Add codegen option about convert enum case name strategy

Sources/ApolloCodegenLib/ApolloCodegenConfiguration.swift

@@ -304,6 +304,9 @@ public struct ApolloCodegenConfiguration: Codable, Equatable {
     /// directive.
     public let warningsOnDeprecatedUsage: Composition
 
+    /// The conversion strategy for the generated code is in this set.
+    public let conversionStrategies: ConversionStrategies
+
     /// Designated initializer.
     ///
     /// - Parameters:
@@ -319,14 +322,16 @@ public struct ApolloCodegenConfiguration: Codable, Equatable {
     ///  - warningsOnDeprecatedUsage: Annotate generated Swift code with the Swift `available`
     ///    attribute and `deprecated` argument for parts of the GraphQL schema annotated with the
     ///    built-in `@deprecated` directive.
+    ///  - conversionStrategies: Conversion strategy for generated Swift code from GraphQL schema.
     public init(
       additionalInflectionRules: [InflectionRule] = [],
       queryStringLiteralFormat: QueryStringLiteralFormat = .multiline,
       deprecatedEnumCases: Composition = .include,
       schemaDocumentation: Composition = .include,
       apqs: APQConfig = .disabled,
       cocoapodsCompatibleImportStatements: Bool = false,
-      warningsOnDeprecatedUsage: Composition = .include
+      warningsOnDeprecatedUsage: Composition = .include,
+      conversionStrategies: ConversionStrategies = .init()
     ) {
       self.additionalInflectionRules = additionalInflectionRules
       self.queryStringLiteralFormat = queryStringLiteralFormat
@@ -335,6 +340,7 @@ public struct ApolloCodegenConfiguration: Codable, Equatable {
       self.apqs = apqs
       self.cocoapodsCompatibleImportStatements = cocoapodsCompatibleImportStatements
       self.warningsOnDeprecatedUsage = warningsOnDeprecatedUsage
+      self.conversionStrategies = conversionStrategies
     }
   }
 
@@ -354,6 +360,23 @@ public struct ApolloCodegenConfiguration: Codable, Equatable {
     case exclude
   }
 
+  /// CaseConversionStrategy is a strategy of convert to Swift enum from GraphQL schema.
+  public enum CaseConversionStrategy: String, Codable, Equatable {
+    /// Default. Nothing different from the definition of a schema.
+    case none
+    /// Convert to lower camel case from `snake_case`, `UpperCamelCase`,`UPPERCASE`.
+    case camelCase
+  }
+
+  /// `ConversionStrategies` is a set about option of code generation naming rules conversion strategy.
+  public struct ConversionStrategies: Codable, Equatable {
+    public let enumCases: CaseConversionStrategy
+
+    public init(enumCases: CaseConversionStrategy = .camelCase) {
+      self.enumCases = enumCases
+    }
+  }
+
   /// Enum to enable using
   /// [Automatic Persisted Queries (APQs)](https://www.apollographql.com/docs/apollo-server/performance/apq)
   /// with your generated operations.

Sources/ApolloCodegenLib/Templates/EnumTemplate.swift

@@ -29,23 +29,50 @@ struct EnumTemplate: TemplateRenderer {
     switch (
       config.options.deprecatedEnumCases,
       graphqlEnumValue.deprecationReason,
-      config.options.warningsOnDeprecatedUsage
+      config.options.warningsOnDeprecatedUsage,
+      config.options.conversionStrategies.enumCases
     ) {
-    case (.exclude, .some, _):
+    case (.exclude, .some, _, _):
       return nil
 
