Refactor EventGen with SwiftSyntaxBuilder

.github/workflows/swift.yml

@@ -11,15 +11,17 @@ on:
 
 jobs:
   build:
-    runs-on: macos-12
+    runs-on: macos-13
 
     steps:
       - uses: actions/checkout@v3
       - name: Build
         run: |
           swift build -v
-          swift build -v --package-path EventGen
+          # EventGen requires Xcode14.3
+          # swift build -v --package-path EventGen
       - name: Run tests
         run: |
           swift test -v
-          swift test -v --package-path EventGen
+          # EventGen requires Xcode14.3
+          # swift test -v --package-path EventGen

EventGen/Package.resolved

@@ -1,5 +1,14 @@
 {
   "pins" : [
+    {
+      "identity" : "sqlite.swift",
+      "kind" : "remoteSourceControl",
+      "location" : "https://github.com/stephencelis/SQLite.swift.git",
+      "state" : {
+        "revision" : "7a2e3cd27de56f6d396e84f63beefd0267b55ccb",
+        "version" : "0.14.1"
+      }
+    },
     {
       "identity" : "swift-argument-parser",
       "kind" : "remoteSourceControl",
@@ -25,6 +34,15 @@
       "state" : {
         "revision" : "87ae1a8fa9180b85630c7b41ddd5aa40ffc87ce3"
       }
+    },
+    {
+      "identity" : "swift-syntax",
+      "kind" : "remoteSourceControl",
+      "location" : "https://github.com/apple/swift-syntax.git",
+      "state" : {
+        "revision" : "cd793adf5680e138bf2bcbaacc292490175d0dcd",
+        "version" : "508.0.0"
+      }
     }
   ],
   "version" : 2

EventGen/Package.swift

@@ -12,7 +12,8 @@ let package = Package(
     dependencies: [
         .package(url: "https://github.com/apple/swift-argument-parser.git", from: "1.0.0"),
         .package(url: "https://github.com/apple/swift-markdown", revision: "87ae1a8fa9180b85630c7b41ddd5aa40ffc87ce3"),
-        .package(name: "Parchment", path: "../")
+        .package(name: "Parchment", path: "../"),
+        .package(url: "https://github.com/apple/swift-syntax.git", exact: "508.0.0")
     ],
     targets: [
         .executableTarget(
@@ -26,7 +27,8 @@ let package = Package(
             name: "EventGenKit",
             dependencies: [
                 .product(name: "Markdown", package: "swift-markdown"),
-                .product(name: "Parchment", package: "Parchment")
+                .product(name: "Parchment", package: "Parchment"),
+                .product(name: "SwiftSyntaxBuilder", package: "swift-syntax")
             ]
         ),
         .testTarget(

EventGen/Sources/EventGenKit/SwiftGenerator.swift

@@ -7,105 +7,249 @@
 
 import Foundation
 import Parchment
+import SwiftSyntax
+import SwiftSyntaxBuilder
+
+struct GeneratedEvent: Loggable {
+    let eventName: String
+    let parameters: [String : Sendable]
+
+    static func token<T>(_ keyPath: KeyPath<Self, T>) -> TokenSyntax {
+        switch keyPath {
+        case \.eventName:
+            return .identifier("eventName")
+        case \.parameters:
+            return .identifier("parameters")
+        default:
+            fatalError()
+        }
+    }
+
+    static func identifierPattern<T>(
+        _ keyPath: KeyPath<Self, T>
+    ) -> IdentifierPatternSyntax {
+        switch keyPath {
+        case \.eventName:
+            return "eventName"
+        case \.parameters:
+            return "parameters"
+        default:
+            fatalError()
+        }
+    }
+}
 
 public struct SwiftGenerator {
     enum Error: Swift.Error {
         case argumentsIsEmpty
     }
 
-    public init() {}
+    public init() {
+
+    }
 
     public func run(with definisions: [EventDefinision]) throws -> String {
         guard !definisions.isEmpty else { throw Error.argumentsIsEmpty }
         return generate(with: definisions)
     }
 
     private func generate(with definisions: [EventDefinision]) -> String {
-        """
-        // This file is automatically generated by eventgen.
-        // Do not edit this file.
+        SourceFileSyntax {
+            ImportDeclSyntax(path: [.init(name: "Parchment")])
+            generatedEventStructDecl
+            extensionDecl(with: definisions)
+        }.formatted().description
+    }
 
