Update MacroTesting example tests (#5)

This brings in the latest versions of Apple's macro demos and tests from
SwiftSyntax.

Author: stephencelis

Tests/MacroTestingTests/AddAsyncCompletionHandlerTests.swift

@@ -0,0 +1,109 @@
+import MacroTesting
+import XCTest
+
+final class AddAsyncMacroTests: BaseTestCase {
+  override func invokeTest() {
+    withMacroTesting(macros: [AddAsyncMacro.self]) {
+      super.invokeTest()
+    }
+  }
+
+  func testExpansionTransformsFunctionWithResultCompletionToAsyncThrows() {
+    assertMacro {
+      #"""
+      @AddAsync
+      func c(a: Int, for b: String, _ value: Double, completionBlock: @escaping (Result<String, Error>) -> Void) -> Void {
+        completionBlock(.success("a: \(a), b: \(b), value: \(value)"))
+      }
+      """#
+    } expansion: {
+      #"""
+      func c(a: Int, for b: String, _ value: Double, completionBlock: @escaping (Result<String, Error>) -> Void) -> Void {
+        completionBlock(.success("a: \(a), b: \(b), value: \(value)"))
+      }
+
+      func c(a: Int, for b: String, _ value: Double) async throws -> String {
+        try await withCheckedThrowingContinuation { continuation in
+          c(a: a, for: b, value) { returnValue in
+
+            switch returnValue {
+            case .success(let value):
+              continuation.resume(returning: value)
+            case .failure(let error):
+              continuation.resume(throwing: error)
+            }
+          }
+        }
+      }
+      """#
+    }
+  }
+
+  func testExpansionTransformsFunctionWithBoolCompletionToAsync() {
+    assertMacro {
+      """
+      @AddAsync
+      func d(a: Int, for b: String, _ value: Double, completionBlock: @escaping (Bool) -> Void) -> Void {
+        completionBlock(true)
+      }
+      """
+    } expansion: {
+      """
+      func d(a: Int, for b: String, _ value: Double, completionBlock: @escaping (Bool) -> Void) -> Void {
+        completionBlock(true)
+      }
+
+      func d(a: Int, for b: String, _ value: Double) async -> Bool {
+        await withCheckedContinuation { continuation in
+          d(a: a, for: b, value) { returnValue in
+
+            continuation.resume(returning: returnValue)
+          }
+        }
+      }
+      """
+    }
+  }
+
+  func testExpansionOnStoredPropertyEmitsError() {
+    assertMacro {
+      """
+      struct Test {
+        @AddAsync
+        var name: String
+      }
+      """
+    } diagnostics: {
+      """
+      struct Test {
+        @AddAsync
+        ┬────────
+        ╰─ 🛑 @addAsync only works on functions
+        var name: String
+      }
+      """
+    }
+  }
+
+  func testExpansionOnAsyncFunctionEmitsError() {
+    assertMacro {
+      """
+      struct Test {
+        @AddAsync
+        async func sayHello() {
+        }
+      }
+      """
+    } diagnostics: {
+      """
+      struct Test {
+        @AddAsync
+        ┬────────
+        ╰─ 🛑 @addAsync requires an function that returns void
+        async func sayHello() {
+        }
+      }
+      """
+    }
+  }
+}

Tests/MacroTestingTests/AddAsyncTests.swift

@@ -8,60 +8,37 @@ final class AddBlockerTests: BaseTestCase {
     }
   }
 
-  func testAddBlocker() {
+  func testExpansionTransformsAdditionToSubtractionAndEmitsWarning() {
     assertMacro {
       """
-      let x = 1
-      let y = 2
-      let z = 3
       #addBlocker(x * y + z)
       """
     } diagnostics: {
       """
-      let x = 1
-      let y = 2
-      let z = 3
       #addBlocker(x * y + z)
                   ───── ┬ ─
                         ╰─ ⚠️ blocked an add; did you mean to subtract?
                            ✏️ use '-'
       """
     } fixes: {
       """
-      let x = 1
-      let y = 2
-      let z = 3
       #addBlocker(x * y - z)
       """
     } expansion: {
       """
-      let x = 1
-      let y = 2
-      let z = 3
       x * y - z
       """
     }
   }
 
-  func testAddBlocker_Inline() {
+  func testExpansionPreservesSubtraction() {
     assertMacro {
       """
-      #addBlocker(1 * 2 + 3)
-      """
-    } diagnostics: {
-      """
-      #addBlocker(1 * 2 + 3)
-                  ───── ┬ ─
-                        ╰─ ⚠️ blocked an add; did you mean to subtract?
-                           ✏️ use '-'
-      """
-    } fixes: {
-      """
-      #addBlocker(1 * 2 - 3)
+      #addBlocker(x * y - z)
       """
     } expansion: {
       """
-      1 * 2 - 3
+      x * y - z
       """
     }
   }