-    case let (.include, .some(reason), .include):
+    case let (.include, .some(reason), .include, .none):
       return """
         \(documentation: graphqlEnumValue.documentation, config: config)
         @available(*, deprecated, message: \"\(reason)\")
         case \(graphqlEnumValue.name.asEnumCaseName)
         """
-
-    default:
+    case let (.include, .some(reason), .include, .camelCase):
+      return """
+        \(documentation: graphqlEnumValue.documentation, config: config)
+        @available(*, deprecated, message: \"\(reason)\")
+        case \(convertToCamelCase(graphqlEnumValue.name).asEnumCaseName) = "\(graphqlEnumValue.name)"
+        """
+    case (_, _, _, .none):
       return """
         \(documentation: graphqlEnumValue.documentation, config: config)
         case \(graphqlEnumValue.name.asEnumCaseName)
         """
+    default:
+      return """
+        \(documentation: graphqlEnumValue.documentation, config: config)
+        case \(convertToCamelCase(graphqlEnumValue.name).asEnumCaseName) = "\(graphqlEnumValue.name)"
+        """
+    }
+  }
+
+  private func convertToCamelCase(_ value: String) -> String {
+    if value.allSatisfy({ $0.isUppercase }) {
+      // For `UPPERCASE`. e.g) UPPER -> upper, STARWARS -> starwards
+      return value.lowercased()
+    }
+    if value.contains("_") {
+      // For `snake_case`. e.g) snake_case -> snakeCase, UPPER_SNAKE_CASE -> upperSnakeCase
+      return value.split(separator: "_").enumerated().map { $0.offset == 0 ? $0.element.lowercased() : $0.element.capitalized }.joined()
+    }
+    if let firstChar = value.first, firstChar.isUppercase {
+      // For `UpperCamelCase`. e.g) UpperCamelCase -> upperCamelCase
+      return [firstChar.lowercased(), String(value.suffix(from: value.index(value.startIndex, offsetBy: 1)))].joined()
     }
+    return value
   }
 }

Tests/ApolloCodegenTests/ApolloCodegenConfigurationCodableTests.swift

@@ -47,7 +47,8 @@ class ApolloCodegenConfigurationCodableTests: XCTestCase {
           schemaDocumentation: .include,
           apqs: .disabled,
           cocoapodsCompatibleImportStatements: false,
-          warningsOnDeprecatedUsage: .include
+          warningsOnDeprecatedUsage: .include,
+          conversionStrategies:.init(enumCases: .camelCase)
         ),
         experimentalFeatures: .init(
           clientControlledNullability: true,
@@ -58,7 +59,7 @@ class ApolloCodegenConfigurationCodableTests: XCTestCase {
 
     static var encoded: String {
       """
-      {"experimentalFeatures" : {"clientControlledNullability" : true,"legacySafelistingCompatibleOperations" : true},"input" : {"operationSearchPaths" : ["/search/path/**/*.graphql"],"schemaSearchPaths" : ["/path/to/schema.graphqls"]},"options" : {"additionalInflectionRules" : [{"pluralization" : {"replacementRegex" : "animals","singularRegex" : "animal"}}],"apqs" : "disabled","cocoapodsCompatibleImportStatements" : false,"deprecatedEnumCases" : "exclude","queryStringLiteralFormat" : "multiline","schemaDocumentation" : "include","warningsOnDeprecatedUsage" : "include"},"output" : {"operations" : {"relative" : {"subpath" : "/relative/subpath"}},"schemaTypes" : {"moduleType" : {"swiftPackageManager" : {}},"path" : "/output/path"},"testMocks" : {"swiftPackage" : {"targetName" : "SchemaTestMocks"}}},"schemaName" : "SerializedSchema"}
+      {"experimentalFeatures" : {"clientControlledNullability" : true,"legacySafelistingCompatibleOperations" : true},"input" : {"operationSearchPaths" : ["/search/path/**/*.graphql"],"schemaSearchPaths" : ["/path/to/schema.graphqls"]},"options" : {"additionalInflectionRules" : [{"pluralization" : {"replacementRegex" : "animals","singularRegex" : "animal"}}],"apqs" : "disabled","cocoapodsCompatibleImportStatements" : false,"deprecatedEnumCases" : "exclude","queryStringLiteralFormat" : "multiline","schemaDocumentation" : "include","warningsOnDeprecatedUsage" : "include", "conversionStrategies" : {"enumCases" : "camelCase"}},"output" : {"operations" : {"relative" : {"subpath" : "/relative/subpath"}},"schemaTypes" : {"moduleType" : {"swiftPackageManager" : {}},"path" : "/output/path"},"testMocks" : {"swiftPackage" : {"targetName" : "SchemaTestMocks"}}},"schemaName" : "SerializedSchema"}
       """      
     }
   }

