Merge pull request #76 from /issues/2

Add handling inout parameter

Sources/SpyableMacro/Factories/ClosureFactory.swift

@@ -13,13 +13,13 @@ import SwiftSyntaxBuilder
 ///
 /// The following code:
 /// ```swift
-/// var fooClosure: ((String, Int) async throws -> Data)?
+/// var fooClosure: ((inout String, Int) async throws -> Data)?
 ///
-/// try await fooClosure!(text, count)
+/// try await fooClosure!(&text, count)
 /// ```
 /// would be generated for a function like this:
 /// ```swift
-/// func foo(text: String, count: Int) async throws -> Data
+/// func foo(text: inout String, count: Int) async throws -> Data
 /// ```
 /// and an argument `variablePrefix` equal to `foo`.
 ///
@@ -81,18 +81,22 @@ struct ClosureFactory {
       )
     }
 
+    let arguments = LabeledExprListSyntax {
+      for parameter in functionSignature.parameterClause.parameters {
+        let baseName = parameter.secondName ?? parameter.firstName
+
+        if parameter.isInoutParameter {
+          LabeledExprSyntax(expression: InOutExprSyntax(expression: DeclReferenceExprSyntax(baseName: baseName)))
+        } else {
+          LabeledExprSyntax(expression: DeclReferenceExprSyntax(baseName: baseName))
+        }
+      }
+    }
+
     var expression: ExprSyntaxProtocol = FunctionCallExprSyntax(
       calledExpression: calledExpression,
       leftParen: .leftParenToken(),
-      arguments: LabeledExprListSyntax {
-        for parameter in functionSignature.parameterClause.parameters {
-          LabeledExprSyntax(
-            expression: DeclReferenceExprSyntax(
-              baseName: parameter.secondName ?? parameter.firstName
-            )
-          )
-        }
-      },
+      arguments: arguments,
       rightParen: .rightParenToken()
     )
 
@@ -111,3 +115,14 @@ struct ClosureFactory {
     TokenSyntax.identifier(variablePrefix + "Closure")
   }
 }
+
+private extension FunctionParameterListSyntax.Element {
+  var isInoutParameter: Bool {
+    if let attributedType = self.type.as(AttributedTypeSyntax.self),
+       attributedType.specifier?.text == TokenSyntax.keyword(.inout).text {
+      return true
+    } else {
+      return false
+    }
+  }
+}

Tests/SpyableMacroTests/Factories/UT_ClosureFactory.swift

@@ -47,6 +47,14 @@ final class UT_ClosureFactory: XCTestCase {
     )
   }
 
+  func testVariableDeclarationWithInoutAttribute() throws {
+    try assertProtocolFunction(
+      withFunctionDeclaration: "func _ignore_(value: inout String)",
+      prefixForVariable: "_prefix_",
+      expectingVariableDeclaration: "var _prefix_Closure: ((inout String) -> Void)?"
+    )
+  }
+
   func testVariableDeclarationEverything() throws {
     try assertProtocolFunction(
       withFunctionDeclaration: """
@@ -115,13 +123,21 @@ final class UT_ClosureFactory: XCTestCase {
     )
   }
 
+  func testCallExpressionWithInoutAttribute() throws {
+    try assertProtocolFunction(
+      withFunctionDeclaration: "func _ignore_(value: inout String)",
+      prefixForVariable: "_prefix_",
+      expectingCallExpression: "_prefix_Closure?(&value)"
+    )
+  }
+
   func testCallExpressionEverything() throws {
     try assertProtocolFunction(
       withFunctionDeclaration: """
         func _ignore_(text: inout String, product: (UInt?, name: String), added: (() -> Void)?, removed: @escaping () -> Bool) async throws -> String?
         """,
       prefixForVariable: "_prefix_",
-      expectingCallExpression: "try await _prefix_Closure!(text, product, added, removed)"
+      expectingCallExpression: "try await _prefix_Closure!(&text, product, added, removed)"
     )
   }