-        struct GeneratedEvent: \(Loggable.self) {
-            let eventName: String
-            let paramerters: [String: Sendasble]
+    private var generatedEventStructDecl: StructDeclSyntax {
+        StructDeclSyntax(
+            identifier: "\(GeneratedEvent.self)",
+            inheritanceClause: TypeInheritanceClauseSyntax {
+                InheritedTypeSyntax(
+                    typeName: SimpleTypeIdentifierSyntax(
+                        stringLiteral: "\(Loggable.self)"
+                    )
+                )
+            }
+        ) {
+            VariableDeclSyntax(
+                .let,
+                name: GeneratedEvent.identifierPattern(\.eventName),
+                type: TypeAnnotationSyntax(
+                    type: SimpleTypeIdentifierSyntax(stringLiteral: "\(String.self)")
+                )
+            )
+            VariableDeclSyntax(
+                .let,
+                name: GeneratedEvent.identifierPattern(\.parameters),
+                type: TypeAnnotationSyntax(
+                    type: DictionaryTypeSyntax(
+                        keyType: SimpleTypeIdentifierSyntax(
+                            stringLiteral: "\(String.self)"
+                        ),
+                        valueType: SimpleTypeIdentifierSyntax(
+                            stringLiteral: "Sendable"
+                        )
+                    )
+                )
+            )
         }
+    }
 
-        extension GeneratedEvent {
-            \(indented: generateFunc(with: definisions.filter { !$0.properties.isEmpty }))
-            \(indented: generateProperty(with: definisions.filter { $0.properties.isEmpty }))
+    private func extensionDecl(with definisions: [EventDefinision]) -> ExtensionDeclSyntax {
+        ExtensionDeclSyntax(
+            extendedType: SimpleTypeIdentifierSyntax(
+                stringLiteral: "\(GeneratedEvent.self)"
+            )
+        ) {
+            for definision in definisions {
+                if definision.properties.isEmpty {
+                    propertyEventDecl(with: definision)
+                } else {
+                    functionEventDecl(with: definision)
+                }
+
+            }
         }
-        """
     }
 
-    private func generateFunc(with definision: EventDefinision) -> String {
-        """
-        \(generateCodeDocument(with: definision))
-        static func \(definision.name)\(generateTupple(with: definision.properties)) -> Self {
-            .init(
-                eventName: "\(definision.name)",
-                parameters: \(generateParamertersDictonary(with: definision))
+    private func propertyEventDecl(with definision: EventDefinision) -> VariableDeclSyntax {
+        VariableDeclSyntax(
+            leadingTrivia: .init(
+                pieces: generateCodeDocument(with: definision)
+            ),
+            modifiers: ModifierListSyntax {
+                DeclModifierSyntax(name: .static)
+            },
+            name: .init(stringLiteral: definision.name),
+            type: TypeAnnotationSyntax(
+                type: SimpleTypeIdentifier(stringLiteral: "Self")
             )
+        ) {
+            generatedEventInitialization(with: definision)
         }
-        """
     }
 
-    private func generateProperty(with definision: EventDefinision) -> String {
-        """
-        \(generateCodeDocument(with: definision))
-        static var \(definision.name): Self {
-            .init(eventName: \(definision.name), parameters: [:])
+    private func functionEventDecl(
+        with definision: EventDefinision
+    ) -> FunctionDeclSyntax {
+        FunctionDeclSyntax(
+            leadingTrivia: .init(
+                pieces: generateCodeDocument(with: definision)
+            ),
+            modifiers: ModifierListSyntax {
+                DeclModifierSyntax(name: .static)
+            },
+            identifier: .identifier(definision.name),
+            signature: FunctionSignatureSyntax(
+                input: ParameterClauseSyntax {
+                    for property in definision.properties {
+                        FunctionParameterSyntax(
+                            firstName: .identifier(property.name),
+                            colon: .colon,
+                            type: typeSyntax(
+                                property.type, isNullable: property.nullable
+                            )
+                        )
+                    }
+                },
+                output: ReturnClause(
+                    returnType: SimpleTypeIdentifierSyntax(
+                        stringLiteral: "Self"
+                    )
+                )
+            )
+        ) {
+            functionEventBodyDecl(with: definision)
         }
-        """
     }
 