Tests/ApolloCodegenTests/CodeGeneration/Templates/EnumTemplateTests.swift

@@ -110,7 +110,7 @@ class EnumTemplateTests: XCTestCase {
     expect(actual).to(equalLineByLine(expected, ignoringExtraLines: true))
   }
 
-  func test_render_givenSchemaEnum_generatesSwiftEnumRespectingValueCasing() throws {
+  func test_render_givenCaseConversionStrategy_camelCase_generatesSwiftEnum_convertedToCamelCase() {
     // given
     buildSubject(
       name: "casedEnum",
@@ -173,6 +173,140 @@ class EnumTemplateTests: XCTestCase {
       ]
     )
 
+    let expected = """
+    enum CasedEnum: String, EnumType {
+      case lower = "lower"
+      case upper = "UPPER"
+      case capitalized = "Capitalized"
+      case `associatedtype` = "associatedtype"
+      case `class` = "class"
+      case `deinit` = "deinit"
+      case `enum` = "enum"
+      case `extension` = "extension"
+      case `fileprivate` = "fileprivate"
+      case `func` = "func"
+      case `import` = "import"
+      case `init` = "init"
+      case `inout` = "inout"
+      case `internal` = "internal"
+      case `let` = "let"
+      case `operator` = "operator"
+      case `private` = "private"
+      case `precedencegroup` = "precedencegroup"
+      case `protocol` = "protocol"
+      case `protocol` = "Protocol"
+      case `public` = "public"
+      case `rethrows` = "rethrows"
+      case `static` = "static"
+      case `struct` = "struct"
+      case `subscript` = "subscript"
+      case `typealias` = "typealias"
+      case `var` = "var"
+      case `break` = "break"
+      case `case` = "case"
+      case `catch` = "catch"
+      case `continue` = "continue"
+      case `default` = "default"
+      case `defer` = "defer"
+      case `do` = "do"
+      case `else` = "else"
+      case `fallthrough` = "fallthrough"
+      case `guard` = "guard"
+      case `if` = "if"
+      case `in` = "in"
+      case `repeat` = "repeat"
+      case `return` = "return"
+      case `throw` = "throw"
+      case `switch` = "switch"
+      case `where` = "where"
+      case `while` = "while"
+      case `as` = "as"
+      case `false` = "false"
+      case `is` = "is"
+      case `nil` = "nil"
+      case `self` = "self"
+      case `self` = "Self"
+      case `super` = "super"
+      case `throws` = "throws"
+      case `true` = "true"
+      case `try` = "try"
+    }
+
+    """
+
+    // when
+    let actual = renderSubject()
+
+    // then
+    expect(actual).to(equalLineByLine(expected))
+  }
+
+  func test_render_givenSchemaEnum_noneConveersionStrategies_generatesSwiftEnumRespectingValueCasing() throws {
+    // given
+    buildSubject(
+      name: "casedEnum",
+      values: [
+        ("lower", nil, nil),
+        ("UPPER", nil, nil),
+        ("Capitalized", nil, nil),
+        ("associatedtype", nil, nil),
+        ("class", nil, nil),
+        ("deinit", nil, nil),
+        ("enum", nil, nil),
+        ("extension", nil, nil),
+        ("fileprivate", nil, nil),
+        ("func", nil, nil),
+        ("import", nil, nil),
+        ("init", nil, nil),
+        ("inout", nil, nil),
+        ("internal", nil, nil),
+        ("let", nil, nil),
+        ("operator", nil, nil),
+        ("private", nil, nil),
+        ("precedencegroup", nil, nil),
+        ("protocol", nil, nil),
+        ("Protocol", nil, nil),
+        ("public", nil, nil),
+        ("rethrows", nil, nil),
+        ("static", nil, nil),
+        ("struct", nil, nil),
+        ("subscript", nil, nil),
+        ("typealias", nil, nil),
+        ("var", nil, nil),
+        ("break", nil, nil),
+        ("case", nil, nil),
+        ("catch", nil, nil),
+        ("continue", nil, nil),
+        ("default", nil, nil),
+        ("defer", nil, nil),
+        ("do", nil, nil),
+        ("else", nil, nil),
+        ("fallthrough", nil, nil),
+        ("guard", nil, nil),
+        ("if", nil, nil),
+        ("in", nil, nil),
+        ("repeat", nil, nil),
+        ("return", nil, nil),
+        ("throw", nil, nil),
+        ("switch", nil, nil),
+        ("where", nil, nil),
+        ("while", nil, nil),
+        ("as", nil, nil),
+        ("false", nil, nil),
+        ("is", nil, nil),
+        ("nil", nil, nil),
+        ("self", nil, nil),
+        ("Self", nil, nil),
+        ("super", nil, nil),
+        ("throws", nil, nil),
+        ("true", nil, nil),
+        ("try", nil, nil),
+      ],
+      config: .mock(
+        options: .init(conversionStrategies: .init(enumCases: .none))
+      )
+    )
+
     let expected = """
     enum CasedEnum: String, EnumType {
       case lower
@@ -259,9 +393,9 @@ class EnumTemplateTests: XCTestCase {
 
