercasedStrings()
+ .map { $0.lowercased() }
+ .joined(separator: "-")
  }
 }

Tests/StringCaseTests/StringCaseTests.swift

@@ -6,11 +6,13 @@ final class StringCaseTests: XCTestCase {
  XCTAssertTrue("snake".isSnakeCase)
  XCTAssertTrue("snake_case".isSnakeCase)
  XCTAssertTrue("snake_case_example".isSnakeCase)
+XCTAssertFalse("SNAKE".isSnakeCase)
  XCTAssertFalse("not_a_SNAKECASE_String".isSnakeCase)
  XCTAssertFalse("notSnakeCase".isSnakeCase)
  XCTAssertFalse("AlsoNotSnakeCase".isSnakeCase)
 
  XCTAssertEqual("snake".snakeCased(), "snake")
+XCTAssertEqual("SNAKE".snakeCased(), "snake")
  XCTAssertEqual("snake cased".snakeCased(), "snake_cased")
  XCTAssertEqual("snakeCased".snakeCased(), "snake_cased")
  XCTAssertEqual("snake Cased_String".snakeCased(), "snake_cased_string")
@@ -20,11 +22,13 @@ final class StringCaseTests: XCTestCase {
  func testLowerCamelCase() throws {
  XCTAssertTrue("lower".isLowerCamelCase)
  XCTAssertTrue("lowerCamelCase".isLowerCamelCase)
+XCTAssertFalse("LOWER".isLowerCamelCase)
  XCTAssertFalse("lowerCamelCase_with_underscore".isLowerCamelCase)
  XCTAssertFalse("UpperCamelCase".isLowerCamelCase)
  XCTAssertFalse("snake_case".isLowerCamelCase)
 
  XCTAssertEqual("lower".lowerCamelCased(), "lower")
+XCTAssertEqual("LOWER".lowerCamelCased(), "lower")
  XCTAssertEqual("LowerCamelCased".lowerCamelCased(), "lowerCamelCased")
  XCTAssertEqual("lower_camel_cased".lowerCamelCased(), "lowerCamelCased")
  XCTAssertEqual("Lower Camel cased".lowerCamelCased(), "lowerCamelCased")
@@ -35,20 +39,40 @@ final class StringCaseTests: XCTestCase {
  XCTAssertTrue("Upper".isUpperCamelCase)
  XCTAssertTrue("UpperCamelCase".isUpperCamelCase)
  XCTAssertTrue("UpperCamelCaseExample".isUpperCamelCase)
+XCTAssertFalse("UPPER".isUpperCamelCase)
  XCTAssertFalse("UpperCamelCase_with_underscore".isUpperCamelCase)
  XCTAssertFalse("snake_case".isUpperCamelCase)
  XCTAssertFalse("lowerCamelCase".isUpperCamelCase)
 
  XCTAssertEqual("Upper".upperCamelCased(), "Upper")
+XCTAssertEqual("UPPER".upperCamelCased(), "Upper")
  XCTAssertEqual("upperCamelCased".upperCamelCased(), "UpperCamelCased")
  XCTAssertEqual("upper_camel_cased".upperCamelCased(), "UpperCamelCased")
  XCTAssertEqual("upper_camel Cased".upperCamelCased(), "UpperCamelCased")
  XCTAssertEqual("_this is* not-Very%difficult".upperCamelCased(), "ThisIsNotVeryDifficult")
  }
+
+func testKebabCase() throws {
+XCTAssertTrue("kebab".isKebabCase)
+XCTAssertTrue("kebab-case".isKebabCase)
+XCTAssertTrue("kebab-case-example".isKebabCase)
+XCTAssertFalse("KEBAB".isKebabCase)
+XCTAssertFalse("not-a-KEBABCASE-String".isKebabCase)
+XCTAssertFalse("notKebabCase".isKebabCase)
+XCTAssertFalse("AlsoNotKebabCase".isKebabCase)
+
+XCTAssertEqual("kebab".kebabCased(), "kebab")
+XCTAssertEqual("KEBAB".kebabCased(), "kebab")
+XCTAssertEqual("kebab cased".kebabCased(), "kebab-cased")
+XCTAssertEqual("kebabCased".kebabCased(), "kebab-cased")
+XCTAssertEqual("kebab Cased_String".kebabCased(), "kebab-cased-string")
+XCTAssertEqual("_this is* not-Very%difficult".kebabCased(), "this-is-not-very-difficult")
+}
 
  static var allTests = [
  ("testSnakeCase", testSnakeCase),
  ("testLowerCamelCase", testLowerCamelCase),
  ("testUpperCamelCase", testUpperCamelCase),
+("testKebabCase", testKebabCase),
  ]
 }