Make EC a class

Package.swift

@@ -159,6 +159,7 @@ extension Array where Element == PackageDescription.SwiftSetting {
       .unsafeFlags(["-require-explicit-sendable"]),
       .enableUpcomingFeature("ExistentialAny"),
       .enableExperimentalFeature("SuppressedAssociatedTypes"),
+      .enableExperimentalFeature("NonescapableTypes"),
 
       .enableExperimentalFeature("AccessLevelOnImport"),
       .enableUpcomingFeature("InternalImportsByDefault"),

Sources/Testing/Expectations/ExpectationChecking+Macro.swift

@@ -105,14 +105,14 @@ func check(
 /// - Warning: This function is used to implement the `#expect()` and
 ///   `#require()` macros. Do not call it directly.
 public func __checkCondition(
-  _ condition: (inout __ExpectationContext) throws -> Bool,
+  _ condition: (__ExpectationContext) throws -> Bool,
   sourceCode: @escaping @autoclosure @Sendable () -> [__ExpressionID: String],
   comments: @autoclosure () -> [Comment],
   isRequired: Bool,
   sourceLocation: SourceLocation
 ) rethrows -> Result<Void, any Error> {
-  var expectationContext = __ExpectationContext.init(sourceCode: sourceCode())
-  let condition = try condition(&expectationContext)
+  let expectationContext = __ExpectationContext.init(sourceCode: sourceCode())
+  let condition = try condition(expectationContext)
 
   return check(
     condition,
@@ -131,14 +131,14 @@ public func __checkCondition(
 /// - Warning: This function is used to implement the `#expect()` and
 ///   `#require()` macros. Do not call it directly.
 public func __checkCondition<T>(
-  _ optionalValue: (inout __ExpectationContext) throws -> T?,
+  _ optionalValue: (__ExpectationContext) throws -> T?,
   sourceCode: @escaping @autoclosure @Sendable () -> [__ExpressionID: String],
   comments: @autoclosure () -> [Comment],
   isRequired: Bool,
   sourceLocation: SourceLocation
 ) rethrows -> Result<T, any Error> where T: ~Copyable {
-  var expectationContext = __ExpectationContext(sourceCode: sourceCode())
-  let optionalValue = try optionalValue(&expectationContext)
+  let expectationContext = __ExpectationContext(sourceCode: sourceCode())
+  let optionalValue = try optionalValue(expectationContext)
 
   let result = check(
     optionalValue != nil,
@@ -166,15 +166,15 @@ public func __checkCondition<T>(
 /// - Warning: This function is used to implement the `#expect()` and
 ///   `#require()` macros. Do not call it directly.
 public func __checkConditionAsync(
-  _ condition: (inout __ExpectationContext) async throws -> Bool,
+  _ condition: (__ExpectationContext) async throws -> Bool,
   sourceCode: @escaping @autoclosure @Sendable () -> [__ExpressionID: String],
   comments: @autoclosure () -> [Comment],
   isRequired: Bool,
   isolation: isolated (any Actor)? = #isolation,
   sourceLocation: SourceLocation
 ) async rethrows -> Result<Void, any Error> {
-  var expectationContext = __ExpectationContext(sourceCode: sourceCode())
-  let condition = try await condition(&expectationContext)
+  let expectationContext = __ExpectationContext(sourceCode: sourceCode())
+  let condition = try await condition(expectationContext)
 
   return check(
     condition,
@@ -193,15 +193,15 @@ public func __checkConditionAsync(
 /// - Warning: This function is used to implement the `#expect()` and
 ///   `#require()` macros. Do not call it directly.
 public func __checkConditionAsync<T>(
-  _ optionalValue: (inout __ExpectationContext) async throws -> sending T?,
+  _ optionalValue: (__ExpectationContext) async throws -> sending T?,
   sourceCode: @escaping @autoclosure @Sendable () -> [__ExpressionID: String],
   comments: @autoclosure () -> [Comment],
   isRequired: Bool,
   isolation: isolated (any Actor)? = #isolation,
   sourceLocation: SourceLocation
 ) async rethrows -> Result<T, any Error> where T: ~Copyable {
-  var expectationContext = __ExpectationContext(sourceCode: sourceCode())
-  let optionalValue = try await optionalValue(&expectationContext)
+  let expectationContext = __ExpectationContext(sourceCode: sourceCode())
+  let optionalValue = try await optionalValue(expectationContext)
 