     let expected = """
     enum TestEnum: String, EnumType {
-      case ONE
-      case TWO
-      case THREE
+      case one = "ONE"
+      case two = "TWO"
+      case three = "THREE"
     }
 
     """
@@ -289,10 +423,10 @@ class EnumTemplateTests: XCTestCase {
 
     let expected = """
     enum TestEnum: String, EnumType {
-      case ONE
+      case one = "ONE"
       @available(*, deprecated, message: "Deprecated for tests")
-      case TWO
-      case THREE
+      case two = "TWO"
+      case three = "THREE"
     }
 
     """
@@ -320,7 +454,7 @@ class EnumTemplateTests: XCTestCase {
 
     let expected = """
     enum TestEnum: String, EnumType {
-      case TWO
+      case two = "TWO"
     }
 
     """
@@ -348,7 +482,7 @@ class EnumTemplateTests: XCTestCase {
 
     let expected = """
     enum TestEnum: String, EnumType {
-      case TWO
+      case two = "TWO"
     }
 
     """
@@ -384,11 +518,11 @@ class EnumTemplateTests: XCTestCase {
     enum TestEnum: String, EnumType {
       /// Doc: One
       @available(*, deprecated, message: "Deprecated for tests")
-      case ONE
+      case one = "ONE"
       /// Doc: Two
-      case TWO
+      case two = "TWO"
       @available(*, deprecated, message: "Deprecated for tests")
-      case THREE
+      case three = "THREE"
     }
 
     """
@@ -421,10 +555,10 @@ class EnumTemplateTests: XCTestCase {
     /// \(documentation)
     enum TestEnum: String, EnumType {
       /// Doc: One
-      case ONE
+      case one = "ONE"
       /// Doc: Two
-      case TWO
-      case THREE
+      case two = "TWO"
+      case three = "THREE"
     }
 
     """
@@ -455,9 +589,9 @@ class EnumTemplateTests: XCTestCase {
 
     let expected = """
     enum TestEnum: String, EnumType {
-      case ONE
-      case TWO
-      case THREE
+      case one = "ONE"
+      case two = "TWO"
+      case three = "THREE"
     }
 
     """

Tests/CodegenCLITests/Commands/InitializeTests.swift

@@ -140,6 +140,9 @@ class InitializeTests: XCTestCase {
       "additionalInflectionRules" : [
 
       ],
+      "conversionStrategies" : {
+        "enumCases" : "camelCase"
+      },
       "warningsOnDeprecatedUsage" : "include",
       "deprecatedEnumCases" : "include",
       "schemaDocumentation" : "include",