Decode captured values within the same scope as the body so that we don't need to figure out a source location

Author: grynspan

Sources/Testing/ExitTests/ExitTest.swift

@@ -60,7 +60,7 @@ public struct ExitTest: Sendable, ~Copyable {
   /// Do not invoke this closure directly. Instead, invoke ``callAsFunction()``
   /// to run the exit test. Running the exit test will always terminate the
   /// current process.
-  fileprivate var body: @Sendable (_ exitTest: borrowing Self) async throws -> Void = { _ in }
+  fileprivate var body: @Sendable (_ exitTest: inout Self) async throws -> Void = { _ in }
 
   /// Storage for ``observedValues``.
   ///
@@ -251,7 +251,7 @@ extension ExitTest {
     }
 
     do {
-      try await body(self)
+      try await body(&self)
     } catch {
       _errorInMain(error)
     }
@@ -307,7 +307,7 @@ extension ExitTest: DiscoverableAsTestContent {
 
     // Wrap the body function in a thunk that decodes any captured state and
     // passes it along.
-    let body: @Sendable (borrowing ExitTest) async throws -> Void = { exitTest in
+    let body: @Sendable (inout Self) async throws -> Void = { exitTest in
       let values: (repeat each T) = try exitTest.capturedValues.takeCapturedValues()
       try await body(repeat each values)
     }
@@ -492,7 +492,7 @@ extension ExitTest {
   /// are available or the child environment is otherwise terminated. The parent
   /// environment is then responsible for interpreting those results and
   /// recording any issues that occur.
-  public typealias Handler = @Sendable (_ exitTest: borrowing ExitTest) async throws -> ExitTest.Result
+  public typealias Handler = @Sendable (_ exitTest: borrowing Self) async throws -> ExitTest.Result
 
   /// Make a file handle from the string contained in the given environment
   /// variable.
@@ -615,14 +615,10 @@ extension ExitTest {
       }
     }
 
-    // TODO: get correct source location
-    Issue.withErrorRecording(at: .__here(), configuration: configuration) {
-      try result._decodeCapturedValuesForEntryPoint()
-    }
-
     result.body = { [configuration, body = result.body] exitTest in
       try await Configuration.withCurrent(configuration) {
-        try await body(exitTest)
+        try exitTest._decodeCapturedValuesForEntryPoint()
+        try await body(&exitTest)
       }
     }
     return result