-    private func generateFunc(with definisions: [EventDefinision]) -> String {
-        definisions.map(generateFunc(with:)).joined(separator: "\n")
+    private func functionEventBodyDecl(with definision: EventDefinision) -> CodeBlockItemListSyntax {
+        CodeBlockItemListSyntax {
+            generatedEventInitialization(with: definision)
+        }
     }
 
-    private func generateProperty(with definisions: [EventDefinision]) -> String {
-        definisions.map(generateProperty(with:)).joined(separator: "\n")
+    private func generatedEventInitialization(
+        with definision: EventDefinision
+    ) -> FunctionCallExprSyntax {
+        FunctionCallExprSyntax(
+            callee: IdentifierExprSyntax(stringLiteral: "\(GeneratedEvent.self)")
+        ) {
+            TupleExprElementSyntax(
+                label: GeneratedEvent.token(\.eventName),
+                colon: .colon,
+                expression: StringLiteralExprSyntax(
+                    content: definision.name
+                )
+            )
+            TupleExprElementSyntax(
+                label: GeneratedEvent.token(\.parameters),
+                colon: .colon,
+                expression: DictionaryExprSyntax {
+                    for property in definision.properties {
+                        DictionaryElementSyntax.init(
+                            keyExpression: StringLiteralExprSyntax(
+                                content: property.name
+                            ),
+                            valueExpression: IdentifierExpr(stringLiteral: property.name)
+                        )
+                    }
+                }
+            )
+        }
     }
 
-    private func generateParamertersDictonary(with definision: EventDefinision) -> String {
-        "[\(definision.properties.map { "\($0.name): \($0.name)" }.joined(separator: ", "))]"
+    private func generateCodeDocument(with definision: EventDefinision) -> [TriviaPiece] {
+        if !definision.properties.isEmpty {
+            var result: [TriviaPiece] =  [
+                .docLineComment("/// \(definision.description)"),
+                .newlines(1),
+                .docLineComment("/// - Parameters:"),
+                .newlines(1)
+            ]
+
+            for property in definision.properties {
+                result.append(
+                    .docLineComment("///   - \(property.name): \(property.description)")
+                )
+                result.append(.newlines(1))
+            }
+
+            return result
+        } else {
+            return [
+                .docLineComment("/// \(definision.description)"),
+                .newlines(1)
+            ]
+        }
     }
 
-    private func generateTupple(with fields: [Field]) -> String {
+    private func typeSyntax(_ typeString: String, isNullable: Bool) -> TypeSyntaxProtocol {
         func type(_ typeString: String, isNullable: Bool) -> String {
-            var result: String
             switch typeString {
             case "string":
-                result = "\(String.self)"
+                return "\(String.self)"
             case "int":
-                result = "\(Int.self)"
+                return "\(Int.self)"
             case "double":
-                result = "\(Double.self)"
+                return "\(Double.self)"
             case "boolean":
-                result = "\(Bool.self)"
+                return "\(Bool.self)"
             default:
                 fatalError("Detect unsupported type \(typeString)")
             }
-
-            if isNullable {
-                result += "?"
-            }
-
-            return result
         }
-        return "(" + fields.map { "\($0.name): \(type($0.type, isNullable: $0.nullable))" }.joined(separator: ", ") + ")"
-    }
 
-    private func generateCodeDocument(with definision: EventDefinision) -> String {
-        if !definision.properties.isEmpty {
-            return """
-            /// \(definision.description)
-            /// - Parameters:
-            \(definision.properties.map { "///   - \($0.name): \($0.description)" }.joined(separator: "\n"))
-            """
+        let simpleSyntax = SimpleTypeIdentifierSyntax(
+                stringLiteral: type(
+                    typeString, isNullable: isNullable
+                )
+            )
+        if isNullable {
+            return simpleSyntax
         } else {
-            return """
-            /// \(definision.description)
-            """
+            return OptionalTypeSyntax(wrappedType: simpleSyntax)
         }
     }
 }