   let result = check(
     optionalValue != nil,
@@ -516,7 +516,7 @@ public func __checkClosureCall<R>(
   isRequired: Bool,
   sourceLocation: SourceLocation
 ) -> Result<(any Error)?, any Error> {
-  var expectationContext = __ExpectationContext(sourceCode: sourceCode())
+  let expectationContext = __ExpectationContext(sourceCode: sourceCode())
 
   var errorMatches = false
   var mismatchExplanationValue: String? = nil
@@ -569,7 +569,7 @@ public func __checkClosureCall<R>(
   isolation: isolated (any Actor)? = #isolation,
   sourceLocation: SourceLocation
 ) async -> Result<(any Error)?, any Error> {
-  var expectationContext = __ExpectationContext(sourceCode: sourceCode())
+  let expectationContext = __ExpectationContext(sourceCode: sourceCode())
 
   var errorMatches = false
   var mismatchExplanationValue: String? = nil

Sources/Testing/Expectations/ExpectationContext+Pointers.swift

@@ -28,7 +28,7 @@ extension __ExpectationContext {
   ///
   /// - Warning: This function is used to implement the `#expect()` and
   ///   `#require()` macros. Do not call it directly.
-  @inlinable public mutating func callAsFunction<P>(_ value: P, _ id: __ExpressionID) -> P where P: _Pointer {
+  @inlinable public func callAsFunction<P>(_ value: consuming P, _ id: __ExpressionID) -> P where P: _Pointer {
     captureValue(value, id)
   }
 
@@ -49,7 +49,7 @@ extension __ExpectationContext {
   ///
   /// - Warning: This function is used to implement the `#expect()` and
   ///   `#require()` macros. Do not call it directly.
-  @inlinable public mutating func callAsFunction(_ value: String, _ id: __ExpressionID) -> String {
+  @inlinable public func callAsFunction(_ value: consuming String, _ id: __ExpressionID) -> String {
     captureValue(value, id)
   }
 
@@ -70,7 +70,7 @@ extension __ExpectationContext {
   ///
   /// - Warning: This function is used to implement the `#expect()` and
   ///   `#require()` macros. Do not call it directly.
-  @inlinable public mutating func callAsFunction<E>(_ value: Array<E>, _ id: __ExpressionID) -> Array<E> {
+  @inlinable public func callAsFunction<E>(_ value: consuming Array<E>, _ id: __ExpressionID) -> Array<E> {
     captureValue(value, id)
   }
 
@@ -90,7 +90,7 @@ extension __ExpectationContext {
   /// - Warning: This function is used to implement the `#expect()` and
   ///   `#require()` macros. Do not call it directly.
   @_disfavoredOverload
-  @inlinable public mutating func callAsFunction<T>(_ value: T?, _ id: __ExpressionID) -> T? {
+  @inlinable public func callAsFunction<T>(_ value: consuming T?, _ id: __ExpressionID) -> T? {
     captureValue(value, id)
   }
 }

Sources/Testing/Expectations/ExpectationContext.swift

@@ -18,7 +18,7 @@
 ///
 /// - Warning: This type is used to implement the `#expect()` and `#require()`
 ///   macros. Do not use it directly.
-public struct __ExpectationContext: ~Copyable {
+public final class __ExpectationContext {
   /// The source code representations of any captured expressions.
   ///
   /// Unlike the rest of the state in this type, the source code dictionary is
@@ -167,7 +167,7 @@ extension __ExpectationContext {
   ///
   /// This function helps overloads of `callAsFunction(_:_:)` disambiguate
   /// themselves and avoid accidental recursion.
-  @usableFromInline mutating func captureValue<T>(_ value: T, _ id: __ExpressionID) -> T {
+  @usableFromInline func captureValue<T>(_ value: T, _ id: __ExpressionID) -> T {
     runtimeValues[id] = { Expression.Value(reflecting: value) }
     return value
   }
@@ -185,7 +185,7 @@ extension __ExpectationContext {
   /// - Warning: This function is used to implement the `#expect()` and
   ///   `#require()` macros. Do not call it directly.
   @_disfavoredOverload
-  @inlinable public mutating func callAsFunction<T>(_ value: T, _ id: __ExpressionID) -> T {
+  @inlinable public func callAsFunction<T>(_ value: T, _ id: __ExpressionID) -> T {
     captureValue(value, id)
   }
 
@@ -203,7 +203,7 @@ extension __ExpectationContext {
   /// - Warning: This function is used to implement the `#expect()` and
   ///   `#require()` macros. Do not call it directly.
   @_disfavoredOverload
-  public mutating func callAsFunction<T>(_ value: consuming T, _ id: __ExpressionID) -> T where T: ~Copyable {
+  public func callAsFunction<T>(_ value: consuming T, _ id: __ExpressionID) -> T where T: ~Copyable {
     // TODO: add support for borrowing non-copyable expressions (need @lifetime)
     return value
   }
@@ -219,7 +219,7 @@ extension __ExpectationContext {
   ///
   /// - Warning: This function is used to implement the `#expect()` and
   ///   `#require()` macros. Do not call it directly.
-  public mutating func __inoutAfter<T>(_ value: T, _ id: __ExpressionID) {
+  public func __inoutAfter<T>(_ value: T, _ id: __ExpressionID) {
     runtimeValues[id] = { Expression.Value(reflecting: value, timing: .after) }
   }
 }
@@ -272,14 +272,14 @@ extension __ExpectationContext {
   ///
   /// - Warning: This function is used to implement the `#expect()` and
   ///   `#require()` macros. Do not call it directly.
-  @inlinable public mutating func __cmp<T, U, R>(
-    _ op: (T, U) throws -> R,
+  @inlinable public func __cmp<T, U>(
+    _ op: (T, U) throws -> Bool,
     _ opID: __ExpressionID,
     _ lhs: T,
     _ lhsID: __ExpressionID,
     _ rhs: U,
     _ rhsID: __ExpressionID
-  ) rethrows -> R {
+  ) rethrows -> Bool {
     try captureValue(op(captureValue(lhs, lhsID), captureValue(rhs, rhsID)), opID)
   }
 
@@ -290,7 +290,7 @@ extension __ExpectationContext {
   ///
   /// - Warning: This function is used to implement the `#expect()` and
   ///   `#require()` macros. Do not call it directly.
-  public mutating func __cmp<C>(
+  public func __cmp<C>(
     _ op: (C, C) -> Bool,
     _ opID: __ExpressionID,
     _ lhs: C,
@@ -315,7 +315,7 @@ extension __ExpectationContext {
   ///
   /// - Warning: This function is used to implement the `#expect()` and
   ///   `#require()` macros. Do not call it directly.
-  @inlinable public mutating func __cmp<R>(
+  @inlinable public func __cmp<R>(
     _ op: (R, R) -> Bool,
     _ opID: __ExpressionID,
     _ lhs: R,
@@ -334,7 +334,7 @@ extension __ExpectationContext {
   ///
   /// - Warning: This function is used to implement the `#expect()` and
   ///   `#require()` macros. Do not call it directly.
-  public mutating func __cmp<S>(
+  public func __cmp<S>(
     _ op: (S, S) -> Bool,
     _ opID: __ExpressionID,
     _ lhs: S,
@@ -392,7 +392,7 @@ extension __ExpectationContext {
   ///
   /// - Warning: This function is used to implement the `#expect()` and
   ///   `#require()` macros. Do not call it directly.
-  @inlinable public mutating func __as<T, U>(_ value: T, _ valueID: __ExpressionID, _ type: U.Type, _ typeID: __ExpressionID) -> U? {
+  @inlinable public func __as<T, U>(_ value: T, _ valueID: __ExpressionID, _ type: U.Type, _ typeID: __ExpressionID) -> U? {
     let result = captureValue(value, valueID) as? U
 
     if result == nil {
@@ -421,7 +421,7 @@ extension __ExpectationContext {
   ///
   /// - Warning: This function is used to implement the `#expect()` and
   ///   `#require()` macros. Do not call it directly.
-  @inlinable public mutating func __is<T, U>(_ value: T, _ valueID: __ExpressionID, _ type: U.Type, _ typeID: __ExpressionID) -> Bool {
+  @inlinable public func __is<T, U>(_ value: T, _ valueID: __ExpressionID, _ type: U.Type, _ typeID: __ExpressionID) -> Bool {
     let result = captureValue(value, valueID) is U
 
     if !result {

Sources/TestingMacros/Support/ConditionArgumentParsing.swift

@@ -678,8 +678,10 @@ extension ConditionMacro {
         // If we're inserting any additional code into the closure before
         // the rewritten argument, we can't elide the return keyword.
         ReturnStmtSyntax(
-          expression: expandedExpr.with(\.leadingTrivia, .space)
-        ).with(\.trailingTrivia, .newline)
+          returnKeyword: .keyword(.return, trailingTrivia: .space),
+          expression: expandedExpr,
+          trailingTrivia: .space
+        )
       }
     }
 
@@ -715,19 +717,11 @@ extension ConditionMacro {
             parameters: ClosureParameterListSyntax {
               ClosureParameterSyntax(
                 firstName: expressionContextName,
-                colon: .colonToken().with(\.trailingTrivia, .space),
+                colon: .colonToken(trailingTrivia: .space),
                 type: TypeSyntax(
-                  AttributedTypeSyntax(
-                    specifiers: [
-                      TypeSpecifierListSyntax.Element(
-                        SimpleTypeSpecifierSyntax(specifier: .keyword(.inout))
-                          .with(\.trailingTrivia, .space)
-                      )
-                    ],
-                    baseType: MemberTypeSyntax(
-                      baseType: IdentifierTypeSyntax(name: .identifier("Testing")),
-                      name: .identifier("__ExpectationContext")
-                    )
+                  MemberTypeSyntax(
+                    baseType: IdentifierTypeSyntax(name: .identifier("Testing")),
+                    name: .identifier("__ExpectationContext")
                   )
                 )
               )
@@ -736,12 +730,11 @@ extension ConditionMacro {
         ),
         returnClause: returnType.map { returnType in
           ReturnClauseSyntax(
-            type: returnType.with(\.leadingTrivia, .space)
-          ).with(\.leadingTrivia, .space)
+            arrow: .arrowToken(leadingTrivia: .space, trailingTrivia: .space),
+            type: returnType
+          )
         },
-        inKeyword: .keyword(.in)
-          .with(\.leadingTrivia, .space)
-          .with(\.trailingTrivia, .newline)
+        inKeyword: .keyword(.in, leadingTrivia: .space, trailingTrivia: .space)
       ),
       statements: codeBlockItems
     )

Tests/SubexpressionShowcase/SubexpressionShowcase.swift

@@ -37,7 +37,15 @@ struct T {
 }
 
 func subexpressionShowcase() async throws {
+  let fff = false
+  let ttt = true
   #expect(false || true)
+
+  #expect((fff == ttt) == ttt)
+  Testing.__checkCondition({(__ec: Testing.__ExpectationContext) -> Swift.Bool in
+    __ec.__cmp(==,0x0,__ec((__ec.__cmp(==,0x3a,__ec(fff,0x7a),0x7a,__ec(ttt,0x43a),0x43a)),0x2),0x2,__ec(ttt,0x8000),0x8000)
+  },sourceCode: [0x0:"(fff == ttt) == ttt",0x2:"(fff == ttt)",0x3a:"fff == ttt",0x7a:"fff",0x43a:"ttt",0x8000:"ttt"],comments: [],isRequired: false,sourceLocation: Testing.SourceLocation.__here()).__expected()
+
   #expect((Int)(123) == 124)
   #expect((Int, Double)(123, 456.0) == (124, 457.0))
   #expect((123, 456) == (789, 0x12))
@@ -101,11 +109,21 @@ func subexpressionShowcase() async throws {
   }
   #expect(await k(true))
 
+  func k2(_ x: @escaping @autoclosure () -> Bool) async -> Bool {
+    x()
+  }
+  #expect(await k2(true))
+
 #if false
-  // Unsupported: __ec is necessarily inout and captures non-sendable state, so
-  // this will fail to compile. Making __ec a class instead is possible, but
-  // adds a very large amount of code and locking overhead for what we can
-  // assume is an edge case.
+  // Unsupported: __ec necessarily captures non-sendable state, so this will
+  // fail to compile because it is capturing __ec in a sendable closure. We
+  // could add locks guarding __ec's mutable state and eagerly capture state,
+  // but that would slow down tests significantly. The type checker cannot
+  // handle the number of `where T: Sendable` overloads of various functions
+  // that we would need in order to provide eager capture only for non-sendable
+  // values. However, this is a relatively narrow case, so for now we'll just
+  // accept it as unsupported and tell affected test authors to refactor their
+  // expectations so as to call m(_:) _before_ #expect().
   func m(_ x: @autoclosure @Sendable () -> Bool) -> Bool {
     x()
   }